Jump to content

Complete Propulsion Installation


Featured Posts

I'm slowly reaching the stage where I shall need to start preparing my hull for the fitting of an engine and continuing right through to the stern tube boss, the hull is of an unknown build (including date) and has never been propelled or had anything fitted before. I have one or two "cunning" plans in my novice head on making everything as "fit for purpose" as possible, but can anyone here on this knowledgeable forum advise me on how to accomplish this ?

Link to comment
Share on other sites

Best to start off by posting some photos of the hull you need to fit all this into, inside and out, in order to get some meaningful advice.

 

Is it a conventional counter-stern or something else? If the former, why is there no stern gear already?

Link to comment
Share on other sites

Hodgkiss cones could be the answer if there is no stern tube and the boat has a flat bottom

 

I've only heard of "Hotchkiss"- Cones, and suppose that that's what you wanted to write, but I could be wrong of course.

 

Peter.

Link to comment
Share on other sites

without specific information as suggested by 'Baron MtB' one could write a 3-volume book on the subject.

 

with specific information the details of the possible installation arrangements can be usefully narrowed down.

 

we have no idea if you are fitting out a narrowboat or a ship's lifeboat, or anything in between.

Edited by Murflynn
Link to comment
Share on other sites

Sorry guys, should of realised that the question kind of "came out of nowhere".

The nb has NEVER been fitted for propulsion before but HAS been afloat. It was an abandoned project of someone else's, and the plan is to complete the works with a trad stern with a functioning back cabin. Another problem i have to overcome is that the baseplate has a center-beam running fore-aft so unless i can remove the relevant area and replace with the standard parallel engine bearers the back cabin is going to be a bit more shorter of headroom than most.

Link to comment
Share on other sites

...... unless i can remove the relevant area and replace with the standard parallel engine bearers the back cabin is going to be a bit more shorter of headroom than most.

what is stopping you?

 

 

once you have done that the installation is straightforward and there have been many books and magazine articles written on the subject. I will not do the search for you.

Edited by Murflynn
Link to comment
Share on other sites

Sorry guys, should of realised that the question kind of "came out of nowhere".

The nb has NEVER been fitted for propulsion before but HAS been afloat. It was an abandoned project of someone else's, and the plan is to complete the works with a trad stern with a functioning back cabin. Another problem i have to overcome is that the baseplate has a center-beam running fore-aft so unless i can remove the relevant area and replace with the standard parallel engine bearers the back cabin is going to be a bit more shorter of headroom than most.

 

 

The engine goes in the engine room, not in the back cabin.

 

ninja.gif

 

MtB

Link to comment
Share on other sites

Sorry guys, should of realised that the question kind of "came out of nowhere".

The nb has NEVER been fitted for propulsion before but HAS been afloat. It was an abandoned project of someone else's, and the plan is to complete the works with a trad stern with a functioning back cabin. Another problem i have to overcome is that the baseplate has a center-beam running fore-aft so unless i can remove the relevant area and replace with the standard parallel engine bearers the back cabin is going to be a bit more shorter of headroom than most.

Your boat has a keelson, and you want to cut it out!

 

Don't do it!

 

Richard

Link to comment
Share on other sites

Sorry guys, should of realised that the question kind of "came out of nowhere".

The nb has NEVER been fitted for propulsion before but HAS been afloat. It was an abandoned project of someone else's, and the plan is to complete the works with a trad stern with a functioning back cabin. Another problem i have to overcome is that the baseplate has a center-beam running fore-aft so unless i can remove the relevant area and replace with the standard parallel engine bearers the back cabin is going to be a bit more shorter of headroom than most.

 

How old is the boat?

 

What kind of boat is it?

 

Any pics?

Link to comment
Share on other sites

I SHOULD have some pics somewhere, I'll try to find them then work out how to show them. I DO realise the engine will be ahead of the back cabin, but the keelson will mean that the lump (being so much higher) will mean that the prop shaft will also pass through the back cabin at a corresponding height too. It would solve the problem if I could install a hydraulic output to the prop then the height of the engine wouldn't be a problem, but the specifics of a hydro system are beyond me to put it in plain English. If the floor plates were originally fitted width ways then I was thinking of cutting out the keelson (WHERE the engine will be located) and replacing with parallel beams (FOR the engine to be located), would this be feasible ? The nb is situated 100miles away so I only get up there every couple of months or so to get anything brought forward (by a local welder when he has nothing else on). And the stern gear?, never been fitted before. Not even a hole.

Link to comment
Share on other sites

suggest you cut the keelson down enough to fit the engine (and stern gear if necessary) in the normal position and then fit parallel engine bearers the full length of where you have cut down the keelson, and fit cross frames fore and aft of the engine to brace it all up and form the oil tray below the engine.

 

fitting the stern tube through the point of the stern swim is straightforward.

 

have you planned the diesel tank, exhaust, skin tank, etc.?

Link to comment
Share on other sites

That's exactly why I've considered hydro, but unless I can come up with a hydro solution that would be "fit for purpose" I'm trying to keep "standard" ie basic for the purpose of prop shaft alignment. This is my first-build with a very steep learning curve, and the distance doesn't help either. The budget is low hence the timescale so I'm trying to maintain the ethos of getting things right from the outset so no cost is wasted, and research suggests that the alignment is crucial for long-term maintainance. As it stands (at the moment) a "high fitting" engine install will need the prop shaft to pass through the cabin corespondingly higher to maintain alignment.

The "project plan" is to complete to "sailaway" standard then the craft can be inhabited and brought back to local waters for lining and finishing, with further cost savings made regarding licencing/insurance etc verses "ground" rent/storage of where it is now. The current location is a two hour drive with limitations on what can be done with progress being slow, the yard is insecure with frequent trespass and theft occurrance of anything left laying around.

