Old Lodge Lane Bridge replacement, UK
ALE has performed the partial bridge replacement of Old Lodge Lane overbridge in Purley, London.
ALE was contracted to supply and erect trestling for both the new and existing bridge decks as well as to jack-up the new bridge deck to installation height and jack-down the old bridge decks for demolition. In addition, ALE was requested to remove and install the partial bridge decks on the north and south spans of the bridge using SPMTs.
ALE used 24 axle lines of SPMT in 2 x 4 file 6 configuration, one set to remove the existing deck and one set to install the new deck.
The existing bridge decks weighed approximately 60t each and the new decks weighed 120t each. This scheme had previously been attempted over Christmas 2015 using a crane but, due to strong winds, had been aborted and SPMTs were reconsidered as being at reduced risk from adverse weather.
The central section of the bridge is a brick arch and the outer sections (north and south span) are steel decks which each carry one line. The planned works were to remove the two steel outer decks without affecting the central brick arch. The steel outer decks would be replaced during one possession each.
The inner girders on both the north and south decks were partially obstructed by the brick arch. ALE, therefore, devised a solution that allowed two beams to cantilever from the steelwork on the SPMTs and protrude through small, cut-out channels in the brick work, thus allowing the existing bridge deck to be lifted clear of the brick arch. Climbing jacks were incorporated into the SPMT steelwork to allow for increased height adjustment due to the effects of the slope in the road. The installation of the new deck folowed the same procedure but in reverse.
ALE completed the removal and installation process within one shift in each of the possessions. The possession works were carried out over 2 separate weekends, 3rd-4th December and 25th-26th December 2016.