Service strikes are the kind of avoidable event that still shut jobs, injure people and burn time. A permit to dig is not a paper exercise; it’s a live control that coordinates utilities information, on-the-ground proving and supervision so excavations happen without hitting cables or pipes. The permit process should start well before the bucket hits the ground and should be used actively each shift, not just signed once and filed.
TL;DR
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– Get current utility plans early, then prove everything with CAT/Genny and trial holes before any plant digs.
– Define the excavation corridor, hand-dig zones, plant limits and stop-work triggers in the permit.
– Brief the exact method, markings and exclusions at the edge of the dig and appoint a nominated supervisor to hold the permit.
– Suspend the permit if markings are unclear, weather changes, plant swaps occur or the scope moves.
– Close out properly: as-built mark-ups, photos and clean reinstatement so the next team isn’t guessing.
A staged permit-to-dig playbook that prevents strikes
# Map and coordinate before mobilising
/> Start with a desktop sweep: obtain up-to-date records for electricity, gas, water, telecoms and any private infrastructure on or near the work. Draw the known and suspected routes onto a working drawing and highlight clash points with the planned excavation. Bring utilities, temporary works, traffic management and the digging subcontractor into the same conversation so plant routes, spoil locations and access are agreed before the permit is even raised.
Use this early stage to tackle constraints you can remove: temporary diversions, isolation windows from utility owners, and sequencing that avoids stacked activities around the dig. If you inherit legacy surveys, treat them as hints, not facts. The permit-to-dig pack starts here—plans, coordination notes and contact details are part of the control, not later add-ons.
# Locate and prove services on the ground
/> Records alone don’t stop a bucket. Use CAT and signal generator to sweep the area and mark findings clearly on the surface with durable paint and pin flags. Always work perpendicular passes and re-scan after obstacles are moved. In congested corridors or where records are poor, commission competent utility surveys and consider vacuum excavation for proving.
Trial holes are the proof. Hand-dig with insulated tools to expose and confirm the exact line and depth before any machine breaks ground nearby. Photograph and tag what you find; pull these into the permit pack and update the markup so everyone is looking at the same picture. If you can’t find a service you expect to be there, don’t assume it’s gone—escalate and pause.
# Design the dig method and set permit conditions
/> With services proved, define the method. Set out hand-dig buffers either side of live services, the maximum reach or slew limits for plant, and the sequence of bites. Specify the banksman position, the need for a service spotter in tight areas, and how communications will work over noise and distance.
Temporary works considerations matter: confirm edge protection, shoring or battering requirements and how they interface with services so you don’t undermine or overload them. Plan spoil placement to avoid covering markings, blocking pedestrian routes or loading buried apparatus. Where isolations are agreed, record who is competent to verify them and what visual/physical proof will be accepted on the day.
# Brief, isolate and establish the work zone
/> On the day, the permit issuer and supervisor walk the line together. Reconfirm markings are visible, barriers are in the right place, and the method still fits reality. Carry out toolbox briefings at the dig edge using the actual markup, photos of proved services and the specific stop-work triggers.
If isolations are part of the plan, get written confirmation and verify locally—tag, lock or certificate as appropriate. If isolation can’t be achieved, reinforce the stand-off measures, non-mechanical digging limits and supervision levels. Establish plant/pedestrian segregation, banksman location, emergency arrangements and first-aid kit access. PPE is the last line; wear task-specific protection but don’t treat it as a substitute for good control.
# Supervise, pause and escalate during excavation
/> A named person must hold the live permit and stay at the workface. Their job is to keep the method aligned with the permit, manage any changes and stop when conditions shift. Weather that washes off markings, a swap to a different excavator, or a design tweak that nudges the trench five hundred millimetres—these are all reasons to suspend and re-validate the permit.
Keep the scanner to hand and re-scan as ground is removed. Maintain clean edges and legible marks; repaint as needed. Use insulated hand tools when approaching known services, and don’t lever on cables or pipes to “get them out of the way”. Where unknowns appear, expose them carefully, tag, photograph and bring them into the control—do not press on.
# Close, record and reinstate responsibly
/> When the dig phase ends, close out the permit deliberately. Record what changed from the plan, capture as-built paths of any services you’ve proved or uncovered, and lodge that with site records. Remove redundant markings so you don’t confuse the next activity.
