trimaran hull design

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Catamaran Hull Design

Post author By Rick
Post date June 29, 2010
2 Comments on Catamaran Hull Design

Part 1: Notes from Richard Woods

Since the America’s Cup experimented with going multihull, there’s been a lot of interest in catamaran performance and the catamaran hull designs that define performance. Many guys are investigating whether to buy a catamaran or design and build their dream boat. Let it be said here that building a large catamaran is not for the faint of heart. People begin building 100s of boats a year, yet few are ever completed, as life always seems to have a way of interfering with a good boat build.

Never the less, since the rest of this website is about selecting and buying a boat , it only seems fair to have at least one webpage that covers catamaran design. This page contains notes on boat hull design goals and an accompanying page from Terho Halme has mathematical formulas used in actual catamaran hull design. It has become a popular research stop and an important reference to the catamaran design community.

The content of this page was reproduced from the maestro of Catamaran designs, renown British naval architect, Richard Woods, who not only designs catamarans, he sails them across oceans…. repeatedly. He has a lot to say on the subject of catamaran hull design.

“…When it’ all said and done, the performance of a sailing catamaran is dependent on three primary specs: length, sail area and weight. If the boat is longer it generally means it’ a faster boat. If she has more sail area, it means she’ a faster boat and if she’ light it means she’ a faster boat. Of course, there are limits: Too much sail area capsizes the boat in brisk winds. If the boat is designed too light, she will not take any kind of punishment. Too slim a hull design and the boat becomes a large Hobie Cat capable of only carrying your lunch. Of course, too long and large and you’d have to be Bill Gates to afford one. Then there are lot of additional and very important factors like underwater hull shape, aspect ratios of boards and sails, wet deck clearance, rotating or fixed rigging and so on….” Richard Woods

All Catamarans are not equal, but all sailboats have two things in common: They travel on water and they’re wind powered, so the Catamaran design equations in the 2nd part should apply to every catamaran from a heavy cruising Cat to a true ocean racer.

Richard Wood’s comments on catamaran design:

We all know that multihulls can be made faster by making them longer or lighter or by adding more sail. Those factors are the most important and why they are used as the basis of most rating rules. However using just those figures is a bit like determining a cars performance just by its hp and curbside weight. It would also imply that a Tornado would sail as fast forwards as backwards (OK, I know I just wrote that a Catalac went faster backwards than forwards)

So what next?? Weight and length can be combined into the Slenderness Ratio (SLR). But since most multihulls have similar Depth/WL beam ratios you can pretty much say the SLR equates to the LWL/BWL ratio. Typically this will be 8-10:1 for a slow cruising catamaran (or the main hull of most trimarans), 12-14:1 for a performance cruiser and 20:1 for an extreme racer.

So by and large faster boats have finer hulls. But the wetted surface area (WSA) increases proportionately as fineness increases (for a given displacement the half orange shape gives the least WSA) so fine hulls tend to be slower in low wind speeds.

The most important catamaran design hull shape factor, is the Prismatic Coefficient (Cp). This is a measure of the fullness of the ends of the hull. Instinctively you might think that fine ends would be faster as they would “cut through the water better”. But in fact you want a high Cp for high speeds. However everything is interrelated. If you have fine hulls you can use a lower Cp. Most monohulls have a Cp of 0.55- 0.57. And that is about right for displacement speeds.

However the key to Catamaran design is you need a higher Cp if you want to sail fast. So a multihull should be at least 0.61 and a heavy displacement multihull a bit higher still. It is difficult to get much over 0.67 without a very distorted hull shape or one with excessive WSA. So all multihulls should have a Cp between 0.61 and 0.65. None of this is very special or new. It has been well known by naval architects for at least 50 years.

There are various ways of achieving a high Cp. You could fit bulb bows (as Lock Crowther did). Note this bow is a bit different from those seen on ships (which work at very specific hull speeds – which are very low for their LOA). But one problem with them is that these tend to slam in a seaway.

Another way is to have a very wide planing aft section. But that can increase WSA and leads to other problems I’ll mention in a minute. Finally you can flatten out the hull rocker (the keel shape seen from the side) and add a bustle aft. That is the approach I use, in part because that adds displacement aft, just where it is most needed.

I agree that a high Cp increases drag at low speeds. But at speeds over hull speed drag decreases dramatically on a high Cp boat relative to one with a low Cp. With the correct Cp drag can be reduced by over 10%. In other words you will go 10% faster (and that is a lot!) in the same wind and with the same sails as a boat with a unfavorable Cp. In light winds it is easy to overcome the extra drag because you have lots of stability and so can fly extra light weather sails.

The time you really need a high Cp boat is when beating to windward in a big sea. Then you don’t have the stability and really want to get to your destination fast. At least I do, I don’t mind slowly drifting along in a calm. But I hate “windward bashing”

But when you sail to windward the boat pitches. The sea isn’t like a test tank or a computer program. And here I agree with Evan. Immersed transoms will slow you down (that is why I use a narrower transom than most designers).

I also agree with Evan (and why not, he knows more about Volvo 60 design than nearly anyone else on the planet) in that I don’t think you should compare a catamaran hull to a monohull, even a racing one. Why chose a Volvo 60/Vendee boat with an immersed transom? Why not chose a 60ft Americas Cup boat with a narrow out of the water transom??

To be honest I haven’t use Michelet so cannot really comment. But I have tested model catamarans in a big test tank and I know how inaccurate tank test results can be. I cannot believe that a computer program will be better.

It would be easy to prove one way or the other though. A catamaran hull is much like a frigate hull (similar SLR, L/B ratios and Froude numbers) and there is plenty of data available for those. There is also a lot of data for the round bilge narrow non planing motorboats popular in the 1930’-50’s which again are similar to a single multihull hull.

One of the key findings I discovered with my tank test work was just how great the drag was due to wave interference between the hulls. Even a catamaran with a modern wide hull spacing had a drag increase of up to 20 % when compared to hulls at infinite spacing. One reason why just flying a hull is fast (the Cp increases when you do as well, which also helps). So you cannot just double the drag of a single hull and expect to get accurate results. And any speed prediction formula must include a windage factor if it is to give meaningful results.About 25 years ago we sailed two identical 24ft Striders next to each other. They were the same speed. Then we moved the crew of one boat to the bow. That boat IMMEDIATELY went ½ knot faster. That is why I now arrange the deck layout of my racing boats so that the crew can stay in front of the mast at all times, even when tacking or using the spinnaker.

I once raced against a bridge deck cabin catamaran whose skipper kept the 5 crew on the forward netting beam the whole race. He won.

Richard Woods of Woods Designs www.sailingcatamarans.com

Tags Buying Advice , Catamaran Designers

Owner of a Catalac 8M and Catamaransite webmaster.

2 replies on “Catamaran Hull Design”

I totally agree with what you say. But Uli only talk sailing catamarans.

If only solar power. You need the very best. As limited watts. Hp.

The closer to 1-20 the better.

Closing the hulls to fit in cheaper marina berth. ?

You say not too close. But is that for sailing only.

Any comment is greatly appreciated

Kind regards Jeppe

Superb article

Calculation and design trimaran hull design to order

Design trimaran hull design to order.

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trimaran hull shapes

Discussion in ' Multihulls ' started by harrygee , Aug 6, 2012 .

harrygee Junior Member

Hi All I'm planning to build a new main hull for my existing 27 foot tri, which currently has a Soling keel-boat hull as the main hull. I've been sailing the converted Soling for a few years and it's done everything that I could've asked but it does have an issue with trying to exceed the hull speed. It does 15 knots easily enough if there's enough wind but it throws a lot of water around in moderate conditions before it gets going. I had planned to build a long, skinny, rounded shape but several modern tris that I've looked at have near-flat sections aft, some having flat sections for most of their length. I can see that a boat will tack easier with flat sections, will have better floor space for a boat with accommodation, will trail better and will tolerate loading but is there any speed advantage, compared with, say, an egg-shell shape? I realize that I'll lose some of the handling of the existing boat, which tacks and sails donuts like nothing else I've sailed. I use the boat for round-the-buoys racing and just blasting around. I'm an experienced builder and will probably build with solid glass over a male mold, for economy. Basic specs, existing boat; 27' loa, 20' lwl, 19' boa, 780 kgs (I expect to lose 100 kg), 13" draft (4' board down), sail area 310 sq ft, cost very little so far. Thanks for any input. Harry

Corley epoxy coated

You will definetely visit Jenny Craig with the conversion because your current boats pretty heavy for a trimaran of that length. You might like to look at the hullshapes that Ted Warren drew for his Warren 23 (actually 25'). There are more pictures in the thread from HASYB for inspiration I really like the boat and think it would be an ideal boat for daysailing and racing. Your chosen construction method is probably the most economic but will yield a heavier than is necessary boat paulownia/composite strip plank or foam sandwich would be lighter and yield better performance. http://www.warrenmultihulls.com/w-23.htm http://nand.net/~josh/boat/index.html

Silver Raven Senior Member

harrygee said: ↑ Hi All I'm planning to build a new main hull for my existing 27 foot tri, which currently has a Soling keel-boat hull as the main hull. I've been sailing the converted Soling for a few years and it's done everything that I could've asked but it does have an issue with trying to exceed the hull speed. It does 15 knots easily enough if there's enough wind but it throws a lot of water around in moderate conditions before it gets going. I had planned to build a long, skinny, rounded shape but several modern tris that I've looked at have near-flat sections aft, some having flat sections for most of their length. I can see that a boat will tack easier with flat sections, will have better floor space for a boat with accommodation, will trail better and will tolerate loading but is there any speed advantage, compared with, say, an egg-shell shape? I realize that I'll lose some of the handling of the existing boat, which tacks and sails donuts like nothing else I've sailed. I use the boat for round-the-buoys racing and just blasting around. I'm an experienced builder and will probably build with solid glass over a male mold, for economy. Basic specs, existing boat; 27' loa, 20' lwl, 19' boa, 780 kgs (I expect to lose 100 kg), 13" draft (4' board down), sail area 310 sq ft, cost very little so far. Thanks for any input. Harry Click to expand...

luckystrike Power Kraut

Hi Harry, lets say so, the flat underwater body has no real disadvantages against the really round one. You have a slightly higher wetted area (around 2%), therefore the "flat", which is a little rounded for compound curves (material stability and stiffness), is producing some dynamic lift, reducing w.a. and creating some sort of planning. The flat bottom has important advantages adding longitudual stability, countering nosediving and hobby-horsing. If your homewaters are not a general a light wind area, I would choose the slightly flatter bottom. I agree with Silver Raven, take a look at Kurt Hughes bulkhead shapes for the smaller tri's, my favorites are the Tomcat 30 and the 26', a little more speedy than the 31. The slight "V" in the bottom is a result from Hughes plywood building method "Cylinder Molding" and can be full round with grp. You will build with solid grp? I think this will be a little to heavy to make it stiff enough if you have a cabin. Think about sandwich or strip planking, or Cylinder Molding with ply and Epoxy. If your amas are meeting the charakteristics of Kurts hulls, you have a very cheap, fast and powerfull design package. Best Regards, Michel

If I recall the boat correctly it was just like a little daysailor/racing style trimaran if you go to the larger Kurt Hughes style main hull it might be a bit more boat than the OP wants. Is that the path you want to continue down or are you looking at more of a cruiser/racer style boat?

