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erations, and the other is the injury to the hands of workers due to con- tact with the cement, which oozes through the sacks. One dock man- ager has devised an ingenious hand hook which makes it possible for sacks to be shifted without their actually being touched, and under actual ob- servation has increased manual effi- ciency by nearly 100 per cent. The hook is designed with five fingers which are curved to fit the curve of the sack, and which, there- fore, offer a minimum tearing effect due to the sharp finger tips. The weight of the sack when it is lifted rests largely against the smooth flat surface of the five fingers and the short prongs on each finger (%4-inch) keeps hooks from slipping. Experi- ence with the use of these hooks over a considerable period has failed to develop any noticeable injury to sacks. Steel Grating for Ships Proper grating is of the utmost importance on board ship. Steel grating of one kind or another is widely used particularly in the en- gine rooms of ships. The quantity will of course vary with the size of the ship but it runs into a consider- able item even for the smallest ves- sel. Shipyards have in the _ past sometimes built their own grating. However they can not be as efficient- ly built in a shipyard as they can in a plant specializing in this type of work. The Blaw-Knox Co., Pittsburgh, have developed an especially high grade steel grating and flooring manufac- tured by an electro-forging process originated by this company in the manufacture of grating. This method produces a strictly one-piece grating. The grating is manufactured by plac- ing twisted bars across the top of the bearing bars without sloting or cut- ting the metal. Resistance welding aug- mented by enormous pressure forges the bars into one piece where the metals cross. There are therefore, no holes or slots in this type of grating either before or after fabri- cation. Another important feature about this type of grating, especially for a marine work, is that it gives per- fect traction. It is impossible to slip because of the twisted cross-bar con- struction. The one-piece construc- tion develops the full strength of the metal used in obtaining maximum loading capacity per pound of grating. As there are no holes, slots, angles or crevices left unprotected corrosive action is largely eliminated and it is possible to thoroughly galvanize or paint it. Wall Fixtures The Connecticut Electric Mfg. Co., Bridgeport, Conn., has developed a complete line of bakelite wall plates, convenience outlets, and combinations. Bakelite is said to be particularly suitable for marine installations as it is not affected by moisture, is chemi- cally inert and will not fade or tarn- ish. It is shock proof, the dead front construction preventing shocks due to exposed metal parts. In finish these fixtures are rich brown egg shell. Special colors can also be furnished in addition to the standard brown and black. Sheave Size Affect Life of Wire Rope No single element is more detri- mental to wire rope than an improper- ly fitted sheave, according to Walter Voigtlander, rope engineer, the American Cable Co., Chicago. A pinch- ing sheave, for instance, will do more PITCH DIA (PD) _GROOVE DIA (6 D) | TREAD DIATD) ___ OUTSIDE DIA. (0D) Tolerance of Groove Diameters + 34/7 min. to + ¥e"” max. + jis min. to + 14" max. + 2’ min. to + 436/" max. + 14" min. to + 14” max. Diameter Rope 1" and smaller {91 , diameters for various sizes of wire -rope Proper Groove damage to a wire rope in one hour than a properly grooved sheave could in an entire week or more, or a sheave with too soft a tread will increase abrasion and grinding action to an extent that will cause premature breaking of the outer wires and loss of rope strength. Because of these facts and because sheaves are cheaper than good wire rope, it may be well to look to the sheave and auxiliary equipment if it is felt that the life and service from present rope is not what it should be. Engineers and operators sometimes overlook the fact that by the time it becomes necessary to install a new rope, the old sheave will have become worn to such an extent that it will cause serious loss to the service of the new rope. Invariably excessive wear to the outer wires can be traced to the abrasive action of worn or too soft .sheave treads. When installing a new rope, therefore, it is economy MARINE REVIEW—August, 1927 to gage both the rope and the grooves of all sheaves and drums. If the groove diameter of any sheave is less than the actual calipered rope diameter, de- creased service is bound to result’ if the condition is not remedied. One of the simplest and most ac- curate methods of gaging sheave treads is through the use of a grooved gage as indicated in the accompanying illustration. If this device is used with care and if the tolerances given are strictly adhered to, there may be reason to expect longer and more sat- isfactory rope service. At the time attention is given to sheaves, it is well also to check up on their align- ment. Misalignment will cause considerable wear to both rope and sheaves. In high-speed work, it is particularly ne- cessary to maintain alignment of all equipment and to balance all sheaves. Powerful Motor Drives Pump on Dredge A 2700 horse power motor, is used for driving a centrifugal pump in the new electric dredge CLACKAMAS for the Port of Portland. This motor was built at the East Pittsburgh plant of the Westinghouse Electric & Mfg. Co. It is the largest motor of its kind ever built for use in driving a centrif- ugal pump and was made on a special order from the Port of Portland com- mission. This commission which is ap- pointed by the governor of Oregon has charge of the navigation clearance of the Columbia and Willamette rivers, as Portland lies about 110 miles inland from the Pacific ocean. The dredge for which the huge motor was prepared is the largest suction dredge ever constructed and 2700 HORSEPOWER MOTOR—FOR DRIVING CENTRIFUGAL PUMP—DREDGE CLACKAMAS is the first large sized dredge to use the diesel electric engine. Four diesel engines of a combined rating of 3300 horsepower are used. Each one drives 39