Effective Tunnel Ventilation Supplied at the King George V Reservoir

Case Study Overview

The Thames Water AMP6 Framework was a design and construct programme that comprised of multidisciplinary activities, including the maintenance of water & wastewater treatment works, pipelines, pumping stations, and reservoirs. Under this programme, maintenance at the King George V reservoir was necessary, and ventilation was required whilst site operatives cleaned out two of the reservoir’s underground tunnels.

Challenge

Dangerous levels of Ammonia were present within the tunnels that required cleaning. Exposure to this dangerous gas can cause severe burns if it comes into contact with your eyes and skin, even causing burns to your respiratory tract and lungs if inhaled.

Solution

The tunnels that required cleaning ran from the King George V Reservoir to Albany and from Albany to Maidensbrook. At all three locations are large underground shafts leading down into the tunnels, accessible via manholes. To achieve effective ventilation of the tunnels, a 450S Ventex® centrifugal fan was placed at the shafts of both the King George V Reservoir and Maidensbrook. Flexible duct runs were then fed through the manholes of the shafts, allowing these fans to vent in fresh air at each end of the tunnels. The contaminated air then exited through the manhole at the top of the Albany central shaft.