Echoing completely what Ritchie has posted, one has to take the hoist seriously. Its not just the hoist but its attachment to wherever you hang it from and the strops you use.
I used a 1 Tonne Chain Hoist (Screwfix part number 46883). Electric hoists have a reputation for all happening too quickly – more like dropping the boat than lowering it. For strops and certified shackles, I got these from Load Straps and Slings http://www.lss1.co.uk/. The hoist is hung within the loft space above the garage on a specially constructed frame to spread the load over two rafters – I needed the extra height so that when lifting, the hoist hook doesn’t crunch up against the bottom of the chain hoist – also, so that the bit of chain you pull on leads outside the boat at a reasonable angle. Width of the strops is a compromise; obviously needs to be strong enough; narrow enough to get into the hooks and shackles; wide enough not to chafe on the boat
Its all worked well, nothing has collapsed. Keel has been taken off and returned; I’m not going to claim that job is easy but its all controlled with a decent hoist. Also, the hoist got used for turning the keel over onto its painting frame – there was a ‘moment’ doing this turn, but everything held together and no bones where broken – the shock-load of the ‘moment’ would surely have demolished an improvised arrangement.
Tips: you’d be surprised how much the boat blows around, even in the wind with the garage door open – needs stabiliser ropes. Get the strops the right length and when you’ve found the balance points, mark the hull so you can tie the strops back in position repeatably – strops need to be tied for and aft
Last point: for sorting dings in the keel, I prefer to jack the boat clear of the trailer and put blocks under the tail of the keel; that way is all stable to leave while fillers and paint dry
Martin Stainsby (3912)
The Flying Fifteen Blog 