Corley said: ↑ If I recall the boat correctly it was just like a little daysailor/racing style trimaran if you go to the larger Kurt Hughes style main hull it might be a bit more boat than the OP wants. Is that the path you want to continue down or are you looking at more of a cruiser/racer style boat? Click to expand...

no arguments here Kurt draws great boats and the telescoping beams would make a straightforward adaptation to the existing floats.

Thanks all There's so much information in those replies, I'm going to spend a few days checking it out. I like the look of that Warren in the US, there's a lot of information in those pictures. I'd grab it at the asking price. I do deliveries but I don't think I'll be taking that on. And if I did, I'd need another project. The reason for building in solid glass is just economy. It's been a "what if" project from the start. I've been into multis for 30+ years so my Soling, though a thoroughbred, was in need of some "improvement". I built the amas in solid glass (foam decks), the beams in oregon / gaboon ply / double bias, the beams sliding onto the amas in sockets. The amas weigh 70 kg each, the beams 35 kg. The amas are 140% (current weight), 25' long. With the help of a fellow "junior sailor" (combined age 130 years) the boat is easily assembled in two hours and I leave the boat on the mooring. It's an open boat with no other purpose than to feel good. Weight is not critical as there are no hot multis to compete against. Our sailing conditions favour a bit of weight as we often encounter "dead spots", with no wind at all, when the heavier monos will glide past me and reach the next breeze - I've sat and watched the whole fleet pass me, unable to steer for an hour. We also get severe squalls, hence the moderate sail area. (Okay, the sails are Etchel sails on a Dragon rig, to replace the Soling rig and sails that collapsed in a bit of wind). I may keep the deck, as heavy as it is, because it's a good working platform. The waterline beam now is 5' so I think I can improve on that. Thanks for the input. Harry

idkfa Senior Member

One great advantage a rounded hull has over a squared one is in strength and stiffness, especially if you're not using coring. It also helps with tacking and having rocker also helps tacking. Having little-no rocker also reduces hobby-horsing, but this is more the function of the amas: The vaka can ride whereas the amas submerge. Having a flared stern (straight bow) can provide some longitudinal stability. ie. differing shape/volume/reserve-buoyancy at the ends.

stove Junior Member

Harrygee, any chance you will share more info on your Soling trimaran, I'm also in the process of building a tri made up out of Tornado amas and a Soling 27.

Hi Stove and All The new boat has been in the water for a month but I don't yet have a clear picture of how it goes. I had a leak at the centre-board case which resulted in 150 kg of water below the sole, slowing the boat and making it handle like a pig. I thought I'd got the numbers badly wrong but, when I hauled her out, found the problem. She now sits right, with the transom well clear and the bow an inch clear, one float 7" clear when empty. All-up weight (empty) about 680 kgs, the new hull being about 400 kgs including the Soling deck, which is heavy. The new hull is 29', the rudder making it 30' overall. Waterline beam is 20". draft 16". The hull shape is a fine oval at the bow, becoming egg-shaped, then becoming a 6" flat aft. With high buoyancy in the stern of the main hull and in the bows of the ammas, the pitch-damping can be felt through the seat of the pants and works very well. Tacking is not as quick but nothing would be as quick as the converted Soling. When carrying the extra 150 kgs, tacking was awful. Performance is still being evaluated but she's faster than the converted Soling in all conditions so far. I've only done a couple of races and I'm able to stay with the Etchells to windward in light conditions (their strength), sail away in fresh wind and reaching. Running square, she matches the Etchells when they fly their spinnakers and I don't, I have to learn the angles and get my spinnaker sorted out. The one (no spinnakers) race in which a multi turned up, we sailed away from a Farrier 9 metre. The Farrier looked heavy and we were dragging around 150 kgs of the bay. This coming weekend is our club's Regatta weekend, when we'll get up to 80 boats from all over to race against and I hope to have the spinnaker working and see how she goes in a 24 mile race and a round-the-buoys demolition race. I'll try to get a photo organized. Stove, none of this is much good to you but I'm happy to share what little I've learned. The Tornado hulls look as if they have less buoyancy than my home-made amas but they may do the job if you're thinking of a light-as-possible day-sailer like mine. I wouldn't think they'd be adequate for a Soling with minimal accommodation. They'll have less than 100% buoyancy, an arrangement which was once described as "safe, semi-submersible floats" by a designer who now offers safer, bigger floats. They could be extended without too much work, I should think, a 5' extension giving you about 100 % (off the top of my head, not calculated). Good luck with it. Harry

Hi Harry. I'm very excited about the photos of your "new" Tri. I hope the results without the water ballast will be what you hoped for. I would love to see more of your "old" Soling Tri as well. I would appreciate some info on the beams you made (dimensions, plywood thickness, type of glass used etc.) The plan so far is to keep the soling pretty much as it is. (open deck day sailer) without the keel and original rudder, pretty much a copy of yours. I might go with a center board and not a dagger board like yours only for safety. She will be sailed inland on a big dam where conditions don't get too rough. I'm very worried about the mast after reading your posts, any advice to avoid what happened to your original mast would be appreciated. I did get a main sail with the Tornado hulls that are still in good condition. The sails on the soling are really old and worn.(Spinnaker is good). What did you mean by scalloping the hull in one of your posts? I want to keep the fore deck with the self tacking jib, might widen the area aft of the mast right up to the aft bulkhead, would love to see the deck layout of your tri because it seems your cockpit extends all the way to the back. I want to keep the mid part free of winches etc so that I can pitch a tent across both trampolines with a cutout in the floor of the tent above the "mid" cockpit area. I will probably add some water stays as well and use only aft running side stays if I' going to use the roachy Tornado main sail. Sorry for all the questions but I am very excited about what you've done and maybe you can help me avoid some of the pitfalls.

Hi Stove The beams are made of curved, laminated oregan, 6" deep tapering to 4.5" where they meet the ammas. There are 1" wide laminations, capped top and bottom with 3/8" gaboon ply, 8" wide, the whole wrapped in 2 layers of 450 gm (1.5 oz) double bias, all epoxied. A glass fairing was then added. My beam is 19'. The beams end in tapers which slide into glass sockets on the ammas. The ammas are held on by sailing forces but I have security lines. The beams are held to the (reinforced) deck by four glass saddles, made of 9 layers of 450 gm double-bias and epoxy. It's all guessametrics but nothing shows any hairline cracks. The Soling mast should cope. I had seen a need for aft lowers to stop the mast pumping forward and tried "temporary" spectra, which worked so well that, eighteen months later, they still worked until I was caught in a sustained 40 knots in a narrow bay with no system of reefing and nowhere to hide. The lowers broke at a chafe point and the rig dropped. I replaced the rig with a Dragon rig, which is 6' taller and almost the same section, (thinner in fact). With some better stays, the new rig is going ok. So far. I use Etchell sails, which don't have much roach so I have retained the adjustable backstay, though I'm nervous about induced bend. My side stays are not adjusted when sailing. They attach to the ammas about 5' aft of the mast. With all the flexing, the leeward stay dangles around. The rig is triangulated by the side stays and forstay, the spreaders and jumper-strut forming diamonds to keep the rig in column. I did fit an aft cockpit on the Soling conversion, to simplify the transom-hung rudder. The new hull is more sensitive to weight distribution so I'm back in the main cockpit, with a pushrod to the rudder. I've cut a hole at the aft cockpit to fit a 3 hp outboard, which gives about 5 - 6 knots (just done it, will know more after this weekend.) The Soling makes a good conversion, the flat sections aft helping to reach 15 knots or so in a good wind, with awesome spray. The new hull does better with no speed hump and no spray. As a Soling conversion, the ammas just kissed the surface and tacking / spinning was sensational. I've now raised the floats a little - there's not much downside in a boat that's just built to go, with no accommodation. My new centreboard case (same board) is off-centre to allow more working room near the mast. I'm learning by doing, not an expert and I expect to have more bloody noses down the track but it's all fun and has cost very little so far. The Soling cost A$3000, with mast, sails, trailer (sort of). The conversion cost a bit more than that (convenient memory, I don't recall exactly), the rig cost me a donation. the new hull A$2000. Good value. My paraglider cost more and the medical expenses more still. I'll get someone to help me with photos after next weekend's regatta. Harry

Hi Harry, what would you suggest the sizes should be of the additional front stay and side stays if I skip the back stay. I will keep the original upper and lower side says as well.

Hi Stove My forstay and side stays are 5 mm (just over 3/16"). The geometry means they're not heavily loaded. the backstay is not structural and is released at times. My original cap shrouds are no longer taken to the deck, they're attached to the base of the mast as a diamond. If they were still taken to the deck, all the load would come onto them as the flex in the boat would ease the side stays. I also have the normal Dragon diamond stays (4mm) for the top half of the rig. My aft lowers are taken to the deck to stop the mast bending forward. They're adjusted to allow the side stays to take the load, the lowers just keeping things in line. The lowers are placed so that the boom touches them at the same time as touching the side stays. I'm progressively fitting staylocks to all rigging but, though reusable, I've yet to find a way to reuse a shroud - removing the staylock taper wrecks the end of the wire. Harry

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The Illustrated Guide To Boat Hull Types (11 Examples)

I didn't understand anything about boat hull types. So I've researched what hulls I need for different conditions. Here's a complete list of the most common hulls.

What are the different boat hull types? There are three boat hull categories: displacement hulls, which displace water when moving; planing hulls, which create lift at high speeds; and semi-displacement hulls, which displace water and generate lift at low speeds. The most common hull types are round-bottomed, flat-bottomed, multi, V-shaped, and pontoon hulls.

But that's all pretty abstract if you ask me, so below I'll give a simple overview of what it all means. After that, I'll give a list with pictures of all the different designs.

A Simple Overview of Boat Hull Types

Your boat hull will be the biggest factor in how your boat handles or sails, how wet it is, how bumpy - absolutely everything is determined by the hull shape. So it's important to understand what different hulls will do for you, and what each hull is best for. First, let's slice it up into rough categories.

Roughly, you can divide boat hulls into three categories:

Displacement hulls - Lie inside the water and push it away when they move
Planing hulls - Lie on top of the water and don't push it away
Semi-displacement hulls - Lie inside the water and push it away, but can generate lift

Everything I'll be mentioning below is one of those three, or something in between.

There are five common boat hull types:

Round-bottomed hulls - handle well in rough water: sailboats
Flat-bottomed hulls - very stable for calm inland waters: fishing boats
Multihulls - very stable and buoyant: catamarans
V-Shaped Hulls - fast and comfortable in chop: powerboats
Pontoon hulls - fast and stable: pontoon boats

And then there's everything in-between.

