Brougham Castle Bridge

Structural Designer

Curtins

Client Name

Cumbria County Council

Location

Penrith, United Kingdom

PRINCIPAL CONTRACTOR
Metcalfe Plant Hire Ltd (Civil Engineering Division)

PROJECT DESCRIPTION

The repair and rebuild of a flood-damaged three-span, 45m sandstone ashlar masonry arch bridge built in 1812. The project featured major temporary works with cross-pier bracing and hydraulic jacking. Repairs used geologically matched stone and compatibly designed lime mortar, while the design solution used the latest innovative techniques to strengthen and build-in resilience to future floods.
 

Judge's comment:

This partially collapsed 200-yr old Grade II listed masonry arch bridge has been repaired following storm flood damage in 2005, extensively scouring one of the piers. During the investigation, it was discovered that the bridge was founded on scour-sensitive materials. The global stability was analysed to understand the new load paths. Foundation stability was restored by means of a temporary cofferdam, underpinning concrete and resin binding of the granular riverbed material, before work began on the superstructure. The barrel vaults had to be unloaded and exposed to restore their shape and original load transfer, before replacing the road surface. The entire construction phase was constrained to a 75-day window due to the river authority’s requirements.
The judges were impressed by the delicate and pure nature of the repair work, honouring the original materiality. The replaced stonework was obtained from salvaged, re-used or locally-sourced geologically identical stone, and sand-blasted to encourage weathering. Over time, the new stone and mortar’s appearance will begin to resemble the original’s. As a result, the bridge’s age and sensitive repair are reflected in its restoration.