As a contractor, whenever you undertake any form of digging you need to be certain that you do not strike any cables or underground utilities, and the simple fact is that they are almost everywhere. There are lots of things to take into account, too, such as the fact that while you may have used a CAT and Genny and taken every care, you may have produced a result that says that the place you need to dig in is clear of all utilities.

However, that may not be the case. While the latest equipment can give you fairly accurate depth readings, there is still a limit to how deep it can read. What that means is that although you have a clear reading, there may still be a utility deeper down. The way that you tackle that is to dig down carefully for a foot or so, and then take another pass with the CAT and Genny which could then show you a utility buried where you are digging at a depth which could not be read from ground level!

Certainly, there could be utilities anywhere, and the way to proceed is always to assume that they are where you propose to dig unless you know otherwise. Everybody who is going to undertake a survey using the CAT and Genny should have taken a recognised course in their use, as it is not enough to buy the equipment and simply read the instructions. There are companies which provide EUSR CAT and Genny training and EUSR cable avoidance training, the EUSR being the Energy and Utility Skills Register.

Naturally, an awful lot of work is undertaken on roads and highways, and there are a lot of utilities that run underneath them. In towns and cities, of course, there are street lamps, and so there will always be electricity cables running underground here.

There are a lot of rules and regulations about undertaking work on public highways, and there is a code of practice issued by the Secretary of State for Transport, Local Government and the Regions, The Scottish Executive and the National Assembly for Wales under sections 65 and 124 of the New Roads and Street Works Act 1991, and by the Department for Regional Development (Northern Ireland) under article 25 of the Street Works (Northern Ireland) Order 1995. This is called simply Safety at Street Works and Road Works and can be downloaded as a PDF.

One of the first things it mentions is the following key question which you must ask yourself: "Will someone coming along the road or footway from any direction understand exactly what is happening and what is expected of them?"

As a contractor, it is your responsibility to sign, guard, light, and maintain your works safely, so you must take time to plan exactly how you are going to do that and what equipment you are going to need. All site personnel must wear a high vis jacket or waistcoat and you may also need other protective clothing depending on what you are doing. You are also responsible for carrying out an on-site risk assessment to ensure that a safe system of working is in place at all times in respect of signage, lighting, and guarding, in order to comply with Health and Safety legislation.

Signs, lights, and guarding must be protected from being blown over either by the wind or by passing traffic. This means that they must be weighed down at low level with sacks containing sand, or similar, or alternatively you can use equipment which has ballasting built in. However, you must not use kerbstones or barrels or similar objects because they could be dangerous if hit by traffic.

You also need to check that signs have not been moved or become damaged or dirty if you have been away from the site for some time. Signs must be kept clean, and they must be reflectorised unless indicated otherwise.

The works area is the area of excavation, while the working space is the area in which you store excavated material, tools, and so on. You need to ensure that the working space is big enough to ensure that plant such as excavator arms have enough room to move without encroaching into the safety zone, and is clear of passing traffic.