Here's a quick and handy overview of the different hull types

In each category, we find different designs and styles that have different characteristics. There isn't a real clear distinction between categories and styles: there are semi-displacement hulls and so on. So I thought the best way to learn you the different hull types is by simply creating a list with lots of pictures, instead of getting all theoretical about it.

So below I've listed all the different hull styles I could possibly think of, mention what category and type it is, the pros and cons of each one, and give you examples and illustrations for each one.

Displacement hulls displace water when moving. These hulls lie in the water, instead of on top of it. The amount of water they displace is equal to the boat's weight. Displacement hulls handle way better in rough waters than flat-bottom hulls. That's why most cruisers have some sort of displacement hulls. There are actually all kinds, shapes, and forms of the displacement hull design, which we'll go over later.

The most important thing to understand about the displacement hull, is that it operates on buoyancy. This means that most of the boat's weight is supported by its capacity to float . Planing hulls, on the other hand, operate on lift instead, but we'll dive into that later.

Sailboats typically have displacement hulls, but also fishing boats, trawlers and crabbers. All in all, it's used for each boat that needs to handle well in rough conditions.

Learn everything there is to know about displacement hulls in this article . It lists all the pros and cons and really goes into detail on the nitty-gritty about how displacement hulls actually work .

But they are also slower than flat and planing hulls because the boat creates more resistance when moving. It has to push the water aside. In fact, this type of hull has a built-in upper-speed limit.

This upper-speed limit is called maximum hull speed . It means that the length of a displacement hull directly determines the maximum speed. It can't go faster, because the water-resistance increases with the boat's speed. To learn everything about calculating maximum hull speed , please check out my previous article here.

A round-bottomed hull is a type of displacement hull - it lies in the water and has to power through it. But since it's rounded, it creates little resistance and is effortless to move through the water. It's a very smooth ride and typical for any sailboat that sort of glides through the waves. In contrast, powerboats really have to eat their way through the water.

Examples: Canoes, sailboats

They are also one of the least stable. Since the bottom is rounded, your boat or canoe will rock plenty when boarding or moving around. They are also easy to capsize. That's why pro canoers learn to do a 360 in their canoes. I've never did a roll myself but came close enough a couple of times.

Almost all sailboats use a round bilge as well. This provides it its buoyancy and makes sure it handles well in waves. But since a rounded bilge is easy to capsize, a lot of sailboats have some sort of keel, which stabilizes the roll.

Nearly all ocean-going vessels use some sort of displacement hull, and the round bottom is the most common one. But our next guest is very popular as well.

The catamaran is similar to the pontoon hull (read on to learn more on that one), but it is a displacement multihull instead of a planing one. So it has two hulls, that lie inside the water and displace it. Like the pontoon, you will have to try really hard to capsize this design (and it won't work).

Examples: well, catamaran sailboats. But also this cool catamaran trawler:

Catamarans are extremely popular ocean cruisers. Their biggest pro is their extreme stability and buoyancy. And they have a very shallow draft for a displacement hull, making them very popular for sailing reefs and shallow waters, like the Caribbean.

Some cons for the catamaran are less agile than monohulls. They have a large turning radius, making them less maneuverable. Also, expect to pay high marina fees with this one.

Speaking of marina fees, our next one can go either way.

I think trimarans are incredibly cool, and especially the second type.

There are two types of trimarans:

a catamaran with three hulls instead of two,
or a displacement monohull with two floaters.

The first has the same characteristics as the catamaran: it's a displacement multihull, but now with three hulls:

The second can be a regular displacement monohull, with two pontoon-type floaters that provide extra buoyancy, making the total thing a hybrid between pontoon and displacement:

This last one has all the pros of a catamaran in terms of stability, but: you can simply wheel in those floaters whenever you head for port. That saves you a lot of money. And you can trailer her! Imagine that, a towing a trimaran home.

So those were the most common displacement hulls, aka what lives in the water. Let's move on to the planing hulls, aka what lives on the water.

Planing hulls are a hybrid between the flat-bottom and displacement hulls. Planing hulls displace water at low speeds , but create lift at higher speeds . The shape of their hull + speed lifts them out of the water, making them glide on top of the water. Most powerboats look like flat-bottom boats but use a shallow V-shape that helps the boat to handle better at higher speeds.

Examples: Water sports boat, powerboats

The most important thing to understand about planing hulls is that they operate mainly on lift instead of buoyancy. This means the weight of the boat is mainly supported by dynamic forces 1 . With the right amount of power, this design generates lift, which results in less resistance. This is why they are a lot faster than boats with displacement hulls, but also a lot rougher, even with mild chop.

A lot of powerboats use some sort of planing hull. Again, there are many designs and variations on the planing hull, and I'll try to mention as many as I can below.

Because the wedge of the hull runs into the water, it is much easier to handle at high speeds. At lower speeds, it is able to keep its course, even with a bit of wind. However, whenever the boat starts planing, it is prone to wind gusts, since the wedge shape no longer stabilizes the boat.

The flatter the hull, the faster it will go, but also the more poorly it will handle. Other powerboats use deep V-hulls, which I'll discuss below. But first, let's take a look at the flattest hulls you'll ever see.

A flat-bottom hull lies on top of the water and doesn't displace water (okay, very little) as it moves. Since there is no displacement, there is also little to no friction when moving. This makes it potentially fast, but it handles pretty poorly. It is one of the most stable hull design.

Examples: rowboats, (old) high-performance powerboats, small skiffs, small fishing boats, tug boats

They aren't just incredibly stable, they're also very practical. Because the bottom is practically flat, they maximize boat surface. But they are also extremely choppy in rough weather and waves. They will handle very poorly with stiff winds, as the wind can simply catch them and blow them across the water surface. That's why this design is almost exclusively used for calm, small, inland waters.

This type of hull operates mainly on buoyancy , like the displacement hull, but it doesn't require the same amount of power to propel, which is why it's faster.

Because of the uncomfortable ride, not a lot of boats use a perfectly flat bottom. Most boats nowadays use some sort of v-hull or hybrid design, like a semi-displacement hull; especially larger boats. So not a lot of boats have a real flat bottom. However, we do call a lot of boats flat-bottomed. How come?

There are two types of hulls we call flat-bottoms:

Of course boats with an actual flat bottom
Boats with almost no deadrise

What is the hull's deadrise? The deadrise is the angle of the front of the hull to the horizontal waterline.

As you can see, the green sailing dinghy in the picture above has a deadrise that's barely noticeable.

Let's move on to other variations of the planing hull. One of the most popular hull design for modern-day powerboats is the Deep Vee hull. And that's as cool as it sounds.

This is a type of planing hull that combines the best of both worlds.

These types of hulls are very popular on modern-day powerboats, and no wonder. With a V-shape that runs from bow to stern, deep into the water, you can handle this boat even in offshore conditions. It handles a lot better than flat-bottomed hulls, while it's at the same time extremely fast.

Examples: Most modern powerboats.

The Deep V-shape acts as a tiny keel of sorts, stabilizing the boat and making it more reliable and maneuverable. The rest of the hull acts as a planing hull, giving the boat its fast edge. Even at high speeds, the Deep V will cut into the water, making it more handleable.

The deep-V design is just one of many variants on the V-hull. Below we'll talk over another, the modified V hull.

The modified V hull is the ultimate crossover of all planing hull types. It's a mix of the flat-bottom and Deep V hull. It is one of the most popular hull designs for small motorboats. It's flat in the back and then runs into a narrow V-shape to the front. The flat back makes it more stable, and adds a little speed, while the V-shape front ensures good handling.

It is, in short, kind of the compromise-family-sedan of boat hulls. It's the fastest design that's also stable, that's also safe, and that also handles well. But it's not the best in any of those things.

Most powerboats you've seen will have some sort of Vee or Modified-V hull.

Stepped hulls are used on high-performance powerboats. It's a type of planing hull that reduces the hull surface by adding steps, or indents in the hull below the waterline. It looks something like this:

It is said to work extremely well at high speed (60 knots and up) and adds up to 10 knots to your top speed.

On to our next design. There are also planing multihulls, and they might even look like catamarans to you. Meet the pontoon hull.

Pontoon hulls float on top of the water using pontoons or floaters that create lift. It's a type of planing multihull that doesn't lie in the water, so it doesn't displace a lot of water. They don't really handle well. As with any multihull, they aren't agile - they're not great at maneuvering. They also have a very large turning radius. But they are extremely stable: there's no chance you'll capsize this.

Examples: Cruisers, modern trawlers, motor yachts, Maine lobster boats

Semi-displacement hulls are smack bang in the center of planning and displacement hulls. They are a bit better for speed than displacement hulls are. They are a bit better for handling rough waters than planing hulls are. This makes them very versatile.

You can see these a bit like being 'half-planing' hulls. These hulls are designed to plane at lower speeds than normal planing hulls - somewhere in the range of 15 - 20 knots, depending on the length of the boat. It also requires less power. When the hull lifts, it reduces drag (water resistance), making it faster and more efficient.

Semi-displacement hulls are perfect for boats that need to be steady and seaworthy but fast at the same time.

For more information about semi-displacement hulls, please check out my in-depth guide to semi-displacement hulls here . It has a diagram and lists all the pros and cons.

So those were my 11 examples, and my step by step explanation of the different types of boat hulls and functions. You now have a solid basic understanding of boat hulls, and can recognize the most common ones. I hope it was helpful, and if you want more good sailing information, be sure to check out my other articles below.

https://www.soundingsonline.com/boats/how-different-hull-types-react-in-rough-water . ↩

I was wondering what your opinion would be on the ship uss Texas as far as hull type and bow type. I think it has a plumb bow and it looks to have a displacement or flat bottom hull. Im doing some research and a better trained eye would be of great help. I used images “bb-35 dry dock” to help see the hull shape. Thank you

Shawn Buckles

Hi Kirk, I don’t know about trained but here we go. I’ve checked the picture, it’s definitely a displacement hull I’d also say it’s a plumb bow.

Hahahahaa imagine liking boats hehehehehe Extremely stable & faster Handles well in rough water Extremely stable & faster Handles well in rough water Extremely stable & faster Handles well in rough water Extremely stable & faster Handles well in rough water Extremely stable & faster Handles well in rough water Extremely stable & faster Handles well in rough water Extremely stable & faster Handles well in rough water Extremely stable & faster Handles well in rough water Extremely stable & faster Handles well in rough water

You may also like, a complete guide to displacement hulls (illustrated).

The displacement hull is the classic go-to hull design for sailboats and one of the most recognizable ones out there. In this guide, I explain all there is to know …

Semi-Displacement Hulls Explained (Illustrated Guide)

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16 Best Trimarans For Sailing Around The World (And a Few For Daysailing)

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Trimarans are growing in popularity worldwide, due to their light construction and high stability these multihulls are even faster than catamarans. Trimarans are still one of the lesser-known boat types so in this article ill be checking out some of the most popular models.

The best trimarans include:

The Neel 43
The Neel 47
Dragonfly 28
The Pulse 600
Corsair 37

These tris are built with your safety in mind while also packing powerful speed and a wide array of comfort features to optimize your sailing experience , some are even foldable making them possible to load on a trailer and transport to the sailing destination of your choosing.

