Coupling two cars joins the knuckles but not the air: a crew member has to go between the cars under proper protection, join the glad hands and open the angle cocks at each end so the brake pipe is continuous. Lacing up a long track of cars takes real time, and an angle cock left closed cuts off every car behind it from the engineer's brake control. Air tests start only after the conductor confirms the air is laced up.
Lace up the air on 4 and 5 while I get the units, we're doubling those two tracks together.
Also heard as
- lace 'em up
- hook up the air
- cut in the air
Related terms
Glad hands
The coupling heads on the ends of air brake hoses, which lock together when two cars are joined.
Brake pipe
The air line running the full length of a train that charges and controls every car's brakes.
Set and release
Applying the train's air brakes and then releasing them, the basic sequence of every air brake test.
Cut
A group of cars coupled together and handled as one piece; as a verb, to uncouple them.