Osprey Heavy Lift was contracted to carry out the replacement of the existing single span under-bridge on the Chester to Warrington line at Mickle Trafford with u-type steel decks on new reinforced concrete cill beams.
Due to buried fuel lines in the area forming part of critical national infrastructure and restricted room for craneage, self-propelled modular trailers (SPMTs) were used to minimise ground loading’s. Extensive liaison with third party stakeholders was needed to enable the works.
Osprey used an innovative gantry lifting system never used on a rail project in the North West before. By designing the bridge so it could be lifted from the top and assembling the bridge at ground level, working at height risks were negated.
On previous projects, the new bridge would be assembled on site on jacks at approximately 5m height two weeks prior to installation. Operatives would then work on the new bridge while working at height off cherry pickers. The same process would be used for removing the existing bridge. On this occasion, using the gantry system allowed the bridge assembly and all preparations to be carried out at ground level.
The existing bridge was driven under the gantry once removed and in turn within the core weekend the bridge was set on the ground at the end of the shift. Normally this process would take a week after the core possession, therefore we reduced the project programme and the amount of plant required on site.
Listening to our customers concerns, thinking outside the box and using existing equipment in innovative ways allowed us to dramatically reduce the risks associated with this replacement operation. We successfully delivered this project safely, on time, within budget and in a value-added manner