An apparatus consisting of an outside shell and a sheave through which a rope may be passed (pulley).

The pressure that would be produced by stopping a moving stream of liquid or gas.

A built in mechanical device to recover a portion of the power consumed by a constant speed centrifugal compressor when operating at reduced capacity or reduced pressure rise, or both.

block

Light-weight foresail similar to a spinnaker but set without a pole.

Small, circular sheets of newly-formed ice that do not impede navigation.

A written contract between the owner of a vessel and the person desiring to employ the vessel (charterer); sets forth the terms of the arrangement such as duration of agreement, freight rate and ports involved in the trip.

A free port in a country divorced from Customs authority but under government control. Merchandise, except that which is prohibited, may be stored in the zone without being subject to import duty regulations.

A common measurement of the internal volume of a ship with certain spaces excluded. One ton equals 100 cubic feet; the total of all the enclosed spaces within a ship expressed in tons each of which is equivalent to 100 cubic feet.

Port of initial Customs entry of a vessel to any country. Also known as First Port of Call.

The triangle formed by the masthead, the base of the mast at deck level, and the lower end of the headstay.

To temporarily stop all movement of a line through a block by placing the hauling part across the sheave of the block. This jams the sheave and holds it tight, and a pull on the hauling part will release it.

A stationary element between stages of a multistage centrifugal compressor. It may include guide vanes for directing the flowing medium to the impeller of the succeeding stage. in conjunction with an adjacent diaphragm, it forms the diffuser surrounding t ...

A structure of heavy timbers placed between ground ways and cradle to support the ship during launching.

A device that indicates pressure differential above or below atmospheric pressure.

The point (speed of sound) at which air flow through an orifice can not increase regardless of pressure drop.

The opening between the jib and the mainsail. Wind passing through this opening increases the pressure difference across the sides of the mainsail, helping to move the boat forward.

A raised portion of the hull forward of the cockpit intended to prevent water entering.

(1) The flag traditionally flown by pirate ships. (2) The name given by sailors to the bubonic plague, whose victims were said to turn black.

An anchor which has become entangled with some object on the bottom, or, on weighing, has it's rode or chain wound around its stock or flukes.