In the construction industry just about every project involves digging into the ground at some point, and the problem that immediately raises is that we cannot see what is in the ground itself. That means that the chances of hitting something is ever-present, and it could be anything. It might be a collection of Roman coins dating back a couple of thousand years, in which case the person doing the digging – whether by hand or using a machine – would be very happy about the find.

Unfortunately, it could also be a gas pipe or an electricity cable, in which case the person doing the digging would be very unhappy and may very well suffer injury: in some cases, it could be fatal. More to the point is the fact that striking an electricity cable or gas pipe is far more likely than finding a hoard of Roman coins.

The simple fact is that underground services can be almost anywhere. Almost every building in the land has electricity, water, and a sewage system. There could also be cable TV, gas, and so on. Now if you are in the centre of a city it is obvious that there are going to be underground services there, but they can also be found in some very unlikely places out in the country as well. You should always follow the advice of the HSE in this respect which is “Underground services are widespread. Assume they are present unless you have been shown otherwise.”

Even though you may know that services are underground where you need to dig, you don’t necessarily know exactly where they are. For instance, if you are in the high street you will know that the shops have services running to them, but where are they? Are they running under the pavement or under the middle of the road with branches off across the pavement to each shop? Are the electricity cables under the pavement and the main sewage pipe under the road or the other way around? Are they both under the road? Or both under the pavement?

If you are the local electricity supplier and you need to renew a cable, you may well know exactly where your cable runs. But you may not know where the gas pipes are. Heck, your cable could be two metres down and you know where it is, but the gas company might have come along several years later and laid the gas pipe directly above your cable at a depth of one metre!

All of this is why you need to undertake due diligence and take every step that you can to locate everything that is possibly in the area in which you need to dig. And this is why we have the CAT, the latest version being the CAT 4, and the Genny, which used in combination can locate and identify a large proportion of underground services.

However, note that we said a “large proportion”. We didn’t say “all of them”. This is because, as clever as these tools are, they do have certain limitations. For example, as a simple illustration, let’s look at depth. The CAT and Genny, or rather the CAT, can only locate to a certain depth. This will depend on the model, and the ground conditions. But let’s say that your CAT can locate services to a depth of about 1.5 metres. That’s great, provided that you don’t need to dig more than 1.5 metres.

But suppose that you need to dig down 2.5 metres to install foundations for a building, for instance. The CAT tells you that there is nothing where you need to dig, but it didn’t know that the sewer pipe was in the same place at a depth of 2 metres. So off you go, digging merrily away, and you hit the sewer pipe! That might explain why, despite the CAT and Genny, there are around 60,000 cable strikes, as they are called, every year in the UK.

And that is why CAT 4 location training is essential for anyone and everyone who needs to dig – whatever the depth may be. It is absolutely vital that you know and understand not just how to use these tools but to understand what their limitations are. And you can only get that training from specialist providers such as our team at Sygma Solutions. Between us, we have over 100 years’ experience of cable location and utility detection techniques, and we can provide you with classes that will teach you everything that you need to know about them. Find out more by clicking on the Courses link at the top of the page.