In this article, I have created a list of the 16 best trimarans in the market and their unique features. You’ll also learn the best options for different purposes such as circumnavigation, weekend sailing, racing, and more.

Table of Contents

What Is a Trimaran?

A trimaran is a multi hulled sailboat with three individual hulls; the main hull ( vaka ) and a pair of outrigger hulls ( amas ). These smaller outrigger hulls are attached to the main hull using beams.

While trimarans have a rich history dating back nearly four millennia, these types of sailboats have only gained popularity in the late 1900s and early 2000s.

Trimarans are primarily used as personal boats for sailing enthusiasts or racing. These sailboats draw their versatility from their lightweight design, making them faster and easier to handle at sea when compared to single-hulled boats (monohulls). Additionally, the three hulls also contribute to better stability, making it very hard to capsize (although more likely than a cat according to this study)

Trimarans come in various sizes, and some can be as small as 19 feet (5.8 meters) in length, while others go up to 60 feet (18meters). They’re also used for different purposes. Most trimarans are used for racing and recreational purposes, although some units are still used as ferries.

As with all things, to find out which is the best we need to understand what it will be used for. There is a big difference in requirements between a boat used for day sailing compared to offshore around the world sailing.

The list below highlights the best trimarans for different purposes.

Best Trimarans For Cruising, Liveaboard and Sailing Around The World

The Neel 43 is a French trimaran best suited for cruising. Its key features include:

Easy maneuverability on the open sea by only a small number of crew members

This unit is also built for comfort, ideal for more extended travels. This 43-feet (13-meter) trimaran is also made with recyclable and bio-sourced materials, highlighting the manufacturer’s commitment to environmental consciousness.

This trimaran has a base price of €329,000 excluding VAT. This translates to approximately $370,138.

2.Neel 47 Possibly The Best

Named the best full-size multihull for 2020, the Neel 47 is a strong contender for one of the best trimarans in the market. This 47-foot (14.3-meter) long trimaran features optimized exterior and interior ergonomics for a unique design and look.

Still on design, the Neel 47 is ideal for couples looking to take a weekend off or spend some time as liveaboard. It has a spacious owner’s cabin and two bedrooms. It also features a spacious living room and kitchen and is optimized to ensure comfort for a couple.

The Neel 47 also has two basic guest cabins so your friends or children can tag along on your sailing adventure. Accordingly, this unit is ideal for those looking to explore the sea for the sheer joy of sailing.

The Neel 47 comes at a 571,139 euro ( $643,600 ) price tag, excluding VAT.

3. Rapido 60 The Fast and Comfortable Circumnavigator

The Rapido 60 offers a blend of performance, safety, and luxury, making it one of the best options for bluewater sailing. Measuring 59.3 feet (18 meters) in length, the Rapido 60 is an imposing unit. It’s made from lightweight sandwiches and carbon materials that provide speed and strength, allowing it to stand up to strong ocean currents.

The Rapido 60 also has spacious living spaces and is built for comfort at all points of the sail. Its design also optimizes safety. While it’s an ideal option for circumnavigating, it’s also an excellent choice for racing due to its speed.

This is also the same boat that The Youtube channel La Vagabond just purchased.

The Rapido 60 retails at $1,400,000 .

4. Rapido 40

The Rapido 40 measures 39.4 feet (12 meters) in length and is ideal for cruising around the world. The Rapido 40 features twin “C” foils, which provide added lift, enhancing its speed and performance whether you are sailing downwind or upwind.

Because it has C foils, this trimaran doesn’t have a central daggerboard, increasing interior space. Accordingly, it’s an excellent option for couples looking to cruise and enjoy great performances .

The Rapido 40 is made from high-tech all-carbon materials for a lightweight yet sturdy design. This material is also used for the countertops and furniture, and the cork flooring adds a touch of style.

This trimaran retails for $595,000 , making it a cheaper option than the Rapido 60.

5. Dragonfly 40

The Dragonfly 40 measures 40 feet (12 meters) in length. It features high-comfort standards, making it one of the best trimarans in the market for taking your family for a cruise. Because of its larger size, it has a better capacity, being capable of accommodating six to eight people, so you can bring your family and friends along.

It’s easy to navigate and extremely safe. With a maximum speed of 24 knots (44.5 km/h), this trimaran also provides fast speeds to make your cruise even more exhilarating.

The Dragonfly 40 retails from €509,000 exclusive of VAT, which rounds up to $572,000 .

6. Dragonfly 32

The Dragonfly 32 is a high-performance cruiser. Like the Dragonfly 28, this unit features a contemporary design for racing. This trimaran can accommodate five to seven crew members.

Although slightly longer than the Dragonfly 28 with its 32-foot (9.8-meter) length, the Dragonfly 32 has a max speed of 23+ knots (42.6+ km/h), making it one of the fastest trimarans for racing. This unit also has comfortable accommodation, which makes it an ideal option for a weekend cruise with family and friends.

The Dragonfly 32 has a base price of $350,000 .

7. Corsair 37

Thanks to a variable draft with a retractable rudder, the Corsair 37 is an ideal choice for shallow water exploration. This 37-foot (11.3-meter) long trimaran features advanced foam-cored construction designed for safety, making it virtually unsinkable.

The carbon hulls minimize weight, this makes for a lightweight ocean exploration sailboat with blistering speeds. One of its selling points is that this trimaran has previously been used for Arctic expeditions, possibly marking it as one of the better options for circumnavigation and offshore sailing in the northern waters.

This trimaran has a base price of $189,000 but can go up to $204,125 .

Best Trimarans For Day/Weekend Sailing

8. dragonfly 28.

The Dragonfly 28 is a 28-feet (8.75-meter) long sailboat that can accommodate up to five people. It comes in two versions:

Touring version: This version is ideal for families.
Performance version: This is built to provide optimal performance for the sports enthusiast within you.

It clocks a maximum speed of 22+ knots (22+ km/h) and is beam-folded. It’s an excellent option if you want a high-performance, comfortable yet smaller unit for your day or weekend cruise.

The Dragonfly 28 starts at €188,280 inclusive of VAT, which comes to around $211,600.

9. Dragonfly 25

Like other trimarans under the Dragonfly brand, this 25-foot (7.62-meter) trimaran is great for both racing and short term cruising. However, this high-performance boat delivers easy handling, making it perfect for couples looking to take a ride out over the weekend and seasoned sailors looking for an exhilarating racing adventure.

The Touring version features a lightweight build and offers comfort and accommodation to keep you, and the few guests you can fit, comfortable during the ride. This trimaran also has a Sport version, which is optimized for racing.

The Dragonfly 25 retails from EUR 86,800 .

10. Pulse 600

The Pulse 600 trimaran is a compact sailboat. It’s made from lightweight, carbon-reinforced construction and vacuum-formed materials for optimal speed. This trimaran is an ideal option if you are looking for speed.

It also features ample deck space, greater stability, and volume than most trimarans of similar size and build.

This trimaran measures 19.8 feet (6 meters) in length and can be sailed single-handedly by one person with minimal effort. The Pulse 600 has a base price of $38,800 , which places it in the lower price range.

The F-22 is one of the smaller trimarans in the market. Developed in New Zealand, the F-22 is a folding trimaran built for speed. The hulls are made from narrow fiberglass tied together using fiberglass beams and aluminum, minimizing bulk while optimizing speed.

The F-22 is roomy and is not as pricey as other models in the market. This trimaran has two main versions:

12. 2019 Weta Trimaran

The 2019 Weta trimaran is a 14.5-foot (4.4-meter) trimaran featuring a carbon frame, centerboard, rudder foil, and rudder shock. The hull is made from fiberglass and foam. The Weta is built for strength and speed based on these lightweight materials.

The 2019 Weta trimaran is easy to sail and is worth considering whether you want to take a quiet sail, race with your friends, or take kids to a sailing lesson. It has a simple design and is easy to set up independently. Thanks to its collapsible design, this trimaran is easily stored away with minimal space demands.

13. WindRider 17

The 17.4-foot (5.3-meter) WindRider 17 is one of the more versatile trimarans in the market. It packs high performance for a low cost. This trimaran has a light rotating mast to boost performance, and a full-battened mainsail optimizes visibility.

This sailboat is made from rotomolded polyethylene, which is more durable than fiberglass and demands less maintenance.

The WindRider 17 has a comfortable interior and can fit six adults. This is an ideal choice for social sailing for a couple or a family and friends. It’s easy to ride, and a shallow draft allows easy maneuverability.

14. Astus 22.5

If you’re looking for something small but still comfortable, this 22.5-foot trimaran is for you. Built for speed and maneuverability, the Astus 22.5 has optional foils to optimize speed. The modern design, coupled with the spacious interior, can fit up to four beds. Accordingly, this trimaran is suited for family outings.

This trimaran also has a foldable design, collapsing to only 16 feet (4.9 meters) for easy storage.

15. Multi 23 Trimaran

The Multi 23 trimaran has a contemporary design, featuring a vinyl ester and PVC foam core construction. The section below the waterline is made of solid glass for a sturdy base.

The beams are made of lightweight carbon, and the trimaran features a 33-foot (10-meter) aluminum rotating wing mast for optimal harnessing of the wind. While ideal for weekend excursions with family, once rigged with the asymmetrical spinnaker will get your heart pumping.

This trimaran packs high performance at a lower cost than most other options in the market. It’s a good choice if you are looking for a high-performing unit without spending an arm and a leg.

16. Challenger Class Trimaran

The Challenger Trimaran 15 is the best choice for persons with disabilities. It’s designed to provide disabled sailors an opportunity to explore their passion for sailing without worrying about aspects like safety or operation.

A man named Geoff Hold circumnavigated the British Isles in 2007, becoming the first disabled person to achieve this feat. He had quadriplegia.

Living up to its name, the Challenger can withstand harsh weather conditions while blending performance with speed.

Final Thoughts

Admittedly, no trimaran is best for everyone. But whether you are looking to race with your friends, take your loved ones or friends for a cruise over the weekend, or circumnavigate the ocean, you can rest assured that these lightweight trimarans will deliver speed, safety, and comfort to make it worth your while.

These brands are innovatively designed and feature intricate safety mechanisms that make them virtually unsinkable. Give them a shot and begin your ocean adventure.

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Dragonfly: Dragonfly 28
Rapido Trimarans: Rapido 60
Neel Trimarans: Neel 43
Yachting World: World’s Collect Yachts: Maxi Trimaran MACIF
Yachting Monthly: Dragonfly 28 Performance
Rapido Trimarans: Rapido 40
Dragonfly: Dragon 32
Dragonfly: Dragonfly 40
Yachting World: Dragonfly 40 yacht tour: This cruising trimaran can do 24 knots
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Farrier International: F-22
Weta Marine: The Boat
WindRider: WindRider 17 Trimaran Sailboat
Astus Boats: Astus 22.5
Boat-specs: Multi 23
National Maritime Museum Cornwall: Challenger Trimaran #1 – BC26

Owner of CatamaranFreedom.com. A minimalist that has lived in a caravan in Sweden, 35ft Monohull in the Bahamas, and right now in his self-built Van. He just started the next adventure, to circumnavigate the world on a Catamaran!

