Rope team may be used in the event of a crevasse accident, e.g. to make a Swiss pulley in order to rescue a fallen climber. For larger groups of about four people or more, recovering a fallen man is most easily done using a team pull. When "walking on a rope", the fall of one person - for example, into a crevasse - must be broken by the rest of the rope team members. So there is a danger that such a fall can endanger the entire team. On steep firn or ice-covered mountainsides, where possible and appropriate, the rope must be
Elevator poor energy efficiency. Gearless traction machines are low-speed (low-RPM), high-torque electric motors powered either by AC or DC. In this case, the drive sheave is directly attached to the end of the motor. Gearless traction elevators can reach speeds of up to , A brake is mounted between the motor and gearbox or between the motor and drive sheave or at the end of the drive sheave to hold the elevator stationary at a floor. This brake is usually an external drum type and is actuated by spring force and held open electrically; a power failure will cause the brake