New Design TMS-20 Racing Trimaran

Discussion in 'Multihulls' started by themanshed, Oct 1, 2009.

  1. themanshed
    Joined: Sep 2009
    Posts: 135
    Likes: 12, Points: 0, Legacy Rep: 162
    Location: Palm Beach County

    themanshed Senior Member

    I started posting on this forum so I thought I'd start a thread on my new boat the TMS-20. This is very high performance trimaran developed by Kurt Hughes for the Worrell 1000 race. The idea was to give the crew a more comfortable ride than the usual perch hiked out on the high side of a beach cat. The very wide overall beam gives it a nearly equal righting moment to the cat. Unlike on the cat, the crew can be rested and focused during the long, wet race.

    LOA 20’0”
    LOW 19-9”
    Beam 17’
    Draft 10” / 2’3”
    Weight 497lbs
    Displacement 906lbs
    Main 147sq’
    Jib 47sq’
    Spin 161sq’
    Total up wind 194sq’

    Working with Kurt I’ve had the Main Hull redesigned with a flare in hull above the waterline to add more room in the cockpit area of the hull, while keeping the wetted area of the hull the same as the initial design. The deck was flattened and the lay-up schedule modified for foam / Carbon Fiber construction. The AMA’s have about 3 more inches of freeboard added and about an inch of beam. The spar and beams are going to be carbon composite instead of aluminum alloy. The 3-D drawing and plans show the original design before the modifications to the lines. The spar that I’ve selected at this time is a 31’ tornado Carbon Fiber spar and I will add more sail area then the plans call for.

    I have a website that I’ve been documenting the progress of this project www.themanshed.net. I plan to race the boat when completed and to pull a mold off of the boat, as a One-Off work is very labor intensive. My plan is that the boat will be very completive to other 20-foot trimarans currently on the market and there will be a market for this unique design.
     

    Attached Files:

  2. themanshed
    Joined: Sep 2009
    Posts: 135
    Likes: 12, Points: 0, Legacy Rep: 162
    Location: Palm Beach County

    themanshed Senior Member

    This post shows the new lines for the center hull and the progress so far. Right now I'm recouping from Rotor Cuff surgery so not much work can be done while I’m mending.
     

    Attached Files:

  3. themanshed
    Joined: Sep 2009
    Posts: 135
    Likes: 12, Points: 0, Legacy Rep: 162
    Location: Palm Beach County

    themanshed Senior Member

    One more angle
     

    Attached Files:

  4. idkfa
    Joined: Sep 2005
    Posts: 329
    Likes: 6, Points: 18, Legacy Rep: 79
    Location: Windward islands, Caribbean

    idkfa Senior Member

    Hi themanshed,

    Will she fly the centre hull? ie. what's your ama displacement like 250%?

    Think there can be a development class here, similar to the F18s, at 20' for tris. Carbon crossbeams are a good idea; stiff without stays, but the disp should be a bit generous, allowing hulls to be made out of glass, keeping cost down. If it were up to me, I would exclude lifting foils and limit ama vol%.

    Also think being so wide, she will go from max speed in control, to flipping without recourse, without much indication/feed back.

    Best of luck and mend well and soon.
     
  5. Doug Lord
    Joined: May 2009
    Posts: 16,679
    Likes: 348, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Tms-20

    Can't wait to see her sailing! Great concept and design... I'm interested in whether or not she's designed to fly the main hull as well? Does the ama CB shift forward relative to the static CB as she heels?
     
  6. Chris Ostlind

    Chris Ostlind Previous Member


    Douglas,

    I'm curious as to why you keep asking this question; As if it were the Holy Grail of ama design, or something, and you are just checking to see if the folks involved know the secret handshake.

    This business of having the CB shift forward as a function of catching lightning in a bottle is not that important. Let me share with you why. In order to put this in the sphere of the info coming from someone who we all know and trust as fab multihull gurus... I give you this article from Seahorse Magazine, in which Marc Van Peteghem and Vincent Lauriot-Prevost, otherwise known as VPLP, share their knowledge about various bow configurations as they have appeared on state of the art multihulls over the last decade of development. (see below)

    To further back up the concept of having very generous forward buoyancy for a multihull (which is the type necessary to shift a CB that far forward when pressed) I direct you to the current designs of the A-Cats and the amas for BP5 and SYZ&CO. In spite of having lifting foils on the last two, both of these boats also are designed to sail quite quickly without the foils in the water... namely upwind. The A-Cats have no lifting foils and they sail in all directions as well.

    If you extend the discussion, you also see strong tendencies for this same kind of wave piercing/shedding bow design motif on both IDEC and Sodeb'O, neither of which ride on lifting foils. They are not mentioned in the article because they are not VPLP designs, but the thinking is similar out of the Irens/Cabaret partnership.

    If one reduces the upper profiles from a bow view, in order to hasten the shedding of waves at speed, then one can not also get a CB shift as there is no volume there to provide the fresh forward buoyancy. Instead, the boat is sailed differently, the mast is typically set well aft and a similar degree of forward buoyancy is achieved due to the length of the form well forward of the mast. Not much CB movement, if at all and yet.... all the boats mentioned seem to exhibit quite a bit of speed under sail.

    Also, keep in mind that these design trends apply to boats that have a decided racing profile attached to their designed needs. More cruising related forms may not likely benefit from this type of design trend. The boat being mentioned, the TMS-20 is decidedly on the racer side of the equation, so it might be appropriate to recognize that not all currently successful trimarans, or cats, need to have shifting CB’s in order to pass muster.

    What Mike (TMS-20) has in mind does not necessarily fall into this process of wave shedding/piercing design, but it’s clear that he does not need to follow the shifting CB threshold in order to have a great boat.

    You may wish to take a look at what is really going on in cutting edge multihull design?
     

    Attached Files:

  7. themanshed
    Joined: Sep 2009
    Posts: 135
    Likes: 12, Points: 0, Legacy Rep: 162
    Location: Palm Beach County

    themanshed Senior Member

    The boat is designed to sail on one ama. Kurt said that one ama should be designed to support 850 lbs. The ama's are canted 15 degrees. So if you look at the flat in the water view and imagine a 15-degree angle so the rudder and dagger board (ama mounted) are 90 degrees to the plane of the water surface I'd say you are just lifting the main hull.

    I would have to have an expert do the math on the connecting tubes to do away with the sea stays. The current design calls for sea stays fore and aft. The tube design calls for a Alum tube 5" x3.2" min wall 4mm mast sect preferred. I'd like to do round Carbon Fiber tube from a 200-gram unidirectional carbon with West System Epoxy. Not vacuum bagged but compacted by heat shrink tubing. Are there any takers out there for the engineering math? Lets call the tubes 17 feet long.

    The dagger boards are fixed case that lift for adjustment. Does the CB change and add lift? I do not have the answer to that. The most I can tell you that it will help the boat sail closer to the wind and is suppose to sail closer to the wind then a catamaran.

    The most unique feature is the rudders that are not transom hung. There are posts mounted about 18 inches in from the stern. They will mount in a cassette that is shaped to the hull. The cassette can be removed and pop up for beaching or hitting obstructions. The idea here is clear water no cavitations.

    Before the redesign of the ama's they had 1400 lbs of displacement. I do not have figures on what the new ama's will displace or the volume percentage. My plan is to have dual steering station so the boat can be sailed from the cockpit or the ama's. The extra freeboard and buoyancy of ama’s should allow at least the crew to be out on a wire if not both the caption and crew, if desired. The width is designed so the boat can be sailed from the cockpit, the carbon and foam for lightweight and stiffness. Will it trip perhaps I am overpowering the boat from the original design. That was another reason for the extra buoyancy.

    I spoke with a local sail designer tonight about coming up with a new sail plan for the boat. I want a full square top main. I extended the boom from 8' to 10', the mast from 28' to 31'. I want a self tacking blade jib, roller feruling Screacher that can be bagged or hot dogged, and a Spin that can be bagged.

    Almost forgot the fun part you sit about 6 inches above the waterline.......
     
