Barnards Lock Bridge
Berkshire, UK
Project synopsis
Option selection report, Form 001 and Track Form A design for Barnards Lock and Skinners Lock.
Contractor
Carillion
End client
Network Rail
The existing bridge at Barnard’s Lock was a steel half-through bridge which carried two rail lines over the River Kennet near Newbury, England. The bridge had reached the end of its working life and was found to be in poor condition and unable to safely support loads from rail traffic, limiting the size and speed of vehicles that could use the line.
Tony Gee designed the replacement bridge, and associated temporary works, which increased the speed and safety of the railway line in the area.
Network Rail’s standard design details were adapted to suit the site constraints. A two‐span continuous bridge was favoured over a simply supported structure. This provided a more efficient design by reducing member sizes for the span lengths and meant 25% fewer bearings were needed. These added value in cutting material and maintenance costs.
The design also made allowance for replacement of the bearings in future by providing jacking points beneath the girders. We developed a number of alternative options, including infilling the bridge and diverting the river through new concrete culverts.
Existing abutments were strengthened and reused for the new bridge, which meant less waste, lower associated carbon emissions and allowed the bridge to be completely replaced during a single weekend possession.
The design to modern standards allows trains to travel at higher speeds over it compared to the old bridge, which in turn reduces journey times and improves reliability for passengers on the rail network.
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