Broken strop on my SEAL 28 - 2

Removing the Strops
 
The lifting keel on a Seal 28 is a daggerboard designed to slide vertically up and down through a suitably shaped slot in the stub keel. The horizontal profile is a symmetric aerofoil. Two wide vertical grooves on either side of the centreboard box are engaged by large nylon block sliders fixed to the keel with three studs in line vertically and secured with nuts on each side. The sliders serve to keep the keel vertical with respect to the transverse and longitudinal axes as it slides up and down. The top stud threads two wire rope strops via slots in the top of the keel; the strops each pass over pulleys turning the cable through 90º, and then 180º, and are secured via copper end stops in a brass block which moves on a screw within a rectangular tube. When the keel is down, the bottoms of the nylon sliders sit on top of the stub keel preventing the lifting part from falling out. To remove the lifting keel from the bottom of the boat, the studs must be withdrawn and the nylon blocks removed.
 
The daggerboard keel weighs in at 454 kg—nearly half a tonne—so it must be treated with a considerable amount of respect. Any process involving moving it when it is not fully and securely supported, must be done in a fail-safe manner. Clearly, replacing the strops was a job for the boatyard using professional people and proper heavy-lifting gear. As well as replacing the strops, the keel and the inside of the stub keel needed to be de-rusted, cleaned, primed, and antifouled. To do this properly, the keel needed to be dropped out of the bottom of the boat; the inside of the stub-keel would have to be cleaned by hand.
 
To remove the daggerboard keel, first it must be lifted right up so that the top 20 cm or so is clear of the keel box. This allows the stud securing the strops, and the two studs below it which secure the two nylon sliders, to be removed. For me, getting the yard to do this was a bridge too far. There was the uncertainty of exactly how to proceed—would the keel jam as it was lifted up? How would it be lifted? More obviously, since it was almost certain to jam going down—the problem in the first place—how would it be unjammed then? Open-ended engineering issues lead to potentially unlimited financial commitments. Given my circumstances—and the value of the boat—this meant that any remedial work would have to be a do-it-yourself undertaking. If extra muscle other than my own meagre ration was needed, I had three enthusiastic members of the Parker Seal Association to call upon.

First things first; whatever process was adopted, it would be necessary to access the keel both inside and outside the boat many times. A safe and secure method of climbing in and out was needed, and this was accomplished by using a stepladder fixed to the central cleat as shown in figure 2.