The Advice Provided By HSG47.

HSG47 is a guide issued by the Health & Safety Executive, which is aimed at all those involved in commissioning, planning, managing, and carrying out work on or near underground services. The HSE says that it will also be of use to the owners and operators of such services.

The guide outlines the potential dangers of working on or near such services with regard health and safety. It also gives advice on reducing any such dangers and refers to the indirect risks arising through damage to services.

Possibly the best piece of advice that the guide gives is that all operators should assume that underground services are there unless they have been shown otherwise. Underground services can be found anywhere. Some places are obvious, such as the high street or a residential area. There will be electricity cables, water pipes, telecoms, and sewers as an absolute minimum, but there could also be gas and other pipes.

Striking an electricity cable can cause serious injury, or even be fatal, while, striking a gas pipe can easily cause an explosion. Even a water pipe can cause injury, since water under pressure can hurl stones and other debris out of the earth. It could also cause serious flooding and perhaps collapse the sides of an excavation while it has men working in it.

Striking a telephone cable may not cause direct injury, but will considerably inconvenience the local populace, and may result in claims for damages. For example, it could shut down a business because it cannot get on to the internet which could result in considerable loss.    

Before undertaking any excavation, the first point of call must be the local utilities for plans of where their cables and pipes run. However, such plans should not be taken as gospel since they are not always accurate and, in some cases, may not exist.

All surveyors undertaking the location of underground services should attend an HSG47course which will show them how to use the CAT and Genny in all modes in order to locate services. Such a course will also explain the limitations of the equipment and how to avoid making any mistakes because of those limitations.