Trimaran with damaged ama/outrigger question?

[thinwater]

If you loose the leeward ama (most likely, since the other is well out of the water) the boat will roll over.


More likely, you damaged the front of the leeward float very badly, back to the front beam. This has happened without capsize, but you can't sail that way. Then the idea of partially flooding the other float could make sense.
(hit a container at 15 knots)

[Redreuben]

You could flood the remaining float to go on the broken side tack but if you had to tack back your screwed.
I’ll assume the loss of the float was from extreme weather ? In which case flooding the float is asking to lose that one too.
If I was the skipper and had to use the bad tack I’d be reducing sail to a minimum and getting all the heavy stuff out onto the nets for movable ballast, water and fuel containers, the propane bottle, anchor and chain that sort of thing.
Apart from Dick Newick fans and wankers the correct and self evident terminology is main hull, cross beams and floats. Ama waka daka describes nothing.

[ejlindahl]

Some non rotating mast Corsair 31s and I think Corsair 27 trimarans had mast shrouds to the cabin tops. Some of these may have had shrouds to the floats but maybe only for big reaching sails. What you are describing is a proa, there's 2 kinds; float to either leeward or to windward, google it.

[billknny]

Lot's of armchair sailing here... "Just do X", or "Just do Y"

But we don't have to imagine what would happen, or make up implausable ideas on how to get home...

We can actually read about what really happens. In the real world a broken ama can be a serious problem.

Transit of Venus

[tenchiki]

For a real-world example of something similar, check out Nigel Tetly's "Victress Around the World" (or something similar -- I'm not near my book collection).

[catsketcher]

The ama being damaged on TOV gives a good indicator of how to do this in fiction. If there is a damaged ama still on the boat it could be more of a problem than a help. I don't really get why anyone would build a modern tri without four watertight bulkheads which should allow you to rupture one and still sail home.

Tetleys tri lost part of the ama bow which let water into the structure and eventually allowed the boat to sink. If this were me, I would use the method shown by Skit - the Cirro - which just broke off the ama cleanly. The designer then went out and sailed the boat home.

Amas and beams weigh a fair bit and so Robin sailed the boat home in company with another boat. The weight of the ama could be increased with some water. Now you have a Pacific proa - the most successful traditional voyaging design ever made - well sort of, it really is a tacking outrigger but they are fine boats when smaller.

tackingoutrigger.com -- tacking outrigger sailing canoes

There was a Hedley Nicol tri called Tryst that lost a float (so did another one called Adventure?). Neither capsized, one went home under tow and the other was abandoned but IIRC a Lodestar called Om lost a float and sailed home as well.

So ensure the tri loses the float, probably due to a fatigue issue along with some impact. Then you can sail on both tacks, just more carefully when the float is to windward. For those who think no one sails this way nowadays - remember the amazing Russ Brown.

KAURI: 37' Pacific Proa designed and built by Russell Brown - Video Sailing through Wood's Hole, MA

cheers

Phil

[robillard]

Originally Posted by gmakhs

How you can write a sequel if you have no knowledge of the thing you are writing for ?

That seems a rather trolling rhetorical question... I doubt you’ve read the first book, so how are you judging the level of my knowledge? Or are you suggesting that since I have a question of any kind, I should not be writing at all?

I have a fair bit of sailing knowledge with monos and cats (and even more with power), but I’ve never sailed a trimaran. I was hoping for informative and helpful responses from those with experience, not trollishness...

Thanks to the other responders, much obliged!

[robillard]

Originally Posted by Dennis.G

Not being a trimaran sailor and just thinking out loud: How about partially flooding the remaining ama with sea water to weight it down? Should allow sailing on either tack as long as sail area is reduced from normal.

Interesting... Sorry to further show my naivety, but how would this help? AFAICT, the problem they would face would be around dealing with the case of tacking against the missing ama, ie having the aka dig into the water on heeling to that side. Or are you saying that because of the added weight in the opposing ama, it would not heel enough for that to happen?

Thanks for this!

[robillard]

Originally Posted by Training Wheels

Ummmm.....do you think the rig would still be standing?

Again, I’m certainly not experienced with trimarans, but I don’t recall seeing any rigging extending to the amas on the tris that I’ve seen around... what rigging is there that would extend to the amas?

Thanks!

Ed: see my subsequent post, wherein I actually got off my butt and found our harbor’s only trimaran. I see what you mean, but it looks to me like the rig would still stand, as the primary shrouds still run to the main hull, but it would definitely not take as much strain... Thanks!

[robillard]

Originally Posted by Sand crab

My Crowther had a traditional mono rig but then also had outer shrouds that went to the amas. If the ama fell off and the shroud somehow became unattached then I think the rig would still stand. Sailing it like that might be a delicate operation.

