Help to operate a dual diesel catamaran.

[Nancy Young]

I am about to charter a dual diesel catamaran in BVI. Although I have my bareboat certificate, I have never operated a dual engine sailing vessel. Can anyone assisit me in locating a source for instruction so that I can prepare prior to my trip?

[joz]

Nancy

Can you please be more specific as what do you mean by Dual Diesel please?

[marshmat]

joz- dual engine = twin engine, so on a cat, one motor in each hull.
Nancy, I'm not familiar with your area, but around here the Canadian Power & Sail Squadron offers courses on seamanship and boat handling.... you might start by looking up their American equivalent.

[Nancy Young]

Originally Posted by joz

Nancy

Can you please be more specific as what do you mean by Dual Diesel please?

Evidently the catamaran has an engine in each hull. The charter company has asked me to study up on how to use a catamaran that has two engines as operation is different from a monohull with only one engine. This is all the information I have at present. Do you know of any books or articles on this subject?

[Crag Cay]

Argh, charter companies and cats. Relax, because it's no big deal. In fact it is probably easier than a monohull, just a little different.

The issue is one of slow speed manoevering, in tight spaces. As you have two engines set a long way apart, it is more effective to use these for manoevering rather than the rudder alone. At reasonable speeds, you can tighten any turn, by slowing (or even stopping) the engine on the inside of the turn.

At very slow speeds, don't even worry about the rudders; leave the helm amid-ships and concentrate on the engines. To turn tighter than as above, actually put the engine on the inside of the turn 'slow astern'.

Finally when actually stopped and making no way through the water, you can still have full manoeverability. By putting one engine 'ahead' and one 'astern' you can turn the boat on the spot.

Make yourself a carboard cut-out of the shape of a catamaran from above (a big letter H). Practice manoevering by thinking solely in terms of one hull going faster than the other, or one hull going backwards while the other goes forward.

I find when rehearsing any ship manoever, it helps to make engine noises as I go. Brrrrrmm. Brrrrmm. We also have to make sound signals. Barrrr Barrr Baarr! "I am operating my machinery in reverse".

Perhaps I should have replied to this before enjoying this evening's Cote de Rhone.

[marshmat]

Oh Crag, the mix of humour and good advice is always a good one
Nancy, as Crag says, the widely spaced twin motors give the cat a huge manoeuvering advantage. Indeed, with judicious use of gearshifts and rudders you can move the twin-engine cat in any direction, even sideways. I can't think of the titles of any books on the subject right now (although I have read some good ones), but your local power&sail squadron does strike me as a good starting point.

[Nancy Young]

My priorties have changed....I think I need the brand name of the Cote de Rhone more than the advice on twin engine maneuvering.

My curiosity is now searching for a sound blend of one engine ahead and one astern...could it be brrrrraaaaammmmm? I won't know until I get the brand name.

Thank you both Crag and Matt.

P.S. Just a quick question. When simply motoring, do you set both engines equal for rpm and then just use the helm in a traditional way?

[Frosty]

Nancy just in case you are serious about this ,--then so will I. Do not come into the Marina where I am, and/or preferably hand in your 'bare boat' certificate ( for what good it was) and go on a nice bicycle tour.

[joz]

Thanks for that, what about a diesel/electric engines in vessels?

[nero]

Nancy do not worry about a "brand name". Next time you make it to france just buy a bunch of bottles from different regions. Then you can discover french wine and piloting a catamaran.

... If you do them at the same time then you may find something challenging. ching, ching

[Crag Cay]

P.S. Just a quick question. When simply motoring, do you set both engines equal for rpm and then just use the helm in a traditional way?

Yes.

Thanks for that, what about a diesel/electric engines in vessels?

Where you have two electric motors running off one generator (some Moorings ? Charter Cats), you still have full independent control over both motors. Control is exactly the same.

However on some cats with hydraulic props driven from one diesel motor, there is less indiependence between the drives in each hull.

[Frosty]

Crag yer flogging a dead orse here me ole mucker.Although I see your genuinley trying to help I dont think its a genuine enquirey. You will get this some times.

The advice she has been given is still incorrect. any engine in reverse gear will have less pull than in forward, the prop was not realy designed to run backwards-- about 30% for starters so you will need 30% more RPM on the reversing engine to stay in one place. This coupled with a seperate gear control and engine control and -- well you know what happens.

Driving a boat in a marina ( I assume she was going to) is iresponsable to say the least. Good advice if I were to be believe such a question would be what I said . However if after all this she still insists on doing so then for Petes sake get some one to take it out and bring it back in and stay on board for the whole trip.
Would some one be so care less as to practise driving a car in Tesco's car park--bump -oops bump --oops -Not fair.
Try going down to the air feild and say " Oh good morning, I want to charter a twin engined Learjet. I havnt flown one before but I have a piece of paper here that says I can fly a single engined, but im not very good at that iether. However I have advice from the forum members on how to handle a twin engined aircraft so it should be OK".

Whilst sitting in the back of the police car on the way to the loony bin for pshyciatric analyisis there will be plenty of time to reflect on the sillyness of it all.