Multihull capsizes in RTIR

[Twister_Ken]

These pictures explain the trimaran capsize http://www.cowesonline.com/d/Round the Island Race Lge.mov

For anyone who sails a multihull, it was a racing incident. The pictures clearly demonstrate the reasons it happened. Probably wouldn't have happened in cruising mode.

Seems to me (a one-huller) the prime reason it happened was that the lee float buried and then acted as a plane (like the diving plane on a submarine), dragging the whole shooting match underwater and - probably - steering the boat around to port. Until the way came off, there was no chance of reversing the process, and by then, it was too late anyway. But least she floated well arse-up and provided a reasonably stable platform for rescue.

Trust she was recovered OK, and no one was too traumatised.

 

[westernman]

From my experience of light racing cataramarans, you have to have very quick reactions once the lee bow starts to bury. Like milliseconds to get of out it.

You need to dump the spinaker/asymetric sheet, and bear off very hard until you gybe and then bear off hard again to get back to a dead run - otherwise you will capsize in a broach on the new tack. If you luff up you will capsize to leward fast and violently.

This does the trick. Sometimes.

Otherwise the result is instead of tripping over one bow fully buried in the sea you will pitchpole squarely over both bows buried up to the mast cross beam.

I know this from extensive pitchpoling experience.

Playing with the mainsheet won;t help. With the main sheeted in, it is providing a little bit of lift. Let out against the shrounds you have more force at the top of the mast pushing the bows down.

 

[AngusMcDoon]

The safe solution would have been to reduce sail by about 50% but if you're racing.

Any twassock can take a small high performance tri out in a F7 and capsize it. It just shows to the world that you've satisfied the equation bravado+stupidity>experience. And that you haven't read the owner's manual.

I suppose it's a bit like driving a Ferrari. If you take your big red knob extender out in rush hour city traffic in the pouring rain you have to be careful with your right foot to arrive home alive. Same with a performance tri. The go fast ability comes with a proviso - sail it appropriately if you want to get home with dry pants.

Racing was no excuse for flying the asym in a F7. If they'd known what they were doing they would have realized that they would have achieved a faster average speed on white sails anyway in those conditions. How much better is it to average 14 knots and never exceding 16 rather than having moments of 25 knots and spending the rest of the time letting sheets fly, bearing away and fighting the beast? With less sail they would still have bettered the times of 99.9% of monohulls, and it would have been so relaxed that the crew could have sailed with 1 finger on the tiller while the skipper went below to heat up the Fray Bentos.

In my opinion, the only failure was the nut on the end of the tiller. Unfortunately, this type of incident, rare though it is, makes insurance difficult for the rest of us.

 

[flaming]

With less sail they would still have bettered the times of 99.9% of monohulls, and it would have been so relaxed that the crew could have sailed with 1 finger on the tiller while the skipper went below to heat up the Fray Bentos.

But they weren't racing the monos, there is no combined multi and mono trophy. They were only racing other multis. The RTI is a one off race, there is no playing it safe, bringing it home in a decent position and hoping to average out well over a series. If you want the win you have to be faster than all your competitors.

I don't know the crew, so I can't comment on whether they simply didn't have the experience necessary, or just got unlucky in some really nasty waves off st Kats, but how many other multis successfully flew their kites down the back of the island?

I'm not a multi sailor but I'll defend their decision to hoist. Racing anything is about finding the limit, and to find the limit you must occasionally exceed it.

 

[Twister_Ken]

I'm not a multi sailor but I'll defend their decision to hoist. Racing anything is about finding the limit, and to find the limit you must occasionally exceed it.

Find the limit on a monohull and you're laid flat for a few seconds until the lead gets to work and hauls you back upright so you can have another go. Find the limit on a multihull and you're left sitting on a raft.

To me that would dictate a more defensive definition of finding the limit if I had one or more spare hulls.

 

[rwoofer]

Racing was no excuse for flying the asym in a F7.

I don't how this boat handles, but for some boats an asymmetric is a good thing downwind in a blow because there is a lot of upwards lift in the sail which keeps the bow from burying. Taking it to the extreme, skiff dinghies are almost impossible to sail well downwind in a blow without that upwards lift.

 

[Seajet]

Not just lift, but speeding away from the true wind and bringing the apparent wind to an easier handled reach - as long as one's skill and stamina hold out.

However the idea of 'finding the limit' seems to me to be ignoring a little thing called seamanship; and I suspect that is what everyone is really saying.

With a 'cruiser' type boat, mono or especially multi, one has to exercise judgement as to what the limit is, or catastrophe awaits; with dinghies, one can push everything to a silly degree and just get wet.

Think of it in flying terms; even the most dramatic aerobatic pilot will be exercising judgement rather than actually going near the true limits, as the penalty will be personally interfacing with terra firma.

A similar fate, just taking a bit longer, is in store for people who push multi's too far; relying on a rescue boat is for dinghies.

 

[AngusMcDoon]

I don't how this boat handles, but for some boats an asymmetric is a good thing downwind in a blow because there is a lot of upwards lift in the sail which keeps the bow from burying.

On a trimeringue, the uplift is not on the hull you need uplifting. And if you have enough uplift to start flying the main hull, the leeward float gets even more depressed as it is now supporting the boat's weight. Trimeringues are not skiffs, and shouldn't be sailed like they are.

 

[Seajet]

I must say I'm a lot more bothered by the cat episode than the tri's though...

 

[AngusMcDoon]

No, for two reasons: firstly the kite was far bigger so the main would make very little difference. Secondly easing at that point of sailing would bring it up against the shrouds, still full of wind.

