الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
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Abstract
A controllable-pitch propeller is a screw propeller with blades rotatable about their pitch-changing axis, usually -hrough hydraulic means to satisfy a whole range of oper¬ating conditions.
A CP propeller is sometimes mistakenly refered to as an adjustable-pitch propeller, a variable-pitch propeller or a varying pitch propeller:
- An adjustable-pitch propeller is different from a CP prop¬eller in that the shaft must be brought to a standstill before pitch changing.
- A variable-pitch propeller is a propeller whose pitch can be altered by a small amount. This is usually carried out in drydock if the original pitch has proven to be too big or too small.
- A varying pitch propeller can be either a solid or a CP propeller with the pitch at each blade section varying from root to tip.
_-.-ery short time after the introduction of the screw prope- _
_er as a means of ship propulsion, changing the propeller :L7ch in order to satisfy different operating requirements --o:S attempted. At first, the designs proved to be inadequate. Fregress began only after the invention of the Kaplan water turbine, and so appeared in 1844 the first CP propeller.
-’ie demand for a fairly reliable propeller with adequate means
changing the pitch arose at the beginning of the present -=-jury. In 1934, the first successful hydraulically operated
propeller capable of absorbing 250 HP was initiated in ---rmany.
73r some time, powering was restricted below 10,000 HP; but
--1974, 46,000 HP have been reached by a 24 feet (7.3 metres) aneter CP propeller built in Japan and installed on the ---jstralian Emblem 11, a single-screw container ship.
1977, the production of CP propellers represented 22% of
- total•propeller production. Two years later, in 1979, it
t2hed 47% of the grand total and is still growing until the --sent day.