This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1914 Excerpt: ...altogether. Floors in inner bottoms are almost entirely fitted as deep solid plates in one piece from centre vertical keel to margin plate, lightened with large manholes to cut out superfluous material and provide access to the various compartments into which the bottom is sub-divided by the floors and intercostal girders. Deep floors should be lapped to the bottom frames just sufficient to take the riveting. In wake of watertight bulkheads or at ends of ballast Fig. 155. Fig. 156. tanks where the floors are watertight, no holes whatever must be cut in them. The margin plate of inner bottom being continuous, is connected to the main frame by a large bracket plate or tail piece, and by double angles having a specified number of rivets and a gusset plate at top, or in the largest vessels a continuous stringer. The connection to the siding flange of main frame is by lap of sufficient width to take the riveting. See Figs. 157 and 158. At the ends of the vessel where the waterline at top of floor would necessarily be comparatively narrow, increased depth must be given to provide compensatory area and also ensure sufficient width to clip the centre keelson to floors. In the fore peak this additional depth is required to resist buckling and panting, and generally to give local stiffening at a part subjected to unusual stresses. It is also necessary to increase the floors considerably in depth in after-peak, owing to the severe stresses encountered when the propeller "races" and the stern is in air. INNER BOTTOM. Double bottoms are fitted in vessels to enable them to safely make voyages "in ballast" without incurring heavy expenses by loading and discharging dry ballast. For this purpose the floors are plated over, forming an inner bottom enclos...