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1901.] MARINE REVIEW. 21 INSPECTION OF AMERICAN SHIP YARDS. Engineering of London lately sent a commissioner to the United States to visit the ship yards and report upon conditions as he found them. He was evidently charged to take note of the employment of special tools and machinery in ship construction. The first of his arti- cles, an editorial, is particularly interesting to the lake region. He said: "Often as the attention of ship builders at home has been directed to the question of pneumatic riveting, one requires actually to see the plant at such works as those of the American Ship Building Co. at Cleveland and Chicago Consolidated lake yards. One is then able to appreciate what a persistent pursuit of this method of riveting will achieve in sim- plicity of arrangement and in thoroughness. At Chicago, when the writer visited the yard, the bottom portions of the frames of a steamer, some 420 ft. in length, were in place, the plates of the inner bottom were for the most part. fitted, and the bottom shell plating was well advanced. This seems to be in accordance with the methods there employed; the bottom plates, being prepared off templets made in the mold loft, so that they are ready as.soon as the lower frames are erected, and are worked into the ship without any wating for the side frames. Even the bilge plates, for the midship portion of the ship at least, are punched and rolled and lie ready alongside until such time as the side frames are up and ready to receive them. The forenoon of the day of the writer's visit had been attended by a heavy rain storm, and all hands had been knocked off; but under the. bottom of the steamer above mentioned a compressed air main, some 5 in. in diameter, lay, running the whole length of the ship; T branches occurred at various positions, and from these flexible branch pipes were led both to port and starboard for the supply of air to the pneumatic tools. On each side of the keel three rivet- ing machines were in place, as left by the workmen, so that on the bot- tom of that steamer it was obvious that six mechanical riveters were working; this number being in addition to the other pneumatic tools for rimering and caulking. .The bottom was kept as clear as possible of OVERLAND. : PART OF CRADLE. shores, and the impression given was, perhaps, that a little less care was taken in this respect than at home; which is perhaps justified by the fact of the ship having no declivity (in view of the subsequent launching being. made broadside), a lesser number of shores and the total absence of bilge blocks (at this stage at least) was thus allowable. "In another steamer, launched a few days previously and lying afloat, the writer was more successful in seeing pneumatic riveting actually in progress. The main air pipe was led along the deck and branches taken off as required through the hatches to the parts below. Some six squads of riveters were working on this ship, and all with pneumatic tools, no sign of hand. riveting being visible from stem to stern. The portions in process of riveting were girders beneath the upper deck, and the lower edges of gussets to the lugs attaching the side frames to the margin plates. Why these had not been completed earlier was not quite obvious. They were in the nature of odd work, and the possibility of applying pneu- matic power to them was correspondingly remarkable. The work pro- duced by the pneumatic riveters is to all appearance excellent. Even the keel rivets seemed all that could be desired. The appearance of per- fection is supported also by the tests made at the Chicago yard in the way of cutting up samples riveted together for the purpose, and by the still more practical consideration of the difficulty actually experienced in cutting out pneumatically-driven rivets in the frequent cases of repair which have presented themselves. The difficulty, said to be experienced at home, of getting the plates well closed with pneumatic work, is over- come in America by the screwing up being done by a special squad, leav- ing nothing for the riveters but the actual work of driving the rivets. Fairness of holes, at least when the work is first put together, cannot be said to be a feature at Chicago. The three-ply work especially might well "be better than it is. The pneumatic rimering, however, brings things into a fairly satisfactory condition before riveting is commenced. "With the very large development of pneumatic working, it is rather noticeable that at the Chicago yard appliances are in some respects dis- tinctly behind first-class appointments at home. The bottom plates are worked in long lengths, covering fourteen frame spaces; the bilge plates, both upper and lower strakes, cover only seven frame spaces; the reason being that to this day the length of rolls (some 16 ft.) at the works de- termines the limit of these plates. The plate edge planer matches the rolls in its want of capacity, and requires two shifts of a long plate to complete one edge. No joggling is yet resorted to, and the management is not convinced of the material advantage to be got therefrom. In this ship yard there is at present one gantry or trestle structure surmounted by a travelling crane, the whole being of the type that has