why don't more boats have v-drives?

[ArthurWood]

Re: why don\'t more boats have v-drives?

Dare I mention that all Sea Ray Sundancers with inboards have V-drives. Allows a nice cabin arrangement under the helm. The Express versions, with straight shafts, have the second cabin almost alongside the master. Not our cuppa tea.
Hurth transmissions are very reliable IMHO.

 

[Guest]

Re: why don\'t more boats have v-drives?

I always thought the problem with v drives was the fact that the stern gear is hidden underneath the engine. Even more of a bastard to get at than normal.

 

[jfm]

Re: sterngland access

Depends. Usually at front of engine, rahter than underneath, depends on precise case. On LS23 frexample, sterngland very accessible see the pic in 3rd column 3rd row on http://www.boatsontheweb.com/leopard

Also some Vee boxes have a sideways offset so the sterngland is inboard of the engine's centreline, not straight underneath it. But I'm sure there are some difficult installations too!

 

[coliholic]

Re: You can\'t be Nick - I\'m Nick!

Since there's some confusion you can be poofy Nic, with no k;-)

They do exactly that in the Sheerline range. Had a look at the 950 a year or so back and that's got a transverse mounted Nanni 5 cylinder (I think) engine with a hydraulic drive. Sheerline range are sold through Val Wyatt (www.valwyattmarine.co.uk) though website doesn't show engine arrangement. Built by Wroxham Marine in Norwich.

I think a lot of the Broads crusiers have this hydraulic drive arangement, don't know why noise should be a problem though.

Of course these are slow river speed type boats, not sure how a high speed planing boat would get on with this type of drive. Maybe losses too high? Someone'll know. Paul the Engineer to the rescue?

 

[Guest]

Re: You can\'t be Nick - I\'m Nick!

I refuse to drop my 'k'. Why does'nt BroomBroom sign himself with a y - Nicky! Thats nice!

(The real) Nick

 

[ArthurWood]

Re: why don\'t more boats have v-drives?

That's true. I had dripless shaft seals installed in my boat and I still can't figure out how they got down there to do it! I guess that's why I pay $85/hr+tax for their service.

 

[MikeBrazier]

hydraulic / electric propulsion

Have a look at...

http://www.vetus.nl/producten/product_main.asp?productid=115&lang=2
and...
http://www.vetus.nl/producten/product_main.asp?productid=92&lang=2

Perhaps you should have taken out those patents afterall ;-)

 

[Guest]

Re: hydraulic / electric propulsion

In principle, I agree. However the Vetus hydraulic offering appears to only be rated to 60hp so something larger would be required. I did'nt actually claim any invented here rights to this, only that it was a means of locating the engine(s) anywhere that suited. Also they can't be all that inefficient as a number of short haul Calmac ferries (the raft shape Ro-Ro variety doing 500yd crossings) have this form of propulsion into swivelling propulsion units - sort of like a saildrive on a swivel.

As far as the electric motor is concerned, my idea was that it could be run directly off the genny rather than carrying all sorts of additional heavy batteries. The limiting factor might be the size of genny required. Typically a 40 foot boat might have a 6-8kw genny which translated to HP would run say a 8-10hp motor - would that be enough to give 4-5knts? I am not sure.

Nick

 

[Col]

Re: hydraulic / electric propulsion

We went on a trip around the bay, somewhere on the north coast of France, in an amphibious vehicle. It looked like a big aluminium 3 wheeled boat, hydraulic drive to wheels and twin hydraulic stern drives. Two transit turbo diesels ran the pumps, It was unbelievably noisy, a sound like power steering on full lock, but much, much louder. It was also very slow. I would imagine the power losses through this set up would be bad. I can't see it would be practical on a fast motorboat, might be OK for canal / river though.

 

[ChrisP]

Re: Girly kitten-type question

No, but it has a John person HE drives.