“STORM TACTICS” Catamarans

[Sos]

Originally Posted by Budawang

Just got back from our trip out to Lord Howe Island in the Tasman sea in a Lavezzi 40. On the way out we encountered a 25-33 knot southerly with 3-4 metre swells. Seas were sometimes breaking and our decks were occasionally awash. Nothing too extreme but it became very difficult to make headway and a strong current, combined with the swell was pushing us away from Lord Howe. Our winning tactic was to have a third reefed main and a small amount of head sail, lash the helm hard over to windward in combination with running the windward engine at 1,500 rpm which prevented us going about. This allowed our cat to slowly move forward at 2 knots all night without making any leeway. With our bows pointing around 45 degrees into the seas we rode up over them with a minimum of crashing and banging. I think this strategy would have also worked for significantly worse conditions.

Thats good information to know. Do you mean leeward engine to prevent you going about?

[Budawang]

Originally Posted by Sos

Thats good information to know. Do you mean leeward engine to prevent you going about?

No, the windward engine is correct. As the yacht rounds and stalls the windward engine pushes the bows back down off the wind so it starts sailing again. It's a form of heaving-to but had the advantage of preventing leeward drift and maintaining way slowly. We even clawed our way upwind a couple of miles. It also allowed my crew to rest all night as the motion was surprisingly comfortable and we felt safe.

[CatNewBee]

Thank you very much for the input. I have to consider something as plan B, maybe a speed limiting drogue. The Jordan Series and the sea anchor require very robust clamps / winches and are also very hard to retrieve - especially if you are alone or just 2 person on board.

A smaller device that just helps reducing speed I guess is easier to handle and would be used earlier and therefore would be probably safer at sea with a smaller crew.

[arsenelupiga]

Originally Posted by Budawang

No, the windward engine is correct. As the yacht rounds and stalls the windward engine pushes the bows back down off the wind so it starts sailing again. It's a form of heaving-to but had the advantage of preventing leeward drift and maintaining way slowly. We even clawed our way upwind a couple of miles. It also allowed my crew to rest all night as the motion was surprisingly comfortable and we felt safe.

Ha ! And I thought I learned it all from books

That is excellent approach for cats that I will explore further.

did you just made it up on the go ?

thanks for sharing.

[Budawang]

Originally Posted by arsenelupiga

Ha ! And I thought I learned it all from books

That is excellent approach for cats that I will explore further.

did you just made it up on the go ?

thanks for sharing.

Yes, we did just make it up on the go by experimenting with several different engine, sail and rudder configurations. In hindsight it would have been better to have trialled it first in a controlled situation closer to shore rather than 200 miles offshore. However, I came out of the experience with more confidence in my ability, the ability of my crew and the seaworthiness of our Lavezzi catamaran. In my opinion a well-found 40-foot catamaran with a good crew is extremely sea-worthy.

[fxykty]

I would caution relying on an engine as a required component in any storm condition due to two possible issues.

The violent movement of the boat will stir up any gunk in your fuel tank and potentially halt or restrict your fuel supply, leading to the engine turning off or reducing rpm unexpectedly.

Another issue that is present in our catamaran is that the cooling sea water intakes for the engines are only 40cm below the waterline and in large waves come out of the water regularly. More possible in catamarans with catamarans and trimarans due to shallow hull forms. YMMV

So rather than putting your helm hard over and relying on the windward engine to turn the bows away from the wind, how about using less helm to balance the boat in a fore reaching attitude or whatever heaving to equivalent position your cat prefers? Then no danger of getting caught in irons and getting pushed backwards because your engine stops suddenly.

[44'cruisingcat]

Originally Posted by Sos

Thats good information to know. Do you mean leeward engine to prevent you going about?

The leeward engine would be more likely to make you go about than to prevent it.

[arsenelupiga]

Originally Posted by fxykty

I would caution relying on an engine as a required component in any storm condition due to two possible issues.

The violent movement of the boat will stir up any gunk in your fuel tank and potentially halt or restrict your fuel supply, leading to the engine turning off or reducing rpm unexpectedly.

Another issue that is present in our catamaran is that the cooling sea water intakes for the engines are only 40cm below the waterline and in large waves come out of the water regularly. More possible in catamarans with catamarans and trimarans due to shallow hull forms. YMMV

So rather than putting your helm hard over and relying on the windward engine to turn the bows away from the wind, how about using less helm to balance the boat in a fore reaching attitude or whatever heaving to equivalent position your cat prefers? Then no danger of getting caught in irons and getting pushed backwards because your engine stops suddenly.

what would be the problem with water intake being out of water here and there ?

Revs are not high - 1500.

Can air come all the way to impeller and impeller stops working ? Seem very unlikely as strainer in between and time required for impeller to suck out all water - cant see water intake be out of water for that long.

