Machine Excavation Near Services

Machine excavation near buried services creates a high risk of cable strikes, gas main damage, and pipe rupture.
HSG47 requires hand digging within 500mm of the indicated position of any buried service.
Machine excavation can only resume once the service has been exposed by hand and its exact position confirmed.
Excavator teeth, breakers, and augers can sever gas mains, water mains, and high-voltage cables instantly.
A permit to dig system must be in place and the operator briefed on service locations before digging.
The excavator operator must be able to see the ground being dug — a banksman assists where visibility is limited.
Service plans, CAT and Genny results, and trial hole findings must all be available at the point of work.
Emergency procedures for gas escape, electrical contact, and water main burst must be briefed before starting.
Fibre optic cables are very difficult to detect and extremely costly to repair if severed.
Machine excavation restrictions also apply near service connections, junctions, and changes in direction.

Fatal strikes	Machine contact with live gas mains or HV cables causes explosions and electrocution that kill instantly.
Service damage	Severing water mains, telecoms, and fibre optics causes costly disruption affecting thousands of people.
Legal compliance	HSG47 and CDM 2015 require a formal safe digging system with hand-dig zones around buried services.

Do

Don't

Obtain a permit to dig before starting any machine excavation near buried services
Brief the excavator operator on all known service locations and hand-dig zone limits
Hand dig within 500mm of any indicated service position before using the machine
Expose the service by hand and confirm its exact position before machine work resumes
Keep service plans, CAT results, and the permit available at the point of work
Use a flat-edged bucket for machine work near services — not teeth or rippers
Position a banksman to guide the operator where visibility of the dig face is limited
Brief the team on emergency procedures for gas, electricity, and water strikes
Mark exposed services clearly and protect them before continuing machine excavation
Report any contact with a service immediately, even if no visible damage is apparent

DON'T machine dig within 500mm of an indicated service without hand exposing it first
DON'T use toothed buckets, breakers, or rippers in the proximity zone of buried services
DON'T assume the service is exactly where the plan shows — positions can be inaccurate
DON'T continue machine excavation if the operator cannot see the dig face clearly
DON'T dig without a permit to dig and operator briefing on service locations
DON'T ignore the CAT and Genny survey results — they indicate probable service routes
DON'T allow machine excavation to resume before hand-exposed services are marked and protected
DON'T underestimate fibre optic cables — they are thin, hard to detect, and costly to repair
DON'T dismiss minor contact with a service — report it for inspection by the utility owner
DON'T forget that services change direction and depth — hand dig at bends and junctions too

See also: Safe Digging Practices (HSG47) | Permit to Dig Process

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