DIY use of mast derrick - manageable or not?

[PaulR]

Got to take down our mast to replace the heel fitting and tempted to use mast crane at local club-manual arrangement.

anyone done this themselves (our mast is i guess 40 feet long - aluminium) any tips /advice gratefully receieved .

have assisted when crane done it before but crane not currently available and keen to get back sailing asap,

 

[tillergirl]

I have my mast dropped by the yard every winter and they use a simple derrick and I help. They use a strop looped about the mast which is hauled up to the spreaders by the derrick to lift the mast. Don't forget a downhaul line - it can jam. Next they take care to get the lift as central as possible (between port and starboard) and immediately behind the mast. They take up the tension and I release all the standing rigging and mast bolt. A very slight lift raises the heel which is pivoted forward as the mast is lowered. Normally the most difficult part is the roller reefing; getting it outside the pulpit not that its that difficult.

Putting up is slightly different; we put in the mast bolt and loosely attach the main shrouds (to keep the mast central). Mast hangs over back of boat which needs support. Back stays are also attached. The lifting point of the derrick is centred between port and starboard and then used to lift the mast upright (strop in same position as lowering) with one person at the back of the boat lifting to get it started and then walking forward to keep the mast rising centrally (to avoid any strain on the mast bolt and deck fitting). Once upright attach forestay and remaining shrouds. If you forgot a downhaul, now climb mast to retrieve strop which will be caught under spreaders!

Suggest minimum of three people - two on boat and one on derrick. Note when derrick is centrally positioned, they have ropes to hold the derrick stationary. They have a block and tackle hanging from the derrick, so the derrick is positioned and tied off and the lifting and dropping is done by the block and tackle. 40 foot is slightly longer than mine so two on the block and tackle might help.

Hope this helps

 

[GrahamC]

Our Club has a derrick and the use of this is that it is your own responisibility to ensure that the derrick is man enough for the job, that you have at least 4 people who are fit and have a good working knowledge of managing swinging loads .This not a job for Ma ,Pa and the two eldest.
Tide has to be taken into consideration and slack taken up as tide rises and tension eased as it falls depending if the spar is coming off or on. Sling the mast under the cross trees remembering to pass it outside the lowers. a big bowline with a length of fall will let you get it back if it jambs. Control of the heel is vital and as said elswhere you need to provide support ashore for the spar.
Take it easy and watch the angle between the derrick head purchase and your valuable mast head fittings.
Regards
GrahamC

 

[boatbuilder]

Take it slowly and you will be ok. Just make sure that you have good control of the foot of the mast, as the balance could be a bit iffy.

 

[William_H]

Firstly it is highly unlikely any heel fitting failure would stop you sailing. The pressure is virtually all down ward. I don't know what your problem is but I will bet it would be OK till next winter.
If you are going to replace heel fitting then consider fitting one that can hinge the mast backwards while still attached to the cabin top. (unless of course it is a keel stepped mast). Mast can then be lowered for bridges or mast top maintenance using a gin pole or pair of spin poles with great precision and safety. (It is much more difficult to remove the mast to shore but it can easily be loiwered to a support at the transom.) Search mast lowering Lake sailor and my name. I posted photos but that was a few years back.

Now your question of using mast crane at your club. Yes it should be OK others have given good advice but the attachment point for the crane sling must be well above the centre of gravity other wise the mast will fall top downward wheras you want ti to remain bottom down. Slinging under the spreaders would be good for a mast head rig keel stepped where the spreaders are above half mast height but for a deck stepped fractional rig where spreaders are well below half height you could be in real trouble.
If that is the case then use a sling around the mast above the spreaders with a down haul to the base to stop it sliding upward. Obviously the derrick must be high enough to allow for sling length and the height you must lift the mast to clear the cabin (especiallly keel stepped mast).
So the easiest is to tie up next to a high jetty on low tide with derrick on the jetty. good luck and be carefull. olewill

 

[VicS]

This is not a job to be undertaken lightly with little experience. I helped with masts many times at the yard but when the yard owner was taken ill and every thing reverted to diy for a while I found it a different kettle of fish. Although I can do it happily now with a disciplined gang of helpers. I would strongly advise that you should have someone in charge who really knows what they are doing. If you must do it youself, and you must feel confident about this, you operate the mast crane yourself and make sure each of the helpers knows exactly what they are to do before hand.
Getting it back up again is slightly more difficult than getting it down as you have to make sure that all the rigging falls into place and none is trapped or the wrong side of the spreaders etc

You really need three helpers. One to look after the foot, one to look after the luff spar if you have one, and one to disconnect the rigging. An extra one or even two are useful for re-stepping it. Make sure you have what ever tools are necessary before you start.

Take care not to damage rigging screws when re-stepping. It is easy to get them "capsized" on the attatchments, especially if you have "U" bolts, and then a bit too much muscle applied on the opposite side bends them!

Make sure you can see what is going on all the time so that you can direct operations.

Take care. If someone gets injured the lawyers will a have a field day. Maybe the Health and Safetey people too.

 

[PaulR]

thanks to all for your guidance- have decided that this time better cautious than not so have now booked mast crane at yard - all being well this time next weekend we shall be all done and sailing again,