NEBOSH CC Excavation & Ground Work Hazards 2

Question 1

Which colour cable sheath is typically associated with electricity supply cables in the UK?

Accepted Answer

Black

Answer

Electricity supply cables in the UK are typically black or sometimes grey. Being aware of cable colours helps identify services when excavating, though all services should be treated as live until proven otherwise.

Question 2

What is the safe digging zone recommended around buried services when hand digging?

Accepted Answer

0.5 metres either side of the marked position

Answer

When excavating near buried services, hand digging should be used within 0.5 metres either side of the marked service position. This reduces the risk of striking cables or pipes.

Question 3

What is 'battering back' in the context of excavation safety?

Accepted Answer

Cutting the sides of an excavation at a safe angle to prevent collapse

Answer

Battering back means cutting the sides of an excavation at a safe angle (slope) so they are self-supporting and less likely to collapse. The required angle depends on soil type, groundwater and other factors.

Question 4

Which document should be used to plan safe working in an excavation?

Accepted Answer

Method statement and risk assessment

Answer

A method statement and risk assessment must be prepared before excavation work begins. These documents outline the safe system of work, identify hazards and specify control measures including shoring methods and emergency procedures.

Question 5

What hazard does water in an excavation present beyond the obvious drowning risk?

Accepted Answer

Increased likelihood of side collapse and soil instability

Answer

Water in an excavation weakens the surrounding soil, increasing the risk of side collapse. Saturated ground is heavier and loses cohesion, making already unstable sides even more dangerous.

NEBOSH Construction Certificate Practice Test

NEBOSH Construction Certificate Practice Test

NEBOSH CC Excavation & Ground Work Hazards 2