Anti-Capsize Technology and Systems

[rob denney]

Originally Posted by catsketcher

Again Rob, we disagree.

Again, we don't. In much the same way as we agree that hitting something at speed is likely to be problematic, we also agree about steering to avert a capsize. Where we differ in the first case is you don't think there is anything to hit. In the second case, you assume everyone will know which way to steer when they come on deck at 3 am in a rain squall with one hull starting to fly.

I think there is plenty of stuff to hit and would rather stay in my bed because the sheet released automatically and the boat is drifting quietly until the squall passes.

Originally Posted by catsketcher

I don't think many people will find the limitations of a free standing rig (lack of extras,

Don't be silly. It is a design issue. see attached

Originally Posted by catsketcher

inability to fine tune luff curve,

The ability is there, but generally not the need.

Originally Posted by catsketcher

extra bending,

This is a plus, not a minus. The mast bends, twisting the top of the sail off. An automatic first reef allowing a much larger mainsail than on a stayed rig.

Originally Posted by catsketcher

increased mast stress)

But easier to engineer and build than having to make the entire boat stiff enough to withstand forestay/traveller/shroud loads.

Originally Posted by catsketcher

worth the benefits.

What benefits?

Originally Posted by catsketcher

That said, I broke more masts when Laser sailing than all my other sailing combined.

Didn't we all, but that is a function of crappy design, not lack of stays.

Originally Posted by catsketcher

As for the described situations, again I don't concur. Every time I have been caught out in a big blow, altering course is the very first thing I do. You have to do it well but it should not be super hard to tell an autopilot to bear away to 150 true or head up to 60 true, depending on your intial course.

It is the "doing it well" in a rain squall in the dark when you have just woken up that is the problem. Your confidence in autopilots and electronics is touching.

Originally Posted by catsketcher

If you are in a squall then there will be few waves, so screaming down a wave will not occur, not for many minutes, which will give you time to react. If there are already big waves then you will have reduced sail up and heading up or bearing away will not be fraught.

Maybe on the east coast of Aus, but read about California-Hawaii cruises to see one of many examples of how wrong this statement is.

[Manateeman]

The last few posts are interesting but I don’t need sailing lessons and I would really, really appreciate it if posters would read my original questions and focus just a bit more on the specifics of the technology.
Please let the members decide how they want to sail their boat.
I think that’s a reasonable request.
Mark

[AKA-None]

Originally Posted by Manateeman

The last few posts are interesting but I don’t need sailing lessons and I would really, really appreciate it if posters would read my original questions and focus just a bit more on the specifics of the technology.

Please let the members decide how they want to sail their boat.

I think that’s a reasonable request.

Mark

Well why should this thread be any different than most others

I’m sure we’ll circle back eventually

To your point taken to it’s extreme wouldn’t we end up with an autonomous boat?

[OneBoatman]

My experience is that sudden doesn't happen very much sailing offshore and I sailed a large cat in 50 plus conditions. A cat can be difficult to handle in much less wind. Good captains anticipate and then pray mother nature doesn't win. As not an expert on such trip devices I believe they could alert the captain in order to prevent disaster. It would seem to me that if the system were set up to release the mainsheet alone a cat would remain vulnerable to being pitchpoled if the jib were still flying as it would immediately head down and if the seas were big enough there you go. The size of jib would matter. If you are more on the wind in these conditions I would feel more at home using a tri-sail or other combination of reduced sail to perhaps not need the system at all. I haven't seen an autopilot able to react quick enough when reaching or runnning off, but perhaps at great expense they are out there. If the system were set up to release both sails a cat may stay upright but it would still be a lot to deal with and you would have to go "outside". Of course how it is ballasted and weight distribution come into play. What about systems that automatically reduce your sail base on wind speed?

[clakiep]

Reminds me of a russian system to prevent capsize of catamarans : a kind of iron canon ball resting in a concav woodden block on deck, with a cable conecting it to a patent schekel at the main sheet. At a certain heel angle the canonball would roll out of its concav resting place, pull the cable and release the main sheet. I am posting this not as a serious sugestion but more for amusement, although it would probbably actually work - also waking up the crew with the canon ball bumping over the deck. Not having access to sofisticated hardware often promotes criativity.

Capt. Claus - ocean tramp of the eighties

[Buzzman]

For those unfamiliar with the work of Jim Brown, can I suggest a read of his 'The Case for the Cruising Multihull' in which he describes a system he invented for use on his Scrimshaw 31' SeaRunner, which was basically a hinge mounted flat, on a horizontal pivot point, with a cam cleat attached to the upper half of the hinge.
The trailing edge of the upper hinge was attched to bungy cord(s) (adjustable for wind strength) such that if the force exerted on the sheet run through the cleat was more than that set up by the skipper (using the bungy cords), the hinge would 'flip' forward and the sheet would automatically release.
He claims it is virtually foolproof and can be used on main or jib sheets.
There is a diagram in the book.

[lo2jones]

Did anyone look into the probability of capsizing a 40ft + catamaran? All of the documented incidents I can find are boats smaller than 40ft. According to engineers in the business, you are more likely to break something than capsize a catamaran over 40 ft. Typical dimensions of a 40+ cat is 50ft on the diagonal.

