Making a wooden 'cradle'

[pcatterall]

Making a wooden \'cradle\'

First time ashore without a marina, cradle, power wash and all those mod cons.
My Colvic Atlanta is being lifted out on Saturday so I need to prepare some sort of supports.
The Atlanta has a long shallow keel so she does not stand too high.
I propose to drop sit her (gently Mr crane man please!!) on to some sawn up railway sleepers and temporally support her on my beaching legs while I construct some wooden supports.

I aim to use four 4x2 supports with plywood pads, to join the base of these supports with 3x1 under the keel with diagonals from these 3x1s up to the 4x2s. I would then use some crossed braces onto the 4x2s to prevent fore and aft movement.
Does this seem a reasonable compromise between a proper cradle and the use off a few stakes and wedges?
I wish I could draw a picture!!
Any other lift out tips most welcome!!

 

[Guest]

Re: Making a wooden \'cradle\'

Masts down I hope?

I built a mast rack from 4x2 for the canals the longest piece was 5'. The wood slowly warped into a dog leg during the month of use.

The old methods of tree trunks and wedges has a lot going for it. Depends on the ground though. A Mexican yard lost most of its boats when the ground turned to liquid during a storm.

Take care. Insurance restrictions?

 

[MrCramp]

Re: Making a wooden \'cradle\'

Support method sounds OK. I would aim to clean the hull immediately, otherwise the weed/slime etc. dry on hard. Could you not use a power washer with a generator, seen it done with good results. Would not even think about leaving a mast up. I would also use cheap tarpaulins to cover the boat and help keep it warm and dry over winter. I used two 24ft by 12ft, costing about £8 each from the local market. They normally last 2 years but it dosn't matter if they get paint on and rip at that price. I would store mast next to the boat, not on it where it is likely to get in your way.

 

[VicS]

Re: Making a wooden \'cradle\'

I would use 4 x 4 as the supports (Fence posts ) 2" in one direction is too small IMHO

Not too happy about the 3 X 1 bits either, maybe OK but increase the size of the bits under the keel perhaps. It would also be a good idea if some of the weight was put on these to anchor them firmly in place, Perhaps some packing and wedges would do the trick. Generally bits of wood that look pretty big suddenly seem pretty puny when you get them under a boat.
[ QUOTE ]
(gently Mr crane man please!!)

[/ QUOTE ] A good crane operator should be able to lower your boat as gently as anyone could wish for.

Unless the lifting is done with spreader beams, which may cost you extra, make sure the crane is equipped with long slings and chains to minimise the crushing forces.

 

[cliffordpope]

Re: Making a wooden \'cradle\'

I'll shortly be in this position myself. Thanks for the tip. For some reason I'd never thought about constructing a wooden cradle, but now you suggest it, it obviously makes more sense than buying a metal one for £500.
I think though the trigonometry of the bracing needs very careful thought. A steel cradle can rely on the tensional strength to hold the uprights in position. Wood, presumably bolted together, would be less secure, so presumably the "uprights" would actually be angled inwards so that they were largely in compression? That might make the structure either very wide, or rather precariously supporting only the lower part of the hull.
Well worth pursuing though. Thanks.

 

[Gin]

Re: Making a wooden \'cradle\'

In the yard where I overwinter, all boats sit their keels on sections of railway sleepers which keeps the keels clear of the earth and three or four posts(sawn to length sections of telegraph poles), each side of the hull, each with a 'hat' of 3/8" ply topped with carpet as pads; then small soft wood wedges driven lightly between upper edge of pad and hull.

All boats stored safely that way and 99% with masts up!

 

[graham]

Re: Making a wooden \'cradle\'

4X2 Sounds light to me .Try to imagine your pride and joy in hurricane strength winds.

Either side of the keel spike down some wooden blocks to stop any sideways movement of the boat on the sleepers.

 

[sarabande]

Re: Making a wooden \'cradle\'

Having seen / read what can happen when wooden supports get knocked out or loosened by wind or by lowlife, I'd be tempted to use at least one (padded) steel RSJ across the widest beam, chained down to another RSJ under the keel. (Not lorry ratchet straps - they are too easily undone) Lock off the chains or use a big bottle screw, and then use shores and chocks all round the boat wherever they're needed.

Scrap yards are still the best source of old RSJs; expect to pay about £2 a foot .

 

[pcatterall]

Re: Making a wooden \'cradle\'

Thanks for all the usefull advice. Only the 4x2 would be under compression , the other bits really are just to stop the props from slipping or being easilly kicked out. but perhaps 4x4 would be better.
Yes, I will take pressure washer and an army of scrubbers.
Thanks again.

 

[Miker]

Re: Making a wooden \'cradle\'

My boat has a lifting keel with 09.m depth when raised. Six or more years ago my son made me six wooden supports, two either end and two in the middle. Top and sides are of 6 by 2 with an 8 by 2 foot. On top of the rectangular base is an askew triangular piece tailored to fit under the hull. The sides of the supports are strengthened by plywood to prevent any buckling/twisting. I wedge the supports in place when the boat is just settling onto the wooden beam under the keel and fasten some metal ties under the hull to the supports to prevent them springing out with any rocking movement of the boat. I find that I can adjust the supports individually once the boat has finally settled down, or can add a wooden wedge or more carpet. The supports have always been rock solid over the winter and can be moved two at a time to allow antifouling under the pads. I leave the mast up.

 

[Col]

Re: Making a wooden \'cradle\'

Check it's OK with your boatyard / marina first. They may not let you DIY due to possible damage to other boats should it fall, and the insurance liability if it does fall.

I certainly wouldn't want anyone who *doesn't know what they are doing* chocking a boat off next to mine. Would you?

 

[pcatterall]

Re: Making a wooden \'cradle\'

Yes, it is ok with the yard. And I do have a fair idea about construction in timber!