I Use to work on the Triton. From memory it was almost 2000 ton and 100 meters long It was a diesel electric propulsion with a max shaft power of 3.2 mw It was fuel efficient for its size using 8 ton of fuel a day at efficient cruising speed of 12knots fully loaded. With a light load of fuel stores and crew on a load test we managed to squeeze out 22 knots from her another feature is that she is made of thin plate high tensile steel. By the way it was not the most comfortable vessel to be aboard in weather she even bob side to side in glass conditions and corkscrewed badly when the swell was on the quarter. When the waves hit between the hulls its like a bomb going off. I feel the side hulls should have been extended further aft. Not a good comfortable sea keeping vessel. But had its advantages in fuel efficiency.

Just discovered your channel, Nick, and I am so impressed by the depth and attention to detail in your videos. I've been a sailor for over fifty years and an engineer for more than forty and it seems like you have a lot of first-hand practical experience on top of some spooky good engineering skills. Yes? I've spent a lot of time on all three hull forms, coastal and bluewater, and I think your take on trimarans is spot-on. Out of all of my boats over the years, I have to say that my tri was my favorite. I'm pretty sure I need to buy or build another one and get back out there. Really appreciate your channel, Nick. Thank you.

Great explication! I am convinced. I will use it for working vessel to help Amazon River communities in need.

Thank you for this series. I have learned so much and love your lectures.

Thank you for your awesome video which have been teaching a lot about my sailing passion as a fellow engineer that loves getting nerdy in the design aspects even if I’m just an electrical controls engineer and not a mechanical design engineer

Dragonfly trimarans is another level with folding amas, they’re superb !

Good post Nick...CAN'T WAIT UNTIL NEXT TIME

Always informative and insightful. I learn something in every video, thanks!

I'm currently building a cutter ketch rigged sailing trimaran! Thanks for your support!

Truly informative- changed my mind entirely about catamarans as a preferred design

When I worked for Honolulu ship yard. We built a vessel named Slice for lockeed Martin, 105 long 55 foot beam, nic

I was hoping you would do a direct detailed comparison between trimerans and catamarans.

That was deep !Great vid great info thanking you sir U deserve a million likes

That Fred Olsen trimaran is a must. i have travelled a lot in it and it is awesome :- D

Thank you Nick, most informative.

Thank You, I learned something.

A clear and concise explanation, thanks a lot! The whole stability advantage could play a big role in designing a offshore mobile space launch platform, just like the one used by the Sea Launch corporation.

Well done! Very coherent and easy to understand.

Definitely learned a lot... Thank you Nick :-).

Really digging the channel

I'm in love with the Neel 43 and 47 (or the older 45)

Excellent video

Talk about the benefits over a cat like POUNDING! No Daggerboards to break off. Usually better protected rudder and props. Considerably harder to flip over. Plus that sporty heel so you feel like your are sailing.

I realize this was posted a while ago however i hope you can shed some light on trimaran, monohull and catamaran characteristics in a heavy sea. Perhaps getting into beam seas at least. I'm of a mind that a BALLASTED center hull on a tri would achieve the greatest stability over a catamaran in say 15'-20' seas. Maybe a revisit to the subject would be a great addition. Tnx!

Thanks for ur video ...👍

The basic design of trimaran is found in the Philippines. Boats with the so called "katig" (amas as you've mentioned it). This is a very stable design suited for major applications like fishing and transportation.

Whenever can I find the acantling numbers, charts, graphs, and formulas required for trimerans?

Dragonfly - a danish yacht builder - has been building trimarans for quite some years now, with great succes....very fast boats.

Great video

What comes to my mind is a design where one can still trailer sail yet have amas that fold up giving greater stability and can still fit on a trailer that doesn't need special permits (8.5' wide in the U.S.) to run on the highways.

The thumbnail had a photo of the 127 metre Austal trimaran ferry in the Canaries, but there was no mention of ferries in the video. There has been some debate about the merits of fast cat ferries v. trimarans, so I was hoping the subject would be covered. :(

Hello! Great videos, really educational, especially for design students looking into boat design, like myself. I'm planning on prototyping a mainly motor-powered yacht, but with sailing capabilities, be it a kite sail or some other sail type that DOES NOT require a full "static" mast (telescopic mast or some other way of anchoring the kite sail). I'm wondering if, given the way in which a kite sail is pulling the boat, the trimaran is the best hull type for this? Also, would you think it is possible to have this kite sail pulling the ship through waves, as it would feature a wave piercing bow, or is it just my imagination thinking that's an amazing idea?

please do a video of catamaran sea behaviour, load distribution, hull design etc.

