Abstract
With years to elapse, ships undergo an unfavorable operationg condition-over-torque of main engine, by their speeds being decreased due to the deterioration of the performance by aging of hull, main engine and propeller.
There are several measures available against such over-torque condition:
—applying a margin to the propeller speed at a propeller designing stage,
—recoditioning main engine,
—cleaning up fouled hull surface,
—polishihng propeller surface,
—modifying propeller particulars, etc.
Among these measures, the modifying of propeller particulars is usually practiced from viewpoints of workability, economy and effectiveness.
This paper describes modifying methods of propeller particulars, with effects on shafting, etc., which will be a useful guide to ship operators and shipbuilders.
