New 24-Foot DIY Trimaran – “LocoMotion”
Here is a great report from Frank Smoot about his new 24-foot trimaran LocoMotion. What he is able to do with so little money in so little time is, IMO, sort of amazing.
This is especially the case for us guys who seem to always take longer to do projects we thought would just take 1/4 of the time — and sometimes easily go over-budget too. (I certainly don’t have myself in mind here, nosireeeee, no way, it’s other guys I’m thinking of ;-)
Frank wrote this article with us in mind here at smalltrimarans, by they way … and we’re sooooooo glad he did. Many thanks my friend!
Our New 24 Footer – “LocoMotion”
By Frank B. Smoot, Jan 2013
Why would a guy with two 16’ trimarans need to build a third boat? Because this 24 footer does things the smaller boats just can’t do.
See, as much as I like my two 16-footers (one belongs to my wife, Laura), they have their limitations. I can’t seem to make them exceed 13 mph, and the ride is bumpy and wet in waves bigger than a foot or so. Plus, both of the 16-footers are just single seaters. They’re great estuary cruisers/explorers, but not really designed for “big water.” So we can’t take them out on Tampa Bay or the Gulf of Mexico to visit some of the local barrier islands that are so appealing.
My goal was to build something faster, smoother-riding, and capable of dealing with waves up to at least 2’. That meant a long, narrow hull with lots of freeboard and enough rocker to be nimble. I also had a couple of 85 sq ft unbattened “plain Jane” sails I wanted to use, so I wouldn’t have to pop for (yet another) rig.
Since these sails have booms of 11’6”, the masts had to be a minimum of 12’ apart. The only practical way I could see to get both of those sails and both my wife and I in a tandem seating arrangement was to design a 24’ boat. Luckily, that length could be built diagonally in my garage if I moved some stuff around.
While all of the dozen or so hulls I’ve built up to now have been 100% stitch and glue, I wanted to try something different this time. I wanted a truly sexy curved bottom, with none of the limitations that plywood imposes. My solution (inspired by a 40-year-old photo of an early home brew California catamaran hull) was to make the bottom 8” of the hull out of 4 layers of 2” Styrofoam – that blue stuff you can (sometimes) find in the big home improvement box stores).
So to get started, I just built a hull 24’ long with slightly flared sides (3mm ply) and a flat bottom of 6 mm ply. Then I turned the hull upside down and started gluing on the foam. I have to say, sculpting that much foam into the shape I wanted wasn’t something I’m eager to try again. The plus is that was able to get exactly the shape I wanted, but geez, is it a messy, fussy process!
Another plus is that I ended up with about 1300 lbs of unsinkable flotation – so much that that flat inner bottom rides 2” above the waterline! But of course, foam is about the most fragile hull material there is, and I always beach launch. Slamming into the shell-strewn beach (and occasional oyster bed) can really take a toll, so I had to make it tough enough for that. My solution was to cover the foam part with 4 oz glass, lapped on to the wood about 2”, and then to cover the entire hull in 6 oz glass. So far, it seems to be holding up.
Also, I am a huge fan of leeboards here in our sometimes-very-shallow local waters. Centerboards get stuck in their trunks when shells and other crud gets jammed in there from beaching, and daggerboards always seem to be in the way of something. Plus, both of the aforementioned require trunks that not only poke through the hull, but are invariably in your way, especially in very narrow boats.
Leeboards, on the other hand, work beautifully. My “friction-fit” pivot system keeps them in whatever position you put them with no need for a chunk of lead to hold them down. They simply pivot up and out of the way when they hit anything underwater, and they can be used to fine-tune your helm balance on all points of sail.
On my smaller boats I just have a single leeboard, directly operated with its handle. But on this bigger boat, I wanted twin leeboards to create enough lateral resistance to offset 180 or so sq ft of sail. And since they needed to be amidships, where I couldn’t reach them directly, they needed to be both synchronized and “remote controlled” – which ended up requiring about all the engineering creativity I could muster.
Finally, I wanted to be able to control both sails from my aft seat, so I set up dual controls for the main sail. Depending on which direction you ran the mainsheet, the main sail could be controlled either from my wife’s seat or from mine. After a few outings where I tried to get my wife to control the main while I controlled the mizzen, we both concluded that it would be “much better” if I just did it all myself ? And the truth is, the mizzen is pretty much a “set it and forget it” sail anyway, especially going upwind.
