308 



ENGINEERING. 



Throughout, the vessels were constructed 

 under the surveillance of Lloyd's agents, and 

 according to the best-approved plans of mod- 

 ern marine architecture. When nearly ready 

 for launching, 7,000 tons of material had gone 

 to the construction of each ship ; the heaviest 

 steel castings for the hulls being the stern-posts 

 (26 tons each), and the heaviest for the engines 

 (50 tons). The steel was all subjected to an 

 anti-corrosive process. 



The hull of each vessel is divided by perma- 

 nent transverse bulkheads into fifteen water- 

 tight compartments, including three for boilers 

 and two for machiuery, the latter being sepa- 

 rated by a longitudinal bulkhead. The doors in 

 the bulkheads are on the upper deck far above 

 the load-water-line, it being determined not to 

 trust to the doors being promptly shut in case 

 of danger. None of the compartments exceeds 

 35 feet long, and the quantity of water they 

 hold to load-water-line is 1,250 tons, or to 

 upper deck, 2,250 tons. Even were two or 

 three filled, tjie flotation of the vessel would 

 not be placed in danger, and her buoyancy 

 could easily be trimmed. As an additional pre- 

 caution, the vessel has two bottoms, the space 

 between them being four feet. They serve 

 a double purpose, for not only will the exist- 

 ence of an inner bottom make it certain that no 

 part of the ship will be flooded by a fracture of 

 the external bottom, but the space can be util- 

 ized for carrying water- ballast, to the extent of 

 1,600 tons, for adding to the stability or alter- 

 ing the trim of the ship. The stability of the 

 vessels is further secured by "rolling cham- 

 bers," similar to those that have been success- 

 fully tried on several modern war-vessels. The 

 chambers in this case are 35 feet long, and ex- 

 tend athwart ship. When partially filled with 

 water, the greatest weight is naturally at the 

 lowermost side, and tends to keep that side 

 down when the ship rolls in the opposite direc- 

 tion. It can not, however, keep it down alto- 

 gether, and a considerable portion of the water 

 finds its way across the chamber before the re- 

 turn roll takes place. Thus there is a constant 

 tendency of the water toward the side that is 

 about to roll upward, and the weight being 

 shifted just at the critical moment, the equi- 

 librium of the ship is partially preserved, and 

 the uncomfortable rolling motion is largely 

 diminished. 



One feature, which adds greatly to the luxu- 

 riousness of the appointments, is the arrange- 

 ment of the main saloon, which, instead of be- 

 ing of the proportions ordinarily dictated by 

 the space between decks, is carried up through 

 three of the five decks, having an arched roof 

 22 feet high, 53 feet long, and 25 feet wide. 



The steering-apparatus has been designed 

 specially with a view to the use of the vessels 

 as armed cruisers in case of war. The plan 

 of the rudder with one of the twin screws is 

 given in Fig. 10. The rudders have a super- 

 ficial area of 250 square feet, larger than has 

 been adopted for the largest war-vessels, and 



the power of the hydraulic steering machinery 

 will be appreciated when it is known that the 

 rudder can be crowded hard over when the 

 ship is going full speed ahead. Of course, this 

 implies a tremendous strain upon all the parts. 



FIG. 10. TWIN SCREW ON STEAMER. 



The steering is effected by a small tiller, that 

 being regarded as more certain of adjustment 

 than the ordinary wheel. The illustration (Fig. 

 10) sufficiently shows the position of one of 

 the twin screws, its mate, of course, being in 

 position on the other side of the stern-post. 

 The machinery in each vessel consists of two 

 sets of engines of the three-crank, triple-ex- 

 pansion type. Each set of engines is capable 

 of driving the vessel at a good rate of speed 

 should the other engines break down. 



The full complement of passengers and crew 

 is in round numbers 2,000 souls, and the total 

 amount of deck area is about 150,000 square 

 feet. Duplicate electric-light systems are car- 

 ried to all parts of the ship. 



In actual performance the " City of New 

 York " is said to have fully equaled the ex- 

 pectations of her builders, though she has not 

 yet "broken the record" in running time. 

 She encountered several very severe storms, 

 however, and behaved admirably. 



A Large Gas-Holder. A conspicuous object to 

 passengers on the East river, N. Y., is the large 

 tank recently constructed for the Consoli- 

 dated Gas Company of New York during the 

 summer of 1888. The engineering difficulties 

 were considerable, since the available land was 

 "made ground" composed of city dumpings, 

 and below this was quicksand. The usual 

 subterranean brick tank was dispensed with, as 

 being too expensive, and an iron tank was sub- 

 stituted, resting on the surface of the ground. 

 To prepare for this, a circle of heavy piles was 

 driven, corresponding with the diameter of the 

 tank, and the inclosed space was filled with 

 concrete to a thickness of two feet. On this 

 the bottom plates of the tank were laid. The 



