Trimaran - Especially Searunner - Owners

[Mark Johnson]

Trisailor,

I'm assuming that you plan to go to sea in this boat, Right? If so...

You have a very ambitious project there, and I doubt that you could be discouraged, BUT just a note of caution...

This "making rigid but demountable AKAS, into folding AKAS", is something that should be done with John Marple's blessing, or not at all. IMO...

I have "well" over 100,000 hours of hands on boat building experience, over 40 years, and a number of inventions out there. I "know" that I could make a folding system from an "A frame", but accurately calculating the direction, and amount of ALL of the loads involved, would be over my head. Not so for John! I didn't finish my engineering degree... he did!

I remember calling John once, (about 28 years back, while building my previous boat), and asked about whether "bonding in" the mast's "U" bolt chainplates, as in the plans, was REALLY strong enough. He said: Let's see... He figured the length of each 6" leg, size of the hole in the wood, square surface area of the hole in the wood, sheer strength of my mahogany, sheer strength of the epoxy, tensile strength of the "U" bolt's rod, and divided that by the two legs. He could determine that within the 20% fudge factor, the glued in mounting, was several times the strength of the "U" bolt, and also, that just ONE of the chainplates, could easily lift the boat. I used them!

John rattled this off and answered my question in about 2 minutes flat! It is important for all of us to know our limitations. If he charged you $1,000 or so to design the system, AND make the safety calculations, it would be money VERY well spent. IF, of coarse, he approved and was interested. Otherwise...

Another thought. A Farrier tri is designed from stem to stern, to the rig... to be folding, and it is STILL a pain in the ass to set it up. I've helped do it. A Searunner on the other hand, is a true "sea boat", designed to be rigid. On the "A frames", mounting the AMAS to the AKAS is just a start. You have the fore & aft support strut planks, the walking side planks, nets to lace on the side & forward, the mast to stand, boom to attach, etc.

The Searunner mast takes a couple of days to tweek into the required perfect tune, WITH sea trials, in order to not break it from getting out of column. It is the polar opposite of a Farrier rig!

The designed demountable "A frame" feature is very useful for Searunner builders in a remote site from the sea. Believe me, this is a big deal. Our 34 was 150 miles inland! Talk about a hassle! The set up for your "A frame", however, IF done like clockwork, might take about a week to 10 days, before you could go cruising. EACH TIME...

Your folding AMAS only knock about 1 day off of this, as it is just a fraction of the overall set up.

If I were you, and wanted to say... do this boat move every year, at the beginning of the sailing season, (only), I would pour all of that thought, time, money, & energy, into perfecting your trailer, perhaps with built in, but movable swiveling booms, for handling the amas better, and use the conventional bolt up system. Then you have "almost" as much speed of set up, (over all), but haven't compromised the seaworthiness of the vessel, with an "unknown" type of folding system, that saves you very little, considering the entire set up time involved either way.

Just a thought...

One other point. Your rudder's tiller arm, with it's vulnerable rubber boot, is too low. It will get blown in by a following wave there. The correct location is about half way up the transom.

Sincerely, Best of luck with your project!

M.

[CharleyAnna]

If I were you, and wanted to say... do this boat move every year, at the beginning of the sailing season, (only), I would pour all of that thought, time, money, & energy, into perfecting your trailer, perhaps with built in, but movable swiveling booms, for handling the amas better, and use the conventional bolt up system. Then you have "almost" as much speed of set up, (over all), but haven't compromised the seaworthiness of the vessel, with an "unknown" type of folding system, that saves you very little, considering the entire set up time involved either way.

I like your idea, Mark!

[Boatguy30]

Marples has a swing wing mod for the CC 35. The one for sale on Vashion Island was intended to be able to sail to Europe then swing to travel the canals. I made a written offer on the boat last year and at that time Marples told me he would help with redoing with fixed amas. Although, I believe he did all the swing wing design work, he did not feel it a good idea for a sea boat. I would imagine, perhaps it would be suitable for a SR 31, but not get the beam down enough?