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Why You Want a Trimaran: Pros and Cons of a Trimaran

Three hulls are better than one! That would be the adage of the trimaran. It consists of one central hull with two smaller side hulls, called amas. The average person conceives of the trimaran as something even more extreme than catamarans. Lighter weight, higher speed, more specialized. The opposite is actually true; trimarans fill an excellent transition role between monohulls and catamaran. Recognize the potential applications by understanding the strengths and weakness of the trimaran hullform.

1.0 What Makes a Trimaran

When you seek trimarans, envision stability. A conventional monohull must balance conflicting needs of resistance and stability. You want a narrow skinny hull to reduce resistance (and fuel consumption). But you need a wide hull to maintain vessel stability and keep the ship upright. The trimaran separates these two design requirements.

In a trimaran, the central hull provides most of the ship buoyancy (90-95% usually). It does this with a long, narrow hull. And then the outer hulls, called amas, provide the stability. This arrangement allows incredible flexibility in the hull design. Due to the wide separation between hulls, it requires very little buoyancy in the amas to keep the trimaran stable. That is why many trimarans barely have their amas in the water. Compare the relative size of the amas vs the main hull in Figure 1‑1. The amas are just there for stability.

2.0 Advantages

The trimaran offers several capabilities to bridge the gap between monohulls and catamarans:

Excellent for high speed
Moderate weight carrying capacity
Good seakeeping capability
Larger available deck area
Moderate space below the main deck

Another advantage is the design of the cross deck (Figure 2‑1) between the main hull and amas. On a catamaran, this cross deck bridges a large empty gap. Large gaps add complexity to the engineering and require stronger structures. We don’t like that. Stronger structures mean more weight and higher costs. But the trimaran’s cross deck is much smaller. It requires less of a gap between hulls, and it does not extend for the entire ship length. Longitudinal bending is less of a concern for the cross deck. This greatly simplifies the design of that cross deck, giving us many advantages:

Heavier loads can be carried on the cross deck
Less structural weight required for the cross deck
Deadweight coefficients closer to monohulls

The long length of the center hull also offers great advantages for seakeeping. This length greatly reduces pitch motions in a wave, and the narrow center hull reduces chances of slamming. To improve things even more, the side amas reduce roll motions. They add stiffness to prevent large roll motions. But they also act to reduce roll accelerations. All together, trimarans make for gentle seakeeping.

The trimaran offers major advantages for damage survival. The side amas provide excellent protection to the center hull, which military designers find especially useful. But the cross deck also helps with damage survival by containing massive reserve buoyancy. Imagine a damage situation where the ship sinks down to its cross deck. On a monohull, that would be game over. But on a trimaran, the cross deck suddenly becomes a barge, easily supporting the entire ship weight. This reserve buoyancy provides extra peace of mind in yachting applications.

Speaking of peace of mind, let’s talk about a sudden loss of stability. In catamarans, you lose stability once a single ama completely leaves the water. Push a catamaran past that point, and stability is a losing battle. A fact that scares many vessel operators. Trimarans do not have this problem. They get stability mainly from submerging the amas. The center hull always stays in the water, and the leeward ama continues to submerge. This creates a predictable increase in righting moment. In normal cases, trimarans never experience the sudden loss of stability.

3.0 Disadvantages

The biggest disadvantage for trimarans is lack of experience. There are few trimarans in military applications, and even less in commercial use. That lack of exposure instills wariness in many operators. I appreciate caution, but don’t let that stop you from realizing the benefits of a trimaran.

Trimarans do have a few genuine detractors. Due to their complexity, they require some extra design effort. The cross deck introduces a few extra ways to twist and bend the ship, and the engineers must check each of these extra scenarios. Finite Element Analysis (FEA) is the ideal tool for this.

Don’t worry about the FEA bill. You should expect a slight increase, but nothing huge. FEA was already a part of the design process for normal monohulls. Most ship designs already require FEA to consider global hull bending. That means the hard part is already done. Your engineer already had to build an FEA model of the hull. With minimal effort, engineers can expand that model to account for the additional design scenarios of a trimaran.

Cost definitely factors into trimaran construction. The cross deck and extra hulls do add extra steel to the design. You have to pay for that extra steel as part of the build cost. (Figure 3‑1) But don’t assume this drastically increases the total build cost. Adding extra structure is far less expensive than adding extra machinery and power.

Consider the alternative to a trimaran: an equivalent monohull. For the monohull, we strip off the side amas and widen the center hull to maintain ship stability. But bad news. A wider hull requires a larger engine, and associated support machinery. In general, the machinery accounts for approximately 50% of the total build cost. The structure is only around 25-30% of the build cost. [3] Adding larger machinery costs twice as much as adding extra structure.

4.0 Applications

You see trimarans most often in high speed vessels and the occasional military vessel.

Car ferries
Military ships

One of the first experimental military trimarans was the Triton, a steel vessel with a displacement exceeding 1000 MT. [3] (Figure 4‑1) These are not little vessels.

Don’t think of trimarans as an expensive hullform. The prevalence of trimarans with expensive ships is mostly a coincidence. Imagine if you wanted a high speed ship. First step is pick a trimaran hullform. But for high speed, you also build it out of aluminum and load it with powerful engines. Those are all high priced decisions that get imposed on the trimaran hullform. The hull shape does not drive the price tag, and trimarans are not limited to high speed.

Aker Arctic even investigated using trimarans as an icebreaking tug. (Figure 4‑2) Aker found the trimaran configuration especially useful for cutting wide channels through the ice with less power. Trimarans are just a hull configuration. How you use the hull is up to you.

5.0 Conclusion

Don’t let the previous trimarans limit your imagination. The trimaran hullform bridges the gap between monohulls and catamarans. It offers some advantages of both deadweight capability and larger deck area. Primarily, trimarans deliver ship stability in a very power efficient package. What uses can you imagine with that flexibility?

6.0 References

How to Design a Ship

Stability Letters Explained

Free Surface Moment

Practical Stability Test: Naval Architect’s Guide

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FSX Drzewiecki Design Moscow City X

By HLJames , November 14, 2017 in The AVSIM Screen Shots Forum

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Link to post, share on other sites, dmarques69 316.

Really nice shots! Performance of that scenery? acceptable?

jt8d9a 1,881

Moscow looks great. Nice shots!

pmb 5,136

Yes, looks good and in my case performs good, too. I miss the traffic in the photoreal scenery, though, and I think it's missing in your shots, too.

Kind regards, Michael

MSFS, Beta tester of Simdocks, SPAD.neXt, and FS-FlightControl

Intel i7-13700K / AsRock Z790 / Crucial 32 GB DDR 5 / ASUS RTX 4080OC 16GB / BeQuiet ATX 1000W / WD m.2 NVMe 2TB (System) / WD m.2 NVMe 4 TB (MSFS) / WD HDD 10 TB / XTOP+Saitek hardware panel / LG 34UM95 3440 x 1440 / HP Reverb 1 (2160x2160 per eye) / Win 11

1 hour ago, dmarques69 said: Really nice shots! Performance of that scenery? acceptable?

Thanks very much for comments.....runs about 30fps.....has seasons, animated trains and smoke stacks...has options static display...very high quality building modeling.....very wide area of photoscenery extending beyond the city!

1 hour ago, jt8d9a said: Moscow looks great. Nice shots!

Appreciate the comment....I had to walk from the airport to Red Square using ORBX BOB

2 hours ago, pmb said: Yes, looks good and in my case performs good, too. I miss the traffic in the photoreal scenery, though, and I think it's missing in your shots, too. Kind regards, Michael

Many thanks for comments....get traffic in the Kremlin districts only with your slider!

Soulflight 95

Anyone else found Putin yet? ;)

On 11/14/2017 at 0:06 PM, Soulflight said: Anyone else found Putin yet? ;)

Big thank you for comments.....He is in southern California visiting Disneyland!

John_Cillis 2,406

Nice flight and choice of aircraft!

On 11/16/2017 at 1:13 PM, Cactus521 said: Nice flight and choice of aircraft!

Huge thank you for commenting!

JYW 2,602

Lovely pics HLJames!

I love Moscow City X and indeed am enjoying a nice week of flying in Russia myself. I found that all of these old addons seem to run perfectly fine in P3Dv4:- - MDesign Domodedovo

- Drzweiecki Sheremetyevo

- Aerosoft Yekaterinburg

- Aerosoft Norilsk

- Aerosoft Kamchatka

- Justsim Nizhny Novgorod

- RDS Severka (nice little GA field 60nm south of Moscow).

.....seasons set to hard winter, get the deicing truck in, and makes for some really lovelyt winter flying in any size aircraft (although you'll need a long hauler to get from Moscow to Kamchatka!!!!!).

UK LAPL-A I fly:- (GA) : COWS DA-42, A2A Comanche, FSW C414, WT SR22T, FSS P2006, BlSq TBM850, FSR M500, Flyboy Rans S6S, SWS Zenith 701, (Airliners) : Fenix A320, Ini A300-600 and PMDG737.

6 hours ago, JYW said: Lovely pics HLJames! I love Moscow City X and indeed am enjoying a nice week of flying in Russia myself. I found that all of these old addons seem to run perfectly fine in P3Dv4:- - MDesign Domodedovo - Drzweiecki Sheremetyevo - Aerosoft Yekaterinburg - Aerosoft Norilsk - Aerosoft Kamchatka - Justsim Nizhny Novgorod - RDS Severka (nice little GA field 60nm south of Moscow). .....seasons set to hard winter, get the deicing truck in, and makes for some really lovelyt winter flying in any size aircraft (although you'll need a long hauler to get from Moscow to Kamchatka!!!!!).

Thank you very much for commenting.....glad to see all those programs working....need to make a flight to Moscow myself!

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Payware Airports and Scenery Reviews

Scenery Review : Moscow City XP by Drzewiecki Design

drzewiecki design

By Stephen September 24, 2016 in Payware Airports and Scenery Reviews

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7 months later...

Thank you for this very thorough (as always) review. I just bought it (it's on sale) and have only one disappointment so far: Red Square has no ILS or any landing aids at all for that matter. And what a nightmare of an approach! Also I was hoping the package would include an add-on that gives my c172 a big cup holder for my Stoli. Otherwise the scenery is gorgeous. What a country!

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Moscow City Agglomeration Competition

Moscow City Agglomeration Development Concept Competition, Architecture Contest, Building, Design

Moscow City Agglomeration Development Concept Competition

Russian Design Contest – design by various architects

17 Oct 2012

Moscow City Agglomeration Competition Results

Moscow City Agglomeration Development Contest

PLANS FOR A NEW MOSCOW PRESENTED

At the end of August nine international teams presented their final projects for the draft concept for the development of the Moscow agglomeration to a group of experts and the client, the Moscow Committee for Architecture. At the beginning of September, they were judged by an international jury, headed by Deputy Mayor Marat Khusnullin. They judged proposals for the Moscow agglomeration as a whole, for the new extension of the city and for a new federal government centre to be located in the new extension. In the last category the project of the Urban Design Associates team was the winner, in the two other categories the team of Antoine Grumbach.

