These works primarily includes prefabricated modules manufactured, tested and commissioned off-site by PBS in our prefabrication facility.

There are 5 types (size of the module varies) of modules running all along the tunnel length. The fixing of the modules including associated connections made in the final location were done by the Sub-Contractor as part of the works.

In cross section from South to North end of the tunnel, there are 5 types (size of the module varies) of modules running all along the tunnel length:

• Central Ceiling Module for ductworks and smoke extract system
• East Cheek Module for Fire Main System and Water Main System
• West Cheek Module for Fixed Fire Fighting System (FFFS),
• Bus Bar and Containments
• East Wall Module for Containment Rack and
• West Wall Module for Electrical Distribution Panels (EDPs)

The Cargo Tunnel provides a critical operational link between the Heathrow Terminal 4/Cargo area and the Central Terminal Area (CTA). It facilitates many vehicle movements for cargo, catering, maintenance vehicles, airport operations and transferring passengers.

The Cargo Tunnel was designed and constructed in the 1960s and received systems upgrade in the mid-1990s. However, since then the tunnel has received limited attention. In addition to life-expired infrastructure, the industry’s understanding of tunnel safety has dramatically improved. As such, the Cargo Tunnel now requires major works to improve its condition to reduce the associated risks and safeguard this key operational link.