Several years ago, when we were sailing to NZ, a tri was leaving for the cook islands. They got caught in a low and it was a swing wing/ demountable design of some sort around 33'. Only thing ever found was one ama with "2 POB" scratched in the bottom paint. I suppose for this reason, I am highly prejudiced against any type of swing/ demounting setup for a boat this size for offshore sailing

It seems John Marples tends to agree. I would go with something like a Tiki 30 with deck pod if I needed to trailer and have a sea boat AND it needed to be a multi.

Cheers,
Jeff

[Mark Johnson]

Originally Posted by Boatguy30

Marples has a swing wing mod for the CC 35. The one for sale on Vashion Island was intended to be able to sail to Europe then swing to travel the canals. I made a written offer on the boat last year and at that time Marples told me he would help with redoing with fixed amas. Although, I believe he did all the swing wing design work, he did not feel it a good idea for a sea boat. I would imagine, perhaps it would be suitable for a SR 31, but not get the beam down enough?

Several years ago, when we were sailing to NZ, a tri was leaving for the cook islands. They got caught in a low and it was a swing wing/ demountable design of some sort around 33'. Only thing ever found was one ama with "2 POB" scratched in the bottom paint. I suppose for this reason, I am highly prejudiced against any type of swing/ demounting setup for a boat this size for offshore sailing

It seems John Marples tends to agree. I would go with something like a Tiki 30 with deck pod if I needed to trailer and have a sea boat AND it needed to be a multi.

Cheers,
Jeff

I agree with your points here Jeff. Most swing wing tris "give up something" for the option. They aren't intended to weather storms at sea, they're intended for a great sailing vacation once in a while.

Among "demountable" tris, the "A" frame is among the best, IF very strongly built to the upgraded specs, and there is no degrading over the years from corrosion, (OR rot in the hull's connective holes).

In a recent talk between Jim & John, (Conversations With Jim Brown), John pointed out that there have been more crossings in the 31 than any other size! (Probably due to there being more of them out there).

There is the downside of having the "connect up" requiring caulked up bolts, (each time). These are all potential leaks, IF the connectives work and flex at all. To me the advantage is primarily, getting her to the water, ONCE, from your building site, way out in the country.

In the previous photo of my SC 28, you see that we are in fact bolting her together, as intended. I had built the boat according to the plans, and it was intended as a trailerable boat, (at considerable effort, mind you). Nevertheless, once we got her to the water's edge, I bolted her up all bedded in thickened EPOXY, rather than caulk. Then I made huge epoxy fillets at the beam's pass through. This made the boat one piece, & never to be taken apart, but solved the problem with leaks where the crossbeams pass through the hull, (Which a previous builder had complained of).

The boat before that, was my Wharram, like the Tiki's that Jeff refers to, (But not nearly as good a boat). With the Wharrams, the connectives are all outside of the boat's interior, and the bolts are not caulked at all, anywhere. Also, the rig was as simple as could be, with huge forgiveness to "tune", as it was meant to be put on a flexible boat.

With the help of 3 men, we had the boat unloaded, bolted together, rigged, and sailing, within 3 hours! When I crashed her into an unseen oyster rake, 2 hours later, the pontoon boat trailer, (which jacks up), was used to haul her back out, for 2 weeks of repairs. (I was 23, and found that the learning curve can be very steep, on your first cruising boat)!

For those still in the thinking stages... The Tiki 31, with a deck pod, would indeed be a good, "trailerable" mini cruiser candidate, in that size range, with out giving up much for being demountable, but being truly, "trailerable". I bet that with helpers, a Tiki 31, (on the right trailer with mechanical booms for lifting), could be up and sailing "almost" as fast as a Farrier 31 tri., but able to handle the rigors of the sea much better than the Farrier rocketship.

M.

[Mark Johnson]

Originally Posted by CharleyAnna

I like your idea, Mark!

Thanks Anna,

I hope that you & Charlie are doing well.
I remember that this "repeated trailering" option was something we discussed during your visit. Was this to save the expense of year round dockage, or to use the boat up there the rest of the year? The problems with this I just mentioned. It is doable, just a really big hassle...