[fxykty]

Originally Posted by arsenelupiga

what would be the problem with water intake being out of water here and there ?



Revs are not high - 1500.



Can air come all the way to impeller and impeller stops working ? Seem very unlikely as strainer in between and time required for impeller to suck out all water - cant see water intake be out of water for that long.

I would guess that momentary sucks of air through the intake are accommodated by the strainer bowl, but too many too often could empty the strainer, then the impeller runs dry and ....

The other issue on our boat and probably most other boats with props close to the sterns is that they’re quite shallow. In heavy seas they ventilate.

In either case, not worth risking for some comfort at sea or for longer term storm handling. Worth risking clawing off a lee shore until the sails can draw or to avert some other emergency.

[Budawang]

Originally Posted by fxykty

I would caution relying on an engine as a required component in any storm condition due to two possible issues.

The violent movement of the boat will stir up any gunk in your fuel tank and potentially halt or restrict your fuel supply, leading to the engine turning off or reducing rpm unexpectedly.

Another issue that is present in our catamaran is that the cooling sea water intakes for the engines are only 40cm below the waterline and in large waves come out of the water regularly. More possible in catamarans with catamarans and trimarans due to shallow hull forms. YMMV

So rather than putting your helm hard over and relying on the windward engine to turn the bows away from the wind, how about using less helm to balance the boat in a fore reaching attitude or whatever heaving to equivalent position your cat prefers? Then no danger of getting caught in irons and getting pushed backwards because your engine stops suddenly.

It's good to have another point of view, but the strategy we adopted in the conditions we had to deal with worked for us. Each situation is different. We were being pushed away from our destination by current and wave action. Heaving to in the traditional sense without any engine power meant we would never have made landfall and would have had to continue for several hundred extra miles back to mainland Australia. There was too much bridge deck slamming to continue sailing normally. As we were only going at 2 knots at 45 degrees to the swells there was no hobby-horsing and, therefore, no risk of either fuel contamination or air intake issues.

[Mr B]

Originally Posted by fxykty

I would caution relying on an engine as a required component in any storm condition due to two possible issues.

The violent movement of the boat will stir up any gunk in your fuel tank and potentially halt or restrict your fuel supply, leading to the engine turning off or reducing rpm unexpectedly.

Another issue that is present in our catamaran is that the cooling sea water intakes for the engines are only 40cm below the waterline and in large waves come out of the water regularly. More possible in catamarans with catamarans and trimarans due to shallow hull forms. YMMV

So rather than putting your helm hard over and relying on the windward engine to turn the bows away from the wind, how about using less helm to balance the boat in a fore reaching attitude or whatever heaving to equivalent position your cat prefers? Then no danger of getting caught in irons and getting pushed backwards because your engine stops suddenly.

I can only speak for my Cat,
But my Diesel tanks and motor are all on the transom, Thats the steadiest part of my boat in any conditions,
Its near level and flat all the time, Thats why I sit out there, past the transom on the hammock,
So stirring up the sludge, If any, on the bottom of the tanks would be negligable,
Sludge in the tanks should be removed constantly, Syphon hose to the bottom of the tanks, gets rid of any sludge, or water that might be in there,


My Motors intake is about 6 feet from the transom, on the inside of the boat, So it leaving the water is near impossible,
Its about 400 mm under the water line, if that, Ive never heard it suck air,
I only have one motor and one central Drive leg,

The bow of my boat is another story, Bad weather, You just dont go out there, It corkscrews thru the water unbelievably,

[double u]

(I can't resist, I just can't!!!)
"...I would caution relying on an engine as a required component in any storm condition..."

I would caution against a type of boat where going upwind in "25-33kn" calls for "STORM TACTICS"...

[Seabeau]

Originally Posted by double u

(I can't resist, I just can't!!!)
"...I would caution relying on an engine as a required component in any storm condition..."

I would caution against a type of boat where going upwind in "25-33kn" calls for "STORM TACTICS"...

"Ouch", That's gonna leave a mark!

[arsenelupiga]

looks like bunch of jelaous monohullers again lurking cross the fence.

find something better to do than spying on other people

For example, check your keel bolts

did you know more people dies from lost keels than shark attacks.

[double u]

we had a welded aluminium structure for a boat...(& sorry to say, even though it sure has been a while: under windvane it would go great guns in those conditions, lady, baby & all, even have something "left" in case wind would increase...
but of course no "...wineglasses on the saloon table..." that I have been reading so often about condition multihulls)
btw: 1 rtw on a 34' Wharram cat in the 80ies here, so no bullshitting me about cats, ...)

I couldn't resist, I just couldn't! (does that make me a bad person?)