The competition for the design of a draft concept for the development of the Moscow agglomeration was announced after president Medvedev agreed with the governor of the Moscow region to transfer a part of the region’s territory south west of the city to the municipality.

The aim of enhancing Moscow’s territory 2,5 times was to relief the pressure on the city that is dealing with enormous traffic problems. At the same time, it was announced that the federal government would move its offices from the centre of Moscow to the new territory. The competition that was commissioned by the Moscow Committee for Architecture and organized by the Moscow Masterplan Institute, was based on the model of the Grand Pari(s) competition that was initiated by French president Sarkozy in 2008. Nine teams were selected on the basis of their portfolio’s.

For the first time in history, planners from all over the world were looking at the development of Moscow not just as a city, but as a metropolitan agglomeration. This is very important, since Moscow’s traffic problems are mainly caused by the daily migration to the central city by people from the agglomeration. The creation of new centers of working and living could be a way to solve this problem. The big question is where to create these centers: in the agglomeration or inside Moscow? Though most of the competitors stress that it is as important to densify the city within its borders, as it is to create new centers outside, the extension of the city is something to be dealt with – it is a development that has been taking place ad hoc for the last 20 years.

Moscow City Agglomeration Development Contest Projects

The Ostozhenka team seems to take the most radical position of all competitors by proposing to freeze urban development in the new territories, using them exclusively for the creation of recreation areas, agricultural land and forestry. All new construction should be concentrated in former industrial sites within the existing borders of the city.

Actually all teams propose to desify the existing city. In general, many teams have produced converging projects where technical aspects or just common sense appear to prevail over conceptual and artistic considerations. In this perspective, three projects can be considered more of less generic – the projects of the Urban Design Associates, TSNIIP and Chernikhov teams don’t really make clear choices but develop their project by juxtaposing obvious development potentials.

On top of this Urban Design Associates team proposes a detailed project for the government centre with an artificial lake as the binding element between the different quarters. With attractive imagery this project was especially liked by the jury, which it to considered this project the best for the federal government center.

The Bofill and Grumbach teams choose to concentrate new construction in a long linear development reaching out of the city, motivating this by the idea that this is represents the natural growth pattern of the city. Bofill’s project consists of a wave-like development that mixes urban settlements with a park landscape. The Grumbach project uses the RER model that we know from Paris, and includes an compehensive public transport plan and detailed projects for the development of the areas around the stations. These appealing proposals made the jury declare it the winning project for both the Agglomeration and the New extension categories.

Almost all projects propose a rail connection between the Vnukovo and Domodedovo airports parallel to the Moscow Ring Road, but only the l’AUC team develops this as the central axis of the new development: a parallel city that connects both existing and new settlements in the extension and links up with the existing express rail connections that currently serve the airports. More detailed projects are presented for 10 sites evenly distributed within the existing city and in the South-West extension. They include a Luxury River Area, A Slow City Area, a University Research and Development Area and the Federal Government center.

The OMA team also works with development clusters, but they are not just located in the city and the Southwest. The displacement of the government agencies and ministries as a trigger for the establishment of urban settlements outside the city is taken to its extreme: they are not concentrated in one new federal government centre but distributed around the city near existing developments that are related to the specific character of a ministry or agency: The ministry of border control near an airport, the ministry of transport near a railroad test site, the ministry of energy near a centre for nuclear science etc. On the whole the OMA project concentrates on the invention of new instruments like taxation, land use regulation and land swap rather then the creation of new urban configurations.

In contrast with the OMA plan the project by the Secchi teams is the most architecturally articulated. Not transport lines define the urban development but urban form. It proposes to shift the centre of gravity of the city towards the south west. For this it creates a large square that reaches over the Moscow ring Road and unites city and countryside. It attempts to erase the Moscow Ring Road, that in all other projects features as a rigid border of the city.

Though the jury has chosen some project as being the best, there is little chance that one or another project will be realized. However, all teams have produced large reports that will be thoroughly studied by the city and the Masterplan Institute. This will give the city a large catalogue of possible solutions and development strategies that it can use to solve the problems of the Moscow agglomeration.

28 Jun 2012

Moscow City Agglomeration Development Competition News

International Consortium including British firm McAdam Architects takes first place in second round of Moscow City Agglomeration competition

Presentations took place in Moscow on 22 June 2012 for the second stage of the competition, in which 9 teams presented the first editions of concepts for the city agglomeration development, including the existing city and the new south western sector of the agglomeration.

The international consortium, lead by well-known Russian urbanist – Andrey Chernikhov, and including McAdam Architects, Tower 151, Georgi Stanishev and Ginsburg Architects were awarded the highest score by a panel of international experts with OMA taking second place.

The consortium suggested that, instead of looking at new development in the south western sector, in the first instance an abundance of brown field and other available sites within the existing city boundaries should be attended to. They highlighted vast areas occupied by goods railways and disused industrial sites from Soviet times, as prime areas for regeneration and expansion, as well as a re-thinking of transport networks to alleviate pressure on existing systems.

Their radical proposals have sparked a debate as to the validity of the brief which emphasises the need to expand development into the south western sector.

James McAdam who attended the presentations said: the process is evolving into a fascinating discourse on how a major capital can tackle the problems of expansion and regeneration on a vast scale. As a consultation procedure the range of ideas being suggested are incredibly diverse and could be pooled as a powerful medium for Moscow’s future.

Final concept presentations are scheduled to take place at the end of August.

Moscow City Agglomeration Development Concept Competition images / information received 280612

McAdam Architects

27 Apr 2012

Moscow City Agglomeration Development Concept Competition 2012

OMA wins first round of the Moscow City Agglomeration Development Concept Competition

Moscow, 27 April, 2012 | A consortium of experts led by OMA scored the highest of the 10 teams that completed the first stage of the competition to develop the concept of the Moscow Agglomeration.

In 2011, the Russian Federation Council confirmed that the city of Moscow will annex 150,000 hectares to the southwest, making Moscow 2.4 times its current size. The expansion is designed to relieve pressure on the historic city center by redistributing the working places to the annexed part of the Moscow Oblast, thereby addressing transport, ecological and social issues that result from high levels of commuting. Before Moscow’s new administrative borders come into force in July this year, the Council called for a concept for the development of the Moscow Agglomeration, and in February this year the Council invited 10 teams to participate in the development of this concept.

For the first round of the competition, focused on a plan for the Moscow Agglomeration as a whole, OMA proposed a joint framework for the development of Moscow and the Moscow Oblast, under which the administrative border and political mandate could address the entirety of the Agglomeration. OMA proposed logistical hubs outside Moscow’s current boundaries which would be linked to the City and the Oblast through high-speed rail, integrating all forms of infrastructure: transport, broadband, industry, and energy provisions. The proposal also suggested that the development would not rely solely on government funding, but could introduce a public/private mix.

On the proposed development strategy, OMA Partner-in-charge Reinier de Graaf says, “We are very honored to participate in such an ambitious project. In launching this plan, the authorities have taken an important step in addressing the problems of the city at the appropriate scale: Moscow’s proposed expansion becomes a reason to develop a single integrated future for Moscow and the Oblast.”

The OMA team working with AMO, its internal research studio, is led by Reinier de Graaf and Associate Laura Baird. The concept is being developed together with a core team consisting of the Strelka Institute for Media, Architecture and Design, Project Meganom and Siemens. This core team will be supported by an advisory board which includes McKinsey, Ricky Burdett, Saskia Sassen, member of the Committee for Global Thought (Columbia University), the Levada Center, West 8, and RWDI.

Moscow City Agglomeration Development Concept Competition images / information from OMA

Rem Koolhaas

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The challenge of building a trimaran from beachcat hulls

Hi Mike! Let me first say I appreciate the depth of information on your web site :)

I've been ‘oogling’ it for years. But now I have a question regarding the potential of building a trimaran out of some old 18' cat hulls. How would you suggest I proceed and what might I expect from the result ?

….. Josh from Kalispell, MT.

ANSWER : Tks Josh … always pleased to hear my work is proving of value to others.

I first need to say that using cat hulls is not a perfect fit for either the vaka (center hull) or even the amas (floats) but sometimes we can make something work as a fun project. The vaka will be the biggest challenge. I could briefly answer your question with just a list of do’s & don’ts , but I think a more detailed reply will give you some specifics and cover a broader range of related questions, so here we go.

First step is to make a weight estimate starting with what a ship designer would call the “Lightship weight” (boat ready to sail, but no supplies, crew or their personal equipment). You then need to decide what weight you wish to tack-on to form the Design Displacement . This we call the ‘Deadweight’. The very minimum would be for solo day sailing .. say 200 lbs added to the Lightship weight, but for an 18footer, this will likely be more like 350lbs as an absolute minimum.

So let’s assume the boat and its rig and gear weigh 550 lbs. Now with 350lbs added, the required Design displacement will now be 900lbs. The volume to support that will be 900/64 = 14 cu.ft. (1 cuft displaces 64 lbs of seawater, or use 62.4 for fresh water)

The difficulty with a trimaran over a beachcat, is that there is initially only ONE hull to provide this buoyancy volume, compared to two for a catamaran, so right away, one can see why a single catamaran hull is WAY too small for a vaka. Let’s say these are your 3 hulls.

Place the widest one with most volume in the center.

Obviously, if you kept the hull in this level position, your trimaran would be dragging 3 hulls through the water with far more drag than for a catamaran.

So you need to lower the central hull, so that it will support your 900 lbs .. requiring 14 cu.ft volume under the waterline. It will clearly not have the volume needed so what can be done ? There are 3 basic ways to go. You can lengthen it, widen it, or sink it deeper. Using all three would be best if designing a new vaka but I suggest that sinking it deeper will be the easiest, as you can then just raise the sides. But you will probably need some frames to support the deeper hull section as the hull will now have to accept more hydrostatic pressure.

It will now look more like this:

You can either raise the sides (C) or a better solution would be to combine this with side extensions (D) to give yourself some form of central cockpit as well as more width to later attach your cross beams (akas). Exactly how deep this central hull will need to go, will decide how practical this whole ‘conversion’ will be, and it’s quite possible you will need to do some major surgery to this central hull (or build a new one) to get the buoyancy volume you need. If you are not already familiar with how to calculate this, I suggest you study this page from the design section.

https://www.smalltridesign.com/Trimaran-Articles/design/simpsons-rule.html

A very rough idea of the sectional area (marked as ‘buoyancy’ in the above sketch) can be obtained by assuming a Block Coefficient* of 0.5. For this, double your required volume and divide by your waterline length .

Block Coefficient is the ratio of actual hull volume to an encompassing ‘block’, that has dimensions equal to: your waterline length: your waterline beam: and underwater water depth (design draft)..

So in this case, this will be 2 x 14 / 17.5 or 1.60 sqft, which will roughly require a beam and draft of (1.60 0.5 ) or 1.265 ft for both waterline beam and for draft .

