Subpart E - Track Appliances and Track Related Devices
This Subpart prescribes minimum requirements for certain track appliances and track-related devices.
Each derail must be clearly visible. When in a locked position a derail must be free of any lost motion which would allow it to be operated without removing the lock.
Derails must be installed when there is any possibility of equipment that has been left standing on tracks other than main tracks or sidings being moved by gravity so as to obstruct a main track or siding.