A Look Back at the Recently Completed Bann Bridge Bearing Replacement Project, Coleraine

Title: Bann Bridge Bearing Replacement Project, Coleraine

Principal Contractor: FP McCann Ltd.

Contracts Manager: Hamilton Walker

Principal Designer: AECOM

Description: A look back at a recent successfully completed project carried out on behalf of NI Railways. FP McCann undertook and successfully delivered the Bann Bridge, Coleraine Bearing Replacement Scheme.

The Bann River Bridge was constructed in the early 1920’s and officially opened in March 1924, and is a listed Industrial heritage Site. The bridge is a multi-span (10 spans) steel structure composed of Dorman Long steel girders on reinforced concrete piers, which themselves rest on precast concrete piles, with a central 25m long, single leaf bascule lifting span, counterbalanced by an underhung concrete block to permit access of river traffic into Coleraine Port Harbour.

The bridge in total is approximately 240m or 800ft long carrying trains on a single track between Coleraine and Derry/Londonderry and is the only railway bascule bridge in Northern Ireland.

FP McCann Bann Bridge bearing replacement Coleraine complete

FP McCann Bann Bridge bearing replacement Coleraine complete2

The project involved the removal and replacement of 36 Nr. Bearings without affecting the Coleraine to Derry/Londonderry rail operations which included but was not limited to the following;

Provision of safe access to the reinforced concrete pier heads, i.e. provision of an underhung tuff coat encapsulated scaffolding system with
fully boarded platform & walkways.
Surveying the existing structure to determine the size of required steel strengthening plates, stiffeners, bearing components as well as concrete
strengthening to the top of the piers.
Modification of existing reinforced concrete pier head as required which included but was not limited to; reduction in level, coring, and adding additional reinforced strengthening bars.
Alteration to the concrete encapsulation of the steel transverse beams.

Design and implementation of a temporary hydraulic jacking system to support the bridge spans during bearing replacement.
Design, installation and removal of horizontal bracing of the superstructure
Design, fabrication and installation of the bearings, ancillary bearing steelwork, steel strengthening plates and stiffeners
Monitoring of vertical and horizontal superstructure displacements
Structural steel paint repairs
Replacement of the emergency refuges
Repairs to the track drainage