NPFC - DOD-P-24562
PROPELLERS, SHIP, CONTROLLABLE PITCH (METRIC)
|Publication Date:||1 November 1982|
This specification covers general requirements for marine propellers of the controllable pitch type. Specific requirements will be in accordance with the contract or order. For this specification, a propeller shall be considered as consisting of propeller blades, a hub with an internal activating mechanism for the blades, propulsion shafting, shafting internal components, an oil distribution box or pitch control unit, hydraulic and mechanical systems required for operation of the propeller pitch mechanism, and associated components, tools, and devices.
Controllable pitch propellers shall be of the following styles, blade designs, types, and levels, as specified (see 6.2.1):
Style H - Hydraulic or hydro-mechanical propeller blade actuating mechanism. Style M - Mechanical propeller blade actuating mechanism. Blade design A - Propeller hydrodynamic blade design provided by the contracting activity (see 3.4.2). Blade design B - Propeller hydrodynamic blade design provided by the contractor (see 3.4.3). Blade design C - Propeller blade design in accordance with American Bureau of Shipping (ABS) Rules with no ice strengthening requirements (see 3.4.3).
Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: Commander, Naval Sea Systems Command, SEA 55Z3, Department of the Navy, Washington, DC 20362 by using the self-addressed Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter.
Blade design D - Propeller blade design in accordance with ABS Rules, with ice strengthening (see 3.4.3). Tolerance level 1 - Very high tolerances on hydrodynamic surface measurements (see 3.17.2). Tolerance level 2 - High tolerances on hydrodynamic surface measurements (see 3.17.3). Tolerance level 3 - Moderate tolerances on hydrodynamic surface measurements (see 3.17.4). Tolerance level 4 - Tolerances on hydrodynamic surface measurements to suit the intended service (see 3.17.5). Type 1 - Hydraulic system main pump, shaft- or gear-driven (see 3.7.4). Type 2 - Hydraulic system main and standby pumps, electric motor-driven (see 3.7.5). Type 3 - Hydraulic system main pump, electric motor-driven; standby pump, shaft- or gear-driven (see 3.7.6). Test level A - Spin testing of assembled propellers (see 4.4.1, 4.4.2, 4.4.5, 4.5, and 4.6). Test level B - Nonrotating testing of assembled propellers (see 4.4.1, 4.4.3, 4.4.5, 4.5, and 4.6). Test level C - Testing of assembled propeller following installation in ship (see 4.4.1, 4.4.4, 4.4.5, 4.5, and 4.6).
This specification is intended to be applicable to any controllable pitch propeller for shipboard use.