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COMPARATIVE TESTS OF OLD AND NEW MANILA ROPE. The following article from the Engin- eering Record concerning comparative tests of old and new manila rope is of considerable interest to vessel owners, and men aboard ship, as revealing the strength of manila lines used in mooring: Heavy bridge erection work is involved in the separation of street grades and other improvements in the six-tracking of the Harlem branch of the New York, New Haven & Hartford R. R. Bridges over the railroad carry street 100 ft. wide or three longitudinal lines of girders with transverse floorbeams. THey "are proportioned for heavy city traffic and for large dead loads, including concrete floors and pavements. This requires mas- sive girders weighing from 35 to 70 tons each, and Lewis F. Schoemaker & Co., who have the contract for a number of these bridges, decided to erect them up to 40 tons conplete with a guyed derrick having both hoisting and) topping lift falls made with 13-part tackles rove with 2-in manila lines over 12-in sheaves. It was observed, as in previous cases, that when the line was new considerably more power was necessary to operate the tackles under a given load than was necessary after it had been some tim? in service and become more pliable. The question, therefore, arose whether the severe bending around the 12-in sheaves might not have developed internal fr'c- tion sufficient to cause a serious deterior- ation in the rope. Little or no data exist on this point, and none being available to the contractor's engineers, it was de- termined to make some practical tests to show the actual strength of the rope em- ployed and to throw such light as might be attainable on a subject of great im- portance to the safety and economy of bridge erection. For this investigation it was decided to take specimens from three coils of 2-in. manila line, each 1,000 ft. long, which were typical of other lots of rope used by the contractor. One coil had been used in the spring of 1907 for the erection of 35-ton girders on the Boston & Albany R. R., and for subsequent lighter service. It had received excellent care and had been protected from the weuther, so that it had never been allowed tu remain wet in the coil, although subject to showers and immediately drying while in service. The other two coils were purchased new this spring, one of them had been used and one of them had not been used, so that an opportunity was afforded of mak- ing comparative tests of similar rope under known conditions. A piece of rope about 15 ft. long was cut from each coil and was closely wrap- ped with 3/16-in. diameter cords from each end to within about 6 in. of the cen- TAE MarRINE. REVIEW ter, which was left unwrapped. The wrapped ends were then bent double, forming bights, and the loose end and the standing part were lashed. together in two places with 3-in. lines, thus form- ing a piece about 7 ft. long with a loop at each end for attachment to the test- ing machines. Specimen 1 was taken from the old rope, which has been used in erecting two 35-ton girders with a nit.v-part tackle and 12-in. sheaves. It had also been used in erecting 40-ton girders with 13 part tackles and 12-in. sheaves. It broke under an ultimate strain of 32,245 Ib., and showed an elongation of 11 in. Specimen 2, which. had been used in the erection of four 40-ton girders, broke under an ultimate stress of 98,490 lb., and SAMPLE TESTS OF ROPE. showed an elongation of 12 in. Speci- men 3, which had never been used, de- veloped an ultimate strength of 35,180 Ib. and an elongation of 13 in. The strength of new 2-in. manila rope is given by Trautwine at about 27,500 lb., by C. W. Hunt at 28,500 Ib., and by E. H. Fitler Co., at 28,210 Ib. The ropes here tested were manufac- tured by E. H. Fitler Co., Philadelphia Cordage Works, who based their value given above on government tests, but state that these specimens were better than the ordinary. grade of manila rope on account of the special hard-laid qual- ity. It was observed that the ropes stretched throughout the whole length, even including that portion of the loop mc which passed around the shackle pins.' The percentage of elongation was, how- ever, much greater in the 12-in. unwrap- ped portion than it was in the remainder of the rope, being 3 in. in one case against 8 in. for the remainder. When the ropes failed the lashings held and only one of the strands was found to have been severed. The ropes were pulled in an Olsen hy- draulic testing machine of 800,000 lb. ca- pacity, used for testing chains at the works of Bradley & Co., Philadelphia. The machine is operated by a belt on the pump, and the balance lever is operated by hand. A long trench is provided with notches about 10 ft. apart to provide bearing for transverse pieces to which 'one of the shackles is attached. The other shackle is connected to the plunger, and the carriage moves on guides on the edges of the trench. o It is to be hoped that more tests will be made along the same line to investigate the stiffness of the ropes, che allowable diameter of sheaves, the effect of internal friction between the strands and the effect of careful service. Such data would be of great value to bridge erectors and to shipping interests. Mr. Lewis D. Rights, eastern manager of the Lewis F. Shoemaker & Co., Schuyl- kill Bridge Works, observed the tests and recorded the data given here. BRITISH SHIP BUILDING SLUMP. Ship building in all the British cen- ters is in a vety bad way indeed. The official returns show that in May the additions to the registers were less than the removals. There were added 30,000 tons of new steamers, and there were removed 32,000 tons. Of new sailing vessels, 2,000 tons were added, and the removals were over 8,000 tons." Thus, in one month, Brit- ish steamer fleets decreased by 2,000 tons, and sailing ships by 6,000 tons, a net decrease of 8,000 tons of ship- ping in the time named. ~PEARY'S SHIP STARTS NORTH. The Arctic exploration ship Roosevelt, in which Commander Peary is again to make an effort to locate the magnetic North Pole, sailed from New York July 6. She was given an enthusiastic send- off. A stop was made at Oyster bay in order that President Roosevelt might have an opportunity to inspect the ship. Commander Peary is not to join the ves- sel until she has reached Sydney, Cape Breton, from whence he will proceed to his first base at Etah, Greenland. Major Graham D. Fitch, government engineer, with head-quarters at Duluth, is making a tour of his district in the government yacht Vidette.