The resulting hull was so long and lean it lookd like a big gray fish. But how did it sail? To be honest, the first outing was not very encouraging. Although I had made a brand new set of 4’ leeboards just for this boat, I had been too lazy to make a new rudder, and simply “borrowed” one from an earlier boat. Also borrowed were a pair of “planning” 12’ long amas that had proved a bit too big (and hard-riding) for one of my earlier 16’ boats.
On top of that, my “remote control” setup for simultaneously raising and lowering the leeboards didn’t work as intended. Just couldn’t get the dang things to stay down! And I also didn’t have vangs on either boom. How I (and the sails) survived for a few years without them still amazes me…
Yet another problem we encountered showed up immediately as we launched into a headwind. The smoothly rounded hull bottom and the barely-in-the-water leeboards just didn’t provide enough lateral resistance, so we very nearly ended up in the mangroves before we’d gone 100 feet!
The “final” major shortcoming of our maiden voyage was that I had opted for us to sit in smallish folding beach chairs. I mean, hey, the floor was flat and sturdy (covered in 6 oz glass) and the chairs were just one more thing I didn’t have to make myself! Well, we soon found out that this, too, was a bad idea…
Once we finally got out into open water, we found that the boat was plenty quick — but not at all nimble. In fact, it was all I could do to get it to come about. Bottom line: This was NOT a fun boat to sail. Verdict: Time for some changes!
What to change? Over the next week or so, here’s what I spent my time doing:
• making a big new rudder
• adding fins (skegs) to the amas
• making a line to hold the leeboards down,
• replacing the beach chairs with fixed seats
• putting vangs on both sails
Result? The 24-footer is now an excellent boat! It goes really fast and comes about easily and almost instantly. I took out my tracking GPS (Garmin Colorado) and discovered the following:
• Top speed (with smaller sails) of 13 mph on a beam reach in 11 mph of wind.
• Points a bit less than 45 degrees off the wind – and makes an astonishing (to me) 9 mph while doing it!
• Comes about almost as quickly as our 16-footers, and never gets stuck in irons.
Now I think it’s a truly amazing boat – smooth as glass and quick on all points of sail. Here are a couple of videos:
Video 1: First sail with “teething” problems fixed:
Video 2: Bunces Pass, FL (near Ft. DeSoto State Park):
I’ve tried this boat now with a variety of sails and the best combination for performance is the 102-sq ft main coupled with the 85-sq ft mizzen. This is the setup we used at a recent meetup of the local trailer sailor’s group, where the wind was 11 mph or better all day.
The “going home” leg was directly upwind for the 2 miles back to the launch point. We (Laura and I) were one of the last to head back, yet we got there so far ahead of everyone else we could barely see them still tacking in. Here’s what our group president said about the 12 boats in attendance when he listed them in an email blast later that day: (We’re #5 on the list – I’ve delete the other names):
1 – O’Day Daysailor – Ft Myers Beach (visiting guests)
2 – Norseboat – had best looking boat
3 – Goat Island Skiff – excellent swimmer and boat rescuer
4 – SP Tri – (dinghy racers from Englewood)
5 – 24 ft Tri – Frank & Laura Smoot – fastest damn thing I’ve ever seen
6 – Escape Rumba – [ ]& daughter – a great sailor
7 – Tri Kayak – back from Georgia!
8 – Potter 15 – solo today
9 – Paradox – Got the cabin top on!
10 – Hunter 26 WB – with lovely lady (forgot name) from Michigan
11 – Sail Canoe – sailed to the ramps
12 – [ ] – visiting – no boat but owns an O’Day DS
“Fastest damn thing I’ve ever seen?” Hey, I can live with that description! And in a subsequent “name the boat” contest, someone suggested “Locomotion.” I thought it was perfect for this boat, and am going to spell it “LocoMotion.” Just seems to fit…
I gotta tell ya, this 24’ tri is just amazing. Points higher and goes faster upwind than any boat I’ve ever seen — and it cost under a grand to build it. And that’s consistent with my ongoing goal as an amateur designer/builder/sailor to make boats that will deliver 90% of the performance of “commercial” boats at 10% of the cost. So far, so good!
Cheers – Frank
Click here to visit Frank’s website at DIY-Tris.com for more on his boats and projects.