Underground utility strikes remain one of the most common and most preventable incidents on UK construction and infrastructure sites. A single strike can shut down a site for days, injure or kill an operative, disrupt services to thousands of homes, and result in significant financial penalties and reputational damage. As a site manager, you are the person best placed to make sure your team follows the right procedures every time they break ground.
Why Strikes Still Happen
The technology exists to locate most underground services before excavation begins. Cable avoidance tools (CAT and Genny) are standard issue on almost every site. Yet strikes continue to happen, and the root causes are almost always human rather than technical. The most common contributing factors are poor pre-dig survey technique, time pressure overriding safe working procedures, lack of training or expired training, and failure to consult service plans before starting work.
As a site manager, you cannot control every swing of every excavator bucket. But you can control the systems, culture, and checks that make it far less likely that someone will dig without surveying properly.
Before Any Excavation Starts
Every excavation on your site should follow a consistent pre-dig procedure. This is not optional and it is not something that can be skipped when the programme is under pressure. The basics are straightforward: obtain up-to-date service plans from all relevant utility companies, ensure the operative carrying out the survey holds a current cable avoidance qualification (EUS CAT1 or ProQual CAT1 as a minimum), and confirm the operative has the right equipment and knows how to use it in all four locating modes.
Service plans should be available on site before digging begins. They are not a formality. Plans show the approximate routes of buried services, and while they are never perfectly accurate, they give the operative a starting point for their scan. An operative working without plans is working blind.
Training Is Not a Tick-Box Exercise
Holding a current card is the minimum. It confirms the operative passed a course, but it does not confirm what they are doing on site today. Competency can drift significantly over the three-year life of an EUS or ProQual card, particularly if the operative does not use the equipment regularly or has picked up shortcuts from colleagues.
Site managers should watch how operatives actually carry out their surveys, not just check that the card is in date. Are they connecting the Genny first? Are they scanning in all four modes? Are they marking out what they find? If the answer to any of these is no, the training has not translated into practice and you have a gap that needs closing.
OSCA (On-Site Competency Assessment) is designed to address exactly this problem. It provides a GPS-stamped, independent assessment of what your operatives are actually doing in the field, not just what they demonstrated in a training centre.
Supervision and Culture
The biggest single risk factor for utility strikes is time pressure. When the programme is tight and the team is under pressure to deliver, corners get cut. The pre-dig survey is the first thing to suffer because it is the easiest thing to skip. Nobody sees you skip it until something goes wrong.
As a site manager, your job is to make it clear that the survey is non-negotiable. That means building survey time into the programme, not treating it as something that happens on top of productive work. It means calling out shortcuts when you see them, even when the team is behind schedule. And it means creating a culture where operatives feel able to stop and say "I need to scan this properly" without being told to hurry up.
Equipment Checks
Cable avoidance tools need to be in good working order. A CAT with a flat battery, a damaged Genny, or a unit that has not been calibrated is not fit for purpose. Site managers should ensure that equipment is checked before use each day and that any faults are reported and dealt with, not worked around. If the equipment is not working, the excavation does not start.
When Things Go Wrong
If a strike does happen, the priority is safety. Stop all work in the affected area immediately. If there is any possibility of a gas leak, exposed live electricity, or ruptured water main, evacuate the area and call the emergency services. Do not attempt to repair the damage or re-energise anything.
Once the immediate danger is dealt with, report the incident to the relevant network operator and your principal contractor. Preserve the scene and any evidence, including the service plans that were in use, the equipment settings, and the identity of the operative and supervisor. This information will be needed for the investigation and will help you understand what went wrong and how to prevent it happening again.
Building Strike Prevention Into Your Site
The most effective approach to strike prevention is not a single intervention but a combination of properly trained operatives, current service plans, working equipment, visible supervision, and a culture that prioritises doing it right over doing it fast. None of these is complicated. All of them require consistent effort from site management.
If you want to go further, consider investing in bespoke training that is tailored to your specific site risks, or using OSCA to get an independent picture of your team's real-world competency.
Frequently Asked Questions
What is the most common cause of utility strikes?
Failure to carry out a proper pre-excavation survey. In most cases, the operative either did not use a cable avoidance tool at all, used it incorrectly, or did not follow the correct sequence of locating modes. Training and on-site supervision are the most effective controls.
Do all site operatives need cable avoidance training?
Anyone who excavates or breaks ground near underground services should hold a current cable avoidance qualification such as EUS CAT1 or ProQual CAT1. Even operatives who are not digging should understand the risks if they are working in the vicinity of excavation work.
How often should cable avoidance training be renewed?
EUS CAT1 accreditation is valid for three years. However, competency can drift well before the card expires. Regular on-site checks or OSCA assessments between renewal dates help catch and correct bad habits early.
What should I do if a utility strike occurs on my site?
Stop work immediately. Evacuate the area if there is any risk of gas, electricity, or other hazards. Contact the relevant network operator and your principal contractor. Do not attempt to repair the damage yourself. Record the incident and preserve the scene for investigation.
Improve Your Team's Competency
Sygma delivers EUS CAT1, ProQual CAT1, and bespoke cable avoidance training across the UK. We also offer OSCA on-site assessments to verify real-world competency. Get in touch to discuss what your site needs.
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