Rotherhithe Tunnel Ventilation Shaft (3)

MQT on 2015-09-16
Session date: 
September 16, 2015
Question By: 
Murad Qureshi
Labour Group
Asked Of: 
The Mayor


Can you confirm if air is actively pumped from the tunnel or if it simply diffuses through the shaft of its own volition?


Answer for Rotherhithe Tunnel Ventilation Shaft (3)

Answer for Rotherhithe Tunnel Ventilation Shaft (3)

Answered By: 
The Mayor

There are four air quality monitors through the tunnel that constantly sample the tunnel environment and activate predetermined ventilation plans if carbon monoxide and carbon dioxide levels are greater than 51 parts per million, nitrous oxide levels exceed 41parts per million or visibility within the bore drops below 401 metres. These parameters are based on guidance from various bodies and represent best practice.

Rotherhithe Tunnel has four vent shafts. Shafts 1 and 4 each have three fans and shafts 2 and 3 each have four fans. Shafts 1 and 4 supply (blow) air into the tunnel and shafts 2 and 3 supply and extract air.