Main brake is band brake or disc brake, the auxiliary brake is eddy current brake (water-cooled or air-cooled)
Features of mechanical drawworks

All bearings are roller bearings. Shafts are made of alloy steel;
Chains with forced lubrication can transmit with high accuracy and high strength;
The drum is grooved. Ventilating air clutches constitute the high and low speed ends;
The brake drum(brake disc) is dealt with forced cooling with circulating water;
The surface case was hardened with medium frequency, and is durable;
The tooth profile of sprocket was hardened with medium frequency. Involute serration tooth clutch worked as shifting clutch;
Main brake is band brake or disc brake, the auxiliary brake is eddy current brake (water-cooled or air-cooled)