Engine removal without chopping a hole in the cabin roof?

[MYStargazer]

I’m taking a couple of 6-cylinder Ford Dorset engines out of my aft-cabin Weymouth 32. She’s on the hard. There a travelift onsite with a crane high up on top of it. The boats are tightly packed in, so there’s no room to get a fork lift anywhere near to the sides. There is only one door – on the port side – with a smaller window on the opposite side of the cabin.

I’m planning to remove the engines by:
1. Buying a job lot of scaffolding and making up a frame that reaches through the boat
2. Using a chain hoist, attached to large shackle, to lift the engines before sliding them out, using grease on the pole rather than a wheeled pulley as height is tight.

I will have removed the gearboxes, flywheels, heat exchangers and manifolds first, and expect the remaining engine to weigh about 400 kg.

Is this the best route?

Would a scaffold pole take this kind of weight?

 

[OAF]

It would be far safer to have the boat moved to a position where a fork lift could be used!

I lift lots of engines in and out of boats, in fact I did so today, once it's dangling in the air it is a bloody big thing to man handle, I do not think that a scaffolding bar of that span would take the weight, I wouldn't fancy doing it!

 

[Firefly625]

wow, what a job. TBH if concerned on pole strength you could double up and half the weight on one pole..., best of luck with this job, its a biggy! but you got a great boat so well worth the effort.

 

[MYStargazer]

It would be far safer to have the boat moved to a position where a fork lift could be used!

I lift lots of engines in and out of boats, in fact I did so today, once it's dangling in the air it is a bloody big thing to man handle, I do not think that a scaffolding bar of that span would take the weight, I wouldn't fancy doing it!

I think given the expense of that option, it would be cheaper to make a hole in the roof!

I'm thinking of a solution that I can also use to hold the replacement (different make) engines in place while I make final adjustments.

 

[david_bagshaw]

Just a suggestion,

remove head , then rotate block and remove crank and pistons, and the engine will drop by another 100 +kg ish. then the scaffold becomes a better proposition.

I used this method to remove a three cyl engine by hand, with no block or tackle. Its replacement as a short block, also by hand.

 

[epervier]

Without trying to teach you how to suck eggs, isn't there already a "soft patch" in the roof for this eventuality?

 

[MYStargazer]

wow, what a job. TBH if concerned on pole strength you could double up and half the weight on one pole..., best of luck with this job, its a biggy! but you got a great boat so well worth the effort.

Thanks - I love her and she's well worth it. Just trying to be hands-on to be a more responsible and understanding owner.

Yes, I'd thought of doubling-up (vertically). Haven't found a resource yet to indicate what loading your average scaffold pole with take under these circumstances...

 

[kashurst]

I think I would take the roof off, probably quicker and definitely safer in the long run.

 

[MYStargazer]

Just a suggestion,

remove head , then rotate block and remove crank and pistons, and the engine will drop by another 100 +kg ish. then the scaffold becomes a better proposition.

I used this method to remove a three cyl engine by hand, with no block or tackle. Its replacement as a short block, also by hand.

Yes - this thought had occurred!

 

[MYStargazer]

Without trying to teach you how to suck eggs, isn't there already a "soft patch" in the roof for this eventuality?

Hi David - there's no soft patch as such. It's all hard enough to walk on. What's yours got? My roof is entirely covered in a nasty light blue deck paint that seems impervious to all attempts to remove it other than (seemingly) an angle grinder! But, there is the outline of a panel which suggests the roof has been opened before and glassed over.

 

[vas]

1. Buying a job lot of scaffolding and making up a frame that reaches through the boat
2. Using a chain hoist, attached to large shackle, to lift the engines before sliding them out, using grease on the pole rather than a wheeled pulley as height is tight.
Would a scaffold pole take this kind of weight?

the span will be close to 4metres. so, you want a 3-4inch steel pipe (not of the best quality) to be loaded with 400kg smack in the middle and then these 400kg slide to the side.
Now, from a structural viewpoint, the scaffolding horizontal pipe may just about miss plastic deformation (i.e. collapse) but I guess it will have at least 20cm flex when fully loaded. Problem is unless you find another hoist to pull it to the side, it wont go (centre will be nice and low for it to "climb" anywhere else...)
TBH, I think it's on the dangerous side and if something fails the mess it'll produce is going to be much larger than a hole in the roof

I vote for the hole in the roof and not mashed up bits all over

cheers

V.

 

[OAF]

If you are going to do it then at least use some H section steel girder but scaffolding won't be strong enough, I used to have a Scafolding A frame and it bent like a banana when I tried to lift anything heavier that a car engine, and that was only the width of a car, yours would be nearly twice that width, stripping the engine is a good idea!

