Engineering Wonders of the World
Volume I

68 ENGINEERING WONDERS OF THE WORLD. shearing machine ; and machines for keel-plate bending, flanging, scarfing, bevelling, “ jog- gling,” slotting, milling, and riveting. Hy- draulic and electric power is rapidly replacing steam for driving the heavier machinery in shipyards ; while for the lighter work—drill- ing, chipping, rimering, caulking, and certain riveting—compressed air is largely employed. Of course blacksmiths’ shops, joiners’ shops, and sawmills, with their numerous appliances, must find a place in the shipyard; while winches and travelling cranes, worked by steam or electricity, must be provided in the vicinity of the plate racks (see Fig. 1), where material is stored when first delivered into the yard, at the building berths, the fitting-out quay, and in other parts of the yard where their use is likely to be required. THE BUILDING OF A SHIP. Generally speaking, the order of procedure is similar in the construction of all iron and steel merchant ships, whether of large or small size ; and indeed the following remarks may be taken as applicable to war vessels, with such reservations as are necessitated by their special requirements, such as the provision of armour, etc. In a comparatively short article like the present it is impossible to do more than mention briefly the chief processes which enter into an undertaking so vast as the build- ing of a steamship of the dimensions now con- sidered quite ordinary. Premising that the general design and speci- fications for a new vessel have been agreed upon by the owners and the shipbuilders, in conjunction with the classifica- . . • ,. , The Working tion society or societies to „ . , , J Model. whose rules the ship is to be built, the preparation of the working model and the working plans is proceeded with, so that the material to be used in the hull may- be ordered from the rolling mills. The half- block model, on a J-inch to the foot or other suitable scale, is intended to show the exterior arrangements of the hull. On it are carefully drawn the positions of the frames, or ribs, which support the shell plating, the edges of the shell and deck plating, and other details. In the case of a warship it is usual also to make block Fig. 4.—ONE OF THE “ MAURETANIA’S ” ANCHORS. WEIGHT ABOUT 8 TONS. (MADE BY MESSRS. N. HINGLEY AND SONS, NETHERTON.) models showing the protective deck, the shape of the inner bottom, etc. From the model or models the sizes of many of the deck and shell plates and portions of the framing are measured, and the necessary speci- fications issued to the rolling mills. While the ordering of a portion of the material is thus proceeding, the “ laying-off ” of the vessel is taken in hand in the mould loft. Briefly, this consists of trans- ferring the form of the vessel from the |-inch scale drawings The Mould Loft and Scrive-Boards. to the scrive-boards, which are laid on the mould-loft floor. The frames are here drawn out full size and “ faired ”—that is, so shaped as to ensure that the form of the ship’s