THE SAFETY OF PASSENGER SHIPS AT SEA. 27 



Let us first consider penetration by collision. Here the damage would be ver- 

 tical and might, if the striking vessel were large and nearly at right angles, pene- 

 trate quite a distance into the side of the vessel. I think, however, that such a dis- 

 aster could not entail more than three adjacent compartments if near amidships, 

 or say 219 feet 6 inches. What would be the condition with three adjacent compart- 

 ments near the center of this vessel flooded? The capacity of one of these com- 

 partments would be 163,345 cubic feet, from which would have to be deducted the 

 displacement of the boilers, less furnaces, tubes and combustion chambers, or 13,120 

 cubic feet. The coal capacity would also have to be deducted, for if half the 

 coal were used the vessel would be 3,000 tons lighter and if the coal were all on 

 board it would displace so much water, and for this we must deduct 52,000 cubic 

 feet and also 1,740 cubic feet for a central watertight passage under the upper 

 deck. This leaves 98,225 cubic feet or 2,806 tons for each of the three compart- 

 ments that we consider may be possibly injured through collision, or 8,418 tons to 

 be carried by new displacement. In order to provide the displacement for the con- 

 dition described above, I would propose to fit what I would term a double upper 

 deck, the upper member of which would be 5 feet 6 inches above the lower amid- 

 ships and parallel to the base line between frames 66 and 254, at which frames it 

 would rise 2 feet and follow the shear line to the stem and stern. In case of a col- 

 lision cutting into the upper member of the upper deck the local damage would be 

 confined practically to the depth of penetration and the width of the striking ship, 

 as the space between these decks would be divided into very small compartments 

 both transversely and longitudinally. As it is, we have between these upper decks 

 9,730 tons of displacement which, in case of three compartments being opened to 

 the sea, would leave the upper member still materially above the water line. If the 

 injury were near the forward end of the ship, the lower member of the upper deck 

 extending downwards reduces the size of the flooded compartments and the dis- 

 placement of the contents of the holds, at least 50 per cent would still further have 

 to be deducted, while the upper member rising at frame 266 and following the shear 

 line would provide sufficient displacement to trim ship till water could be introduced 

 into the double bottom aft. These same conditions would apply in case of serious 

 injury aft. It will be understood, of course, that all openings through the upper 

 deck, such as boiler and engine casings and hold hatches, would be watertight 

 structures for at least 16 feet above the load water line. 



We come now to another form of disaster, the ripping open of the side of a 

 ship for a considerable proportion of her length by striking the projecting edge of 

 some obstruction under the water line. In case under consideration this might hap- 

 pen between the lower and the upper deck for a great portion of the vessel's length. 

 The five large compartments would add 14,030 tons to the displacement, while the 

 forward holds, assuming that the cargo occupied one-half the space, would add 3,800 

 tons more, and the after compartments, if they had to be flooded to trim ship, 

 would add 3,400 tons, a total of 21,230 tons. This would sink the vessel 11.86 feet, 

 or 6.36 feet above the upper member of the upper deck amidships, and she would 