Reinstatement should not compromise services: no sharp backfill near plastic, no point loads from kerbs on shallow ducts, and no buried temporary markers that won’t make sense later. Sign the permit off, hand back isolations where used, and brief the next team on what’s now beneath their boots.
Site scenario: the near-miss that changed a civils crew’s habits
/> On a busy housing infrastructure job, drainage crews were cutting a run of manholes along a new estate road. Records suggested a gas main in the verge and an LV cable crossing the carriageway mid-plot. The team scanned and found the LV; they spray-marked it and proved with a small trial hole. The gas crossing wasn’t found on the first pass, but time pressure pushed the gang to start digging the next manhole with the 8‑tonner.
On the first bucket, a dull clunk stopped progress. They uncovered a yellow service at shallow depth just offset from the record—an unrecorded gas spur feeding a show home. Work stopped, the supervisor suspended the permit, and the utility owner attended. The lesson landed: unknowns do exist, and if a service you expect isn’t there, you don’t start anyway. The site changed its routine—every crossing now had a trial hole before plant, and permits were revalidated after lunch or weather events.
Permit-to-dig checks that stop service strikes
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– Confirm current utility plans are in the permit pack and the ground markup matches them, with photos of trial holes.
– Validate isolations or protection measures and record what proof has been seen by the permit issuer and supervisor.
– Define hand-dig zones, plant slew/height limits, and set a hard stop distance from known services.
– Establish who is the permit holder on shift, where the banksman stands, and how you’ll communicate over noise.
– Prepare the ground: edge protection in place, spoil and materials positioned without covering markings or loading services.
– Set escalation triggers: unclear markings, plant change, route deviation, or unexpected service—stop, suspend, and re-brief.
– Capture close-out: as-built notes, updated drawings and removal of obsolete markings before handing over.
Common mistakes that still lead to hits
# Relying on drawings instead of ground truth
/> Treating record plans as gospel and skipping trial holes results in surprises. You only know where a service is when you’ve proved it in the ground.
# Letting the permit go stale across shifts
/> A permit signed yesterday doesn’t cover today’s rain, new plant or layout tweaks. Re-validate at the start of each shift and after significant changes.
# Allowing uncontrolled plant swaps
/> A “similar” excavator arrives with a longer dipper and suddenly the slew envelope reaches a cable. Build plant specifics into the permit and suspend if anything changes.
# Burying lessons during reinstatement
/> Backfilling quickly without photos or notes loses valuable knowledge. Record what you found so the next phase isn’t guessing.
Bottom line: keep the permit live and visible
/> A strong permit to dig makes services visible, aligns people to one method and gives supervisors clear authority to stop when conditions change. Done well, it is a working control at the edge of the trench, not a form in the cabin. Expect more scrutiny on how permits are briefed and held on shift, and whether changes trigger suspension. Ask yourself before the next dig: who owns the permit here, what would make us stop, and how do we prove we’re not guessing?
FAQ
# When should a permit to dig be raised on a UK site?
/> Raise it before any ground is broken, ideally after coordination and utility searches but before the exact method is finalised. It should be in place and briefed once services are proved and control measures are defined, and then revalidated at the start of each shift.
# Who is competent to issue and hold a permit to dig?
/> Sites generally expect a trained supervisor or manager familiar with utilities risks to issue the permit. A named on-the-ground supervisor should hold the live permit during the work, staying at the workface to manage changes and stop if controls are no longer valid.
# How do CAT and Genny scans fit with trial holes?
/> Scanning is a locating tool that helps narrow down likely routes; it doesn’t replace physical proving. Use CAT/Genny first to mark suspected lines, then hand-dig trial holes to confirm exact positions before bringing in mechanical plant.
# What if records and ground markings don’t agree?
/> Don’t pick a favourite and carry on. Escalate, pause the permit, and either resurvey or expand proving until you reconcile the difference; work should not proceed on assumptions.
# How do permits interface with temporary works and traffic management?
/> The permit should reference any shoring, edge protection and access constraints set by temporary works, so excavation won’t undermine structures or services. It also needs to align with traffic plans so plant movements, pedestrian routes and spoil locations are segregated and markings remain visible throughout the dig.
