Dynamo's take very little in the way of "horespower" to drive them, however the output amperage is very low, scale wise you would be looking at maybe getting 3 - 5 amps out, even a full size dynamo only kicked out 22 amps when new.
Alternators are a different beast, full size versions on your car take over 2 hp to drive under full load and I cant see a scale version taking much less to drive.

Its a nice idea, but not really practical, far better to just take a spare set of batteries along for extended sailing.

Bayoueagle I agree it is a nice idea an see where your coming from but have to agree with Expatflyer.
Mind you the early Del-tics locomotives had their diesel engines screaming to get the amps to the motors. Why that was a good idea was that the electric motors were on the bogies and that was a no no for diesel engines there.

Seaspray

No doubt that it is an exercise for satisfaction - like steam power - and to be encouraged. That is one of the reasons for our hobby.

I have seen an article about a model with a home built four cylinder marine diesel engine driving a generator/electric motor - superb engineering.

It needs a large scale heavy displacement model such as a tug or trawler, or a very large battleship or liner.

Economically any generator system would really be just an expensive way of replacing batteries or ballast.

Practically, in a normal model, with the availability of modern lightweight electric motors and batteries, there is nothing better to achieve longer duration than putting in more amp hours - but where is the challenge!

Jerry

Has anyone tried to build a model ship with a gasoline or butane powered generator/alternator providing the electricity to keep the batteries charged for longer run times?
Hi
When I was in the model engineering club. One or two of the lads had locos that were powered by a Briggs and Straton lawnmower engine which turn an alternator. it was a good setup but the work involved (to me) I would have just stuck to a gas(petrol) engine drive.

One lad had a dynamo from a car driving (altered to a motor) his loco on a 12 volt battery.

Good idea and lots of info on the net.Lets know how you get on

Seaspray