CPCS Crane Operations and Signals 2

Question 1

When a crane is lifting a load and the wind speed increases, what effect does this have on the operation?

Accepted Answer

It increases the dynamic loading on the crane and can cause the load to swing dangerously

Answer

Wind increases the dynamic forces on both the crane structure and the suspended load. Wind can cause loads to swing uncontrollably, increasing the effective radius and potentially exceeding the crane's capacity. Most cranes have maximum wind speed limits specified by the manufacturer.

Question 2

What does the term 'duty chart' or 'load chart' refer to on a crane?

Accepted Answer

A table showing the maximum safe load the crane can lift at various radii and boom lengths

Answer

The duty chart (load chart) is a critical document showing the crane's safe working loads at different radii and boom configurations. The operator must consult this before every lift to ensure the load does not exceed the crane's capacity at the planned working radius.

Question 3

Who is the 'Appointed Person' in a crane lifting operation under BS 7121?

Accepted Answer

The person responsible for planning and directing the lifting operation

Answer

The Appointed Person is the individual with overall responsibility for planning, supervising, and directing the lifting operation. They must be competent, have practical and theoretical knowledge of lifting, and ensure the lift plan is followed throughout the operation.

Question 4

What must a slinger/signaller verify about the load before attaching slings?

Accepted Answer

The weight of the load, its centre of gravity, and the condition of lifting accessories

Answer

Before slinging, the slinger must verify the load's weight (checking delivery notes or markings), identify the centre of gravity, inspect the slings and lifting accessories for damage, and ensure the correct type and capacity of slings are used for the load.

Question 5

What is the minimum safe clearance distance that should be maintained between a crane and 400kV overhead power lines?

Accepted Answer

15 metres

Answer

For 400kV overhead power lines, the minimum safe clearance distance is 15 metres from the nearest line. This distance accounts for the risk of electrical arcing and the potential movement of the crane's boom, jib, and load. Lower voltages require smaller but still significant clearances.

CPCS Theory Practice Test

CPCS Theory Practice Test

CPCS Crane Operations and Signals 2