Depowering the main on a DF when apparent wind is greater than 60 degrees is not easing the sheet or dropping the traveller. It won't work for the reason you say. Depowering the main is letting go of its halyard. That's the reason these rigs have ball bearing batten cars so that the main will fall even when loaded, substantial lazy jacks to catch the boom, and you always keep the main halyard so that it can run free. It's described in the same owner's manual that says don't fly the asym in a F7.

But as you said, it wouldn't have made any difference anyway. It was using the asym that caused the lee float to bury, then the windage of the tramps that took them over. It's quite tricky to depower the tramps in a hurry.

 

[flaming]

Find the limit on a monohull and you're laid flat for a few seconds until the lead gets to work and hauls you back upright so you can have another go. Find the limit on a multihull and you're left sitting on a raft.

To me that would dictate a more defensive definition of finding the limit if I had one or more spare hulls.

I would tend to agree. Which is why I'm not a multihull sailor.

Takes all sorts though....

 

[snowleopard]

It's quite tricky to depower the tramps in a hurry.

We heard recently about someone who did that though IIRC it was the leeward one that was folded away

 

[AngusMcDoon]

I must say I'm a lot more bothered by the cat episode than the tri's though...

Me too. The tri capsize is explainable. But that cat should not have done that, or be sailed in a way where there was any risk of that happening.

 

[AngusMcDoon]

We heard recently about someone who did that though IIRC it was the leeward one that was folded away

Operator error. The trick is to furl the tramps in the 28 milliseconds you have available. Getting ready for berthing as well is just overdoing it.

 

[snowleopard]

When cruising in a multi the rule is to reef for the gusts. On a mono it's safe to reef for the lulls and ride out the gusts by heeling, spilling wind or bearing away.

When racing it's another matter. If you are prepared to risk damage to the boat for the sake of a better result I guess that's up to you. Those who take that attitude to racing will enjoy this clip.

 

[SHUG]

........and let me hasten to assure you that multihulls are a perfectly safe mode of transport.....occasional capsize......bows occassionally break off......sometimes trapped underneath the trampoline.....incapable of self-righting....pitch-poling.......but otherwise perfectly safe and seaworthy and ideal for taking the family for a jaunt round an island.

 

[westernman]

When cruising in a multi the rule is to reef for the gusts. On a mono it's safe to reef for the lulls and ride out the gusts by heeling, spilling wind or bearing away.

When racing it's another matter. If you are prepared to risk damage to the boat for the sake of a better result I guess that's up to you. Those who take that attitude to racing will enjoy this clip.

You don't see experienced guys capsizing like that. Flying a hull and keeping it under control is basically straightforward. To windward luff when the hull starts to get too high, bear off a bit as it starts to come back down. Downwind with the asymetric - you do the opposite. You aim to keep the windward hull just above the waves.

The tricky bit, where you see even the good guys pitch poling (e.g. extreme sailing series) is when bearing away and the leeward bow goes under a wave and starts acting as a submarine dive plane.

It is hard to get out of, and requires radical action (letting go of asymetric sheet and gybing and then as what was the submarining hull comes out of the water just before flipping over on the new tack to gybe back to the orginal tack and then to hold course dead downwind) which will stop the boat almost dead in the water (not good in a race). So often you will see the guys just hanging on and hoping that the bow comes back up and does not go so far down that it starts acting like a submarine dive plane.

It is probably something your average cruising cat skipper won't be well practiced doing.

 

[AngusMcDoon]

........and let me hasten to assure you that multihulls are a perfectly safe mode of transport.....occasional capsize......bows occassionally break off......sometimes trapped underneath the trampoline.....incapable of self-righting....pitch-poling.......but otherwise perfectly safe and seaworthy and ideal for taking the family for a jaunt round an island.

Your sarcasm does your argument a disservice. Performance trimarans are a different kind of boat for a different kind of sailing to what you want to do. You choose your boat for your kind of sailing, but why not accept that is not what everyone wants to do, and therefore they choose different boats?

 

[AngusMcDoon]

You don't see experienced guys capsizing like that. Flying a hull and keeping it under control is basically straightforward. To windward luff when the hull starts to get too high, bear off a bit as it starts to come back down. Downwind with the asymetric - you do the opposite. You aim to keep the windward hull just above the waves.

The tricky bit, where you see even the good guys pitch poling (e.g. extreme sailing series) is when bearing away and the leeward bow goes under a wave and starts acting as a submarine dive plane.

It is hard to get out of, and requires radical action (letting go of asymetric sheet and gybing and then as what was the submarining hull comes out of the water just before flipping over on the new tack to gybe back to the orginal tack and then to hold course dead downwind) which will stop the boat almost dead in the water (not good in a race). So often you will see the guys just hanging on and hoping that the bow comes back up and does not go so far down that it starts acting like a submarine dive plane.

It is probably something your average cruising cat skipper won't be well practiced doing.

That may work on a cat with a rudder on each hull, but less effective on a tri with only a central rudder like the DF's. Once you start flying the main hull your rudder becomes a not very efficient alieron, as can be seen in the photos. You've then lost it. Much better not to get in that situation in the first place.

 

[Twister_Ken]

Performance trimarans are a different kind of boat for a different kind of sailing to what you want to do. You choose your boat for your kind of sailing, but why not accept that is not what everyone wants to do, and therefore they choose different boats?

Presumably, then, performance trimarans have drip-dry interiors. Or are totally gimballed.