Iron Ship-Building; With Practical Illustrations

Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: A further improvement has been introduced in the formation of iron beams, which gives a neat finish to the work; this is shown in fig. 8, and represents the end of the beam, which is split, and the lower part, A, bent downwards, leaving the open part, B, into which an angular piece of plate, shown by the dotted lines, is welded, and is a substitute for the usual knee plate, as shown in fig. 3. In the upper flanches of these beams holes are punched at short intervals, and wood screws are driven up from below into the deck plank, to secure the latter to the beams. Bolts and nuts are sometimes used, the bolt head being sunk below the surface of the plank, and the hole plugged up to keep it watertight. A bolt of each kind is seen in dotted lines, marked A, B, figs. 10, 11. Gunwales And Stringers. The gunwale is the point of junction between the sides and the upper deck. It is a part of the ship at all times requiring great care and skill, but in iron ships demands peculiar attention, as in no part have they been more defective. There are two principal causes for this. First, sufficient care has not been taken to unite the wood-work to the iron, hence a serious leakage has resulted; and secondly, the construction of the iron stringers, or deck-plates, and other fastenings has been very deficient in strength. The recent attention given to iron structures in the form of wrought-iron tubular bridges, has thrown much light upon the best proportions to be given to iron girders, of which an iron ship is one modification; the experiments lately tried haveshown that great strength should be given at the upper edge, and clearly prove, what indeed has long been evident, viz., that, to make a sound ship, the gunwale must be very differently constructed from what it generally has been. ...