For sailing especially, trimarans seem like the best design, combining the best of monohulls and catamarans. The stability of a catamaran and the center hull of a monohull - having a center hull has a lot of advantages. This is true on both the small- and large-scale, if I ever had a sailboat (I live in Colorado, very far from any large body of water, so owning such wouldn't make a ton of sense - but a surprising number of people have boats here for some reason), anywhere from a skiff to a yacht, a trihull would be my ideal approach. For a large sailing merchant ship - an idea that would be really interesting in the era of composite materials, computer-controlled automated sails, and climate concerns - a trimaran again seems like the best approach. The amas provide far better stability and performance than a monohull when sailing, allowing greater sail area per weight and not needing a heavy and/or deep keel, while also allowing for more slender hulls. All the fastest sailboats nowadays are multihulls, most trimarans. For cargo or passengers, a monohull's tendency to heel over on a beam reach would be disadvantageous, or at least unsettling. A trimaran has advantages over a cat of having a central hull - this allows for not requiring duplication of equipment, mainly rudders and engines, as needed with catamarans. (Though there still would be the option of putting engines in the amas to provide more maneuverability through differential steering as seen in catamarans, trimarans have the option of doing either.) The center hull provides space for cargo or passengers, always a problem for catamarans, especially for sailing where a high-profile superstructure is disadvantageous. Same is true for small yachts, catamarans' lack of a central hull makes cabin volume a challenge. The center hull also provides a better place to mount masts. The drawback of a trimaran for any of these applications - pleasure yacht or merchant vessel - is the far greater width, problematic for berthing or cargo loading/unloading. Always a drawback, but I still think it could have potential.

Thanks. I’ve considered a small coastal vessel fir some future time. I noticed many newer boats having a (just learnt) axe stern. It seemed it would lessen pitching by cutting through rather than planning upwards. I like the trimarans to lessen rolling and flipping. The vessel that intrigues me most is the astus 22.5 as a beginner overnighter (after a sailing learning curve). Any thoughts on that personal vessel?

Thanks, this will help with my project to design a trimaran seaplane hull

What are advantage of Monohaul and catamaran power boats? Thank yoi

Aircraft Carriers is the first class of ship that comes to mind that would benefit from a trimaran hull...IMO

Interesting video but I think it leaves more questions than answers. Looking at blue water cruising, how would the tri perform with hulls that are more evenly distributed in their responsibilities (not all designs seem to have the amas "pulled back")??? That would seem to be a more stable ride but does it take away from the performance? Example: the larger Neel series have what looks like nice living space since the hulls are more useful. But, some other designs have motors in the amas which you seem to indicate they are expecting much heel action to be going on. What are your thoughts on these design parameters?

Do Trimarans still have a disadvantage in heavy seas causing more yaw roll over starboard or leeward waves similar to catamarans sailboats bc they want to stay parallel to the water surface compared to monohull sailboat? Where the monohull sailboat tends to mitigate yaw roll caused by waves do to a heavy keel keeping them balanced like a gyroscope, allowing the monohull yaw axis to stay relatively stable in rough seas with exceptions to sail wind gusts causing some yaw roll. I know the monohull has a good safety factor when high gust of wind pick up... the boat will pivot along the yaw axis, acting like a blowoff valve in a sense allowing the sail wind to bleed off a heavy gust without causing damage to the mast were the catamaran hull prevents this pivotal affect and usually results in damage to the mast or retention cabling. Yes I know high wind gusts can still damage monohull rigging and sails but it seems to absorb much higher gusts of wind with minor damages compared to multihull catamaran. What is the advantage and disadvantages from that sailing point of view in heavier seas when crossing oceans?

In these cat and tri programs, you've assumed blue water applications. However, in sheltered waters, life becomes more simple: Brisbane, Oz has used tris for streetcars for more than 20 years. The Brisbane River snakes thru town, making them a reasonable option.

I'm getting a 23ft trailor sailor but ide like a tri so I thought of adding 2,like hobie Odesys either side. Fold upwards or sideways. Then you can also have a quick relies and paddle them. Any advice would be welcomed.

As far as smaller recreational trimarans.. is it true that they can point closer to the wind so more of a straight line towards the destination and less tacking?

This guy is great ...

Motor Yachts are a good candidate for Tri-Hull design as most owners of Yachts want large amounts of stability while anchored or underway. Another use is for shallow water compared to a comparable ship. With a slightly larger Amul ( I hope I said that correctly) you can decrease the draft of the vessel and thereby go into some shallower areas than a traditional hull which will allow the yacht to reach some areas for water sports that a mono-hull vessel of the same tonnage and size would not be able to get into.