[smj]

Originally Posted by lo2jones

Did anyone look into the probability of capsizing a 40ft + catamaran? All of the documented incidents I can find are boats smaller than 40ft. According to engineers in the business, you are more likely to break something than capsize a catamaran over 40 ft. Typical dimensions of a 40+ cat is 50ft on the diagonal.

Plenty of documented incidences of cats over 40’, even over 50’.

[macieknan]

An approach to reef for gusts and accept slower speeds would easily remove majority of risks. An idea of reefing alarm based on AWS seems awesome in its simplicity

5k for ACS might also be acceptable price for large cat owners.

[double u]

Originally Posted by ItDepends

..... Do people really sail catamarans sitting in the saloon while the boat is on autopilot? That just seems—dumb.

as I have been frequently told by the multihull advocates "the cat is no more likely to capsize than the monohull to sink" & "the capsized cat is far to be preferred to a sunk mono"...so why not sit...

[Franziska]

Originally Posted by macieknan

An approach to reef for gusts and accept slower speeds would easily remove majority of risks. An idea of reefing alarm based on AWS seems awesome in its simplicity

5k for ACS might also be acceptable price for large cat owners.

You can set an AWS alarm on most, if not all wind instruments.
I my view a TWS alarm (which you can set too) is better, because on any point of sailing you get the true wind speed which should be your reefing indication.
Downwind apparent wind feels a lot less than upwind as the boat speed deducts itself from the wind speed, which can lead to ugly surprises when you luff up to reef.

Such an alarm is generally helpful to indicate the necessity of reefing, but, it does not safe your bacon when a squall hits very suddenly. It does not see the squall coming. Your eyes can at daylight. Nightsailing is the dangerous bit.

Radar can help to spot rainsqualls.

Reefing early in doubtful weather is best. So maybe we should also discuss weather indexes which indicate that white squalls and similar are possible.

We reef at night and/or when the wind is generally unstable or in the presence of thundercells.

The mechanisms discussed here are primarily meant to help in a situation when you are distracted by other things and possibly sailing short handed.

Sometimes things can develop so fast that you can not react in time. An automatism to reduce that risk would be great.

And yes, I do prefer sitting on a flipped multi over having to swim above a sunk mono.

[Manateeman]

Please let’s stick to the thread not how to sail. It’s clear some very experienced sailors have capsized both mono hull and catamarans.
Mark

[catsketcher]

It's called thread drift - it's a fine thing.

I think the capsize of Anna is really instructive because it is an example of a large (57ft) well designed and built (Chris White) catamaran. The crew were doing things well up to the point they capsized. They were monitoring the weather by radar and using Mk1 eyeball. The great thing is that the skipper was gracious enough to write a journal about the capsize. I think the sailent points are in the paragraph attached.

Suddenly just after 1500, while observing the anemometer (wind speed and direction indicator), which was displaying apparent and not true wind since we were beating, I noticed that the wind was backing to the South so
that rather than beating into the wind, suddenly we were on a beam reach. I began turning Anna via the autopilot so that we would remain head up. Then the wind speed jumped from 18 knots to 25, then to 30, then to 35 in the
blink of an eye, and both Glen and I yelled "let's reef" and we bounded out into the cockpit. When I saw the anemometer in the cockpit a couple of seconds later, the wind speed showed 45 knots, so I moved to the
autopilot and again tried to head the boat up into the wind, while Glen tried to reef the jib. The wind was ferocious, however, and Glen could not control the jib outhaul line so that it started flapping wildly. I was afraid we
would rip the sail (which I did last year because of my own operator error) and so shouted at him, "What are you doing?", then reached over and closed the jammer cleat that prevented more line from getting loose. Realizing
finally that the wind was overpowering us to a perilous extent, I moved towards the mainsheet to release it, but in a flash we were up in the air, flying a hull as if we were on a Hobie Cat, and I lost my balance and started tumbling to port. We hung at that position -- roughly 45 deg. -- for a second then over we went. I used the S word. Loudly

Even with flapping sails being pulled in (or at least attempting to pull the genoa in) the boat was overpowered and capsized. I think this is important for those who argue for sheet releases only. IMHO the crew should have grabbed the helm first and considering they were on a beam reach, born away quickly by hand steering aggressively. Squalls are short lived and waves that can overwhelm a cruising cat will take hours to develop so seas will not be an issue, so bearing away would have reduce the risk and given time to furl the genoa.

I think that any anti capsize system that does not alter course as a vital part of its function is going to be much less capable than it could be.

For anyone who wants more on the Anna capsize, very interesting reading on

LossOfAnna

https://www.chriswhitedesigns.com/capsize-of-anna

[smj]

A good read on another Atlantic 57 catamaran that capsized named Leopard.

https://wavetrain.net/2016/11/25/atl...te-of-leopard/

[fxykty]

Sobering stories. Sh*t happens. Just like with any other human endeavour. We can plan for it, but shouldn’t fear it nor live differently to try to avoid it.

Load cell based anti capsize systems can have merit, but the current systems have quite narrow bands of effectiveness and wouldn’t have helped at all in the types of conditions that capsized the two Atlantics.