When you鈥檙e 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, you鈥檙e likely to be badly injured or even killed.
Cable-strikes, as they鈥檙e known in the industry, are a common hazard, especially in streetworks where buried services tend to cluster along the route.聽
It鈥檚 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 鈥榓rc-flash鈥� as a result of striking a live underground electricity cable.聽
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 d鈥橝rco, group health, safety & environment leader with civil engineering contractor O鈥橩eefe.
D鈥橝rco joined O鈥橩eefe in April 2019 from Careys Civil Engineering where he was health & safety manager. The year before that, O鈥橩eefe 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 鈥� by which time chief executive Patrick O鈥橩eefe had decided that a new approach was needed.
鈥淧atrick asked me to systematically review the group鈥檚 entire cable avoidance procedure and the training around it,鈥� says d鈥橝rco. 鈥淗e wanted to increase awareness of the risks and improve the health and safety capabilities of those involved in utility excavations.鈥�
One common misconception about cable-strikes is that they only occur during streetworks excavations. 鈥淏ut you鈥檇 be surprised,鈥� says d鈥橝rco. 鈥淵ou could have a football pitch in the middle of nowhere and think 鈥榶eah, no problem鈥�, start digging only to find a cable or pipework from the 1950s that wasn鈥檛 on the plans you鈥檇 been given.鈥�
There are well-established rules and guidance on the detection and avoidance of buried services, the most important being PAS128 鈥� Specification for Utility Surveys, which is published by BSI and guidance note HSG47 鈥� Avoiding Danger from Underground Services, published by the HSE.
O鈥橩eefe, 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 d鈥橝rco thinks it鈥檚 mostly too theoretical and lacks sufficient depth to really make a difference on site. 鈥淎 lot of it is outsourced, too,鈥� he says. 鈥淢ost of the external [training providers] don鈥檛 actually deliver the activity themselves 鈥� they鈥檙e just delivering a course,鈥� he says.
In his previous role with Careys, d鈥橝rco had worked closely with a company called 色猫直播 Skills Training Academy (CSTA) Global, and its founder, Ed Tai. Now at O鈥橩eefe and with a remit to carry out a root-and-branch review of health & safety training, d鈥橝rco 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.聽
The first stage was to compile a classroom-based training syllabus that covered all the relevant aspects of safe excavation around live utility services. 鈥淭he 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,鈥� explains d鈥橝rco.
The CAT (Cable Avoidance Tool) & genny (signal generator) is the main weapon in the site operative鈥檚 armoury but it is often misused and its functions and limitations widely unappreciated, says d鈥橝rco.
D鈥橝rco鈥檚 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.聽
Careys (d鈥橝rco鈥檚 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. 鈥淚t was a good idea, but very basic,鈥� says d鈥橝rco. 鈥淓d and I thought we could do better.鈥�
Consequently, d鈥橝rco and Tai drew up basic plans for a practical cable-detection training facility that would 鈥� as far as possible 鈥� replicate actual real-life site conditions.聽
Together, d鈥橝rco and Tai designed a replica streetscape incorporating reconstructions of as many of the common features found in buried utility installations as possible. 鈥淚t鈥檚 basically a mock road next to a pavement with inspection chambers, ducts etc,鈥� says d鈥橝rco.聽
鈥淭he first third of the trench is pretty straightforward; then there鈥檚 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 鈥� like pieces of legacy metal to confuse them, and we made the cables a little more wiggly so they鈥檇 have to pay attention when marking them out, and we made it so we can change the side the current flows through so it isn鈥檛 always the same,鈥� d鈥橝rco explains.
D鈥橝rco then took his plans to Patrick O鈥橩eefe and asked for a few square metres of land on which to build his mock-road (complete with road-sign reading: What-if Way). O鈥橩eefe obliged with a location at the company鈥檚 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 O鈥橩eefe鈥檚 extended supply chain in early September. Representatives from clients including Wates, Willmott Dixon, Quintain, ISG, BAM and Caledonian Modular responded with enthusiasm, says d鈥橝rco.聽
One attendee, Martin Glover, SHE manager with Wates Residential, was moved to congratulate d鈥橝rco on the 鈥榦utstanding鈥� course:聽
鈥淎s a result we have upgraded one of our 鈥楤old Commitments鈥� 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,鈥� he wrote.
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