218.25—Workers on a main track.
When workers are on, under, or between rolling equipment on a main track:
(b)
If the rolling equipment to be protected includes one or more locomotives, a blue signal must be attached to the controlling locomotive at a location where it is readily visible to the engineman or operator at the controls of that locomotive.
(c)
When emergency repair work is to be done on, under, or between a locomotive or one or more cars coupled to a locomotive, and blue signals are not available, the engineman or operator must be notified and effective measures must be taken to protect the workers making the repairs.
[44 FR 2175, Jan. 10, 1979, as amended at 48 FR 6123, Feb. 10, 1983]