996Re:: Drop Keel Overhaul
- Mar 28, 2015
> Not all privateers have a second drop preventing bolt.
Another upgrade from the Shipmate Owners' Association,Their boats do not have a second bolt to prevent the plate dropping dangerously far, and there are two possible serious risks should it ever be allowed to do so. One is that if the plate is lowered too far there is insufficient remaining inside the case to give adequate lateral support, particularly if the pivot bolt is sited low down; this will be less of a problem with the higher position of the pivot bolt. When the location of the pivot was changed on the Shipmates the blade was reprofiled, and when fully lowered it now rested against the "headledge" of the case, which was suitable strengthened. I would expect that similar design changes would have been made with the Privateers, but I have no confirmation of that.If a boat has the pivot bolt in the lower location, and does not have some means of preventing the plate being lowered too far, this becomes a very serious risk.The other risk is that if the winch strop should fail for any reason the falling plate could slam hard into the front of the slot and case, or the "headledge" if present, and the impact could do structural damage. There have been a (small) number of known cases where the strop has indeed failed, allowing the plate to go crashing down.A number of Shipmate Owners reduce this risk by a simple modification; "The modification is to simply wedge some impact absorbing material between the leading edge of the keel and the keel box casing. Now readily available from DIY stores such as B&Q are impact absorbing rubber tiles that are used for impact attenuating surfacing beneath and around children’s play equipment." This is glued in place.Those members of this Group who choose to follow my recent suggestion (made for other reasons) of joining the Shipmate Owners' Association will be able to read up the details in their Handbook.Oliver
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