 

[Jcorstorphine]

How about a small hole in the roof for a chain block.

One problem you may find is that if you are going to use a chain block to lift the engines prior to sliding them out on greasy planks is that you may not have enough clearance between the top of the wheelhouse and the engine sump by the time you allow for chains or straps round the engine plus a means of securing the block to the scaffolding poles.

My 1 ton chain block from the top hook to the highest point the chain will lift to is approx 16” To this you would need to add another 6” to allow for securing and then you will have the bend in the scaffolding pole. When I lifted out my puny little Ford 1.6D engine which weighs about 220kg, the ropes I used to wrap round the engine stretched up about 6” when I took the load on the chain block.

I know this is not perhaps the best solution but I would look at cutting a small hole in the wheelhouse roof (say 9” square) such that you could get access to put your lifting tackle thorough. This would also let you use some substantial timber beams running between the fwd and stern cabin tops to take the load of the chain block.

I would also look at taking the head off as this would reduce both the weight and engine height.

I do not think that one scafolding pole with take 400 ks when supported at two points with a 120" span. Take a look at this site and work out the deflection for a tube.

http://www.calculatoredge.com/civil engg calculator/beam.htm#tube

Good luck and watch your toes. !!!!!!!

Just ran the calculation and defection will give you a nice "U" shaped piece of scaffolding. Not a safe system of work.

 

[epervier]

Hi David - there's no soft patch as such. It's all hard enough to walk on. What's yours got? My roof is entirely covered in a nasty light blue deck paint that seems impervious to all attempts to remove it other than (seemingly) an angle grinder! But, there is the outline of a panel which suggests the roof has been opened before and glassed over.

Mine has a "soft patch" a lot of Nelsons and Weymouths have, it could be she's been glassed over, mine has a painted bronze/copper bead over the joint, outlining the patch, starts just after the helm and co seat sun hatches ends just after my mast.

 

[MYStargazer]

the span will be close to 4metres. so, you want a 3-4inch steel pipe (not of the best quality) to be loaded with 400kg smack in the middle and then these 400kg slide to the side.
Now, from a structural viewpoint, the scaffolding horizontal pipe may just about miss plastic deformation (i.e. collapse) but I guess it will have at least 20cm flex when fully loaded. Problem is unless you find another hoist to pull it to the side, it wont go (centre will be nice and low for it to "climb" anywhere else...)
TBH, I think it's on the dangerous side and if something fails the mess it'll produce is going to be much larger than a hole in the roof

I vote for the hole in the roof and not mashed up bits all over

cheers

V.

Hadn't thought about the deformation and subsequent uphill journey it'd have to make to the edge.

I do have room to put a vertical support in the middle of the pole, though.

Perhaps an RSJ would solve this...

 

[vas]

Hadn't thought about the deformation and subsequent uphill journey it'd have to make to the edge.

I do have room to put a vertical support in the middle of the pole, though.

ah, that would improve things by halfing the loadbearing span. Where is that vertical support going to be resting? The keel I presume, should be fine. An I-beam or a U section would be much stronger. TBH I wouldn't be happy doing this, if anything wrong happens it can quickly become lethal

good luck

V.

 

[MYStargazer]

Mine has a "soft patch" a lot of Nelsons and Weymouths have, it could be she's been glassed over, mine has a painted bronze/copper bead over the joint, outlining the patch, starts just after the helm and co seat sun hatches ends just after my mast.

My hard patch is in exactly the same place, so, yes, it must have been glassed over. How interesting - I just thought the hole had been cut at some point in lieu of engine removal via the door. I've often had half a mind to replace this hard section with a soft top or polycarbonate clear roof section...

 

[MYStargazer]

ah, that would improve things by halfing the loadbearing span. Where is that vertical support going to be resting? The keel I presume, should be fine. An I-beam or a U section would be much stronger. TBH I wouldn't be happy doing this, if anything wrong happens it can quickly become lethal

good luck

V.

It can rest on a steel section of the engine bed...

 

[jfm]

I was about to type, but see that Vas has already said it, that this is a question not merely of strength (as in yield) but of stiffness. The scaffold pole will sag, meaning you will have (a) even worse clearance issues and (b) an uphill slide on the greasy pole. So in short it seems very unliklely work. But the concept is fine: you just need a steel beam way stronger than 400kg yield strength; you need an I beam with a 4 inch web kinda thing. Good luck

 

[MYStargazer]

If you are going to do it then at least use some H section steel girder but scaffolding won't be strong enough, I used to have a Scafolding A frame and it bent like a banana when I tried to lift anything heavier that a car engine, and that was only the width of a car, yours would be nearly twice that width, stripping the engine is a good idea!

Now I understand exactly how much it's going to bend - thanks!!