Tunnel Description

Length of the tunnel (m)

900

Effective width (m)

9.5

Effective height (m)

7

Open cross-sectional area (m2)

66.5

Camber (%)

0.5

Open area of discrete drains or continuous slot (per Xd m) (m2)

0.22

Interval between drains, or slot length used to define Ad (m)

50

Time taken to activate emergency ventilation (min)

10

Volume flow rate extracted from emergency ventilation regime (m³/s)

206.15