Striking it out: How can the industry cut down utility strikes?

One of the biggest health and safety dangers that water sector workers can encounter when working below ground is making accidental contact with electrical cables or gas pipelines. Without the right preparations, these utility strikes – also known as service strikes or hits – can occur alarmingly regularly and can result in serious injury or even death.

Tens of thousands are believed to occur in the UK every year, exposing workers to risks including electrocution and explosion. The issue is costly and disruptive as well as dangerous: huge sums can be spent rectifying the damage caused by ill-judged digging, while at the very least, incidents of this type – including hits on unlooked-for water pipes – lead to delay and have a service impact on customers.

In the absence of a unified, mandatory reporting structure, the numbers are impossible to verify, but there are estimated to be around 4 million excavations in the UK annually, resulting in approximately 60,000 strikes.

The Health and Safety Executive (HSE) received 6,746 reports of incidents involving pipelines and the escape of flammable substances liable to cause harm between 2012 and 2017. Over the same period, 318 reports were submitted of injuries, including fatalities, caused by underground electrical cable strikes.

However, there is no legal obligation to report most strikes, and while companies will generally have in-house reporting structures, the way they are categorised can vary so significantly as to make the data impossible to collate. Furthermore, there is a suspicion that some may even be covering up strikes, to avoid the onerous investigation, delays and costs associated with them, and to avoid being blamed for their poor practice.

So what can be done to bring this vital issue out into the open, and to drive the risks down to the lowest possible levels?

PREPARATION

It is widely agreed that better preparation in advance of works commencing on site is critical if strikes are to be avoided, and that involves establishing the best possible mapping of the excavation area.

One organisation that exists to simplify that task is LinesearchbeforeUdig (LSBUD), a free-to-use service that began life as linesearch.org in 2003, with Fisher German providing information on the networks of high-pressure fuel pipelines that, if ruptured, could result in a major disaster.

It has since evolved: Pelican Corp brought the ‘Before U Dig’ element, introducing automation technology that meant users could receive plans within a matter of minutes rather than a couple of days, and the service now incorporates a range of asset owners, including most of the oil industry as well as gas, electric and telecoms companies.

Water companies, though, have been slow to sign up. At present, the Northumbrian Water and Essex & Suffolk networks are covered, along with part of the Severn Trent network and Hafren Dyfrdwy, but the majority of the UK’s water pipes are not on the database.

“We’ve struggled historically with the water companies because there hasn’t been as obvious a risk to the people working near their assets,” LSBUD managing director Richard Broome says. “They’re one of the biggest users of the data, but they’re one of the least represented on the member side.”

LSBUD covers approximately 650,000km of underground utility infrastructure and wants to increase that to 1,050,000km – 70 per cent of the estimated 1,500,000km total – within the next two years, with the eventual goal of reaching 100 per cent.

LSBUD provides contact details for utility owners that are not members of the service, but as the current legislation allows these organisations 28 days to respond to enquiries, and some still send maps by post, the supply of information does not always match the requirements of the company carrying out the search.

“At our Damage Prevention Day in June, contractors said one of the big problems was that there was often a time pressure for the work,” Broome adds. “Water companies in particular are looking to improve their leakage rates and customer service levels and they want to repair leaks ASAP, but that can potentially make it difficult to do things properly.”

Further complicating the matter is that maps are often found to be unreliable. For example, many water records originate from drawings that became microfiches and then computer records; across each iteration, errors may have crept in, while changes to nearby roads or buildings can skew the original descriptions.

Cost considerations may also lead to substandard work. Someone installing a cable might record that it was laid in the position the utility originally requested but instead have placed it at a shallower depth. Or, because removing an old utility from a site costs time and money, it may be left in the ground but still get recorded as removed in the plans.

Murray Ambler-Shattock, strategic operations manager at K M Plant Hire & Groundworks Ltd, says: “The quality of documentation is surprisingly poor.

“Occasionally you’ve got secondary gas pipelines laid in parallel alongside or underneath old pipelines, and the old pipelines are on the records but the new pipelines have never been added. It’s staggering, but this does happen.”

SAFE WORKING PRACTICE

According to PAS128 – a specification for underground utility detection, verification and location – quality practice depends on ‘active service detection’, where the location of services is an activity that is kept entirely separate from that of excavation. That means plans should be sought and checked through all appropriate channels before arriving at the site, with a CAT (cable avoidance tool) and genny (signal generator) then used to detect the buried utilities and verify the information.

