Scarborough Bridge, York

Background:-
Before the huge task of replacing the original Victorian structures of Scarborough Bridge, York, could begin, HBPW needed to design the temporary works access and support for lifting operations, which were a logistical exercise in their own right.

Challenge
The bridge carries the York to Scarborough railway line across the River Ouse and, whilst major structural bridge deck replacement work was required, the available access for the installation crane was very restricted by residential areas, narrow streets and the proximity to several important railway lines. As a result the crane would need to be positioned in the small car park between the railway embankment and the residential bed and breakfast. To add to the challenge HBPW found that the existing railway embankment had historical slip failures founding on alluvial river deposits.

Solution
Geotechnical engineers from HBPW initially carried out ground investigation and slope stability modelling, to establish the existing condition of the embankment slope. This helped to direct the design development so that the engineered solution for the crane access provided a long term benefit for the current embankment slope. Two piled crane beams were installed to enable the large crawler crane to safely access the site for the demolition and reconstruction of the bridge and, in total, 200 piles were installed to depths of 14 metres.

Outcome
One of the biggest cranes in Britain was able to swing into action, on time and within budget, to give the 140-year-old bridge a £6m makeover.