ENGINEERS IN Yorkshire this week completed a critical section of a £5M project to save the Leeds to Ilkley railway line from slipping down a hill.
Contractor May Gurney has installed the last fi ve of 90 drains either side of a 1km stretch of track running across Ilkley Moor These will divert water which is surging through the hillside, destabilising the railway embankment. They will connect to interceptor pipes on either side of the track and channel the water downhill to the River Wharfe.
'Massive artesian pressures are forcing water through to the surface. Draining the water will stabilise the slope, ' said contractor May Gurney Rail's project manager Andries Liebenberg.
As well as the drains, a series of 18m deep pipes has been sunk alongside the railway to pick up and divert high pressure ground water which is being forced to the surface. The pipes will also connect to the interceptor.
But diverting the water under the live railway line through two new 900mm diameter concrete culverts has had to be delayed because directional drilling to make way for them was unsuccessful.
'We made three attempts to push the 50mm diameter pilot drill through, but we kept hitting boulders which we couldn't remove because of the railway line, ' said Liebenberg.
Scheme designer Atkins is now designing temporary works for a pipe jacking solution.
'Basically we will push in an oversized pipe and a man will go in using a pecker. Soil and any boulders will then be brought out and temporary supports will be installed as needed, ' said works manager Rob Proctor.
More drains and 18m deep pipes will be installed along another section of track when the fi nal part of the project begins next month.