I envision a fairly lightweight, aluminium/composite vessel ~60m x 40m with an almost full width bridge deck, providing a two deck structure some 40m x 30m. As far as possible, the bridge would be built to provide aerodynamic lift helping to increase potential speed.The interior can be a boutique cruise ship, Scientific RV, Expedition ship, inter-island ferry or w.h.y. She (sorry, I’m an old salt and ships are always feminine) will have two sources of motive power: wind, using kites and electricity, using that 40 x 30 upper deck for solar, plus regenerative drive units whenever there is an oversupply of wind. Her load carrying ability should give her masses of battery storage. Depending on actual design and load requirements, I could see her powering upwind, Vmg in the mid teens, her fully automated kite initiating tacks at the push of a button and her prop putting kWs into her batteries. Then she turns on a broad reach and suddenly she’s up in the thirties. A couple of miles before her destination her kite is recovered and she glides effortlessly, silently and electrically to her berth where her bow thruster and 360° steerable, retractable, main motor manoeuvre her gently into place. The potential for very low carbon operations providing eco-educational cruises ought to be good, in my opinion. It would certainly be a selling point

great vid, thanks, for those interested in blue water sailing tris, look at Neel trimarans

I am installing a diesel engine in one of Jim Brown's Searunner 31s. I am building a pod in the aft section to house the engine, like was done with sailing vessels when they first started powering them, the Sea Bright skiff has a structure like that. I expect truly awesome fuel economy using a 20HP Saab diesel with a CP propeller. Jim Brown himself has told me he hates the idea, so no technical help is available

What's keeping someone from using 18 foot hobbie cat hulls as outriggers on a monohull sailboat six foot out from the side. Like how the south Pacific canoes are outriggers but on both sides not just one.

please talk about hull shapes for cats and tris to max out speed vs. stability.

Very informative video, I definitely learned something. Thanks :-) It would have done well with a mention of the Ady Gil, though, she was one of my favorite designs and really went to show what can be achieved with a trimaran. A shame she met such an ignoble end :-/

I currently own an F-27 sailing tri AND a 62-foot power trimaran which is also called a stabilized monohull owning to the limited volume and length of the floats. This boat can reach 10 knots with only a 60 HP Mercury Bigfoot outboard for power.

Sir, what do you think if ship design like fred olsen trimaran replaced RoRo ship. I try to compare it for indonesian

Very cool Nick. I stumbled on the Neel 4x in a sailing magazine, got curious.... well, okay.... Wait. What!? it can sail at the speed of the wind? Where do I sign up??? I just saw a video of a couple of guys crossing the Atlantic in 17 days, no record, but no bumping along either. I turned a couple kayaks into trimarans. I was after speed so I made two kayaks long and narrow - all I got was instability (which I expected but no speed?? seemed unfair) so I made outriggers and amas. By the second one (a skin on frame Iqyax) I had the amas dialed in. Single 1.25" diameter aluminum poles, bulky vertical floats...because as you well know not much touches the water. (and just the pole and little bit of weight 4' out added a lot of stability and balance). The vertical bulkiness was enough buoyancy to act as a paddle float in case I was in the water and needed to get back in. A surf ski coach happened by while I was hosing down after a paddle. He just couldn't contain himself, repeatedly telling me 'how stupid they looked.' I thanked him and kept hosing and wiping down. He totally didn't understand what he was looking at. I explained that almost nothing touched the water, and he went off again.... One thing I noticed with my amas is that even if I leaned over and put a lot of weight to the side the kayaks still tracked straight. (The yaks were 18' and 18'6" long, 17" and 16" beam less in the water). I think I figured out how the Aleuts were able to plane if anyone is interested.

I have owned 3 trimarans of cruising size. I have also owned 2 mono-hulls. A Cross trimaran is an excellent sea boat. I am currently looking for another one.

Take a look at Corsair sailboats. They are foldable, trailerable trimarans that can cross oceans.

Nice what is the best haul design on a large vessel for speed?

Great explanation. The only thing not covered were stresses over the cross decks in heavy weather. Been seeing the amas torn from the main hull. Would like to know how trimarans would handle loads in +50 ft. seas.

I think a Trimaran would be great as a farly small to large Cabin cruiser

What if you put the outer hulls deeper and a larger percent width of center .Narrow entire vessel.

I am an amateur, but am planning a trimaran hybrid, sailing, electric/solar and a back up diesel for my retirement home/world sailing boat.

