IUSSCAA Message Board


UNCLASSIFIED, NON-POLITICAL, and  NON-SENSITIVE POSTS ONLY
IUSSCAA Posting Guidelines


IUSSCAA Wallpapers
Ocean Night 1280x1024 1024X768 800X600
Mid-Watch   1280x1024 1024X768 800X600



IUSSCAA Message Board
Start a New Topic 
Author
Comment
Useful Background Information for Any Analyst

See Link.

Sample:

Steam turbines gearing arrangement

Steam turbines operate at speeds up to 6000rev/min. Medium-speed diesel engines operate up to about 750rev/min. The best propeller speed for efficient operation is in the region of 80 to l00 rev/min. The turbine or engine shaft speed is reduced to that of the propeller by the use of a system of gearing. Helical gears have been used for many years and remain a part of most systems of gearing. Epicyclic gears with their compact, lightweight, construction are being increasingly used in marine transmissions.

Example:

The PAPA Class, designed mid-1960s with an epicyclic (planetary) gear system. See specs below:

Machinery
2 V-5R nuclear reactors, 2 GTZA-618 geared steam turbines units
Power, h. p.
80000
Max speed, kts
16 / 45

PAPA was designed to have a 10-knot speed advantage over US carriers and be able to run them down in the open ocean which it once did in late 1971.

Visits: