Practical Metal Hull Construction: The Results of the Experience of Many Years in the Erection of Flying Boats

HAVING completed the erection of all the frames, we can now turn our attention to the assembly and fitting of side keel‐sons and stringers. Side keelsons are usually fitted intercostally—that is, between frames—although a few boats have them fitted longitudinally. In my opinion, when intercostally fitted, they are much stronger and less trouble to assemble, and this type will eventually become standard. Being intercostal, they are very simple to make up owing to their short lengths. There is a slight difference between the design of a centre and a side keelson, the latter having only one angle fixed at the top and the bottom, forming a Z‐ The correct shape of the webs can be obtained from the lines on the scrive board, and after the web and angles have been shaped, the side keelsons should be drilled off, lightening holes punched, and sent to be anodically treated before being riveted up. When they are ready for erecting on the hull, their correct position is ascertained by means of the angle lugs that have been riveted on to the web of the frame. This will be found quite a simple operation, the point to watch being that when putting them into place they do not cause any distortion of the frames owing to incorrect length. They should only be hand tight, as any forcing into position will destroy the anodic films on both frame and keelson. They must be faired in by means of a wooden batten, which should be long enough to extend across three or more frames.