There may be a third option, and that would be to haul the boat at a small, out of the way boatyard, and put her in long term storage when you're not in sailing mode. (The 31 is < 19' beam, so can be hauled at small yards). You may even want to use your OWN trailer? This, "storage", might be half of the expense of dockage! ($1,000 / yr)?

Last winter, we rented a truck to get our furniture from KY to here, and the rental + gas, (one way), was about as much as a years dockage for your boat... Even using Charlie's truck, I don't think that repeated trailering will save you much, if anything, over leaving her here. If she is stripped of canvass, and on the hard, your hurricane prep is already done, or if in the water, I could go over & double up your lines for you.

My latest boat gadilla...

I already mentioned that we are currently in Boatyard hell. Part of the problem is the size of yard that has a 200 ton lift, required to haul our 21' beam. These yards are HUGE, and cater mostly to the rich & famous. We had 110' mega yachts TOWERING above our boat, up wind in 20 to 30+ knots, and their 10 man crews were bombing us with wax, overspray, or water... For weeks! AND, I was/am driving 1.5 hrs a day, round trip!

When they eventually lifted us to move to the much smaller yard across the street, the huge straps with 200# buckles, smeared the new bottom paint right off of the amas. I'm doing that area over now.

After I suffer through this haul, I am "considering" making my own custom trailer, "CHEEPLY", similar to the way that Jack Molan has hauled out regularly in the Sea of Cortez. (He will be sending photos). I'm talking about a SHORT RANGE trailer, using mobile home axles, with no springs or brakes, JUST for hauling & storage.

This would enable me to haul myself, locally, at a small boat yard, or possibly even the back lot, "sorta boatyard", a block away. It could be any place with permission, a wide launching ramp, and a semblance of security. It could even be as much as a few blocks away from the launching ramp!

Besides getting us out of the "mega yards" next time, the boat would not be lifted with straps, possibly damaging the new paint. The down side, with the boat on her keel, would be painting the CB.

With more expense, We could even lift the boat by the wings, using welded in place jack stands in the wing tunnel. This would allow us to service the CB as well!

It sounds a bit hair brained, I know, but I am crunching the numbers, and looking around, to see if this might actually be a hauling out option for us?

#2...

Beefing up the lifting chainplates so that I'd really trust them, and using a truck crane, is the other option. The thing is that crane rentals are quite expensive, and it limits your "spot", to within 100' of the water's edge...

We'll see..

Kindest regards to both of you,
Mark

[Cavalier MK2]

Its is interesting to see designs that were once innovative become static to some, protected by a conservative old guard that wants new hands to pipe down while they "learn ya one..." The old guard should be headed however if the mechanisms aren't engineered and built to take the load.
There are seagoing folders that do very well if maintained such as the Farrier system, now out of patent and used by others and of course the Dragonfly. On the vintage front the old Telstars have held up and here is one of the original greats, the very strong Ocean Bird.

[Cavalier MK2]

It might be more constructive to look at what trisailor is doing and figure out what would or wouldn't work at sea. If he is attaching plates to the bulkhead of sufficient thickness in the areas of the A-arm attachments and carrying them through the skin that connection should be strong. He then has to use latge enough shoulder bolts for the lower pivot and top bolt to take the loads with a large safety margin. The challenge is they are going to elongate the holes in the pivot plates over time, so more material should be added to them for a larger bearing. If he shortens the new A-Swing arms so their extended length is the same as the originals he hasn't added any more load for them to withstand. When the pivot and upper bolts are torqued there shouldn't be movement, you have the rigid Searunner system. The advantages are not having to fasten and caulk all the connective bolts every time you trailer. The things to watch are the details like perhaps adding plastic hard washers in the pivots so anodizing isn't rubbed off and watching out for electrolosis when mixing metals. Perhaps steel A- arms would be better. In any case the pivot fastenings and joints are outside the boat where they can be watched for wear and movement. It is the searunner 25 system expanded which ought to work if done correctly and built strong enough, not a bad idea. I personally am not a A-frame fan and prefer my boats rigid too and would probably do something different for a demountable boat. For a trailer sailer I use a small monohull cutter. Here is a modification for the frustrated wing deck trimaraner who wants to travel those narrow canals....

