Section 218.121 - Purpose and scope(a) The purpose of this subpart is to ensure that each train is adequately staffed and has appropriate safeguards in place for safe train operations under all operating conditions.(b) This subpart prescribes minimum requirements for the size of different train crews depending on the type of operation and operating conditions. The minimum crew size requirements reflect the safety risks posed to railroad employees, the public, and the environment. This subpart also prescribes minimum requirements for the location of a second crewmember on a moving train and promotes safe and effective teamwork. Each railroad may prescribe additional or more stringent requirements in its operating rules, timetables, timetable special instructions, and other instructions.(c) The requirements in this subpart are not applicable to a train operation controlled by a remote control operator as defined in § 229.5 of this chapter.