Oxford Road Footbridge Deck Replacement
Oxford Road footbridge is located near Clacton-On-Sea station on the Colchester to Clacton line. It was constructed in circa 1920. The footbridge carries a footpath between Oxford Road and Clacton Leisure Centre, with a single span over four Network Rail tracks. There is Overhead Line Equipment (OLE) in place over each track supported by gantries. The bridge was in poor condition and was identified for deck replacement with a trestle modification scheme.
The proposed intervention work included replacing the main span and landings with a new steel plate girder structure and landings. The new main span and landings were adapted from Network Rail’s standard non-station footbridge details and suited to the longer clear span requirement of 28 metres approximately.
The existing trestle supports and stairways were assessed for re-use, strengthened and modified as required to receive the new landing. Condition based repairs to remaining trestle and stairway elements were also specified. The proposed repair works to the remaining existing structure were as follows:
- grit blast and paint all remaining exposed metallic elements
- replacement of severely corroded trestle bracing elements
- replacement of tee connections between trestle columns and bracing members at mid-height where severely corroded
- repair of severely corroded trestle columns at interface with concrete footing
- isolated plate repairs to existing trestle columns
- reinstatement of staircase parapets
- concrete crack repairs to stairway soffit
- minor concrete repairs to staircase and addition of stair nosing.
The main span of the deck was supported by steel trestles. The loads transferred to the trestle supports were not expected to be larger than existing loads. Robert West proposed to re-use the existing approach stairways and metal trestle supports, with refurbishment of the trestles in order to repair existing defects. Altered and repaired structural elements were expected to have a design life of 30 years.
The works were completed without issue and the bridge went in to service soon after. Upon opening it was said that the bridge looked "like it did before the works", which is a testament to the sympathetic nature of the strengthening design solution.