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Viking 26 Wide Beam. DIY Davits - by Andy Lawrie

Last year I wanted to carry a dinghy on our trip to the Medway, and looked at fitting davits. I was advised by Peter at Walton Marine that the superstructure was insufficiently strong for the purpose, and he recommended I gave up the idea. I have great respect for his opinion, yet still wanted to fit davits if possible, which meant I had to approach the problem by making the structure appreciably stronger and by spreading the load. This I was able to do and the result has been entirely satisfactory.

The main element in both making the structure stronger and spreading out the load is a pair of large 5mm thick alloy plates mounted in the stern lockers, as shown in the first ‘photo. These spread the load over 3 surfaces at different angles, which is partly where the extra strength comes from. The main section is just above the rubbing strip, extending upwards and through nearly 90 degrees to the shelf and downwards through about 12 degrees below the rubbing strip. I had these plates made up by a local metal workshop to my drawings as the bends had to be done on a hydraulic press; there was no chance of me shaping them myself. The most important part of the job was measuring up the plates and getting the angles exactly right, and then transmitting this information to the workshop.

The inside of the lockers is not smooth and flat. I therefore interposed some pieces of wood between the alloy plates and the glassfibre, and furthermore approximately shaped the side of the wood in contact with the glassfibre to a reasonable fit over the whole area. When the holes had all been drilled and everything offered up to fit, final assembly included Plastic Padding between wood and glassfibre to even out the remaining inconsistencies and provide the maximum contact area.

On the outside, the load in the main central area was again spread by pieces of plywood, stained and varnished, on the outside of which the davit sockets were mounted. This is shown in the second ‘photo. The main stainless steel bolts pass through the socket, external plywood, glassfibre, internal plywood and alloy plate, and there are extra, smaller bolts round the periphery of the external spreader which also pass through the alloy plate inside.

Finally, there are small strip spreaders at top and bottom each side to transfer some of the load away from the main section – the lower one is apparent in the second ‘photo just below the boat’s name, the top one is on the shelf as shown in the third ‘photo.


 


(Many thanks to Andy for his kind permssion to include his © photos and text on this site)