Link to comment
Share on other sites

Surely "high fitting" prop --> prop in wrong place at the end of the swim, meaning you can't swing such a big prop and/or it will be adversely affected by the weedhatch baffle/uxter plate. If I were building a shell, I'd put the prop in the middle, for obvious reasons.....

 

But without seeing pics or even a vague description of the kind of boat, I'd not know for sure.

Edited by Paul C
Link to comment
Share on other sites

Murflynn, that's what I was expecting to do regarding the keelson. There IS a fuel tank fitted (integral) across the stern but not sure of its integrity as yet and I'm considering its removal due to not knowing what's inside, rudder stock not yet fitted and although the tank has flow/return fitted I would prefer a small "sump" with a draincock to be present too (perhaps I'm being over cautious there).

Skin tanks yet to be decided and fabricated, I'll try to "knock up" a cardboard equivalent of the BMC 2.2 to see where the wet bits will present themselves, as a "model" lump will be easier to manipate around. When ready the intention will be to remove the proposed roof panel for engine installation, but not until the cabin sides and roof is complete (security).

18" prop in the middle of a 20" area, I've posted pics previously (and got ripped apart) but I'm using a mobile at present which has limitations.

Link to comment
Share on other sites

I don't know if this will work, here are some of the pics when first purchased. Since then the complete cabin has been removed from the gunnels up and currently has new framework ready for fitting new sheets upon them.

https://www.dropbox.com/sh/q23zyvgtgg4q2lk/AABeStOry0NqfxPZmGNxzzFea


Not much to show sternwise I'm afraid, 58" with basic swims but should suffice for canal work.

Edited by Roustabout
Link to comment
Share on other sites

Thanks for posting the pics. The boat is NOT a trad stern boat. It is an incomplete cruiser stern boat. It would be bonkers to put the engine within the cabin, forwards of a back cabin. There is a space for it already, underneath the stern deck - there's engine hole hatches etc there already. That's probably why it has a keelson forwards of this - because there's no reason not to have one here, because there will be no prop shaft here and no engine forwards of it.

 

That said, and I'm afraid its not 100% possible to say due to the angle the pics are taken at, it looks like quite a "stumpy" stern so it might restrict the engine which could comfortably fit, to the smaller side of the range of engines available out there.

Link to comment
Share on other sites

My Les Allen hull has a substantial, rectangular keelson but it ends at the engine room bulkhead. Two massive angle irons support the engine. Then again, a BMC 1.5/1.8 (~1.5cwt?) mounted a few (<three?) inches higher than ideal will have much less effect on stability than my Gardner 3LW at over a ton with the 2UC gearbox.

 

The reduction gearbox provides an offset to the drive shaft that runs under the back cabin. Headroom in the back cabin is ~5' 4" and I often hit my (5' 8") head on the decorative quadrants that would have supported the wooden roof of an old, trad' working boat!

 

You could consider offsetting the drive shaft further with 'universal joints'. My boat has, I believe, a 'Cardan Shaft' - Google Cardan Shaft.

 

Damn, I have wasted my time; as Paul C says it is a cruiser stern boat with a space udner the rear deck fro the engine.

 

Alan

Link to comment
Share on other sites

My Les Allen hull has a substantial, rectangular keelson but it ends at the engine room bulkhead. Two massive angle irons support the engine. Then again, a BMC 1.5/1.8 (~1.5cwt?) mounted a few (<three?) inches higher than ideal will have much less effect on stability than my Gardner 3LW at over a ton with the 2UC gearbox.

 

The reduction gearbox provides an offset to the drive shaft that runs under the back cabin. Headroom in the back cabin is ~5' 4" and I often hit my (5' 8") head on the decorative quadrants that would have supported the wooden roof of an old, trad' working boat!

 

You could consider offsetting the drive shaft further with 'universal joints'. My boat has, I believe, a 'Cardan Shaft' - Google Cardan Shaft.

 

Damn, I have wasted my time; as Paul C says it is a cruiser stern boat with a space udner the rear deck fro the engine.

 

Alan

But is it STILL a cruiser stern or has that bit been changed.

Link to comment
Share on other sites

The rear deck (at this stage) is still up for "adjustment" and the hatch thats visible in some pics is a weed hatch so unless I'm mistaken then a trad stern is preferred. Sorry for not keeping up with replies but hadn't realised there were updates. I'm also planning to "angle" the forward face of the weedhatch to make it easier to get my whole arm in from the front side, if I go ahead with that I'll show the results.

Link to comment
Share on other sites

Murflynn, that's what I was expecting to do regarding the keelson. There IS a fuel tank fitted (integral) across the stern but not sure of its integrity as yet and I'm considering its removal due to not knowing what's inside, rudder stock not yet fitted and although the tank has flow/return fitted I would prefer a small "sump" with a draincock to be present too (perhaps I'm being over cautious there).

Skin tanks yet to be decided and fabricated, I'll try to "knock up" a cardboard equivalent of the BMC 2.2 to see where the wet bits will present themselves, as a "model" lump will be easier to manipate around. When ready the intention will be to remove the proposed roof panel for engine installation, but not until the cabin sides and roof is complete (security).

18" prop in the middle of a 20" area, I've posted pics previously (and got ripped apart) but I'm using a mobile at present which has limitations.

In which case the prop shaft will be 10" from the floor anyway, so its a matter of getting the drive down to that level from the gearbox. I have a hydraulic drive as I wanted full headroom in the cabin.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.