49 C.F.R. § 230.70 – Safe condition.

(a) Pre-departure inspection. At the beginning of each day the locomotive is used, the steam locomotive operator shall ensure that:
1. (1) The brakes on the steam locomotive and tender are in safe and suitable condition for service;
2. (2) The air compressor or compressors are in condition to provide an ample supply of air for the locomotive service intended;
3. (3) The devices for regulating all pressures are properly performing their functions;
4. (4) The brake valves work properly in all positions; and
5. (5) The water has been drained from the air-brake system.
(b) Brake pipe valve required. Each steam locomotive shall have a brake pipe valve attached to the front of the tender, the rear of the back cab wall, or adjacent to the exit of a vestibuled cab. The words “Emergency Brake Valve” shall be clearly displayed near the valve.