Which NSTM provides general information about reduction gears?

NSTM 241 is the correct reference for general information about reduction gears. This document serves as a comprehensive guide outlining the principles of operation, maintenance, and repair of reduction gears that are typically used in marine propulsion systems. It includes information on the various types and configurations of reduction gears, their components, and their applications, making it an essential resource for Machinist's Mates who deal with propulsion machinery and its associated systems on naval vessels.

In contrast, the other NSTM references cover different aspects. For example, NSTM 252 deals with the operation and maintenance of fuel oil systems, NSTM 267 focuses on the principles concerning steam propulsion plants, and NSTM 300 pertains to indicators and their installation. Each NSTM is specialized in its relevant area, so understanding NSTM 241's focus helps identify why it is the appropriate source for reduction gears.