Trimaran with damaged ama/outrigger question?

[robillard]

I’m an author writing a sequel to a sailing adventure book, and have a question...

Assume for a moment that a trimaran suffers a catastrophic integrity failure with one of the outriggers (amas) due to alliding against an object. Further assume that the allision is violent enough to detach the outrigger from the support struts. So we are left with a trimaran with one outrigger completely gone, but the support beams remaining.

Would it be at all possible to limp into port, assuming the sailor took great care at helm to remain only on the tack that would use the remaining ama? Would she lay completely down (or even roll over, given the lack of weighted keel) if she heeled too much to the side of the missing ama? Would striking sails and motoring help the seaworthiness? How bad would swells have to be to make things sticky?

Thanks in advance and if this is not the right forum to pose this question, I apologize in advance, and if someone can set me right (maybe the seaworthiness or ship design forums?), I’d appreciate it...

[heron237]

sure sail back to port on what ever tack works....there is no weighted keel on a trimaran, it relies on a wide beam for stability great initial stability-- terrible once it reaches the tipping point

[sailormed]

Yeah,.... but now the wind is turning, you keep your "safe" tack and now you are sailing away from the coast.

[robillard]

Originally Posted by sailormed

Yeah,.... but now the wind is turning, you keep your "safe" tack and now you are sailing away from the coast.

Right, which is why I’m thinking that when the wind turns, they drop sails and motor. But even under motor, will decent swells cause problems? If they catch a swell on the side that still has the ama, that would likely stuff the opposing support beams into the water, causing instant drag, which might cause the boat to spin momentarily, and either tip, or even pitchpole (if we caught a perfect storm of a bow stuffing at the same time)?

I’m looking for both ideal circumstances, as well as worst case, and the probability of either happening...

Thanks!

[Training Wheels]

You’re sailing towards the coast......somewhere.

[gmakhs]

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

Would be easier to turn the issue in a "lost rudder " story ?

[heron237]

Originally Posted by sailormed

Yeah,.... but now the wind is turning, you keep your "safe" tack and now you are sailing away from the coast.

it's a freaking book he can write any scenario that provides drama or he could go whole hog and pull a Deus Ex Machina

[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.

[sailormed]

Excellent idea!

[Training Wheels]

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

[admiralslater]

Originally Posted by Training Wheels

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

If it was a Brown searunner it would be standing as that design was basically a monohull rig ie everything attached to the main hull except runners

[Training Wheels]

There you go! We’ll done✔️

[Tusitala]

This has actually happened, I believe to a Chamberlain Cirrostratus design down under. It's a solid wing aka boat, so there was a little more than just crossarms and nets dragging in the water on the unfavored tack. I'll poke around when I get time and see if I can find the old Multihulls magazine with the story they wrote about it

Pat

[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.

[admiralslater]

The back stays on the Browns are really just for big flying sails