GB744257A - Improvements relating to welded aluminium or like boats - Google Patents

Abstract

744,257. Sheet metal boats. MECHANS, Ltd. March 23, 1954 [May 7, 1953], No. 12705/53. Class 113. [Also in Group XXII] A boat shell is made from aluminium or aluminium alloy plates by cutting gores inwardly from the edges of the plates to facilitate shaping to the shell contour, attaching the plates to the frame of the boat, and buttwelding the adjacent edges of the plates and the gores together along the length thereof. Gores 10a, 10b, 10c are cut in each of two plates 10, 11 which together form the upper part of one side of the shell of a lifeboat and a gore 7a is cut in each of two plates 7, 8 which form the lower part of one side of the shell, the gores terminating at their inner ends in rounded holes to inhibit tearing. The plates are drilled to correspond with some of the holes in the frame of the boat, bolts therethrough into the frame are tightened and adjacent edges of the plates and gores tack welded. The seams are then continuously butt-welded, the upper plates 10, 11 together at the seam 13 forward of the transverse centre line A-A of the boat, the lower plates 7, 8 together at the seam 14 aft of the transverse centre line, and the upper plates to the lower along a continuous seam B-B. The shell is then hammered where necessary to flatten any high spots and drilled opposite the remaining frame rivet holes and finally riveted at all holes. The lower plates are attached to a keel 15, Fig. 2, through keel angles 16, the upper plates are riveted directly to the gunwale and all the plates are countersunk riveted at 20, Fig. 4, to angle frames 21.