Rhomberg Sersa UK (RSUK) achieves new firsts for slab track on the Barking Riverside Extension project
In 2018, transport for London (TFL) commissioned new rail infrastructure to provide transport links for a residential development at Barking Riverside. In this article, we reveal the critical role played by RSUK in the delivery of this project.
Transport for London (TfL) chose slab track to provide new railway infrastructure for their Barking Riverside Extension project. Their decision was influenced by the steep inclines and tight curves of the new viaduct that joined existing track to the Barking Riverside Terminus. TfL also wanted a track solution requiring minimal maintenance and reduced noise impact on neighbouring properties.
Rhomberg Sersa UK was preferred by the main contractor, a joint venture between Morgan Sindall and VolkerFitzpatrick, to install a slab track solution. The client benefitted from our integrated ability to design and build the new track system, reducing cost and programme delivery time.
Strategic partnerships with the suppliers of our slab track system, fastenings and concrete benefitted our client during the design and construction phases. They collaborated with the Design Team using 4D BIM to reduce risk and create a more buildable design. They collaborated with the Construction Team to make Just-In-Time product deliveries at the point of use.
Concrete works before track system installation included an intermediate layer, which acts as a load transferring element into the main bridge structure below. Linking stirrups were fixed in the intermediate layer to couple it with the concrete used at the track fixing stage. We laid out steel reinforcement for the Self Compacting Concrete layer that would fix and support the precast slab track units. Specially designed mobile gantries were used to position the precast STA slabs in the correct sequence. The position of the slabs was adjusted using threaded spindles, five in number for a standard slab. The tolerance of this process was targeted at +/-10mm, but the positio-
ning activity consistently achieved +/-5mm.
Surveying played a critical role for the level of installation quality we achieved. Our surveyors were challenged to achieve ‘best in class’ tolerances. They surpassed themselves and consistently achieved +/-2mm horizontal and vertical absolute tolerances. This was impressively well inside the required project tolerances of: (i) horizontal of +/-6mm; (ii) vertical of +0/-15mm; (iii) cant of +/-5mm; (iv) maximum twist of 4mm; (v) gauge of +/-2mm; (vi) horizontal versine over 10m of 4mm; (vii) vertical versine over 10m of 6mm.
For the Barking Riverside project there are a total of 711 slabs, including 32 Switches & Cros-sings (S&C) slabs. The track alignment characteristics include a three percent vertical gradient, a horizontal curve radius of 220 metres and a track cant of 100mm. These are the highest applied values for UK installed PORR slab-track.
When the Barking Riverside Extension opens in Autumn 2022, it will be able to operate four trains an hour. These trains will run from Barking, along the renovated and modernised Tilbury line, before heading south along the new extension to Barking Riverside Station. The four-train per hour service will support 4,000 homes currently being built at Barking Riverside and directly unlock a further 6,800 homes.
