Reducing damage to underground pipes and cables

Overview

Digging holes in the ground is a fundamental part of construction and of the installation and maintenance of buried utilities. Unfortunately, every time ground is broken there is the risk of damaging buried cables and pipes. Damage can be both expensive and dangerous and can also seriously impact companies’ reputations. Being able to excavate safely is a fundamental competence for utility companies, their contractors and the construction industry as a whole. Fortunately, there is a range of well-established techniques, based on the use of cable and pipe locators,  that can be used to reduce these risks cost-effectively.

It's a big problem…

In the USA, there were 340,000 strikes in 2014 (Common Ground Alliance 2014), the United Kingdom sees around 60,000 strikes each year (Institute of Civil Engineers). Excavation in both the UK and the US is highly-regulated so rates of damage are likely to be higher in those regions with less regulation. The mega-trend of increasing urbanisation across the world means that there will be more cables and pipes in the ground and more frequent excavation. Damage to underground assets is a large problem with the potential to become more serious unless the correct steps are taken.

… with some serious consequences

Damaging underground utilities can be dangerous: news reports across the world describe serious injury or death to workers and bystanders that can result from striking buried electricity cables or gas pipelines. Damage is also expensive: the utility will have to be repaired, productivity will be reduced, reputations are weakened and compensation paid. In many countries, injury at work can result in criminal prosecution and large fines.  For example, in the UK the Health and Safety Executive (HSE) will prosecute, in the criminal courts, if it believes that companies have not met their obligations.  In serious cases, fines are calculated as a percentage of revenue. Insurance companies will frequently look at damage rates as they assess premiums. In many countries, the average cost of cable strikes can exceed £20,000 per event.

What to do?

Damage happens for four main reasons:

1. No detection tools are used
2. Not using the best tools
3. Working practices are not adequate or are not understood
4. On-site behaviours do not correctly reflect desired working practices

Fortunately, there are simple solutions for each of these problems that have been adopted by customers across the world.

Use detection tools

This is the simplest, and most important step.  Don’t excavate before the area has been scanned and marked-up by trained people using reliable cable and pipe location tools.  Use tools in conjunction with maps (where they are available), but never rely on maps alone.

There are two main approaches to finding buried services with electromagnetic locators: cable avoidance tools and precision cable and pipe locators.  For the avoidance tool approach, Radiodetection’s CAT and Genny products provide easy-to-use but powerful tools to locate buried services. They are targeted at excavation teams for them to use as part of their excavation process.

For precision cable and pipe locators, Radiodetection’s 8100 locator series are designed for use by professional utility locators and survey professionals; they offer a much broader choice of modes and frequencies for the precise identification of individual services.

No matter which approach is taken, it is vital that locators are used with matching signal transmitters e.g. Radiodetection’s Genny4 or TX-10 transmitters. The correct use of transmitters allows straightforward location of cables that are otherwise very difficult to find.

Use the best available technology

Use the best technology you can to detect buried services. Choose products that have been designed with the user in mind and which have modern features to make locating easier. For example, high accuracy and sensitivity, protection against interference from strong nearby power sources, selectable or multi-frequency signals, and warnings to the user for common incorrect use patterns.

Implement good working practices and training

Many countries offer recommended or mandatory practices for underground location and safe excavation.  One such is the UK’s guidance from 2014 (HSG47 2014) which contains procedures for planning excavations, locating buried services and safe excavation; similar guidelines are available in several other countries. Forward-looking companies use these guidelines as the basis for their own safe working procedures.

Effective training in safe working and in underground location is extremely important. Training can be vendor-delivered, in-house or externally-provided. Whichever route is chosen, they must be experts in both the tools you have chosen and the practicalities of underground cable and pipe location. Training can be supplemented by material on vendors’ website and by instructional videos.

Change on-site behaviours

Even when the first two elements are in place, they will not be effective unless the tools are actually used, and used correctly, and unless procedures are properly followed. Radiodetection’s locators support customers in this task by recording what is done with our CAT tools and our RD7100 and RD8100 precision locators. This data-logging functionality records key locator parameters every second, and stores the logs in on-board non-volatile memory. The locator stores what mode was being used, what signal was being detected, the sensitivity setting of the locator, the depth of the located service and many more parameters. We also have built-in GPS on selected models in our range which is also stored in the logs.

With the data that is logged, supervisors can check if locators were used, if they were used correctly, and assess the compliance to procedure. For GPS-enabled locators, the location where the locate was performed can also be retrieved. This information can then be used to identify training needs.

The future

Our customers tell us that they particularly value the ability to see how their teams are using their locators and to address any weakness found as soon as possible. To meet this need, we are rolling out our new on-line logging and analysis product – C.A.T Manager Online. For users of our gC.A.T product – our avoidance tool with in-built GPS – C.A.T Manager Online provides a cloud-based, near real-time view of their fleet of locators. The data from each locator is uploaded to the cloud where it can be visualised and analysed by the customer to measure compliance and further reduce utility damage and harm.

Summary

Damaging underground pipes and cables when excavating is a serious and expensive problem of growing importance. By focusing on three key straightforward steps companies can significantly reduce the risk of damage and harm:

1. Use the best cable and pipe detection tools
2. Develop excellent working procedures and ensure that people are trained
3. Change on-site behaviours by effective supervision and monitoring

This will allow best-practice to be driven into the business and will help reduce utility strikes.

For more information, contact your local Radiodetection sales office.

References

Common Ground Alliance. 2014. Annual DIRT Report. Arlington, VA: Common Ground Alliance.

HSG47. 2014. Avoiding danger from underground services. London: UK Health & Safety Executive. http://www.hse.gov.uk/pubns/priced/hsg47.pdf