When the headache ball moves close to the bottom boom
nose sheave, it makes contact with and lifts the anti-two
releases a spring-held limit switch that locks out further
upward movement of the headache ball, thus preventing
physical contact between the headache ball and the lower
boom nose sheave. The headache ball can be lowered
away from the boom nose sheave.
Install anti-two block weight by placing two weight halves around the hoist cable. Insert
cotter pins to join the two halves.
Attach a light load to headache ball.
Remove the load.
Change 1 6-29