Ah, got it. I guess I didn’t notice any shrouds extending to the amas on the tris I’ve seen around. We have one in the harbor, and I just checked it out, and it has shrouds to the main hull, but also a single shroud to the ama on each side. It looks to me like the rig would still stand without the ama shroud, but it would have to be babied along. (Which is kinda perfect for my purposes in the story...)

Thanks!

[robillard]

Originally Posted by Redreuben

You could flood the remaining float to go on the broken side tack but if you had to tack back your screwed.
I’ll assume the loss of the float was from extreme weather ? In which case flooding the float is asking to lose that one too.

In the story, it will be from alliding with a shipping container. I know that sounds unlikely, but there is a believable rationale in the story.

Originally Posted by Redreuben

If I was the skipper and had to use the bad tack I’d be reducing sail to a minimum and getting all the heavy stuff out onto the nets for movable ballast, water and fuel containers, the propane bottle, anchor and chain that sort of thing.

That sounds along the lines that I was thinking. Except the skip was going to use his wife as the movable ballast... the ensuing pissed wife would provide opportunity for spice to the story... Adding some more ballast would make sense, though, thanks!

Originally Posted by Redreuben

Apart from Dick Newick fans and wankers the correct and self evident terminology is main hull, cross beams and floats. Ama waka daka describes nothing.

My apologies. My uncle used to have a tri back in the mid-70s, and he used those terms, but then he was a navy man who spent a good deal of time I Polynesia during his time, so maybe that was just what he was used to. Again, I’m not a tri expert, which is why I’m here seeking guidance, so thanks!

[robillard]

Originally Posted by billknny

Lot's of armchair sailing here... "Just do X", or "Just do Y"

But we don't have to imagine what would happen, or make up implausable ideas on how to get home...

We can actually read about what really happens. In the real world a broken ama can be a serious problem.

Transit of Venus

Wow! This is just the ticket, thanks! What a wonderful story with a happy ending. (I suppose any first-person narrative of disaster at sea has, by definition, a happy ending...)

[robillard]

Originally Posted by thinwater

If you loose the leeward ama (most likely, since the other is well out of the water) the boat will roll over.


More likely, you damaged the front of the leeward float very badly, back to the front beam. This has happened without capsize, but you can't sail that way. Then the idea of partially flooding the other float could make sense.
(hit a container at 15 knots)

This is super-helpful, thanks! My plan in the story was that the windward ama/float was the one that was damaged, as it struck a floating shipping container. Given how far your ama/float is out of the water, though, I suppose my container would have to be a pretty high-floating container to strike the windward ama like I’m proposing?

Given the other posts about rigging integrity, I will likely modify my plan to just have a compromised ama that would take on water, rather than completely detached...

So if the ama had a major hole like that, and say you were able to put a fuel bladder inflated with air inside of it for bouancy, do you think you could limp a ways like that, if you stayed as much on a favourable (damaged ama windward) tack as much as possible?

Thanks for your help!

[robillard]

Originally Posted by catsketcher

The ama being damaged on TOV gives a good indicator of how to do this in fiction. If there is a damaged ama still on the boat it could be more of a problem than a help. I don't really get why anyone would build a modern tri without four watertight bulkheads which should allow you to rupture one and still sail home.

Tetleys tri lost part of the ama bow which let water into the structure and eventually allowed the boat to sink. If this were me, I would use the method shown by Skit - the Cirro - which just broke off the ama cleanly. The designer then went out and sailed the boat home.

Amas and beams weigh a fair bit and so Robin sailed the boat home in company with another boat. The weight of the ama could be increased with some water. Now you have a Pacific proa - the most successful traditional voyaging design ever made - well sort of, it really is a tacking outrigger but they are fine boats when smaller.

tackingoutrigger.com -- tacking outrigger sailing canoes

There was a Hedley Nicol tri called Tryst that lost a float (so did another one called Adventure?). Neither capsized, one went home under tow and the other was abandoned but IIRC a Lodestar called Om lost a float and sailed home as well.

So ensure the tri loses the float, probably due to a fatigue issue along with some impact. Then you can sail on both tacks, just more carefully when the float is to windward. For those who think no one sails this way nowadays - remember the amazing Russ Brown.

KAURI: 37' Pacific Proa designed and built by Russell Brown - Video Sailing through Wood's Hole, MA

cheers

Phil

Great stuff, and more food for thought. Thanks!

[Sand crab]

Gosh redrueben, I always called them floaty doohickes things amas and all my other tri buddies did too. They must be wankers too.
I think the author should have a short conversation inserted near the beginning where he describes what they are to a non-wanker noob. A guy walks the dock and calls them a float and then the central character says "nosiree them there things is amas". He's going to be a hillbilly isn't he?