WATER JACKET: Internal passages and cavities cast into the cylinder block of engines and air compressors through which water is circulated around and adjacent to friction (heat) areas.

WATER TUBE BOILER: Boiler in which the water flows through the tubes where it is heated by the gases of combustion.

WATT: The unit of electrical power.

WATTMETER: An instrument for measuring electrical power in watts.

WINCH: A hoisting or pulling machine fitted with a horizontal single or double drum. A small drum is generally fitted on one or both ends of the shaft supporting the hoisting drum. These small drums are called gypsies, or winch heads. The hoisting drums either are fitted with a friction brake or are directly keyed to the shaft. They are in the form of a spool and carry the working wire rope. The driving power is usually electricity, but hand power is also used. A winch is used principally for handling, hoisting, and lowering cargo from a dock or lighter to the hold of a ship and vice versa.

WINDLASS: An apparatus in which horizon-tal or vertical drums or gypsies and wildcats are operated by means of a steam engine or motor for the purpose of handling heavy anchor chains, hawsers, and so forth.

WIPED BEARINGS: A bearing in which the babbit has melted because of excess heat.

WORK: The transference of energy from one body or system to another.

WORK REQUEST: Request issued to naval shipyard, tender, or repair ship for repairs.

WORM, WORM SHAFT: A threaded shaft designed to engage the teeth of a wheel lying in the plane of the shaft axis. This type of gear is used for the transmission of heavy loads at low speeds.

WYE GATE: A fitting with two separately controlled hose fittings, designed to connect to an outlet.

YOKE: A frame or bar having its center portion bored and keyed or otherwise constructed for attachment to the rudder stock. Steering effort from the steering gear is applied to each end of the yoke for the purpose of turning the rudder.

ZERK FITTING: A small fitting to which a grease gun can be applied to force lubricating grease into bearings or moving parts of machinery.

ZERO SETTING: The output of a device when its input is minimum.

ZINC: (1) A primary metal useful in a number of anticorrosion applications. (2) A metal block or form placed in seawater systems to counteract the effects of electrolysis.