A Brief Introduction To Drawworks

A drawwork is a large spool of wire--think of a fishing reel or winch but on a much larger scale. A drawwork can contain hundreds of feet of thick steel alloy cable that is capable of holding thousands or several hundred thousand pounds. They are often used primarily for drilling, mainly oil and gas drilling. The primary purpose of a drawwork is to move the traveling block up and down. The traveling block consists of various pulleys that help at the process of moving the drill bit. Through the use of this pulley system, some drawwork cables on very large drilling rigs can have a cable tension of upwards of a million pounds. The drawwork is made up of five main parts: the drum, the motor, the reduction gear, the auxiliary brake, and primary brake. The drum is where the cable winds around or unwinds from depending on the current state of use. The motor itself needs to be extremely powerful, and depending on the size of the drawwork it is on could be upwards of several thousand horsepower. The gear sets the speed of which the drawwork operates, and the brakes are to help in stopping the cable's momentum.