What is a railroad detective?

Plailnclothes security men employed by Railroads and transit authorities ( such as the MTA for subway cops- some of them are uniformed. In former Soviet Union there is a transportation security division of the Ministry of Internal Affairs and these operate undercover on all public transit, especially railways. They are almost the equivalent of KGB officers but have the transit beat. On low-priority assignments, they pack old gas-seal revolvers ( .32 Moisin-Nagant) on the more important tasks they use modern automatics as to KGB men.