If your hull is much smaller, you either have to go deeper than 1.3ft draft OR find ways to widen that hull to get the cross-sectional area you need. (Typically, a central trimaran hull has a waterline width of about double that of the ama beam).

Moving forward .. let’s assume you now have chosen your best workable solution for the vaka.

As far as the overall beam is concerned, the issues involved and a way to select a suitable beam is already explained in this Q&A from earlier this month.

We now need to connect the amas with the main hull using beams. As I understand you are planning to use a similar folding system to my W17 and using my design of fiberglass hinge and latch , I will explain what you will need.

Beam and latch strength will be defined by the maximum righting moment that the ama can apply, plus a safety factor.

As a safety factor, it is common to apply the full buoyancy of the ama (when fully underwater) to the main beam ... and multiply by the Beam Lever (shown here), which might be ~4ft in this case. IF the full ama volume is say 800 lbs, then the bending moment on the beam would be 3200 lbs.ft

Once you have fixed the hinge location, you can calculate the bending moment at the hinge, using the same 800 lbs (just assumed for this example) but with a smaller lever. Let’s assume it is 2.5ft in this case, so the Bending Moment will now be 2.5 x 800 or 2000 ft lbs. This would mean that IF your vertical distance between the upper hinge and the lower latch is 5” deep (0.42ft), that the latch will need to take 2000/0.42 or 4762 lbs in tension, for the hinge to be as strong as the beam. This shows the important value of 'beam depth' with a hinge system.

There will also be a download on the upper hinge, due to whatever crew weight you place on the flying windward ama (plus the weight of the ama and outer beam itself). With a large volume ama, this download is typically about 70-80% of the upload, so the hinge is a little less stressed in tension than the lower latch, but with a small ama, it could be the reverse, so you need to do the maths..

In Fig 3. note that I show the amas inclined out at 10-12 degrees. If this is not done, they are more side-loaded when heeled and this adds an unnecessary load to their beam attachment as well as making the ama more resistant to push through the water, so personally, I consider some outward angle is essential.

In addition to their location in the above sectional view, the outer hulls that will work as amas, also need to be positioned in profile view , relative to the central hull.

In the sketch below, they are shown with slight lift of the bow that some designers in the past have incorporated with the assumption of less resistance and 'to ride over the waves'. In the 1970’s many amas were then banana shape d and even back then, Hobie 16 hulls were sometimes used as trimaran floats. Having sailed on one a few times, I found such boats (like Newick’s Tremolino for one) were very jittery in any seaway, were very wet, and also pitched excessively. Even using the straighter and therefore more suitable H18 hulls, their stability role for a trimaran is still compromised if installed as shown here in Fig 6.

Just compare these two sketches in Fig 7 that both show an identical assumed heeled water line (in red) and you can see that IF the bow of the ama is raised that the ama will not give any bow lift UNTIL the whole bow drops, severely increasing the risk of pitch-poling, so unless the bow is very full with a wide vee, its more effective and safer to actually LOWER the buoyancy of the ama bow so that it quickly immerses, to provide more effective lift when heeled.

So what can be done to make the beachcat hull more like this ama? The bow is deep and narrow, not vee’d. Think of the Hazelett mooring buoy that is a vertical tube. While it still offers buoyancy, it moves very little in waves. When a bow is like that, its not easily launchied in the air to only fall again, over and over again. It just stays quiet and cuts horizontally through waves and it certainly increases the waterline length. Early rockered amas, had short waterline lengths and were also vee’d … two things I advise against. After all, we are ’sailing’ on this ama and need it to act like an efficient boat hull. But as it would be complicated to deepen the forefoot of an existing beachcat hull, its easier to lower the bow as shown above and then raise the deck forward of the forward beam.

As a picture is a 1000 words …, check out what I would do. 3 days of 4 hours could see both done if you plan your work.

You might find a collision bulkhead inside that will need cutting across, but it should not be hard to raise that with rigid foam, so that the raised deck can be bonded to it and keep it watertight. The ¾” holes in the sides will stop the end of the cut from splitting and cracking, and will be filled and covered over by the fill piece.

This should give one enough to make the important decisions and calculations, but as can be seen, catamaran hulls are not ideally interchangeable with Trimaran hulls, so their use like this will always be a compromise.

You also have to decide which hull will hold a centerboard or daggerboard. It’s much easier to reach one in the center hull, but this is your choice and dilemma. Either can be made to work but do not use ama boards unless you are operating in deep water, or you may end up IN the water while trying to adjust them from an ama, especially in rough water.

As far as the end result , it depends on so many things that it’s hard to predict. But it could be made to perform quite well in relatively flat water and give you some fun at least … but it will not be a dry boat like the W17, nor as comfortable or have as low leeway, as the round hulls are just not as ideal for slicing waves with minimum disturbance as the W17 hulls are. While rounded hulls are very effective in lowering surface friction, they seldom slice waves as well and certainly do not provide the leeway resistance of the W17 hulls.

It's also frequently forgotten (or just not understood) that often, the greatest resistance from a small boat is wave resistance or wave making … being the most critical in the 4 to12kt range. Optimizing for this range with non-round hulls can more than make up for their added skin drag. See this article for more on this, where there is a chart showing what proportion of residuary (wave) resistance applies at what speed.

Hope this helps to get you going in the right direction, and good luck with your project.

Also note that there was an earlier question of using the reverse ... Trimaran hulls for a Catamaran and as my graph showing the proportion of residuary resistance versus the total is also there, it may be of some interest too.

Mike ... March 2022

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Moscow Has a New Standard for Street Design

Written by Strelka Magazine
Published on August 25, 2016

Earlier this year the development of a new Street Design Standard for Moscow was completed under a large-scale urban renovation program entitled My Street , and represents the city's first document featuring a complex approach to ecology, retail, green space, transportation, and wider urban planning. The creators of the manual set themselves the goal of making the city safer and cleaner and, ultimately, improving the quality of life. In this exclusive interview, Strelka Magazine speaks to the Street Design Standard 's project manager and Strelka KB architect Yekaterina Maleeva about the infamous green fences of Moscow, how Leningradskoe Highway is being made suitable for people once again, and what the document itself means for the future of the Russian capital.

Strelka Magazine: What is the Street Design Standard and what does it include?

Yekaterina Maleeva: The Street Design Standard is a manual for street planning in Moscow . The Standard is divided into four books, each one of them covering particular aspects of street design. Many cities across the globe have developed their own standards and the concept has gained a lot of popularity over the last decade. The New York Street Design Manual is a famous example; the book has even been translated into Russian. However, Moscow streets have little in common with New York streets, for example; every city has its own unique urban typology and simply copying existing solutions from another manual is not a viable option.

When we started our work on the Standard , the first thing we did was study Moscow streets, their peculiarities and common features. The first volume of the Standard focuses on the typology and distinctive attributes of the streets of Moscow. We gathered data on more than 3,000 streets and processed the data. Despite the large sample size, we discovered certain similarities. We managed to identify ten of the most common street types, but some unique streets could not be categorized. For instance, Tverskaya Street, built in 19th century, originally fell under category "10C." But after it was widened in the 1930s, Tverskaya ended up in a unique place within the urban fabric of Moscow. Such objects as that require a case by case approach and an individual project.

What can be found in the other volumes?

After we identified these ten street types, we started working on defining the best way to approach the development of each. The second book describes what a street of each type must have. We developed a general profile and functional zoning for each type. The pavement is more than just a pedestrian lane: there is a buffer zone between the roadway and the walking lane where the parking posts, street lights and communication lines are located. It’s a mandatory utility zone that has to be paved in such a way that any section can be easily unpaved and replaced. There is also a pedestrian fast lane for people walking to their workplace and a promenade with benches and other objects. Building façades have a large impact on the street they are facing. Restaurants and shops are located in these buildings. Making the adjacent zone retail-friendly is important. Cafes and restaurants must be able to open street patios to attract customers without disrupting the pedestrian traffic. How to apply these concepts to each of the street types is thoroughly explained in the Standard .

The third book describes eleven groups of design elements, including surface materials, benches, trash bins and lights. This catalogue of elements contains no mention of suppliers. It does not promote any manufacturers; instead it describes the attributes which define a quality product. For instance, the third book explains which type of tree grates will serve the longest while causing no damage to the root system of a tree. Styles of grates, bins, benches and other elements may vary, but all the items must comply with the quality standard.

Finally, the fourth book focuses on the planning process: how to perform preliminary analysis, how to apply user opinions during the development and how to achieve quality implementation. Additionally, there is a special emphasis on the fact that street planning cannot be carried out without any regard for the context of the street. A street should be regarded as a part of an interconnected system of various public spaces, together with adjacent parks, garden squares, yards and plazas.

Does the Standard have an official status? Should it be considered a law or merely a guideline?

There are a number of state-level laws and regulations relevant to street design issued by the Moscow Government. They were taken into account during the development of the manual. These regulations ensure safety standards and must be complied with. While the existing legislation covers safety aspects, our books introduce comfort standards. The Standard is basically a non-binding, advisory guideline created with the goal of improving the urban environment everywhere across the capital and maintaining it at a high level.

What happens if a street does not fit any of the mentioned types (and is not as significant as Tverskaya)? For instance, what if a street located in the New Moscow territory has cottages on one side, apartment complexes on the other and an entrance to the Moscow Ring Road somewhere along the way?

A standard is not a ready-made solution. The streets share common features yet also retain their individual attributes at the same time. Applying a single standard profile to every street is impossible. Adjustments are always in order.

The Standard offers three sets of solutions for each type of street with a large potential for combining various elements. The manual basically offers a convenient database that a designer working with a new space could use. That does not mean that all the new projects will look exactly the same. Some solutions featured in the Standard are yet to be implemented anywhere in Moscow . For instance, our collaboration with Transsolar, a German company consulting us on environmental comfort, revealed that Moscow’s largest environmental problem was not in fact CO2, but small-particle dust produced by studded tyre traction. And a simple method to control this type of pollution already exists. Many busy streets outside the city center have a green buffer zone separating the roadway from the sidewalks. A 1.5m high ground elevation running along this zone could filter out up to 70% of the tyre dust, preventing it from spreading into the residential areas. Western countries have been successfully using this technology for many years. Now it is a part of Moscow Standard . By the way, a terrain elevation could also help reduce the level of road noise.

Does the Standard offer anything for the main roads? For example, nowadays Leningradskoye Highway basically splits the city into two disconnected parts; it’s a car dominion.

The Standard does not offer solutions for transportation problems. When we were defining our street typology, we relied on traffic load data calculated using Moscow ’s transportation model. We pursued a goal of only offering solutions that would not aggravate the current transport situation. Any planned sidewalk extension or addition of a bicycle lane or road crossing should first be approved by the Moscow Department of Transport.

As for the main roads, our research revealed that the streets with the highest traffic load also have the heaviest pedestrian traffic. One would think that it should be the other way around. However, the main roads have metro stations, which generate a lot of pedestrian traffic, which in turn draws retail. Treating main roads the same way as highways is impossible. The needs of both vehicle traffic and local residents must be taken into account, which creates a paradox.

