A crown block is the stationary section of a block and tackle that contains a set of pulleys or sheaves through which the

drill line In a drilling rig, the drill line is a multi-thread, twisted ''wire'' rope that is threaded oreevedthrough in typically 6 to 12 parts between the traveling block and crown block to facilitate the lowering and lifting of the drill string into and ...

(wire rope) is threaded o
reeved
and is opposite and above the

traveling block A traveling block is the freely moving section of a block and tackle that contains a set of pulleys or sheaves through which the drill line (wire rope) is threaded oreevedand is opposite (and under) the crown block (the stationary section). The ...

. The combination of the

, crown block and wire rope

gives the ability to lift weights in the hundreds of thousands of pounds. When running heavy casing strings hook loads occasionally exceed one million pounds.

See also