When youāre digging up the ground or busting out concrete with a hand-held breaker, the last thing you want is to hit a live power cable because if you do, youāre likely to be badly injured or even killed.
Cable-strikes, as theyāre known in the industry, are a common hazard, especially in streetworks where buried services tend to cluster along the route.Ā
Itās not just power cables that pose a risk. Hitting a gas main or high-pressure water main can also prove catastrophic and severing a telecommunication cable will create mayhem for local users.
Worryingly, the incidence of cable-strikes appears to be on the rise. According to the Energy Networks Association (ENA), the body representing gas and electricity distribution licence-holders, in the past five years 354 people have suffered life-changing injuries from āarc-flashā as a result of striking a live underground electricity cable.Ā
And data published recently by the Health & Safety Executive (HSE) reveal that incidents of cable-strikes have increased by 46% since the national lockdown. Between July and September 2020, there were 475 reports of cable damage on work-sites, compared with 395 for the same period last year.
A survey conducted on behalf of the ENA indicates that the main cause of cable-strikes is both a lack of understanding of the risks and inadequate knowledge of correct procedure by those working on site. Few will be surprised to hear that, least of all Lucian dāArco, group health, safety & environment leader with civil engineering contractor OāKeefe.
DāArco joined OāKeefe in April 2019 from Careys Civil Engineering where he was health & safety manager. The year before that, OāKeefe had recorded a worrying increase in cable-strikes, with 14 incidents including one which ruptured a live gas main requiring the entire site to be evacuated. January 2019 saw another incident ā by which time chief executive Patrick OāKeefe had decided that a new approach was needed.
āPatrick asked me to systematically review the groupās entire cable avoidance procedure and the training around it,ā says dāArco. āHe wanted to increase awareness of the risks and improve the health and safety capabilities of those involved in utility excavations.ā
One common misconception about cable-strikes is that they only occur during streetworks excavations. āBut youād be surprised,ā says dāArco. āYou could have a football pitch in the middle of nowhere and think āyeah, no problemā, start digging only to find a cable or pipework from the 1950s that wasnāt on the plans youād been given.ā
There are well-established rules and guidance on the detection and avoidance of buried services, the most important being PAS128 ā Specification for Utility Surveys, which is published by BSI and guidance note HSG47 ā Avoiding Danger from Underground Services, published by the HSE.
OāKeefe, like many other contractors, has its own company handbook containing bespoke documents, such as rules for excavation around underground utilities and permits to dig, developed in line with the statutory documents. But with cable-strikes actually increasing in frequency, the message was clearly not getting through.
There is no lack of training available on the market for safe excavation best practice; but dāArco thinks itās mostly too theoretical and lacks sufficient depth to really make a difference on site. āA lot of it is outsourced, too,ā he says. āMost of the external [training providers] donāt actually deliver the activity themselves ā theyāre just delivering a course,ā he says.
In his previous role with Careys, dāArco had worked closely with a company called ĀÜĄņŌ““ Skills Training Academy (CSTA) Global, and its founder, Ed Tai. Now at OāKeefe and with a remit to carry out a root-and-branch review of health & safety training, dāArco brought Tai on board with a view to developing a completely new training course.
The result is an NVQ Level 2 qualification in Utility Avoidance & the Location of Buried Services.Ā
The first stage was to compile a classroom-based training syllabus that covered all the relevant aspects of safe excavation around live utility services. āThe course covers published guidance, regulations and legislation; how to read service drawings; understanding control measures around service isolation; procedures for contacting service owners; CDM compliance; practical use of CAT and genny equipment and the limitations of electro-magnetic locators,ā explains dāArco.
The CAT (Cable Avoidance Tool) & genny (signal generator) is the main weapon in the site operativeās armoury but it is often misused and its functions and limitations widely unappreciated, says dāArco.
DāArcoās main innovation was to add a second, practical, module to his training package, allowing trainees to put their classroom theory into practice under safe, controlled conditions.Ā
Careys (dāArcoās previous employer) had set up a training facility at its depot in Milton Keynes that included an aggregate-filled trench with a couple of cables running through it on which trainees could practise their cable-detection skills. āIt was a good idea, but very basic,ā says dāArco. āEd and I thought we could do better.ā
Consequently, dāArco and Tai drew up basic plans for a practical cable-detection training facility that would ā as far as possible ā replicate actual real-life site conditions.Ā
Together, dāArco and Tai designed a replica streetscape incorporating reconstructions of as many of the common features found in buried utility installations as possible. āItās basically a mock road next to a pavement with inspection chambers, ducts etc,ā says dāArco.Ā
āThe first third of the trench is pretty straightforward; then thereās a section for safe digging, where the guys can learn how to excavate around a cable correctly; then in the third section we threw in a few curve-balls ā like pieces of legacy metal to confuse them, and we made the cables a little more wiggly so theyād have to pay attention when marking them out, and we made it so we can change the side the current flows through so it isnāt always the same,ā dāArco explains.
DāArco then took his plans to Patrick OāKeefe and asked for a few square metres of land on which to build his mock-road (complete with road-sign reading: What-if Way). OāKeefe obliged with a location at the companyās Kent depot in Borough Green.
The training facility was built earlier this year, during lockdown, and inaugurated with a series of training sessions for invited personnel from OāKeefeās extended supply chain in early September. Representatives from clients including Wates, Willmott Dixon, Quintain, ISG, BAM and Caledonian Modular responded with enthusiasm, says dāArco.Ā
One attendee, Martin Glover, SHE manager with Wates Residential, was moved to congratulate dāArco on the āoutstandingā course:Ā
āAs a result we have upgraded one of our āBold Commitmentsā namely avoiding buried services. I have attended several similar courses over the last 20 years yet yours was by a country mile the most useful and professional particularly the bespoke practical training area,ā he wrote.
Got a story? Email news@theconstructionindex.co.uk
