What is the maximum permissible slip (in centimeters) of the winding drum when the conveyance is loaded to the maximum weight of persons?

What is the maximum permissible slip (in centimeters) of the winding drum when the conveyance is loaded to the maximum weight of persons?

• A. 30 centimeters
• B. 20 centimeters
• C. 40 centimeters
• D. 10 centimeters

Answer: (A)

This tests understanding of how much drum slip is allowed under full load in a hoisting system. Slip is how much the rope lags behind the drum’s rotation—the drum turning doesn’t translate into rope movement exactly the same amount, usually because of friction limits, rope condition, or wear. When the conveyance is loaded to its maximum weight of persons, the drive is under its highest torque demand, so a clear, enforced limit on slip is needed to keep control, ensure the brake can hold, and prevent the rope from slipping enough to cause uncontrolled movement. The specified maximum is 30 centimeters. This value provides a safe margin for rope wear, drum surface condition, and drive friction, ensuring reliable control and stopping under the heaviest load. If slip approaches this limit, maintenance should be checked (rope condition, drum grooves, braking system) to maintain safe operation. The other numbers aren’t the official limit: 40 cm would exceed the safe tolerance, while 20 cm or 10 cm are simply lower than the required maximum and would not reflect the designed safety margin for full-load operation.

This tests understanding of how much drum slip is allowed under full load in a hoisting system. Slip is how much the rope lags behind the drum’s rotation—the drum turning doesn’t translate into rope movement exactly the same amount, usually because of friction limits, rope condition, or wear. When the conveyance is loaded to its maximum weight of persons, the drive is under its highest torque demand, so a clear, enforced limit on slip is needed to keep control, ensure the brake can hold, and prevent the rope from slipping enough to cause uncontrolled movement.

The specified maximum is 30 centimeters. This value provides a safe margin for rope wear, drum surface condition, and drive friction, ensuring reliable control and stopping under the heaviest load. If slip approaches this limit, maintenance should be checked (rope condition, drum grooves, braking system) to maintain safe operation.

The other numbers aren’t the official limit: 40 cm would exceed the safe tolerance, while 20 cm or 10 cm are simply lower than the required maximum and would not reflect the designed safety margin for full-load operation.