Drop keel line

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Drop keel line

Postby Jeremyfisher » Wed Jan 10, 2018 7:52 pm

Has anyone managed to changed the keel line whilst the boat is on a trailer?

To explain a little further:
Jeremy Fisher is a drop keel version where the keel is raised and lowered via a line that comes under the hull of the boat and up through the drainage hole by the transom. It then winds round a large wheel giving a 10-1 ratio for raising the keel. The line is fixed to the keel with a shackle inside the skeg and I cannot see a way of undoing that shackle without raising the whole boat with a crane.

Any ideas, anyone??


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Simon
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Re: Drop keel line

Postby jerryevans » Sat Jan 13, 2018 12:27 am

Hi Simon,
No experience with Prelude drop keel, sorry, but,
Here are two ideas I have used previously with success on other boats.

1. Working in a large enough space, roll the boat off the trailer, ideally with the mast up. Using a strong anchorage, heave down from the mast hounds to lay the boat on her side, enough to access the keel and its housing and control wire. Take great care to secure the boat in a stable position with chocks, blocks etc as required so that she cannot slew round or move when you take the keel out as that will, of course alter the boat's C of G.

2. Alternatively, depending on your trailer design and the nature of the ground, it may be possible to shift the boat rearwards on the trailer to enable the keel to pass between the frame members, then be lowered into a pit dug beneath the boat. Dig the slot shaped hole first, then roll the trailer and boat into position over it. Don't try this on sand!

There is no easier way that I can think of unless you have access to a boat hoist.

I do NOT consider jacking the boat up in stages onto blocks to be feasible as the working height would need to be considerable. Neither the use of a fork lift, unless using a purpose built cradle.

I manage, with some considerable ingenuity, to move my bilge keel Prelude Tropical Kitt around a bit with levers and rollers, but was surprised at her weight at over i tonne, not the 750 kg quoted in the brochure in 1973. I used my son's boat hoist last year, just the job, no sweat or risk either. It made my trailer mods and anti-fouling much less back breaking. That is when I had the opportunity to weigh the trailer on its own and then deduce the weight of the boat. The all-up towing weight, and an empty boat, between 1400 and 1500 kgs. All the boat gear I carry in my tow vehicle, Suzuki Grand Vitara.

You could always ask a boat specialist?

Good luck. Keep us informed.

Jerry.
Last edited by jerryevans on Sun Jan 21, 2018 8:27 pm, edited 1 time in total.
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Re: Drop keel line

Postby Jeremyfisher » Sat Jan 13, 2018 9:09 am

Thanks Jerry,

My trailer does not have rollers!! and as you say the hull is a fair weight so would be impossible to slide the boat. Good ideas though.

You mention a wire for the keel. Jeremy Fisher does not have a wire, it is cord which is why I feel I ought to change it. Any cord must have a limited life, I would have thought.


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Simon
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Re: Drop keel line

Postby jerryevans » Sat Jan 13, 2018 11:16 pm

Hi Simon.
As my boat just sits directly on her bilge keels, no trailer mounted rollers, it takes some considerable effort with a long 3 cm steel bar to shift her. As recovered from the water the boat rarely sits positioned as I would wish, usually about 30 cm too far back. I use a heavy rope bridal round the keels attached to the trailer winch cable to encourage her forward to the stops on the trailer, also the long bar to get it just right! This problem is related to the angle of the slipway as the boat locates on the keel guides.

The only boat I have owned with a winch lifted keel was fitted with a galvanised wire cable. I chose this because I found that synthetic line wore out fairly quickly, as you said, and I wanted a neater arrangement. I tried stainless but found it became brittle in use, resulting in sharp strands ends when they broke. Galvanized wire will show rust when it gets old and does NOT break without warning. I think Hiscock was of the same opinion. Correction, I agree with Hiscock!

Regards, Jerry.
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