CPCS Forward Tipping Dumper — Questions and Answers
Question 1: What is the most common cause of fatal accidents involving forward tipping dumpers on UK construction sites?
- Engine fires
- Overturning (Correct answer)
- Brake failure on flat ground
- Electrical short circuits
Correct answer: Overturning
Overturning is the leading cause of fatalities involving forward tipping dumpers. Contributing factors include travelling too fast, operating on slopes, uneven ground, overloading, and poor visibility. Seatbelts and ROPS (Roll Over Protection Structure) are critical safety features.
Question 2: What must a forward tipping dumper be fitted with to protect the operator in the event of a rollover?
- An ejector seat
- A Roll Over Protection Structure (ROPS) and a seatbelt (Correct answer)
- Air conditioning
- A fire suppression system only
Correct answer: A Roll Over Protection Structure (ROPS) and a seatbelt
All forward tipping dumpers must be fitted with a ROPS (Roll Over Protection Structure) to maintain a survival space around the operator if the machine overturns. The operator must also wear the seatbelt at all times to remain within the ROPS protection zone.
Question 3: When travelling a loaded forward tipping dumper downhill, what is the correct procedure?
- Drive forwards downhill at normal speed
- Travel in reverse so the load is uphill, in a low gear (Correct answer)
- Tip half the load before descending
- Freewheel in neutral to save fuel
Correct answer: Travel in reverse so the load is uphill, in a low gear
When travelling downhill with a loaded skip, the operator should reverse down so the weight of the load is on the uphill side, using a low gear for engine braking. Driving forwards downhill with a loaded skip raises the centre of gravity on the downhill side, increasing the risk of the machine tipping forward.
Question 4: What should an operator do before tipping a load at a spoil heap or trench edge?
- Drive at speed to the edge to save time
- Ensure stop blocks are in place and approach cautiously at a safe distance from the edge (Correct answer)
- Tip the load while still moving
- Flash the headlights to warn others
Correct answer: Ensure stop blocks are in place and approach cautiously at a safe distance from the edge
Before tipping, the operator must ensure suitable stop blocks (baulks of timber) are positioned to prevent the machine from going over the edge. The operator should approach slowly, stop against the blocks, apply the brake, then tip the load. Spoil heap and trench edge collapses cause fatalities every year.
Question 5: What is the safe maximum gradient on which a forward tipping dumper should typically operate?
- Any gradient as they are designed for all terrain
- As specified by the manufacturer, typically not exceeding 1 in 6 (approximately 16%) (Correct answer)
- 1 in 1 (45 degrees)
- Only completely flat ground
Correct answer: As specified by the manufacturer, typically not exceeding 1 in 6 (approximately 16%)
Forward tipping dumpers should not operate on gradients steeper than those specified by the manufacturer, typically around 1 in 6. Steeper gradients significantly increase the risk of overturning, especially when loaded or turning. Site-specific risk assessments should determine safe operating limits.
Question 6: What action must an operator take before leaving a forward tipping dumper unattended?
- Leave the engine running for quick restart
- Lower the skip, apply the parking brake, switch off the engine, and remove the key (Correct answer)
- Leave it in gear with the skip raised
- Park on a slope pointing downhill
Correct answer: Lower the skip, apply the parking brake, switch off the engine, and remove the key
Before leaving the machine unattended, the operator must lower the skip fully, apply the parking brake, switch off the engine, remove the ignition key, and park on firm, level ground where possible. This prevents unauthorised use and accidental movement.
CPCS Forward Tipping Dumper
What is the most common cause of fatal accidents involving forward tipping dumpers on UK construction sites?