Using mast as crane

[davidpbo]

Would you use your mast and boom to with an extension lashed to it to lift an outboard (44kgs.) I would use main halyard to lift point, topping lift would be attached and maybe another halyard as well. Probably use a pulley block underneath to raise and lower outboard.

The boat is a Jeanneau Tonic with a heavy cast iron keel, on its trailer which is shaped to cradle the boat, stub keel 450kgs (cc 450mm) is between two substantial metal box sections and I would pack with wood to ensure no lateral movement. Trailer is on blocks with wheels just floating. I would chock back of trailer although it shows no sign of being unstable and already has the weight of the existing outboard which would be removed first in the well.

Plan is to lift existing outboard out of well and swing it over side and lower it. Taking the weight as it is lifted off the bracket should give an indication of any problem with the arrangement I would have thought. Bottom of leg needs to clear about 8ft so lift point needs to be quite high say 14ft. Mast and boom are large section for size of boat (23.5ft) and deck stepped with a pillar underneath, fractional rig. I would take the gib halyard to the samson post as an addition the forestay.

I would probably need to leave the backstay off to give me enough room to swing the boom. I would imagine my back stay tensioner (Which is 2 double block pulleys tenioned would put a downforce on the mast equivalent to 40 +kgs.

The mast is 10m so the main halyard is probably about 30 degrees to the mast . Is the front of the boom which would probably angled up wards 30 degrees put an excessive load on the back of the mast?

My alternative would be to rig a gantry out of ladders ratchet strapped/lashed together. That leaves me with the problem of swinging the outbpoards on and off the boat.

Several blokes lifting is not an option.

 

[maby]

I think the mast plus boom should be easily strong enough to take the load - far heavier men regularly go up the mast in a bosun's chair! We use a similar arrangement to lift a heavy dinghy out of the cockpit locker - though the boat is a bit bigger than you describe. Be careful about the stability of the boat on the trailer as you off-load the outboard - if you swing it too far out from the hull, I guess you could make it unstable.

 

[NormanS]

It depends how long an "extension" you propose lashing to the boom. The mast, boom, and rigging regularly carry more load than that of your outboard.

 

[dom]

It's not really possible to give hard advice here without knowledge of the section strengths, trailer dimensions, etc.

But if you do decide to go ahead -- and my instinct (that's all it is) is that you should be fine -- do have a good read through your insurance policy first to be sure that such activities are not excluded.

 

[KellysEye]

We used our mizzzen boom to lift our outboard and when our engine was taken out it was lifted out by the main boom and swung over the pontoon also we lifted an aluminium bottomed dinghy to the foredeck wth the mainsail halyard. Basically you can lift anything with a boom or mast but I wouldn't try a car. Removing a backstaty is not a good idea.

 

[Ceirwan]

Yes.

I've used the boom to lift out the engine on many a boat. (Well 2 actually!)
Just make sure the halyard is over the load so there are no unsupported sections of boom and you'll be fine.
The boom will take a compressive load (which is what it's designed for) and 44kg is nothing for the mast, its a lot more when someone gets hoisted up.

 

[Daydream believer]

When someone gets hoisted up a mast it is in straight compression. When the halyard goes to the boom it is pulling sideways at 30 degrees ( or whatever) & induces a side force. If the mast is a fractional rig this could be dodgy
If you are really worried go & hire a builders tower. Put 2 halves each side with some timber across. lift the engine then pull the trailer out & lower the engine. No strain on the boat whatsoever
Another way- get 3 scaffold poles & a couple of swivel clips & build a tripod over the boat. Tie the feet with rope to stop the feet spreading. Hoist the engine. Pull the trailer out.
I had a set of poles with a bolt through the top for years which I used for lifting RSJ's & lintels using a tirfor hung from the centre

 

[rogerthebodger]

I regularly lift my 3 meter GRP dingy on to my foredeck with my spinnaker pole and halyard.

I lift my 2.3 KVA petrol generator with my boom and 4 part block and tackle.

I have lifted my 70+ kg PRM gearbox from my engine room on to then dock with the boom and block and tackle.

Also lifted my 15hp mariner outboard with a 2 meter extension on my boom as a cantilever past the topping lift attachment.

 

[guernseyman]

A couple of years ago, while dealing with a split mainsail in a heavy sea, I realised I was relying on the aged and thin topping lift to support a least some of my weight.
Consequently I replaced the topping lift with a modern, equally thin, cord with a 5 ton breaking strength. Now I can contemplate using the main boom as a crane e.g. for use with MOB.

 

[prv]

Worked ok with a heavy load of beer, soft drinks, and books

Pete

 

[xeitosaphil]

When I had my Hurley 22 it had a 8hp Mercury outboard fitted in the stern engine well which weighed about 35kgs. I regularly used to lift it in and out with my boom which was 3mtrs long with no problem at all.

I might be wrong but I would have thought with your size boat there would be no problem.

