This specification covers reduction gears (including fittings, accessories and reports) for use in Naval submarine and surface ship main propulsion systems where such gears are not integral with or part of the prime mover.

Main propulsion reduction gears are of the following classes and arrangements as specified (see 6.2):

    Classes.

        Class A - For use in Naval submarines.
        Class B - For use in Naval surface ships.

    Arrangements.

        1 - Twin input-dual torque
             path-tandem-articulated, double
             reduction, double helical (see figure 1).

Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: Commander, SEA 03Q42, Naval Sea Systems Command, 2531 Jefferson Davis Hwy, Arlington, VA 22242-5160 by using the self-addressed Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter.

        2 - Twin input-tandem-articulated, double
             reduction, double helical (see figure 2).
        3 - Single reduction, one or more power inputs,
             double helical (see figure 3).