Tun. Large cask holding 252 gallons (four hogsheads) of wine. 2. Wine measure of same quantity.
Tunnage. Duties levied on every tun of wine, and pound of goods, shipped from or to England. Introduced about 1348. Was the beginning of the present Customs duties.
Tunnel. Arched casing around propeller shafting. Extends upwards in after holds of cargo vessels with engines amidships. Goes to stern gland and allows access to propeller shaft bearings.
Turbine. Machine in which rotary motion is produced by high velocity of a fluid acting on blades appropriately mounted in its path. Can be divided into two types, 'impulse' and 'reaction'. Broadly stated, an impulse turbine is turned in same manner as an undershot water mill; reaction turbine being turned on same principle as a windmill. Marine turbines are steam or (petroleum) gas-driven. The latter needing no boilers.
Turbulence. Disturbed, or eddying, movement of any fluid when passing over any obstruction-solid, liquid, or gaseous-in its path. Is of importance in meteorology.
Turk's Head_________ _367__ ______Twiddling Line
Turk's Head. Knot put in end of rope by unlaying strands, making a 'wall' and crowning it, then following through twice. Can be made with a single line. Resembles a turban in appearance.
Turn. Complete encirclement of a cleat, bollard, or pin by a rope.
'Turn.' Order given to man holding sand-glass when heaving the (hand) log and stray line is out. He then turns glass so that sand runs down, and reports, 'Done'.