49 CFR §230.82

1. (a)General provisions. Each steam locomotive shall have a fire door which shall latch securely when closed and which shall be maintained in a safe and suitable condition for service. Fire doors on all oil-burning locomotives shall be latched securely with a pin or key.
2. (b)Mechanically operated fire doors. Mechanically operated fire doors shall be so constructed and maintained that they may be operated by pressure of the foot on a pedal, or other suitable appliance, located on the floor of the cab or tender at a suitable distance from the fire door, so that they may be conveniently operated by the person firing the steam locomotive.
3. (c)Hand-operated doors. Hand operated fire doors shall be so constructed and maintained that they may be conveniently operated by the person firing the steam locomotive.