When carmen or other workers inspect or repair equipment, they display a blue flag by day or a blue light at night at the end of the track or on the controlling locomotive, and line and lock the switches leading in. Equipment under blue flag protection cannot be coupled to or moved, and no other cars can be placed on that track; only the craft that put the signal up may take it down. It is a federal requirement, and violations draw the heaviest discipline a railroad hands out.
Track 7's under blue flag, the car knockers are in there doing the air, so pull out of 8 instead.
Also heard as
- blue signal
- blue flag protection
Related terms
Car knocker
A carman, the mechanical worker who inspects and repairs railcars and tests their brakes.
Derail
A device on a rail that lifts a rolling car's wheels off the track before it can reach another track.
Rip track
A yard track where carmen make light repairs to cars without sending them to a heavy shop.
Line
To throw a switch so it routes a train or car onto the intended track.