Really liked what you had to say about trimarans. Here's a crazy thought I had; would it be practical to take a used 42-47 foot Southerly swing keel and add the hulls of say a 40 foot cat (unfinished from production so it's just the hulls and bridge deck). Cut out a section of the bridge deck and glass/bond the two hulls to each side of the Southerly? This could possibly give you extra cabins and storage and there would be changes in the Southerly as well. Your thoughts?

You are very smart very good video

Trimarans are very good in the shallows or littorals. Can go much nearer to shores.

Here is an idea, to check the chinese type 022 stealth boat design...looks like a catamaran but also like a trimaran. I wonder what would be the largest size of such a design, for example to create a heavy cruiser or larger for a pre ww2 era

Can somebody tell me the history/origin of trimaran design? It is the most common boat design here in the Philippines.

I am wondering if the trimaran would make a decent low drag buoy.

Thank you for your consistent videos. The most of all vessels are small recreational, fishing or roundabout boats. Would it be possible to know your opinion: why the most of them are monohulls? If the extra cost of construction of trimarans is less than the benefit from engine power decrease and fuel economy (to say nothing about ecology), why small boat producers do not take this advantage? Thanks.

how do you compare submersible to non submersible Amas

what are your thoughts on the Horstman trimaran design for blue water cruising? This is my dreamboat to cross the pacific.

how is a trimaran in big water does it yaw a lot???

I'd like to see a trimaran SWATH vessel loosely based on the Lockheed Martin Sea Shadow, but with a central submerged torpedo hull added.

i wondering if it would work for a crab boat?? heavy heavy loads on one side as pulling in the gear!! i can see for seeing gear it would save lots time with ability to haul more gear per load less trips back!!

Thx. for the video. Could you clarify if Trimaran's are easier to Capsize than Catamarans', if so why? Also for open voyages, from a safety perspective, would you recommend a mono hull or a Trimaran?

Very interesting. Got a suggestion for you for future "studies". What is you take on whether inverted bows will make it into the "pleasure" boat ranks? Either power or sail - or both. Or is the concept relegated to large ships?

Interesting video. As someone who has designed and studied resistance, maneuverability, sea keeping and strength of mono, cat, SWATH (T-AGOS) and tri hulls and having worked for the company which has built and continues to build large tris, I can say that the interdependence of stability, motions and resistance is most intricate in the case of tris than any other hull form. Trimarans are built for speed. Steel trimarans will not be economical. Heard several times "steel weight". There are more profound and significant challenges which have not been addressed. e.g: Jet or propeller propulsion?

I have a beach cat now, and plan to get a sailing trimaran (24' - 28') in the next few years; in addition to the stability, speed and handling advantage, it's also trailerable thanks to the folding arms for the amas which will save on marina fees and lift / hull cleaning fees which can add up quickly. Cheers!

interested in the trimaran choice in the seadoo switch

I really want to know how a quad hull would perform in a sailing vessel, Would 4 identical hulls be easy to build provide stacks of deck space for a live aboard but still have fast hulls, How would you configure the hulls, with the central hulls longer that the armars or in a square shape. Perhaps the extra deck space would be better for a those solar panels on the next gen solar electric ships. A shallow draft would be great at Anchorage, 4 hulls sounds safer than 2. How would it perform

Just stumbled across your channel. Been watching videos about sail boat living and ocean cruising. Dreaming about living on a boat and sailing all over the world. My twist is I want to make it easy and safe for a less physically fit older person. Want to look for ways to use modern ingenuity to make the whole process of sailing far less work or even totally mechanized.

Is it a monohull with outriggers?

what about a trimaran with [ big + small+big ] hulls ?

Philippines have been using tri hull for decades

Wheelchair friendly sailboat!

Have they experimented with different percentages of buoyancy of the center hull? You stated 90-95%, leaving 5-10% for the amas. What if you changed it to 80% center hull and the amas then were enlarged providing the remaining 20%? Also, you stated the tri has a wider deck, but didn't give specifics. How much wider? If it is a significant amount, you would think it would be worth mentioning the amount.

I'm designing a swath trimaran that I think is the best of all worlds. M.P.G instead of G.P.H. is worth pursuing.

