Storage Cradle: Supporting the hull correctly

including Amas (Floats), Akas (Beams) , Swing Wing system and all other hull related issues.
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Bo Wetzel
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Storage Cradle: Supporting the hull correctly

Post by Bo Wetzel »

[originally from: Larry Furst, USA, 4 Dec 2002]

Placement of the 920 on the storage cradle is extremely important.
If using a lift or rail-launching system to place the boat in storage, incorrect placement can cause point-stresses that can deform the hull as it settles. The hull is foam core, and the cradle is designed to rest on reinforced structural hull sections that are solid (not cored). The forward support must be directly under the forward beam, and beneath or just ahead of the front waterstay attachment point...almost touching it. The aft end of the centerboard should be just slightly ahead of the cradle's aft support pad, so that the centerboard can be lowered while the boat is on the cradle (I leave it raised). It is also important to make sure all cables are clear before the boat comes to rest on the cradle (a cable caught between the hull and the cradle can also cause damage).
New owners should take note of the way the boat is positioned on the cradle or trailer as it comes from the Quorning factory.
buckle.roger
Posts: 73
Joined: Sat 07 Jun 08, 15:43
Your Country: spain,benissa/alicante

Post by buckle.roger »

Hi Bo

If you have the time could you please answer this before monday 13 Oct as I am lifting my 920 then

I am going to antifoul my 920 but have no cradle or trailer.
you say to put crade aft, just of the cernter board, is this strong enough to be placed on a flat timber support?

Can I place a similar support just forward of the center board also?

Can all the weight other than the aft of cernterboard support be put on the two forward wing hinge points, again useing timber supports not a crade?

Or how should I do it with normal yard gear

Thanks for the site and any help you can give

roger
Bo Wetzel
Site Admin
Posts: 166
Joined: Thu 01 Jan 70, 1:00
Your Country: France, Provence

Cradle support for DF920

Post by Bo Wetzel »

Hello Roger

Most boat yards have universal cradles which are adjustable and have 4 support legs for the boat.

Place each of those legs directly under the beam supports (those stubs on the hull which act as hinges to the beams).
Make sure you use some padding and straps to avoid any movement.

Let the boat yard people do the work of placing and securing the boat after showing them the support point. It's then their responsibility that the boat doesn't fall off.

Above method allows access to all hull sections for cleaning and antifouling.

With a good cradle you should be able to fold out the floats. Again, consult the boat yard people. However, it is best to place some support under the folded-out float for security reasons when working under the boat.

I hope this answers your question.
buckle.roger
Posts: 73
Joined: Sat 07 Jun 08, 15:43
Your Country: spain,benissa/alicante

Post by buckle.roger »

Hi Bo thanks very much for the quick reply.

Just to be totaly clear on this. you are saying that it is Ok to have the boat supported by only the 4 hinge pivot points with nothing under the main hull?
Bo Wetzel
Site Admin
Posts: 166
Joined: Thu 01 Jan 70, 1:00
Your Country: France, Provence

Cradle support for DF920

Post by Bo Wetzel »

Yes, as these are also the areas on which the lifting rings are located on which you lift the whole boat on 4 wire cables.
buckle.roger
Posts: 73
Joined: Sat 07 Jun 08, 15:43
Your Country: spain,benissa/alicante

Post by buckle.roger »

Thanks very much for the quick replies Bo and for the great web site, keep up the good work

PS do YOU know the correct size of prop for a 920 with a 10 hp honda by any chance, I am getting nothing back from the engine thread
Bo Wetzel
Site Admin
Posts: 166
Joined: Thu 01 Jan 70, 1:00
Your Country: France, Provence

Don't know the prop size

Post by Bo Wetzel »

PS do YOU know the correct size of prop for a 920 with a 10 hp honda by any chance, I am getting nothing back from the engine thread
Sorry, can't help you on this one. I haven't got a DF920 anymore.
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