 

[fergie_mac66]

Our cat 8 meters heavier mast but lifted 96 kg engine several times wouldn't think 2ce for 44 kg on your mast. Jus make sure ropes are ok.. AND check cleats etc for other end of halyards. It wouldn't be the first time that a cleat and or a halyard winch has flown up the mast after rivet pulling out

 

[NormanS]

When someone gets hoisted up a mast it is in straight compression. When the halyard goes to the boom it is pulling sideways at 30 degrees ( or whatever) & induces a side force. If the mast is a fractional rig this could be dodgy
If you are really worried go & hire a builders tower. Put 2 halves each side with some timber across. lift the engine then pull the trailer out & lower the engine. No strain on the boat whatsoever
Another way- get 3 scaffold poles & a couple of swivel clips & build a tripod over the boat. Tie the feet with rope to stop the feet spreading. Hoist the engine. Pull the trailer out.
I had a set of poles with a bolt through the top for years which I used for lifting RSJ's & lintels using a tirfor hung from the centre

It's only an outboard weighing 44kg, for goodness' sake.

 

[davidpbo]

It depends how long an "extension" you propose lashing to the boom. The mast, boom, and rigging regularly carry more load than that of your outboard.

Extension would probably be <1M and is to get height rather than swing so would increase the load pushing into the mast at a point about 700mm from its base. I would be swinging the outboard no more than necessary to clear the side of the boat an lower it. Trailer is wide and fairly level across it, there is a very slight angle forwards, just enough to stop the cockpit draining completely.

I am wondering whether to drop it on to its wheels which would probably lower the whole lot about 150mm and widen the base, the blocks it is on are inboard of the wheels a bit. It would mean that it was on the fairly hard trailer suspension. A combination of jockey wheel at front and packing at rear would stabilise that.

 

[xeitosaphil]

Our cat 8 meters heavier mast but lifted 96 kg engine several times wouldn't think 2ce for 44 kg on your mast. Jus make sure ropes are ok.. AND check cleats etc for other end of halyards. It wouldn't be the first time that a cleat and or a halyard winch has flown up the mast after rivet pulling out

When I used to do mine I used to use the Main Halyard fixed to the boom end and hoisted up at a fixed length and made off fast, which then made the boom into a derrick. Then I used the 4:1 Main sheet tackle for the hoist, fitted to one of those Davies Lifting slings fitted to the engine.

Worked a treat - good point about checking the ropes and cleats though.

 

[fergie_mac66]

Seem to recollect that a. Female writer can not think of her name was up a mast when the rivets holding the halyard winch on to the mast gave way and it went up the mast!

 

[Tranona]

Plenty of people have lifted inboard engines 3 or 4 times that weight using the boom. Just make sure you have lines from the end to control it. Use the main sheet to lift it and then you can lower it down tot he ground. Can't see why you would need to let of the backstay as surely the boom will not hit that - after all it goes out at near 90 degrees to the boat when sailing downwind.

 

[Ceirwan]

When someone gets hoisted up a mast it is in straight compression. When the halyard goes to the boom it is pulling sideways at 30 degrees ( or whatever) & induces a side force. If the mast is a fractional rig this could be dodgy
If you are really worried go & hire a builders tower. Put 2 halves each side with some timber across. lift the engine then pull the trailer out & lower the engine. No strain on the boat whatsoever
Another way- get 3 scaffold poles & a couple of swivel clips & build a tripod over the boat. Tie the feet with rope to stop the feet spreading. Hoist the engine. Pull the trailer out.
I had a set of poles with a bolt through the top for years which I used for lifting RSJ's & lintels using a tirfor hung from the centre

It weighs 40kg.
The mast is more than capable of supporting it.

How much load do you think the top of a fractional rig takes when the backstay is wound on hard? Its a lot more than 40kg.

And yes it can withstand that load from the side.

Your method is needlessly complicated and overkill.

 

[Daydream believer]

The Tonic has a fractional rig &I seem to recall that it is 3 /4 rather than 7/8 so a lot of the upper mast is unstayed
As an example of what can go wrong a friend of mine took a squib ( 20 ft & a tonic is, i think,23 ft) to lowestoft for an open meeting. At the start the spinnaker halyard went up the mast so he put the boat against the pontoon & went up on the quay side. He pulled on the main halyard to pull the mast tip in to get hold of the spinnaker halyard. Now bear in mind he did not put any great force on it & he only wanted to tip the boat a few degrees in the water ( far less heal than when sailing) to reach the mast. the mast promptly broke & he had the pleasure of wearing the "Dick of the week" jacket.
If the mast is not pulled in the direction & in the way it is designed it will break if the safe load is exceeded

The OP is clearly concerned because he asked the question in the first place

 

[Ceirwan]

The Tonic has a fractional rig &I seem to recall that it is 3 /4 rather than 7/8 so a lot of the upper mast is unstayed
As an example of what can go wrong a friend of mine took a squib ( 20 ft & a tonic is, i think,23 ft) to lowestoft for an open meeting. At the start the spinnaker halyard went up the mast so he put the boat against the pontoon & went up on the quay side. He pulled on the main halyard to pull the mast tip in to get hold of the spinnaker halyard. Now bear in mind he did not put any great force on it & he only wanted to tip the boat a few degrees in the water ( far less heal than when sailing) to reach the mast. the mast promptly broke & he had the pleasure of wearing the "Dick of the week" jacket.
If the mast is not pulled in the direction & in the way it is designed it will break if the safe load is exceeded

The OP is clearly concerned because he asked the question in the first place

Having sailed on a squib before and owned an even less substantially rigged Flying Fifteen I can say there was clearly something very wrong with his mast if it broke by him pulling it over by a few degrees. Even on a 3/4 rig.

Obviously the Op is welcome to do what he wants, but it will handle 40kg without any problem.
Even the masthead probably gets subjected to that kind of load when sailing.