These territories have every opportunity to become more comfortable. Some have relatively large green buffer zones that currently remain underused. The Standard proposes to augment these zones with additional functionality. On one hand, some of the main streets will gain attraction centers, especially near intersections connecting them to the adjacent residential areas. Weekend markets are one example of such centers. On the other hand, the Standard involves the creation of zones able to absorb extra precipitation flowing from the roads and filter it. There is a list with types of vegetation best fit to handle this task. The same zones could be used to store snow in the winter. The meltwater will be naturally absorbed by the soil, alleviating the need for moving the snow out to melt. This, however, would require decreasing the quantity of melting chemicals sprayed over the snow, as the plants underneath might be susceptible to their effects.

Can the new Standard rid us of green lawn fences, yellow curbs and other eternal eyesores?

The choice of yellow and green appears random, so we have no idea how to actually fight that. The Standard offers no colour schemes. As long as fences meet the set requirements, their colour does not matter. However, currently they seem to fail to comply. The Standard states that lawns do not require fencing. This is a waste of materials: people will not trample grass and bushes just for the sake of it, while dog owners will trespass anyway. There are many other options for protecting lawns from being trampled. For instance, a same-level pavement strip with a different texture could protect a lawn from accidental intruders just as well as a curb can.

Natural soil water absorption is currently largely ignored, with most precipitation going down the storm drains. Meanwhile patches of open terrain on a street are able to absorb water. Employing these natural cycles in street layout could save resources.

Does the Standard provide any financial estimations? For instance, an approximate cost of renovating a street of a particular type?

No, as the Standard does not list any products of any particular brand, there are no prices to refer to. Nonetheless, the Standard was developed to fit three potential price ranges. Whether their estimated price is low or high, all the elements ensure that quality requirements are met. The same quality level must be maintained across the whole city and never drop below the set standard.

Let’s say a world-famous architect arrives to Moscow to design a street. He puts incredibly beautiful things into his project, which, unfortunately, contradict the Standard and are not guaranteed to work as intended. In that scenario, will the architect be told to stick to the Standard ?

This could happen and I think it would be a good thing. If an architect plans to place a sculpture on a 1.5 meter wide sidewalk, would that really be a good idea? Following the Standard ensures smooth movement. Its goal is to reinvigorate the streets. In Copenhagen, new design manuals helped increase average time spent by residents outside by 20% over 10 years. That was achieved through creating convenient and attractive public spaces. Moreover, implementation of the Standard enables the creation of professional documentation for architects, which excludes the possibility of any instructions that will later be unclear to the experts trying to work with them. Finally, the Standard also pursues the task of providing the opportunity for the development of street retail.

Isn’t retail a whole different story? How can retail be introduced in such places as Strogino District, where the ground floors are living floors and have security bars on windows? By reintroducing street vendors?

True, business has no direct relation to street renovation. However, there is a strong connection between them. In Strogino, building façades are mostly located far from the sidewalk. Moreover, facades are often concealed by shrubbery and trees, making local businesses even less noticeable. Another problem is that first floor apartments cannot be used for commercial purposes due to insufficient ceiling height (3 m compared to 3.5 m required minimum). Nonetheless, we discovered multiple examples of shop owners reconstructing apartments in residential districts to meet the requirements.

Our British consultant Phil Wren, a street retail expert, travelled Moscow ’s residential districts and studied the existing examples. He came up with a great idea: building an expansion connected to the façade and facing the sidewalk. This makes it possible both to achieve the required ceiling height and increase the visibility of the business to the passers-by. The part of the shop located in the apartment can be used as a utility room or a stockroom. This way the noise level is reduced, regulations are met and store space is increased. Our Russian consultants confirmed the viability of the proposed concept. And the Standard will ensure that any added expansions will look presentable.

Does the Standard also regulate façade appearances, an architectural element? What should be expected from this? It is unlikely that all houses which fail to comply will be demolished once the Standard is implemented.

Renovation works with what is given. Of course, façades cannot be changed. Central Moscow has a problem with mansions and many other buildings being fenced off, which prevents them from accommodating street retail. Central streets are also relatively narrow. The Standard proposes sidewalk expansion wherever the access to the first floors is open. Street renovation does not always involve planting trees. Some places require enhanced crossings so that people can quickly reach the other side of the street to get to a shop or a café. Those streets where the facades are windowless are a more suitable place to plant more vegetation.

Can an average person – not an architect, designer or construction worker – understand the new Standard , or is it a technical document which can only be interpreted by a professional?

Any person can. The Standard is written in a way that both professionals and common citizens are able to understand. The Standard contains multiple images, photos, infographics and diagrams and is written in plain language. We would love for more people to read it: the books contain many interesting solutions for our city that affect every pedestrian.

In late March it was revealed that Strelka KB would be developing a standard for recreational zones and public areas in Moscow . What differences will that document have from the Street Design Standard ?

The two standards will have a lot in common. The city currently faces a task of developing a connected system of public spaces. The first logical step was to work with the streets which actually connect areas of attraction and other public spaces. Now the work on all other public spaces takes off. Parks, garden squares, yards, water bank recreation areas, plazas near metro stations must all fall into place. Work with these territories will set a single quality standard. In addition, it will improve Moscow ’s quality of life and reduce air pollution. Simple solutions could improve airflow, increase biodiversity and reduce noise levels at the same time.

The renovation program is quite long and depends on numerous standards and documents. But when exactly will the endless repair works end? Are there any time estimations for when all these concepts will finally get implemented?

This is not an easy question. Full renovation may last decades. The Standard is the first step towards actually controlling the renovation process and its timeline. Until now renovation has been proceeding rather haphazardly. Now the city has decided that the way the streets are designed should be clarified. We understand that the Standard cannot last unchanged for eternity and should, just like any regulation, undergo periodical updates. The Standard uses flexible typology: a street of one type could transition to another within a few years under certain conditions, such as changes in its usage and its user categories. Everything must stay regularly updated according to the accumulated experience.

During our work on the Standard , we held regular roundtables joined by experts and ordinary citizens. One of our guests mentioned that he had recently started paying attention to Moscow ’s facades, their beauty and their drawbacks. He was able to do that because he no longer had to watch his step. So the process has already started and we already see some results.

Sustainability

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COMMENTS

Trimaran Hull Performance
Recent tests (2009) on a small prototype trimaran with this Box-hull form and flat bottom, demonstrated that performance can be surprisingly good and some of what is lost through increased wetted surface is indeed made up by the slimmer form. While this may not be true at low speeds (below say 4 kt), the flat of bottom may give enough dynamic ...
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Small Trimarans Report. Back in 2010, sailor/naval architect Mike Waters published a 22-page report covering 20 small trimarans. It includes charts, graphs, photos, and critical objective reporting on many of them. Read more…. Review of nine Small Trimarans. Mike Waters' review of nine small folding trimarans 14-20 feet including six ...
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My new blog: MultihullBlog.com. 3123 Fairview Ave E. Seattle, WA 98102. Order the Latest Design Portfolio today to see over 85 multihull plans in stock. Besides illustrating my stock designs, for which I sell study plans and full construction plans, it also contains my design philosophy of multihulls; an article on the rapid Cylinder Mold (pdf ...
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Then the design of the alternative hull forms of a 120 m WL L fast RoRo Trimaran Dinav1 of medium size capacity (800 passengers and 240 cars), featuring round bilge main hull and in-board ...
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Overall beam is significantly higher (14ft vs 12ft), so adding to stability and power to drive the boat. B/L ratio is 0.82 compared to 0.67 for the earlier Cross. This increased stability allows more sail. While the W17 Cruising rig is about the same as the Cross 18, the so-called Race Rig has nearly 20% more sail, which is much appreciated in ...
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The Antrim 40 Cruising Tri is a development from our 40' Racer/Cruiser (design #72). This model features full standing headroom in the main hull. Combining the most up to date composite building technologies with the comfort of a spacious main hull makes this the perfect choice for the serious offshore sailor. Plans are available for a custom ...
Catamaran Hull Design
Typically this will be 8-10:1 for a slow cruising catamaran (or the main hull of most trimarans), 12-14:1 for a performance cruiser and 20:1 for an extreme racer. ... The most important catamaran design hull shape factor, is the Prismatic Coefficient (Cp). This is a measure of the fullness of the ends of the hull.
Custom Trimaran Hull Design: Efficient & Stable Boat Hulls
Whether you're looking for a sleek, modern design or a timeless classic, we'll work with you to create the ideal hull that embodies your vision. Discover the future of hull design. Contact metadecod co today to start the journey towards your tailor-made trimaran hull.
Trimaran Plans
The DESIGNER'S book TRIMARAN and CATAMARAN CONSTRUCTION is part of the plans (over 21') and covers all phases of construction. ... boats may be built with flared hulls, with the exception of the TRI 25, TRI 26MT, CAT 27PC and the CAT 27. A DESIGN FEE for customer modifications to stock plans. TRI-STAR 18. Click for complete details. TRI ...
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USA-17—a 90-foot-long (27 m) trimaran, type BOR90. A traditional paraw double-outrigger sailboat from the Philippines. A trimaran (or double-outrigger) is a multihull boat that comprises a main hull and two smaller outrigger hulls (or "floats") which are attached to the main hull with lateral beams. Most modern trimarans are sailing yachts designed for recreation or racing; others are ...
trimaran hull shapes
Waterline beam is 20". draft 16". The hull shape is a fine oval at the bow, becoming egg-shaped, then becoming a 6" flat aft. With high buoyancy in the stern of the main hull and in the bows of the ammas, the pitch-damping can be felt through the seat of the pants and works very well.
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Trimaran Hull. I think trimarans are incredibly cool, and especially the second type. There are two types of trimarans: ... Most boats nowadays use some sort of v-hull or hybrid design, like a semi-displacement hull; especially larger boats. So not a lot of boats have a real flat bottom. However, we do call a lot of boats flat-bottomed. ...
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As noted above, the Froude Speed/Length ratio is very significant in boat design. Most descriptions and findings re hull resistance are directly related to it. For example it has been shown that a displacement hull creates a wave equal to its length at a S/L ratio of 1.34 and at that point, there's such a hump in the resistant curve that most ...
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These smaller outrigger hulls are attached to the main hull using beams. While trimarans have a rich history dating back nearly four millennia, these types of sailboats have only gained popularity in the late 1900s and early 2000s. ... The Multi 23 trimaran has a contemporary design, featuring a vinyl ester and PVC foam core construction. The ...
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Using catamaran hulls to make a trimaran
Place the widest one with most volume in the center. Obviously, if you kept the hull in this level position, your trimaran would be dragging 3 hulls through the water with far more drag than for a catamaran. So you need to lower the central hull, so that it will support your 900 lbs .. requiring 14 cu.ft volume under the waterline.
Moscow Has a New Standard for Street Design
Published on August 25, 2016. Share. Earlier this year the development of a new Street Design Standard for Moscow was completed under a large-scale urban renovation program entitled My Street, and ...