Bow thrusters and wooden boats

[prv]

right, there's nothing in the rules that says it must be mounted along/through the keel. Off set to either side is ok.

All the "extending" thrusters I've seen only protrude by about the diameter of the prop, plus a couple of inches. Given a fairly steeply-sloping hull side as most wooden boats are near the bow, then to fit the thing in width-wise it's going to have to be mounted fairly high up. Anything based on a standard model will then extend into a position approximately next to the keel, instead of below it, and will probably work badly in one direction and not at all in the other. The shape of the fairing plug below the prop housing is also going to be interesting.

I'm sure something suitable could be engineered, but it's not going to be simple.

Pete

 

[Poignard]

No one need know

Vetus were marketing a water-jet system for a while. All you need are two3inch skinfittings on each side of the bow , a water pump and a control valve.....simples.
Like this: http://www.usmarineproducts.com/pdf/Jettrhusters_eng.pdf

I like that! It's supposed to be silent so you could use it without everyone on other boats rushing up on deck to put out extra fenders and watching you anxiously.

 

[Elessar]

I have used one, several in fact. Must admit that I am so used to not using one that I do tend to forget that it is there. Don't get me wrong, I can see where they would be useful. Probably a case of old dogs and new tricks.

A near neighbour has a 28', twin screw sports cruiser that has no keel to speak of. At low speeds on a windy day his bow thruster is a godsend. But then, as much as I admire the design, the build quality and the comfort, its not my sort of boat, and I suppose the same can be said of bow and stern thrusters.

Then we totally agree

I wasn't trying to say you should have one. I just don't like attitude that if you have one you are somehow inferior. I inferred that from your first post sorry.

I agree with marsupial too. I kick myself if I have to use it due to a misjudgement. But other times I plan to use it because it is the solution.

Yesterday was a kick myself day.......

 

[prv]

Maybe, I was visualising a vee shaped hull where the keel was "inside" the Vee,

Hmm, I was too, but perhaps didn't explain myself clearly. Let's try a quick (very quick ) drawing.

1. Keel
2. Planking (starboard side only shown)
3. Thruster prop
4. Thruster control box etc

In the "Up" picture, I've mounted the thruster as low down in the hull as I can - any lower and it will either protrude through the planking or be above the keel and unable to descend.

In the "Down" picture, I've extended the prop by its own height plus a little more, which is what all the commercial ones I've seen do. In this layout it doesn't even clear the planking, let alone the keel.

It's not meant to be a scale drawing, but hopefully it illustrates the problem that seems pretty clear to me.

Pete

 

[SHUG]

Nah! The only possibility is to build a sortof beer barrel into the bowand install a normal bow thruster. I have seen lots of wooden-hulled cruisers with bow thrusters so it can't be that difficult.
I still favour the water jet idea for minimum structural impact.