R/V Vema deep-sea winch

Various types of deep-sea winches have been used aboard oceanographic vessels. Their design has been limited to use of electrically powered drums and winding engines utilizing rather elaborate speed regulation and braking devices, and of diesel-driven winches utilizing multi-ratio geared transmissions for hauling and the engine itself for braking. These winches have been able to lower cable at rates of 50–80 fathoms (100–150 m) per minute and to hoist at rates of 25–40 fathoms (50–75 m) per minute.

The recently redesigned heavy trawl winch being used aboard the R.V. Vema of the Lamont Geological Observatory (Columbia University) is described herein. During the lowering operation a Parkersburg Hydrotarder is used for braking. It provides a varying positive braking action functioning as a water brake which converts the mechanical energy into heat. For raising, a diesel engine drives the winch through a torque converter. This permits full utilization of the developed power of the engine, a method of exerting a fixed tension when pulling the apparatus out of the bottom, and eliminates the necessity of shifting gears and engine lugging (running over-loaded at slow speed) as with geared transmissions. With the new equipment, cable lowering speeds of 120 fathoms (220 m) per minute and raising cable speeds of 50–70 fathoms (100–130 m) per minute are possible.