“PAS128 includes some really good, positive advice about the desktop records request process, using site clues to marry those records with what is on site as well as the use of locating equipment and trial holes to identify assets,” Broome says. “It’s a really good benchmark which is replicated around the world.”

The reality is that much of what happens in practice can fall short of that benchmark. The CAT and genny should be used by utility survey experts and not site operatives, but 57 per cent of those responding to a 2012 Civil Engineering Contractors Association (CECA) survey said that had not been the case in their experience. In addition, 86 per cent said service location was not carried out as a separate exercise, and the same percentage said the genny was not used as much as it should be.

One contractor commented: “When you have gangs going through CAT and genny training, it might be done by a firm pulled in to educate the sub-contractors. You’re sitting in a room with people who should be paying attention and they’re on their phones, gambling on football matches or whatever, instead of listening to what they’re being told. They then go out to site half-knowing how to do the job and, frankly, that’s not good enough.

“I’m a bit old fashioned. I’ll scan a couple of feet, then dig, then scan, then dig, then scan, then dig. You get guys who wander about a bit but don’t think they’ve picked anything up so just crack on.”

However, detection may not be possible even when the technology is used as intended: the CAT and genny cannot pick up plastic pipes – often used for low-pressure gas and water – unless there is a trace wire. Although surveys can be carried out for water pipes using soundwaves, gas remains problematic.

Where possible, K M Plant makes use of air lances and vacuum excavation to minimise the strike risk on undocumented, or incorrectly documented, underground assets when working in congested areas.

Some jobs may allow for alternative solutions to further minimise the risk – Ambler-Shattock suggests horizontal directional drilling, which removes the need to open cut trenches and can sometimes avoid the danger zone entirely – but ultimately good practice comes down to a genuine commitment to adopting the best methodology.

“It’s more important to work safely than fast,” he says. “It’s not about finishing so you can go home at 3pm, it’s about finishing so you can go home.”

DATA AND MAPPING

LSBUD revealed in its Digging Up Britain report that it had received 2,268,868 searches in 2017, representing an increase of 27 per cent on the previous year. Still, given that the total number of work projects is estimated at 4 million annually, that would suggest almost half take place without a thorough asset search.

“It’s not just us that sees this,” Broome says. “I’ve just come back from Australia where they’ve got almost all the asset owners covered by the Dial Before You Dig service and they’re still seeing a 25 per cent growth every year in enquiries. There’s always lots of people that might not have searched before they start digging.”

Ambler-Shattock suggests there is a 50/50 split between those who take strike avoidance sufficiently seriously and those who do not.

“Diligent people are only as good as the records they can pull,” he adds. “If we find gas mains aren’t where they’re supposed to be, or fibre optics are on the wrong side of the road, we will send it back and notify the utility, but we’ll pull the maps six months later and find nothing has been done.

“In an ideal world, you’d have a situation where as soon as you’re scanning and locating, that’s uploaded to some cloud-based centralised system that updates a kind of pseudo-BIM network, so every time something is located in physical reality, that precise location is uploaded to a central library.

“There needs to be a significant change in the approach to these things. If that requires legislation or an operational standard that is accepted within the industry as ‘the rules’, so be it.”

UTILITY AVOIDANCE WHEEL

Developed by the Civil Engineering Contractors Association (CECA) in association with Kier, BAM Nuttall, Skanska, Morrison Utility Services, UK Power Networks Services, Barhale, Crossrail and UKCG, the Mechanical Excavation Utility Avoidance Wheel can be used to assess how to proceed when working around gas, electric and third-party pipelines.

“It’s a nice, simple device that gives an idiot-proof guide to where something might be located, what the safe dig distances are, what the appropriate practice is to use,” K M Plant’s Murray Ambler-Shattock says. “When these are used properly, they’re very effective.”

VR TRAINING

Anglian Water is currently in the pilot phase of a VR training programme that makes use of 360° images, videos, CGI features and multiple-choice questions to deliver targeted training across various subjects. One module takes the user from start to finish on a dig, including selecting the right PPE, proper CAT and genny use, and identifying hazards.

“The whole module will be used to assess the competency of the workers both before and after a live dig,” VR programme manager Steve Havvas says. “Where we identify a lack of understanding, that will enable us to focus our physical training efforts.”

“VR also enables us to be able to simulate what it’s like to have a live cable strike and is essential in making new and existing members of staff fully aware of the dangers.”