Engine beds for JP3 ?

[waterworks]

Can anyone show me what kind of steelwork a large vintage engine sits on, I have a NB shell I'm converting from a rear modern engine to a traditional engine room with a JP3 (  hydraulic drive no propshaft ),  I have 120 x 75 angle floor bearers at 450 mm spacing , this engine needs 350 mm + clearance from the floor to mounting brackets, that's a lot of height to make up. How has it been done on your boat ?

 

 

[Tony Brooks]

not sure if tihs is any help, but such engines usually sit on timber bolted to the beds, probably hard wood. So I suppose it may come down to the cost of such thick timber against the costs of supply and welding a steel box section onto the top of the beds.

[GUMPY]

When I had mine redone after the originals cracked they were  half Inch thick steel verticals welded to the base plate with the same horizontal and gussets every foot underneath. These ran the length of the engine room and we're braced to the sides of the boat as well as being welded to two steel bulkhead/cross members at the front and rear  The engine was mounted on 3 inch thick oak bearers on top of this structure.

You can never have too much steel supporting  a JP3

[Alan de Enfield]

1 hour ago, waterworks said:

Can anyone show me what kind of steelwork a large vintage engine sits on, I have a NB shell I'm converting from a rear modern engine to a traditional engine room with a JP3 (  hydraulic drive no propshaft ),  I have 120 x 75 angle floor bearers at 450 mm spacing , this engine needs 350 mm + clearance from the floor to mounting brackets, that's a lot of height to make up. How has it been done on your boat ?

 

 

 

What age is the boat ?

[David Mack]

This is what Harland and Wolff provided for a Large Woolwich with a National 2DM (similar size to a JP2). Enginerooms like this have also had JP3s fitted.

 

And with the engine in. The steelwork is capped with hardwood (iroko) bearers about 3" wide by 1.5" thick.

Edited May 6 by David Mack

[Jon57]

Mine is similar to David Mack. The timbers on mine are oak 2 in by 4 in. 

[BEngo]

In an ideal world one would bolt the engine to 4x4 or 5x5  softwood, say Douglas fir / Oregon pine, then separately bolt the timbervto the steelwork.

 

Softwood absorbs the thump of a lbig slow  diesel better than a hardwood.

 

Bolting separately ensures there is not a direct steel transmission path for vibrations.

N