Sailing multihulls are totally different from motor multihulls. Sailing monos and multils have their source of power (the sails) far above the deck, not aligned with the hull(s) thus creating transversal and longitudinal stability problems. Modern racing trimarans since 30 years have been flying on a ama, and are now using foils. Nowadays maxi tris (more than 30 meters) have top speeds around 45-50 knots, sail about 900 nautical miles a day in good conditions, cross the North Atlantic in less tha 4 days, and make a circumnavigation in 41 days. No motor is able to do that. Very few naval architects is the world are able to design a high performance successful sailing multi and most are French with the exception of Nigel Irens, the most French of the British NA. You need also highly skilled and experimented shipyards used to composites specially carbon, and a bunch of engineers able to make the structural calculations on so extreme and big wind machines. compared to that a Formula One chassis is a piece of cake. (i'm a retired Naval Engineer and I've worked in this peculiar field until 1996, I know a bit about the subject). Motor multis have not these constraints as the power is aligned with the hull, the center de gravity is lower, and the construction is far simpler, using aluminium or steel. The shape of the hulls are totally different of the sailing boats. Cats have been pretty successful, see the catamaran ferries by Incat and Austal for example with speeds ranging from 35 to 62 knots. The ancestor of motor tris is Ilan Voyager by Nigel Irens. Made in 1988, very simple in low tech composite (wood, fiberglass, epoxy) with a single engine diesel Yanmar of only 235 HP, long of 21.30 meters. This boat is able of 28 knots with its modest power, is very seaworthy, and hold a record around Britain of about 2600 NM if I remember well, at 21.5 knots without refueling. The commodities are very modest as the main hull is extremely slim. the boat has a long career of small ferry in Cabo Verde Islands There are very few military motor tris. the British Triton (sold in Australia) and the French CNM Ocean Eagle 43 a very economical small 143 feet patrol ship, using 1 metric ton of fuel for 238 NM at 15 knots. A video in sea state 5 kzfaq.info/get/bejne/oZqboM1-2dWaiKs.html But the ferries company Fred Olsen had ordered in 2004 Benchijigua Express, a 127 m stabilised monohull (trimaran) vessel that Austal built for Fred Olsen. It was the biggest ship made entirely in aluminium at the date. Olsen has ordered this years 2018 2 more trimarans to Austal.

Hi nick. Are boats with outriggers considered trimarans? Here in South east asia, almost all small fishing vessels have bamboo outriggers mated to a very slim wooden hull.

Overall a good video. One problem you didn't cover that I've seen on test sails of the Neen and Leen yachts is they tend to hobby horse even in fairly calm seas. Maybe there was something they did wrong or could do different. This occurrs with sailing yachts as well as motor yachts. I'd be seasick most likely in a short time after leaving dock or anchorage. Also the smaller vessels had less comfortable usable space it seemed to me as amma cabins were very narrow and heads had to be under steps or in cubby holes.

Dive/launch platforms so they may be great for exploration/salvage

I have a interesting question.. Conversion from sailboat to trimaran.. Im asking because sailboat is built in aluminium and not finished.. So it would make sense from financial stand point but.. I dont know if would be possible?

Do you think we will see more navy trimerans after the Independence/Coronado class trimeran frigates? The US Navy loved their handling but they had some serious structural and mechanical defects. Clearly, a lack of design/manufacturing experience.

Hi Nicholas, I got another strange stupid question for you. How difficult would it be to make a sailing trimaran that could also double as a wing in ground effect vehicle? Assume the sail could be retractable.

Is this video talking about residential boats or larger industrial military ships? A Tri-maran ferry & a Tri-maran a regular sailboat hobbiest would buy are very different animals all together.

Also, would in terms of cost of docking fees factor in trimarans as a disadvantage compared to monohulls in the length rages of 20-50ft which the avg person middle class person can afford? Would a Trimarans owner be forced to pay for 2 docking births just like most catamarans in the 20-50ft range? I’m curious on doing a cost analysis between a trimaran to a monohull with the trimaran’s lower cost to operate compared to the lower costs in yearly docking and storage fees (I live in Cleveland Ohio so I would have to winterize and store the boat at a dock yard during winter)

Denison yachts review had me convinced trimaran are inferior to Catamarans, now I'm watching this and it seems Trimaran should be Superior to a Cat in almost all cases except for cost??? So which is it would love you two to hash it out in a vlog

Have you seen the Neel 51 Trimaran? I've only seen it in promotional videos, but it looks like the amas are enormous, compared to traditional small ones.

Drat thought this was going to be about sailing trimarans - like the Rapido.

Are there any ships that go beyond 3 hulls? Any benefits to a design like that?

I’m thinking about trying a 4-5m aluminium tri with twin 70hp outboards. A super sharp entry and plumb bow. How worried should I be about broaching? There are no great video explanations of broaching in power boats.