DURING THE PAST THREE MONTHS, the work of building up the skeleton hull of the lifeboat (Fig, 1), swiftly sketched out in Part III of this article, has been progressing at William Osbornes with meticulous care. Each of the very many pieces of wood making up the whole is a unique member needing to be shaped and fitted individually. So, before planking begins, let us take a closer look at the craftsmanship of this work.

The timbers, the boat's ribs, steamed to take up the transverse curve of the hull, each have to be rebated at the correct angle into the longitudinal members: tunnel cant, deck shelf and main gunwale (Fig. 2). The forward and after timbers are solid oak, 1|" x li", but amidships, where there is maximum bend, they are built up of two glued laminates.

Between the timbers, and to lie flush with them, the longitudinals are built out with mahogany filler chocks (Fig. 3).

Each filler has to be shaped by hand on both its inner and outer face to take up the fore and aft curve of the boat. In way of watertight compartments the chocks are fitted tight to the timbers and glued; elsewhere a vertical waterway is left on the lower side to allow drainage.

Fig. 4 shows the propeller tunnels with their cants and curved laminated timbers, giving the outboard curve of the tunnels, in place. Chocks shaped to give the inboard curve to the tunnels have still to be fitted, one down each side of the deadwood, after the tunnels have been planked. Three long bolts, the longest being 3' 6", tie the whole structure of tunnel cants and hog together at the after end. The dowelled bolt holes can be seen in the photograph in way of the stern post.

Each tunnel flattens out as it runs forward, with a return chock of solid mahogany at its forward end (Fig. 5).

This is the changeover point at which the hull planking, instead of being landed on the tunnel cant, becomes continuous down to the hog. Note the drain tube through the hog just aft of the return chock, allowing one bilge suction to clear bilge water from both sides of the hull. Drainage and limber holes are so arranged that water is given little chance to lie in corners or on ledges; it is such stagnant pools of water which would lead to dry rot with resultant structural damage.

(To be continued).