been so much discussed of late years. . "Naturally, if one wishes to see modern labor-saving appliances on a bolder scale, one. must go to the large establishments, such as Cramp works at Philadelphia or the New York Ship Building 'Co.'s works at Camden, opposite Philadelphia. As is well known, the former works have three gantry structures. Each is surmounted by a double cantilever crane, so that six ships under construction are served by these appliances for handling the material. At Camden the roofs at present erected cover three bays--one over the fitting out basin, the other two over building berths, and capable of taking two ships in the breadth. Electric cranes, suspended from the roof, traverse these bays. At the Camden works the problem set by the management seems to a casual observer to be how to carry on work differently from the way it is done elsewhere, especially in Britain. The mold loft is a beehive indeed, although there are only some four ships under construction, and none of them has any very special feature about it. Apparently nothing is shaped without a mold from the © loft, and, further, nothing is done by hand. The frames are set cold and a tool something like a bean squeezer is used for the purpose. So far as possible also the tool is taken to the work instead of the work to the tool. If an odd hole has to be drilled in fitting together the parts of, say, a hold stringer (this fitting is done on shore), a pneumatic drill is brought to do it. The above remark as to hand work does not quite apply to riveting. For some reason or other, probably a temporary one, the only shell squad of riveters the writer saw were riveting by hand, notwithstanding the fact that close beside them pneumatic rimering and caulking were freely in progress. "Neither at the Cramp works nor at the Camden works is any jog- gling of shell plates resorted to, speaking, that is, of work now in hand. At the former works some bulkhead plates and other minor portions are joggled, but not the heavier work. Hydraulic plant appears less effective- ly employed than at home. The writer saw little hydraulic riveting, and such hydraulic punches and presses as are in use seem to have the four supporting columns, instead of being open in front, as in the best modern machines. In the plate edge planers at the Cramp works the plates are held to their work by hand clamps, instead of by hydraulic presses. In the Camden works less flanging is resorted to than at home, but this is, LAUNCHING IN BAKER'S BAY--WORK AT LOW TIDE. -perhaps, because things are not. fully organized.» Certainly at Chicago flanging is used quite as effectively as in Britain. oThe impression borne upon the writer from his somewhat hasty visits iwas that a judicious selection'of American methods is well worth the most careful attention of the British ship builder. The American, on the other hand, has something to learn from the methodical equipment of an up-to-date yard in the old country, both in the relative positions of and space allotted to ships' bending blocks and sheds, and also to the provision of machine tools of ample capacity for work now common." MASONRY DRY DOCK AT HUNTER"S POINT. Considerable progress is being made upon the new masonry dock which the San Francisco Dry Dock Co. is building upon a site adjoining its old' dock at Hunter's point. The old dock is '498 ft. long and 90 ft. wide at entrance. The new dock is 750 ft. long from the gate seat with a width of coping of 122 ft., and at bottom 74 ft., having a depth over sill of 80 ft. at high water, making it one of the largest and commodious graving docks in the world. At the entrance to the dock on either side are located wharf approaches, 60 ft. wide and 200 ft. long. Both docks are connected by a tunnel under pump pit, and the pumping plant is capable of emptying the new dock at high water in two hours and the old. dock in forty-five minutes. This means a solid stream of water 8 ft. in diameter with a velocity of 500 ft. per minute. The engine house is virtually completed; pumping engines are on the ground, and well advanced in course of erection. The large 8-ft. gates are in place; the tunnels into both docks are completed. The pumps are on the ground, and four out of six are in place. The centrifugal pumps, three in number, lack but ten days of completion, and would have been ready some thirty days ago but for the. machinists' strike. The cofferdam at the entrance is in course of construction, and one-fourth of the excavation of the dock proper has been made. The chimney over the engine house is a handsome stack of unusually graceful proportions. It is cylindrical in form, and will be the landmark for all vessels passing up and down the bay; it is 110 ft. high and 12 ft. in diameter, being 60 ft. higher than the stack which was used for the old engine house. The engine house will be fitted throughout with natural. Oregon pine, and is most complete in all details. The work on the caisson, or gate, for the dock is commenced. Percy & Small, Bath, Me., have stretched a keel for a four-masted wooden schooner for Capt. Sidney G.-Hupper of Rockland, Me. The vessel will be launched about Dec. 1. : _ The steamer Olympic for the E. K. Wood Lumber Co. is nearing completion at George W. Hitchings yard, Hoquiam, Wash. a I