Assisting with tunnel ventilation system design for New York's Cross Harbour Tunnel, a 3D thermo-dynamic model was used to monitor temperatures as trains move through the tunnel
Mott MacDonald’s world-class tunnelling expertise encompasses every aspect of tunnel systems engineering – from environmental and traffic control systems to lighting, communications and power supply systems.
Mott MacDonald’s experience in the design, specification and implementation of mechanical and electrical systems for road, rail and utility tunnels extend over many decades. Our expertise encompass road tunnel lighting, power supplies (both HV and LV), drainage and pumping, fire detection, air quality monitoring, communications and control, SCADA, CCTV, PA, traffic control and detection, toll collection, radio (including rebroadcast facilities), telephone and HVAC. All these facilities are fundamental to the safety and operability of transportation tunnels and are a key part of the service Mott MacDonald can offer to our customers.

For the UK’s Dartford Tunnel we have designed and supervised installation of sophisticated traffic control and surveillance systems Designing tunnel systems and control
The full range of our capabilities in the design of tunnel systems and controls can be illustrated by two highway tunnels only 15 miles apart – the Dartford and Medway tunnels in the UK. Our involvement with the Dartford crossings extends over 40 years. The tunnel control building is continually manned, with surveillance of the tunnel continuing on a 24-hour basis, 365 days a year. The control building for the Medway tunnel is designed to be unmanned, with the tunnel systems operating automatically, and traffic control being undertaken from police headquarters at Maidstone. The systems for both tunnels were successfully designed and specified by Mott MacDonald.

We carried out specialist inspection of lifts and escalators for the new London Bridge station on the Jubilee Line Extension Our expertise also extends to less public facilities such as high voltage cable tunnels, where the control of temperature and the provision of life safety facilities for such a hazardous environment is a major feature of the design.

Leading the way in tunnel lighting design
The importance of the design of lighting of road tunnels cannot be understated. At entry portals drivers need to quickly adjust to the different intensities between outside and tunnel environments. Drivers must also be able to clearly distinguish other vehicles within the tunnel, which may be masked by the silhouette of larger vehicles towards the exit portal. Mott MacDonald’s lighting designs are carried out using an in-house software tool – Tunlit – which provides comprehensive design data including lighting levels for all areas within the tunnel, quantity of luminaires and verification of uniformity levels.

Notable projects undertaken in recent years include the following railway and highway tunnels:

• Dartford Tunnel, UK
• M25 Tunnels – Hatfield, Holmesdale and Bell Common in the UK
• North Wales Tunnels – Conwy, Pen-y-Clip and Penmaenbach
• Route 5, Hong Kong
• A20 Round Hill, Chestfield and Medway tunnels, Kent, UK
• Heathrow Terminal 5 Airside Road Tunnel, UK – opening 2005
• SMART tunnel – Malaysia
• A3 Hindhead, UK – opening 2008
• Channel Tunnel, UK
• Heathrow Express rail link, UK
• Crossrail, UK
• Delhi Metro, India