Engine placement at bow

[Wckoek]

Originally Posted by Dougtiff

I have seen one boat with the engine in the bow, it was a replica of Joshua Slocums SPRAY, built by Pete Culler in 1929 at Oxford, Maryland, She eventually ended up on the West coast [i saw her at Napa marina in 2010, hauled out on the hard], she was falling apart, had been sitting there for about 10 year's, one of the unfortunate project's, where an inexperienced person bit off more than he could chew, and gave up, it was interesting to go aboard [carefully], and have a look around, the Big gas engine was situated in the bow, with a shaft supported by a number of pillar block bearing's, this opened up the aft area of the cabin for the main state room, The Oxford Spray was finally broken up a few year's ago, i was able to obtain a couple of item's off Her. Pete and his Wife sailed her up and down the East coast and also out to Burmuda in the winter, they would load her up with rough sawn timber, sail south and sell the goods along the way, thereby finacing there holladay, but i digress.

I have read that is the most accurate reproduction of Spray or at lease one that is approved by Slocum himself, it is a sad end for what she was.
Did they take any lines off before she is broken up? I have learn that no accurate linea of Spray exists.

[Captndave1]

I once delivered a 40' Nevelt sailboat from South Florida to Cartagena Columbia that had the diesel under the cockpit, but it only drove a hydraulic pump which powered a hydraulic motor mounted at the mast base with a long, almost horizontal shaft to the folding prop. This is an unusual setup, but worked very well. The Nevelt was an all out racing boat built in France.

[roland stockham]

Main issue I think is going to be flex in the prop shaft, that is going to add weight and cost so most designers would avoid it unless the had a very good reason. Looking at the shape it may be that to put it in the more conventional position would have necessitated a box in the accommodation area producing noise and heat. Looks like it may work well for an estuary boat

[Cheechako]

I can't really think of a good reason to put an engine in the bow. Often low overhead up there, weight in the wrong place, long whipping prop shaft, long fuel lines, battery weight up there too or long cables... and more..

[hzcruiser]

Originally Posted by Wckoek

Not necessary asking if the design was good or bad, but just why this isn't done more.
Probably good sound isolation as well and good use for a wasted space.

It certainly has some advantages as mentioned before and might work well in such a trawler with a fairly wide bow, hence more buoyancy up front. Which it needs since the engine weighs half a ton! Add to add the weight of the ground tackle (unless you run that around the engine to some aft position...) and it's clear you won't see a sailing boat with this layout anytime soon. The disadvantages are just too big.


As mentioned by Brewgyver, a diesel electric setup with a fairly small, high-reving turbo charged engine up front might be an option. Still leaves the exhaust issue, as a dry stack on the fore deck is a challenge, too.

[SV Bacchus]

Originally Posted by Wckoek

Not necessary asking if the design was good or bad, but just why this isn't done more.

I think everyone is saying it isn't done more because it is a bad idea. Your first sentence is trying to eliminate the reason it isn't done more and asking for some other reason that doesn't exist.

It is a bad design for all the reasons given in the prior posts in this thread.

If it was a good idea it would be done more!

This is, or course, JMHO.

[thinwater]

Originally Posted by Terra Nova

The ridiculously long prop shaft would create vibration problems.

No longer than the shaft on a bus. Different engineering, no point in commenting without seeing the details.


One obvious result is a low shaft angle.

[Terra Nova]

Originally Posted by hzcruiser

It certainly has some advantages...

Actually there is no good reason to put all that weight in the bow, which increases the pitching.

[Terra Nova]

Originally Posted by thinwater

No longer than the shaft on a bus...

Buses are typically rear engine--no long drive shaft.

[Wckoek]

Originally Posted by SV Bacchus

I think everyone is saying it isn't done more because it is a bad idea. Your first sentence is trying to eliminate the reason it isn't done more and asking for some other reason that doesn't exist.

It is a bad design for all the reasons given in the prior posts in this thread.

If it was a good idea it would be done more!

This is, or course, JMHO.

Your logic is flawed, its like saying Socrates is a man hence all man are Socrates.

There are disadvantages with engine place at the bow obviously, and there is also advantages, does it mean that all boats with engine in front means that it is a bad design?

Obviously vibration might be a problem with the longer shaft, but this is a relatively small boat in terms of trawlers, 46 and 49 feet for the Tasman Sea. So the positive may or may not outweight the negatives.

The only few boats that mentioned earlier that our members have experienced with engine up front are sailboats, 2 or 3 if we counted the Yamaha are racers, and the Spray wasn't build with an engine in mind in the first place.
We still don't know how a powerboat will behave at sea with an engine up front.

[Wckoek]

I love the layout; that engine in the bow opens up the entire rest of the hull. This isn’t a common installation to put it mildly, but neither the owner or I could see why it wouldn’t work. The whole trick would seem to be to make sure the shaft is well supported by “pillow blocks.” And, with a couple “U-joints” in the line, there should be absolutely no vibration. One guy said it wouldn't work because the motion of the bow lifting and falling would mess up oil flow. But, if you look at the stress a dune buggy or stunt airplane engine deals with, what this boat's bow would do even in a real storm seems small time. One change I'd do is give her a wet "north sea" exhaust. I don't care for the look of the stack sticking up like it is here.

In the word of Mr Buehler.

[Pelagic]

So many issues from torsional shaft vibration issues, to G forces in head seas (can you imagine doing any critical fuel filter changes in large waves)
Protected Ventilation, auxiliary equipment plumbing and wiring runs all artificially extended.

This design is so incredibly stupid it could only have been done by an interior desecrator turned yacht designer.

[Terra Nova]

Originally Posted by Pelagic

...This design is so incredibly stupid it could only have been done by an interior desecrator turned yacht designer.

[RaymondR]

Originally Posted by Pelagic

So many issues from torsional shaft vibration issues, to G forces in head seas (can you imagine doing any critical fuel filter changes in large waves)
Protected Ventilation, auxiliary equipment plumbing and wiring runs all artificially extended.

This design is so incredibly stupid it could only have been done by an interior desecrator turned yacht designer.

Unthinking reaction of the determined orthodox thinker.

The "Emma Maersk", biggest container ship, has the engine midships rather than the more orthodox aft engine room. Requires an exceptionally long prop shaft - why?

The Israelis build tanks with the engine in the front rather than the back like everyone else because it provides greater crew protection - why? Because they value highly trained tank crews more than the tanks.

I can imagine doing a filter change in a warm dry forward engine room in say the arctic conditions which prevail in much of north America, Asia and Europe during the winter versus doing it in a crawl space under the aft deck, or in the open with deck hatches open, where many of the orthodox power cruisers have their engines.

Cannot see that there would be much difference in wiring runs.

I would want to see the designers full reasoning before branding them as idiots.

[Wckoek]

Emergency fuel filter or oil change at sea would be uncommon, more so in a large sea as for me such maintenance or preparations would be done before going out to sea, and for that I would prefer a larger space to work at.

The biggest problem aside from weight distribution is shaft vibration and ventilation, not that it can't be all be mitigated in a design.
Many also use the bow compartment as a collision bulkhead, larger boats can afford this at the expense of space, but utilizing such a space for smaller boats for engine might worth all the benefit despite the drawbacks?

I hope there are examples of designs like this being build and see how they works.