Reconstruction - Part 4

Hull

Timber Work

January 2011

A measuring jig is set up on the foredeck to take the existing offsets and ascertain the symmetry of the lines at deck level. These offsets have been compared to those obtained from the 1:25 scale lines plan to assist us to confirm the best side of the boat and decide how best to make the corrections.

The measuring jig, having been marked up to what has been judged to be the closest to the correct lines, is being converted into a laminating jig from which to produce the deck clamps. Fastening these into place will mark the first operation of the task to correct the collision damage at the bow, providing a fixed shape and dimension at deck level.

Having converted the measuring jig into a laminating jig, some iroko boards have been re-sawn to form 14 boards of 11mm and 9mm thick for laminating the deck clamps in the bow. They have been dry clamped to the jig for three weeks so that they take a set prior to glueing up with epoxy resin. They will stay on the jig with a heat tent over them for a week, followed by a further month to six weeks at ambient temperature to allow a full cure and to give the timber time to fully acclimatise to the required shape. Once we are satisfied that there will be minimal deflection when removed from the jig, they will be trimmed and fitted into the boat.

Hull

February - March 2011

The pitch and timber has been cleaned away from edges of the forward collision bulkhead, revealing the degraded aluminium support frame. This exercise also revealed an area of significant buckling, just below the knuckle on the starboard side.

Two stand alone floor members have been removed, chipped, cleaned and primed ready to be reinstalled..

An internal mould was set up in the bow to check for anomalies in shape between the port and starboard side and ultimately provide us with a symmetrical section from which to re-form the forward hull.

Hull Structure

Hull planking was removed to assess the structural integrety of the bent oak timbers, the stringers and their associated fastenings. This investigation showed considerable degredation to the bent oak timbers and fastenings. The majority of the stringers had been cut during the course of some previous repair work.

Considerable damage and degredation, along with a considerable amount of expanding foam, was found in the knuckle strakes and associated stringers. Sections of these members have been cut out at station positions and saved as patterns so that the section profiles can be replicated when they are replaced.

Torpedo Exit Scoops

April - June 2011

Male moulds of the starboard torpedo exit scoops being constructed from which to form the aluminium sheet to the desired shape.

A carcase is constructed on the vertical surface above the scoop, on which the mould itself will be attached. Ultimately this will become the stand.

The shape of the scoop is dummied off the existing aluminium, at a number of stations, onto lengths of 4 x 4 which are then shaped before being fastened to the aluminium. Once all the pieces are shaped and in place they are then incorporated into the carcase.

The whole structure is then disconnected and lowered to the ground for finishing. The first mould has now been set up, up side down, to be worked on

General longitudinal fairness is checked before each station piece is removed and re-made, fairing out the dents and bumps of age, prior to cutting mirror copies.

A second carcase stand has been made and both sets of stations are being set up to mirror each other.

The next stage is to produce a fair surface over the extent of the curves, using 3/4" x 2" larch battens fastened across the stations, and to fabricate and fit clamping arrangements along the length of both jigs to make them into dedicated sheet metal forming tools.

The framing around the lower perimeter of the torpedo exit scoops is made up of three layers of timber which form a complex and integrated structure which includes the foredeck clamp, main deck clamp, principal stringer #16, knuckle stringer and strake, upper bow planking, main deck wale and sheer strake.