    1 person likes this.
  8. Doug Lord
    Joined: May 2009
    Posts: 16,679
    Likes: 348, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Tms-20

    Its an exciting project and sounds like it will perform very well. I'm always curious how other designers handle cb shift with ama immersion. If the CB of the ama shifts a little forward of the boat CG as the boat heels then there is a designed in resistance to the pitching force of the rig without having to alter the pitch trim of the boat but it is tricky to get right-I was just curious how Kurt might have approached it.
    Best of luck!
    PS- you might consider contacting Eric Sponberg -who is a boatdesign member and naval architect/marine engineer and see if he can help with the carbon tubes. Look under members.
     
  9. Chris Ostlind

    Chris Ostlind Previous Member

    Mike,

    I want to complement you on your willingness to openly share your build process of the TMS-20 with all the members here. Your efforts are a shining example of a guy putting it out there for all to see; possible warts, terrific work and all.

    If more folks had the willingness to share in this fashion, the BD Forum members would all benefit from the lessons learned and the victories achieved during the process.

    Weirdly enough, one of my long time fishing buddies has also just had an RC surgery (he stuffed his shoulder while riding his dirt bike on a fire road up in the mountains) He missed opening day at his favorite lake because he can't cast. I feel your pain, Bubba. ;-)
     
  10. themanshed
    Joined: Sep 2009
    Posts: 135
    Likes: 12, Points: 0, Legacy Rep: 162
    Location: Palm Beach County

    themanshed Senior Member

    Chris, Doug, and idkfa thanks always open to suggestions and comments, be it good or bad.

    This is my 5th rotor cuff surgery. When I was in my early 20’s I crashed a motorcycle doing 95mph street racing. I had about 10 years, still young, without any pain. I was in pain for 6 years before I had the first one done, late 30’s. I could not sail anymore so I went in told the doc ok the time is now, not that bad after several months. When the second one started to hurt I went right in and had it done. Basically they went in with the scope removed old scar tissue took care of the impingements, bursa, rips, and ground the bone away to make more room. That lasted several years then the pain came back. Seems the bone they caved out grew back. So they went back in and took out a lot of bone. The next two surgeries spaced out by pain, about matched the first surgeries timing. and I had each one done again. So after 4 surgeries in 20 years I was in pretty good shape for an old beat up guy, the last ten years have been pretty good.

    In January I fell on a job in a jail while removing a camera assembly out of some of our equipment. It weighs 150 lbs and caught on my pant leg when I was setting it down. It flips me over and I fell hard while holding it. I landed on the edge of a 2” metal plate, rotor cuff first.

    I've been running around 7 months like this so it was time to get it done. This way when I finish the boat I can use it. I figure it is better to wait while building it then to wait to sail it, both are painful in more then one way…I expect a full recovery and a fast boat ;)
    .

    Mike
     
  11. Samnz
    Joined: Nov 2008
    Posts: 235
    Likes: 4, Points: 0, Legacy Rep: 47
    Location: Auckland

    Samnz Senior Member

    I think your mistaken, The LCB is always forward on floats on all racing Trimarans in a static design phase, this is created by the rocker in the profile view, not the width at the deck. When in sailing trim the deck is well clear of the water anyway, so has no effect on the LCB, its only when in big waves or nosediving the top part of the float shape will effect the LCB and in this case the successfull boats are going for reduced drag, rather than extra volume (as discussed in the article)

    If the LCB of the floats isnt foward of the LCB of the main hull, then the boat will sail bow down when lifting the main hull, thats not right.

    From Kurts designs iv raced on and against, the floats have a lot of forward boyancy.
     
  12. Chris Ostlind

    Chris Ostlind Previous Member

    I didn't say that LCB wasn't forward, I said that on wave piercing designs that there appears to be little movement forward of the LCB while being pressed. That is a very different discussion.

    Additionally, if you look at the amas of let's say, IDEC and Sodeb'O in profile, you will notice that there is very little rocker evident. The volume is place well forward from the outset and tapers to a very small profile well aft, but also well clear of the surface.

    This means that there is no further rocker oriented volume to be had when pressed; That almost all of the primary resistance is present and a linear progression, also well forward, is applied throughout the immersion process.

    I also indicated that the masts are set well aft, providing a huge amount of pitching resistance, due to increased lever arm advantages.

