CPCS Crane Operations and Signals — Questions and Answers
Question 1: In the UK standard crane signalling system, what does the signal of one arm extended horizontally with the palm facing down, moved up and down, indicate?
- Hoist up
- Lower the load (Correct answer)
- Slew left
- Emergency stop
Correct answer: Lower the load
In the standard UK crane signals (as defined in BS 7121), an arm extended horizontally with the palm facing down, moved repeatedly up and down, is the signal for 'Lower'. The signal must be clear, deliberate, and given by the appointed slinger/signaller.
Question 2: What is the maximum number of appointed signallers who should communicate with a crane operator at any one time?
- Three
- Two
- One (Correct answer)
- As many as needed
Correct answer: One
Only one appointed signaller should communicate with the crane operator at any one time to prevent confusion. If the crane needs to be directed by a different person, a formal handover of signalling duties must take place.
Question 3: Under BS 7121, what must happen before any lifting operation with a crane commences?
- The crane must be painted in high-visibility colours
- A lift plan must be prepared by a competent person (Correct answer)
- All site workers must leave the area completely
- The crane must be tested to its maximum rated capacity
Correct answer: A lift plan must be prepared by a competent person
BS 7121 and LOLER 1998 require that every lifting operation is properly planned by a competent person. The lift plan must assess the load weight, ground conditions, radius, environmental factors, and identify suitable equipment and exclusion zones.
Question 4: What does the term 'radius' mean in crane operations?
- The height of the crane's mast
- The horizontal distance from the crane's centre of rotation to the load (Correct answer)
- The length of the crane's boom
- The diameter of the slew ring
Correct answer: The horizontal distance from the crane's centre of rotation to the load
The radius is the horizontal distance from the centre of the crane's slew ring to the centre of the load being lifted. As the radius increases, the crane's safe working load (SWL) decreases. Operators must always check the load chart for the relevant radius.
Question 5: What is the emergency stop signal used in UK crane operations?
- Waving one arm in a circle above the head
- Both arms extended horizontally, then moved rapidly inward and crossed (Correct answer)
- Pointing at the ground with both hands
- Blowing a whistle three times
Correct answer: Both arms extended horizontally, then moved rapidly inward and crossed
The emergency stop signal involves both arms extended horizontally, palms facing forward, then moved inward and crossed above the head. This signal means all crane movements must cease immediately. Any person on site can give this signal.
Question 6: What is the purpose of a crane's rated capacity indicator (RCI)?
- To count the number of lifts performed per day
- To warn the operator when the crane is approaching or exceeding its safe working load (Correct answer)
- To measure the wind speed on site
- To record the operator's working hours
Correct answer: To warn the operator when the crane is approaching or exceeding its safe working load
The rated capacity indicator (RCI) is a safety device that monitors the crane's load against its capacity at the current radius. It provides visual and audible warnings as the load approaches the safe working load and will typically cut out crane movements if the SWL is exceeded.
CPCS Crane Operations and Signals
In the UK standard crane signalling system, what does the signal of one arm extended horizontally with the palm facing down, moved up and down, indicate?