Counterweight safeties are to be _______ on the rail.

Counterweight safeties being centered on the rail ensures proper alignment and function during operation. This alignment is crucial because the safeties need to engage accurately in the event of an emergency or malfunction. When the counterweight safeties are centered, they can effectively prevent the counterweight from dropping too far, thus contributing to the safe operation of the elevator system.

Achieving this centering is not simply about positioning but involves meticulous calibration and alignment to ensure the safety mechanisms activate correctly. If the safeties were off-center, it might lead to improper engagement, which could compromise the protective measures designed to prevent accidents.