    This approach is very different from what you see on trimarans with rockered ama profiles and fuller forms above the waterline. On the plus side, the above waterline tapered amas can slice through oncoming waves far easier, rather than ride up and over them. This, in itself, reduces pitching moments on the boat and allows more of the thrust of the rig to be transmitted to drive.




    My experience while sailing aboard Sodeb'O showed the boat to be sailing with the leeward ama regularly immersed to half way with the odd wave cresting the ama and others dipping below. The main was reefed once, there was only a Solent flying forward and we were in 18 knots of breeze, clipping along comfortably at 26 knots. Clearly, the boat had a lot more in her, should Coville have decided to press things more aggressively. We were not racing, but instead, out for a spirited and fun day sail.

    Check out the two photos I've attached on this post, showing the windward and leeward amas while under sail. Also, please look at the shot of Sodeb'O tied up to the dock in my previous post above. In the previous opst you will see that the wave piercing elements of the ama bos do not extend aft of the forward aka beam. Well before that point, the amas begin to take on significant additional volume above the ama horizontal midpoint. It is only well forward that the amas have the reduced upper volume component.



    It will probably attain the attitude you suggest with a more conventional design, I agree. The shapes and layout I am describing, however, are not of the conventional type, as in production style designs and, as a result, sail somewhat differently.

    A close look at the trimarans of Joyon (IDEC) and Coville (Sodeb'O) show that they have main hulls that extend well past those of the amas. They also have mast positions, which are well aft of those one would see on conventional trimarans. These mast positions move the diagonal vectors well aft where they coincide comfortably with the resistance capabilities of the amas. Additionally, the extended main hull also provides increased forward resistance to pitching moments, contributing to a very stable boat in a wide variety of sea states.

    This potential has been proved, time and again by both Joyon and Coville with outrageous reductions in elapsed time and average speed for the Jules Verne RTW record and the 24 solo records, respectively. One does not bang out this level of record setting without a superior design component being driven hard by remarkable skippers.

    Clearly, there is something going on here with state of the art multihull design at the sharp end of the stick.

    Do these kinds of design features have a place in day sailing race boats? Good question.

    I feel that they do once the sailors discover just how to sail boats of this type. This is witnessed by the near complete conversion of the A-Cat Class events to hulls of this type. It is further supported by the design study process being shown by the SYZ&CO cat foiler out of Switzerland, where these guys have just begun to understand the potential of their boat, either with, or without the use of lifting foils.

    I have just designed a solo, daysailing trimaran of 18' LOA that incorporates many of the design ideas being discussed here. I hope to get this boat built over the North American winter in foam core sandwich and on the water by mid summer of next year. We'll see from that process, whether, or not, the ideas have as much merit at the small end of the trimaran scale as they do at the Maxi end of things.

    It may be that the boat is touchy and really suited for very skilled sailors, or it may show itself to be a positive change in design ideas that provides a real advantage over conventional design thinking.

    We'll see, is the best I can give you right now for this end of the scale.
     

    Attached Files:

  13. Samnz
    Joined: Nov 2008
    Posts: 235
    Likes: 4, Points: 0, Legacy Rep: 47
    Location: Auckland

    Samnz Senior Member

    Cats arent really relevant, not sure why you are mentioning them. One of the big advantages of tris is the ability to have the LCB move forward slightly (say 5%) as the main hull lifts and the float gets pushed into the water to prevent the bow down look typical on many cats.

    So if the LCB moves aft as the float gets immersed and there is no foil to lift the bow how does the boat not trim bow down with the main hull flying?
     
  14. redreuben
    Joined: Jan 2009
    Posts: 1,963
    Likes: 207, Points: 63, Legacy Rep: 349
    Location: South Lake Western Australia

    redreuben redreuben

    RE-Les Monstres, great article thank you Chris, would you be able to post part 1?
     

  15. themanshed
    Joined: Sep 2009
    Posts: 135
    Likes: 12, Points: 0, Legacy Rep: 162
    Location: Palm Beach County

    themanshed Senior Member

    Shoulder is getting better and I finished the A-Cat Carbon Mast repair broken in three pieces.

    I hope to start slowly back on the TMS-20.

    In question of AMA / hull volume percentage how is the volume calculated?

    I'm also looking for suggestions on Carbon Tube contruction.
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.