UK railway engineering company 1stinrail has completed extensive track replacement work on the Keadby Drawbridge, the unique structure crossing the Stainforth and Keadby Canal that connects Doncaster with Scunthorpe and the Lincolnshire coast.
1stinrail Project Manager Ryan Hughes said: “This was a fascinating project to be a part of due to the unique design of the drawbridge and the fact that it is one the busiest routes for freight trains in the UK. The drawbridge dates back to the 1860s and was converted into a sliding bridge in 1925.
“The existing structure consists of an open riveted steel framework on a rectangular plan in which the railway crosses the canal at an angle to allow the passage of trains. Canal traffic is accommodated by the bridge and all the attached infrastructure retracting in a sliding motion back into a ‘draw pit’ when required.”
Ryan said 1stinrail, part of the RSK Group, was contracted by AmcoGiffen (working on behalf of Network Rail) to manage the replacement of the existing longitudinal timber way beams and all associated track.
The 1stinrail work included planning, surveying, setting out of track position, management, supervision, skilled labour, track related materials and equipment, road/rail equipment, rail welding, track tamping management and ensuring that the track was complete and handed back to running traffic at the required line speed upon completion of the works.
Ryan added: “The nature of the project meant that works had to be undertaken within a nine-day blockade, with multiple contractors working around the clock on their own specialist element of the works, starting at midnight on the first day and ending in the early hours of the final day.
“The age of the existing structure, the varied fixing arrangements (and their modification/repair over the years), the complexity of the overall repairs/renewals required, together with the canal environment, created many challenges, which through cooperation, collaboration and sheer perseverance were successfully and safely overcome.”
Ryan said the project included the removal of all existing tracks, including four approach panels, one of which comprised longitudinal timbers in a concrete chase secured by grout.
Preparation for this work included studying historical information and comparing this to the existing structure to assess where the track panels required cutting for removal and how access for removal of the fixing arrangements was to be achieved. This was crucial to minimise the time required for removal and to maximise the use of a 350-tonne road crane. Once the track removal element of the works was completed, the bridge was retracted into the draw pit to enable other contractors to start work on the north canal wall.
The unique construction of the bridge required a complex, specific track configuration design including:
- 22 running rails (including adjustment switch tips, 30° scarf cuts, all in varying lengths due to the angle of the bridge)
- 200 linear metres of guard rail
- 2 Sekisui synthetic (FFU) way beams
- 56 Vanguard anti-vibration units around track joints
- 178 Vipa baseplate systems – over the steel deck structure
- 114 guard rail baseplate systems
- Circa 200 linear metres of tamping operations to the existing infrastructure either side of the bridge, to adjust alignment and level in accordance with the new design
- 120 t track ballast – delivered by road
- 14 welds.
Ryan said that the overall installation element of the works was a slow and careful process, undertaken in two phases around the position of the bridge, as when in the draw pit, no works could be undertaken to that portion of the bridge.
He said: “A further complication to the installation process was the horizontal angle at which the bridge crosses the canal. This meant we needed a 30° angle scarf cut for all infrastructure on the bridge, enabling the bridge to slide in and out of position with the confidence that no points of the structure would collide with each other and that they would align perfectly when closed.
“Once the bridge was in its closed position, 1stinrail set about installing the track configuration on that section, which included adjustment switches, securing the rail into the new baseplates and setting the critical dimension on the scarf joints ready for welding.
“Collaboration is a word that is often used in the railway industry but not always fully understood or implemented; however, in this case, all parties involved truly collaborated throughout the planning and delivery of the works. There were a number of challenges associated with this unique structure, but the whole delivery team worked together tirelessly to ensure that each aspect of the works was delivered. The plan was monitored and adapted and each party’s needs were met so that the works could be completed safely and ultimately, so that the tracks were handed back to traffic on time.”
Ryan added that 1stinrail was supported by its capable and consistent subcontract supply chain (Smarttrax, Ballycommon, Weld a Rail and Story Plant). He said they were reactive, supportive and always working hard to assist with the overall needs of the project team.
Photo credit: 1stinrail