[ImaginaryNumber]

Does anyone know if the system used by Kurt Hughes' demountable/retractable 38' trimaran is rough-water capable?

[ImaginaryNumber]

Originally Posted by ImaginaryNumber

Does anyone know if the system used by Kurt Hughes' demountable/retractable 38' trimaran is rough-water capable?

Here's the website for that model

Kurt Hughes Multihull Design - Catamarans and Trimarans for Cruising and Charter - 38' Demountable Trimaran

[Cavalier MK2]

That is a well proven method of hooking a tri together, used on many tris including Tennants, kelsals etc....I think the main thing is to know when to replace the tubes, wire and the like. Good for rough water.

[Boatguy30]

That pic cavalier posted of the tri with the tiny amas and main hull that looked like a Columbia monohull looked like the one lost of NZ. Seriously looks like some fence pipe, columbia bare hull and Hobie amas. Hard to imagine how anyone would go out an inlet on something like that.

Mark, you should come on down to Oasis boatyard in St Augustine. The SR 34 JUST makes it into the slip. Seriously about 1/4" on each side to spare. Travelift is well under 200T maybe 70??? Biggest boat in yard is around 60' and they are making a huge amount of dust. Yard crew doesn't vacuum sand anything. At the end of the day, they "cleanup" by using about 5 leafblowers and blow the dust all over the residencial neighborhood outside the gates!

Anyhow, price isn't too bad and they can handle the SR and is a DIY yard. One of the best I have been in.


Cheers,
Jeff

PS Would be interested in hearing the story of the Tri with the ama on the deck going down a canal. Maybe the best SR 31 would be 1/2 A-frame and 1/2 fixed wing. Worst case scenario you end up with a Proa.

[Cavalier MK2]

That funny looking swing arm tri was designed for the waters off England, some of the roughest in the world- don't judge a boat by its amas' they have a great reputation.

The Nicol was modified so it has a bolt on wing ama and has been a success.
These are very different solutions but if the design and engineering are there don't discount the unusual!

[CharleyAnna]

Mark, your point is well taken regarding cost of trailering the boat, vs. dry storage. A nice trailer to store the boat with the ability to occasionally/rarely haul to new cruising grounds wouIld be ideal. I like TriSailor's trailer idea.
Wow you've had a rough few months. What happened to you, is exactly what I'm wanting to avoid.
I love our little 31', and find it interesting that so many have made the crossing. I think research is needed to determine the best method of sealing the ama bolts into the bulkhead for safe sea travel, but yet something that eventually can be removed for dismounting (and also some way to close up the gap to prevent leaking).
We have been using alot of LifeSeal in the current refit of our 'learning boat', a Catalina 25. I wonder if something like that would work.

[trisailer]

Talked with John Marples.
The original plans call for a hinge in the lower arm of the a-frame.
They are used to help align the top frames of the akas.
I ordered the plans so I can better fit the hinges.
He felt with some beefing up of the a-frames, folding might be possible, but he would withhold judgement.
The wood braces would stay permantly mounted to the akas, so would only require bolting to the main hull, they would as be helpful levering the akas into final position.
The mast would be raised, using the boom as a gin pole, per Jim's design.
The shrouds as the most difficult part.
I painted the turnbuckles threads so I can see where they were tensioned before, so that should help.

[trisailer]

She still would be wide on the trailer at 11 feet.
The main saving factor would be, no crane (or helpers) needed to mount the akas and raise the mast.
The akas would start raising as the boat is backed into the water, so main hull could only tip over a small amount.
Also the akas would support the main hull from tipping on the trailer, no cribbing needed except under the minnie keel.
So that clears the boat to float off the trailer, with no obstacles in the way.
All told I fell 3-4 hours is a do able time to setup.
Was real fun finding a boat ramp that not only wide enough, but also deep water fairly quick, but I found one.
Now to see if my truck has enough power to pull her out of the water.
Thanks for all the good feedback and advice.
Bob