The 270m Farnworth Tunnel has been used since the 1830s. In this £20.8 million project, the line between Manchester and Preston was converted from diesel to electric. Due to space constraints, the tunnel needed to be filled with 7,500m3 of specially formulated foam concrete and then re-bored.Challenge
Sand unexpectedly poured into the excavated area twice, and 100,000 tonnes of material had to be removed by hand.Solution
A temporary 800CF ventilation kit with adjacent generator was installed to maintain a safe working environment. With this, fresh air was forced through the tunnel via 30m of 800mm duct. Then, a VENTEX 800CF fan extracted and filtered the dust, protecting site operatives.