[MrForbes]

The cylinders do hold a lot of air, but the system starts out with 120 psi in 4 tanks, and the compressor can run continuously between shots. The big air use is in returning the cylinders to the down position.

I'll see if I can get a student to calculate the air use per shot, as well as the amount of air that the compressor can pump in a lap (estimated time 15 seconds, which is probably optimistic).