Tunnelling

A tunnel is any excavation that is approximately horizontal and starts at the surface or from within another excavation. Tunnelling work is often highly complex and involves the use of a range of engineering and construction techniques, plant and equipment.

There are a number of risks with tunnelling work, including the risk of collapse, contaminated atmospheres (toxic, flammable, etc.), and risks associated with heavy plant or equipment.

There are often a range of activities taking place inside a tunnel that are not directly associated with the boring or tunnelling component. These include building support and other internal structures, installing services, and constructing the surface. Workers carrying out these activities are exposed to a number of additional risks that must be managed, including:

• noise, which can be amplified in an enclosed space
• heat stress
• air quality
• the movement of vehicles and mobile plant in an enclosed space.

In addition, issues that might usually be straight forward to manage (e.g. pedestrian routes, facilities and amenities) are complicated by the enclosed and limited space in a tunnel construction environment.

Legislation

The Guide for tunnelling work provides guidance on managing the risks associated with tunnelling work.