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38 are not affected by the exaction of a $20 bonus. On the principle of "In order to cure a disease it is necessary to remove its cause," let shipowners agree to em- ploy only those seamen who are will- ' ing to finish their task before request- ing payment for same. The entire mis- erable business of "advance" has re- sulted' in making seamen proverbially improvident, besides being the cause: of the existence of the "shipping mas- ter' who now, like a veritable slave owner, dictates: "You cannot hire MY sailor unless you pay MY- price." By making it illegal to issue allot- ment notes; in short, by summarily stopping the practice of paying for a promise to work in the future, a great benefit will be done 'to both the ship- 'owner and the seaman. F. H, ELECTRIC TUGS AT NIAGARA : FALLS. One of the most serious problems: of the several power developments located at Niagara Falls has been the handling' Not' of ice during the winter months. only is the normal formation of ice in the river serious, but under certain wind conditions in the great lakes large floes of ice are discharged from Lake Erie into the head of the Niagara river com- pletely filling the river from shore to shore. When the plant of the Niagara Falls Power Co. was first started, there was no similar installation of its kind in the world, and consequently there was no previous experience from which the en- gineers could draw for guidance in de- termining just what conditions could be expected in drawing water in consider- able quantity from a comparatively shal- low, but wide river, under severe ice conditions. The intake canal was set at an angle slightly less than 90 degrees with the up stream bank of the river. With this arrangement, it was thought that floating ice would be deflected by, instead of into, the canal entrance. As a further protection, log booms composed of a series of floating logs were placed across the mouth of the canal. This proved partially effective, but as the output of the plant, and consequently 'the volume of water .entering the canal, increased, large amounts of ice were drawn into its entrance. This ice, if allowed to pass into the penstocks, tends to clog the turbines, causing loss in effi- ciency and output, or even serious dam- age. To dispose of the ice entering the canal, a vertical shaft was sunk at its far end, emptying into the discharge tun- nel from. the wheel pit. As this shaft is necessarily located beyond the in- takes to the penstocks, there is no draft of water towards it except that THE MARINE. REVIEW - which is produced by the small amount of water which is allowed to pass through the sluiceway leading to the head of the shaft. Some additional means was therefore found necessary to pro- pel the floating ice towards this sluice- way, as otherwise the ice accumulates, and builds up in the lower end of the canal, It has been found that a tug boat is the most efficient and economical method of accomplishing this result. When moored with the propeller running at full speed, a large surface current of water is set in motion from the stern of the boat. By varying the length of the moor- house through an overhead trolley and cable. ' Two years ago, the Niagara Falls Power Co. installed in its intake canal on the American. side of the river a. small experimental elec; tric tug to supplement the work of a steam tug. This tug, which is still in service, is 25 ft. long by 8 ft. beam by 4 ft. draught, with a propeller 52 in. in diameter by 2 ft. pitch. It is supplied with power through an over- head trolley 750 ft. long composed of two No. 00 copper wires, 2 ft. apart, suspended about 35 ft. above the water, running lengthwise down the middle of ELECTRIC TUG OPERATED BY TROLLEY. ing cable, or by changing the point of mooring, this current of water can be directed from any point in the canal so as to effectively propel: all floating ice towards the ice sluiceway. When not moored, the tug boat can be used to break up, and stir up any unusual accu- mulation of ice tending to block the in- take canal. For several years, steam tugs were employed for this purpose by the Niagara Falls Power Co., but as the work is only ~ intermittent, it was felt that an electric tug would be more economical on ac- count of lower operating expenses. With steam tugs, the government regulations require the steady employment of a pilot, engineer and fireman, and the nature of the work necessitated the keeping up of steam 'constantly, as the tug might be called for on a moment's notice. The area within which the tug had to operate was small so there was no physical limi- tations to prevent the use of an electric tug supplied with energy from the power the canal. The aluminum trolley car- riage travels on these wires, and is of special construction designed by the power company's engineers. From the carriage a No. 00 duplex flexible rubber and braid cable leads di- rect to the motor controller through a hollow mast over the pilot house of the boat itself, the top of the mast_ being about 15 ft, from the. surface of the water. The cable has sufficient slack to allow the tug to operate at either side of the canal giving an effective atea of work the full width of the canal and the full length of 'the overhead trolley wires. The electric equipment in the boat con- sists of one 75-H. P., single-phase, 220- volt, 25-cycle alternating current motor of the standard railway type with drum controller and grid resistances. The motor is geared to an extension of the propeller shaft through a single pinion and gear having a ratio of 16 to 66. This gives about 240 revolutions per minute to the propeller shaft with the