Using the boom as a derrick for hoisting an engine.

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BurnitBlue

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I wonder what is a sensible limit to the weight of an item (like a small engine) to be hoisted aboard. In my case the boat is ashore. The engine is on the ground beside the boat. The engine is a brand new Yanmar 3YM20 which weighs 130 kilo with the gearbox. The boat is a Moody 346 and has Kemp spars. It is centre cockpit so the engine must be suspended somewhere near the middle of the boom to get it over the cockpit floor and the engine bay.

Any tips would be gratefully received.

Thanks. BTW the boatyard crane has difficulty getting near the boat.
 
I've done it several times. Either support the boom where the load occurs with a spare halyard or topping lift, or alternatively use the boom only in compression mode by supporting the whole weight of the engine on the halyard, but use an outhaul on the end of the boom to pull the halyard 'out as far as you need to go. I use a small (1 tonne) chain hoist which I have lent to someone and they have forgotten to give it back to me!!!)

It would be a wise precaution to put a loose-ish lashing round the boom at the point where the halyard is meant to be to prevent any untoward movement away from the boom as you swing the boom sideways.

When I lifted a Volvo 2040 engine out and back in on our Westerly Sealord I had to swing the engine along the boom using the chain hoist and another lashing, and then moving the supporting halyard as appropriate. I used webbing straps round the boom to avoid crushing the cross section.

There are some on here who might say, "Don't do it". But I and lots of others have done it successfully on several boats. (I changed the engine on our Sigma 33 in exactly the same way.)
 
Well you will need a good topping lift and be sure that you have a reasonable forestay on the mast. Wouldn't have thought is would be a big problem as booms are quite strong although you may need a good wide strop to prevent point loads. I hang off my boom when aground and swing out over the edge and that is from the furthest tip so greater leverage. I don't weigh 130 kilos but I guess the moment makes up for that. Check that you can't make the engine lighter by removing the odd bit. It is amazing what adds up.
 
Plenty of fairly portly people are hoisted up masts every year - a "well built" adult man can weigh 100kg easily, so your engine is not orders of magnitude heavier.

If the boat is ashore, I would be more concerned at avoiding making it topple over in its cradle - if the engine is next to the boat, that is quite a large force to apply tending to rotate the hull within the cradle - do take care to inspect the supports and insert extra props if necessary.
 
pmagowan said:
Well you will need a good topping lift and be sure that you have a reasonable forestay on the mast. Wouldn't have thought is would be a big problem as booms are quite strong although you may need a good wide strop to prevent point loads. I hang off my boom when aground and swing out over the edge and that is from the furthest tip so greater leverage. I don't weigh 130 kilos but I guess the moment makes up for that. Check that you can't make the engine lighter by removing the odd bit. It is amazing what adds up.
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Never mind (or in addition to your) hanging off it, I bet there's more than 130 kg load on the boom when a Moody 346 is sailing hard on the wind. Have you ever tried to pull the main in by hand without any purchase? There's a LOT more than your body weight on the end... Just support the middle as I suggested to avoid any too much bending moment.
 
If you look at the home page of my website you will see a pic of Owen and myself lifting a big old Volvo into a boat using the boom. That engine probably weighs twice as much as a Yanmar 3YM. As you see from the photos we hung it half way along the boom to position it correctly and tied the topping lift and main halyard off at the same point. The boat was only 30 ft, with a relatively slender mast and boom. No problems at all.
 
Thank you for the excellent advice. I really like the tip about using the boom in compression by using the halyard with an outhaul to position the lift point. I guess I could use a well padded block lashed to the boom to stop the halyard from swinging out but still free run from mast head, through the block then down to the engine.

The boat is in an earthquake proof cradle (I am told) so she is very secure.

Thanks again.
 
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I agree with all the precautions mentioned above.

Do check your pulley set up that it has sufficient lift, so it won't go ' chock a block ' with the wheels meeting before you can get the engine over the guardrails and coamings.

Also be very wary of having actually useable insurance for helpers just in case something goes wrong !

It sounds like you should be fine.
 
vyv_cox said:
If you look at the home page of my website you will see a pic of Owen and myself lifting a big old Volvo into a boat using the boom. That engine probably weighs twice as much as a Yanmar 3YM. As you see from the photos we hung it half way along the boom to position it correctly and tied the topping lift and main halyard off at the same point. The boat was only 30 ft, with a relatively slender mast and boom. No problems at all.
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Wow. That is a very heavy engine to suspend from the centre of the boom. Thanks for that because it gives me the confidance to get my engine aboard myself without using the boat yard crane ... again. I had to use them to remove the heavy Thornycroft but the crane fouled the rigging because of poor access which nearly brought the mast down. The boatyard staff are really very busy at this time of the year so cannot take the time to do a carefull job.

BTW. Got a very good price on the Yanmar 3YM20 at 4800 pounds from Athens distributor via Ionion Marine dealership which included the VAT. They also accept cheques on a British bank in sterling so the whole thing was no hassle. Beta Marine quoted me 5,500 Euros through their Greek Distributor for the 2 cylinder 14HP engine. So I am very pleased.
 
You might find it easier to lift it in stages - on to something like an oil drum first, then to a couple of joists across the cockpit so that you can get it position exactly where you want it to drop into the engine space or companionway hatch if it is going in that way. Again some blocks directly below the hatch to rest it on before sliding back onto the bearers.
 
vyv_cox said:
If you look at the home page of my website you will see a pic of Owen and myself lifting a big old Volvo into a boat using the boom. That engine probably weighs twice as much as a Yanmar 3YM. As you see from the photos we hung it half way along the boom to position it correctly and tied the topping lift and main halyard off at the same point. The boat was only 30 ft, with a relatively slender mast and boom. No problems at all.
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+1

This is exactly how we did it with our 376, which is pretty much the same as the OP's 346. EDIT - We were in the water that time, used a forklift last time for new engine when in the yard.
 
GrahamM376 said:
+1

This is exactly how we did it with our 376, which is pretty much the same as the OP's 346. EDIT - We were in the water that time, used a forklift last time for new engine when in the yard.
Click to expand...

Last season we watched the owner of a boat change a four-cylinder Mercedes engine without taking the boat out of the water, alongside the wall at Leros. New engine was delivered on a pallet, he removed the old one, lifted it out on his boom, lifted the new one in, transferred the old one onto the pallet and somebody took it away. I was intending to photograph the operation but it all happened so fast that it was complete before I realised.
 
BurnitBlue said:
I wonder what is a sensible limit to the weight of an item (like a small engine) to be hoisted aboard. In my case the boat is ashore. The engine is on the ground beside the boat. The engine is a brand new Yanmar 3YM20 which weighs 130 kilo with the gearbox. The boat is a Moody 346 and has Kemp spars. It is centre cockpit so the engine must be suspended somewhere near the middle of the boom to get it over the cockpit floor and the engine bay.

Any tips would be gratefully received.

Thanks. BTW the boatyard crane has difficulty getting near the boat.
Click to expand...

I think that the load on the mainsheet is normally way more than 130Kg. A 10mm double braid halyard has a 2.5 tons breaking load average. You should be fine up to 50% of it. For piece of mind distribute the load with webbing as previously suggested.
 
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