Chocking a boat

[Captain Coochie]

Looks like i will finally be getting Flare back to my front drive soon . She needs alot of work and as i live on a main road im starting to worry that the local scroats will find it fun to knock the chocks out from under her .
I also need her off the floor because i need to work on the drop keel and get a trailer in at some point . I was thinking of scaffolding to frame around her . Good idea or not ?

 

[orizaba]

that sounds a good idea,make it tall enough tarp over the top and you can work on her in all weathers,i built a building round orizaba in an old yard makes life alot easier

 

[sandeel]

why not adapt an old polytunnel greenhouse to work under?

 

[misterg]

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as i live on a main road im starting to worry that the local scroats will find it fun to knock the chocks out from under her.

[/ QUOTE ]

Jason,

Firstly, can you nail batttens between the chocks? This might be a problem if you need to work underneath, though.

On a couple of occasions I've needed to support Pippin (22' GRP bilge keel ~1300kg) to take the weight off the keels, and I've made a 'cradle' using ratchet straps and a few lengths of timber - not easy to describe, but easy to make: Lay a length of timber (6" x 2", say), considerably wider than the beam on the ground under the boat. At each end fix another length of timber, slanting inwards from the end of the base, and resting on the gunwale, but extending above it. Thread a long ratchet strap under the base, around the outside of one side piece and over the top of it, back under the boat, over the top of the other side piece, and down its outside, to join the other end of the strap. If you tighten the strap, it holds the 3 pieces of timber together, and can hold the weight of the boat, with minimal obstruction. It's stable side - side because the base is wider than the beam, but not front- back, though I suppose you could use two or more of these and brace the side pieces to each other.

May help:

You can see the base just below the trailer board (it's resting on timber at either end to keep the strap off the ground - ignore the 4x4 lying next to it), with one upright just behind the ladder. I jacked her up on the trailer before tightening the straps (two 2 tonne ones joined together), and letting the jack down. The trolley jack is only there to tip her onto one keel (the bow is supported, too).

Maybe not the whole answer, but perhaps food for thought as a back up.

Andy

 

[William_H]

A friend has a 21ft fin keel and he has made a pair of steel gantries ie 2verticals and a cross member. (2 off braced to one another). The height is sufficient that he can mount it above the boat on trailer lift the hull with 2 chain blocks with webbing straps under the hull.

I have borrowed the structure and hoisted my boat up high enough to get the trailer out and drop the drop keel right down. His gantry would be perfect for you but for the 10000 Nm and the fact that he uses it every winter.

I would suggest to you that you invest in something similar.

For all the work you want to do on the boat it will be far more convenient and safer to have the hull as low as possible. You will be climbing in many times. But with the gantry you will be able to hoist the boat up when you want to work underneath or on the keel.

If you are really interested I might be able to get a picky for you. but the structure has vertical square box steel with a cross member of similar steel and longer than the beam of the boat. The two bolt together. Another lighter piece of steel joins fore and aft the two gantries. The height of the legs must be the distance from the tip of the keel down to the top of the cabin plus enough room for a chain block. The cost was not insignificant but is very usefull to have available.

Incidentally you are probably limited to locations where you can work on the boat but mine on a trailer is parked very close to a 1 metre retaining wall so that from the ground on the high level it is easy to step onto the deck. It just makes it so easy.

good luck with the boat. Don't let the project last too long as boats really need to have water under them and be used. olewill

 

[Guest]

Make 2 supports like they use on racing yachts. 2 pieces of ply wood cut to the hull profile with a thin piece on top approximating the lateral hull shape. Then foam the gap with plastic against the hull.

Place them either side and bolt them to logs/planks/scaffold across and lengthways. Then there is no chance of it falling over. Also there will not be a distortion of the hull by single props.

The keel on that boat was originally held with a galvanised pin. They are considered a replaceable item just like an anode is replaced regularly. The drop keel is quite a weight and is hard to handle L shape.

Since you are rebuilding the cockpit then take a thought about the lack of self draining when redesigning it. Wonderful boat to sail, you can go places no one else can.

 

[andrewbodenham]

For similar reasons I had a couple of steel portal frames made up in 100x50 channel.

These allow me to lift Valkyrie with strops and chain hoists, as well as supporting a tarpaulin-and-batten roof to keep the worst of the weather off. An excellent investment, allowing easy removal of the centreplate amongst other things. You'd need something a bit more meaty for your boat though.

 

[Captain Coochie]

I like that idea once i have finished what needs to be done on the hull . I was thinking about scaffold for the ease of stricking it and moving it around .

 

[damo]

FWIW, I work in a boatyard and have seen lots of different ways of chocking boats. From what I guess of the hull profile of yours I would suggest putting the keel down on blocks to the height you need (not too high though).

Your idea of scaffolding braces is OK, and allows a lot of options. Acrows could also be incorporated (as long as you can secure them from the local scallies). Just remember that high winds can produce a lot of side pressure, so either have the props at a reasonable angle, or strap the sides down as already suggested.

Poles or props could be tack-welded in place, which would stop anyone moving them, and the tacks can easily be ground off when you want to pull it apart.