Refurbishment of London Underground bridge D141

Bridge D141 carries the District line of London Underground over the River Lea and Bow Creek in the east of London in the Greater London area. The District line is one of the three west-to-east lines of the London Underground, the others being the Central line and the Jubilee line. As such, it is of major economic importance. The bridge was built in 1888, and is of relatively light construction compared with modern bridges. The track form was of short longitudinal timbers, and corrosion had reduced the live load capacity. The light form, coupled with the short timbers, gave constant track and ride problems. As the bridge spanned two waterways, maintenance was difficult, and major works became necessary to avoid restrictions. The site being ‘landlocked’ hampered refurbishment works, and closure was not an option, as to do so would have caused unacceptable economic effects. This paper covers the history of the bridge, the problems that developed in the bridge, the solutions to the problems—both structural and in the track form—the refurbishment and strengthening of the bridge, and the problems encountered in the work.