Maritime History of the Great Lakes

Marine Review (Cleveland, OH), May 1931, p. 48

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rT fl | a | LI Ld =| Care and Operation O Conducted by H.E.STOCKER fr ajay, C a | 3 Electric Cargo Winches an Aid to E ICIENCY important pieces of apparatus on a ship in port. They can be either a source of pride or a source of worry, depending upon the care- taker. Because of location on an open deck, occasional submergence by seas, operation in weather ranging from a blistering sun to a blizzard, they have to be built to stand a lot of punish- ment. Apparatus that cannot with- stand the elements has no place on a ship. Cargo winches are operated by steve- dores of all nationalities, all creeds and all colors. Printed instructions, oral instructions, or brass signs are of little use. Their operation must both be simple and obvious. From this, it looks like the manufacturer has taken quite a little responsibility on his hands, and so he has. When he took a chance on the elements, or depended upon operating instructions being given to the stevedores, every- thing went wrong. Control finger tips were burned, fuses were blown, and resistors melted. Anyone of these items can put a cargo winch out of commission temporarily, and there is nothing quite as useless as a cargo winch that will not work. The history of cargo winch electrifi- cation is short but exciting. The read- ing of the early records is an. educa- tion in itself. The turning point came C ARGO winches are about the most The author, Frank V. Smith, is a member of the staff of the Federal and Marine Department of the General Elec- tric Co. 48 By Frank V. Smith when the manufacturers ceased trying to do the impossible and set up a bogie based on actual ship conditions. The ideal condition set up for the design- ers to meet read about as follows: Motors—To be of totally en- closed type, to resist the entrance of water even if submerged for short intervals, and self-draining of water that might seep along the shaft, or of condensate caused by temperature changes. All fittings to be noncor- rodible and to withstand damp salt air. Insulation to be nonhydroscopic. Frame to be heavy and rugged to with- stand seas. Lubrication to be effective when motors are operated at a tilt. Operating Stand—One lever op- eration; to operate easily so as not to tire the operator, and situated at a convenient height—the height of a man’s elbow. Operating stand to be small and rugged, and not to obstruct view of either the hatch or side of ves- sel. Operation of control lever: Upright position “Off”; forward movement, SFLOISt’’= backward movement, “Low- er.” Speeds to be gradually higher as lever is moved from central position. Graduated, automatic acceleration or retardation of load, irrespective of the speed with which the stevedore may move the lever. Braking—Brakes to automatically set when the control lever is moved to the “Off” position and also in case of any line disturbance, or cessation of power supply. Retardation of load to be accomplished by dynamic brak- ing and shoe type of brake to come into play as a holding brake only in order to save brake linings wear and tear and eliminate renewals. Control Panel—Solenoid actu- MARINE REVIEW—May, 1931 ated contractors with are chutes, and of sufficient capacity to give continu- ous service over long periods of time without renewals. Under-voltage and over-voltage protection, and automatic relays to provide smooth rapid accel- eration without jerk or high peak cur- rents. Overload circuit breaker to be reset when controller handle on oper: ating stand is moved to “Off’’ position. In summing up the advantages of the ideal system, it will be noted that the stevedore has been relieved of all re- sponsibility and it presupposes only enough knowledge on his part to push or pull a small lever in the direction he wishes the load to travel. He is even relieved of the responsibility of working a foot brake. Before the days of automatic control, the stevedore was supposed to move the control handle slowly so as not to cut out all of the line risistance before the motor had a chance to accelerate. In an American port this might be accomplished in a measure by proper instructions, but when a ship arrived in some foreign port with all of the language difficul- ties, it was not easy. When stevedores were told to move the control handle slowly, they generally jerked it over all the faster, with the result that fuses were blown and finger tips weld- ed. Too much persuasion even led to strikes, with the result that ships were delayed. Spare parts were ordered by the gross—a good business for the elec- trical manufacturer, but a poor adver- tisement for electric cargo winches. During the transition period, be- tween the use of manual control and

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