The Medway town of Rochester, some 30 miles east of London, is an historic place. It was a centre for the pre-Roman Cantiaci tribe. In the late-Roman period it became a walled town and construction of the current cathedral began in 1080.

Sadly, Rochester lost its status as a city in 1998 upon the creation of the Medway Unitary Authority. However, it has now gained something else – a brand new station.

That’s not to say that Rochester didn’t have a station before. It did, on the Chatham main line, but that only had ten-car platforms and services were planned to start using twelve- car trains.

In conjunction with the local council, Network Rail made a bold decision. Rather than enlarge the old station, and therefore disrupt travel while the changes were being made, it would build a completely new one.

A site was chosen that was 500 metres west of the existing station and which could form part of an integrated transport hub, connecting trains, buses and, via a new subway, give pedestrian access to the station, the high street, and the new mixed- use Rochester Riverside development, which will include 1,500 new homes.

The new station would allow twelve-car trains to call at the town, in conjunction with improvements to the signalling and track in the area. Further development, including the removal of the signal box and a third platform introduced at the station, would further increase flexibility and improving reliability.

Network Rail appointed three key contractors to work on the project. Atkins were to act as lead designer for the resignalling, with Spencer Group building the station and Balfour Beatty building the track and electrification.

Pedestrian underpass

One of the biggest challenges of the project was the construction of an 850-tonne pedestrian subway connecting with the new station. It was built ‘off line’ and adjacent to the existing rail embankment, then installed during a 96-hour blockade over Easter 2015.

The reinforced concrete subway, which is 28 metres long, 7.6 metres wide and 4 metres high, was slid 36 metres into place after the Spencer Group team had excavated through the embankment the previous day. The team, assisted by specialist contractor Freyssinet, used ten jacks to lift the structure off the ground by 100mm. Each jack was bolted to a compressed nitrogen pad, which ran along a steel skid-way, with each pad then being pressurised with nitrogen gas.

The pads acted like a ‘mini- hovercraft’, riding on a cushion of nitrogen along the skid-way. This greatly reduced the friction between the subway and the skid-way, meaning that a pushing force of only eight tonnes was required to slide the structure into place.

Tom Kerins, operations director at Spencer Group, said: “Installing the subway was an extremely important and challenging aspect of the works at Rochester. Moving such a large structure into place presented us with a number of logistical challenges but, by using innovative technology, it was completed without incident and ahead of schedule. It was the first subway slide of this type carried out in the UK using this technology.”

A wider context

The replacement of Rochester Station is at the heart of the £145 million East Kent Phase II programme to upgrade a 33-mile stretch of East Kent’s railway network which was last renewed in 1959. This major multidisciplinary undertaking has involved several of the industry’s main contractors, with the Spencer Group being responsible for delivering all of the civil engineering elements throughout the programme.

This included the extension of platforms at Strood and Sole Street Stations to accommodate the 12-car trains now in service. In addition, the team created a turn-back facility at Rainham in the form of a new 12- car bay platform.

The project in the Medway area followed on from the award-winning remodelling of Gravesend Station, which Spencer Group delivered during an intensely successful 15-day blockade.

East Kent Phase II has been described as an industry model for collaborative working, with the achievement of BS11000 accreditation for Spencer Group.

To create a culture of collaborative working from the outset, an alliance was formed between all supply chain partners and Network Rail. Working as a one solutions-driven team, Spencer Group and its collaborative partners designed innovative delivery approaches and achieved engineering savings in the provision of a successful engineering solution that will benefit millions of passengers every year.

Local content

Throughout the project, Spencer Group endeavoured to use a supply chain representing a wide and diverse spread of local organisations.

Companies included: Sian Formworks from Gravesend, a family-run contracting company for civil engineering; Reinforced Concrete Projects; CCS Scaffolding from Gravesend; ASH from Ramsgate; CRS from Ashford; Gallagher from Maidstone; and McNealy Brown from Sittingbourne. A concerted effort was also made to use local workers, with around 90 per cent of the Spencer Group workforce employed from the area.

Spencer Group has an excellent record of maintaining good community relations in civil engineering projects of this kind and Rochester Station was no exception. Everyone in the team worked hard to minimise disruption in the town centre during the works.

The result is a new station in Rochester that is crucial to Network Rail and Medway Council’s shared vision of regeneration – improving access to Rochester’s historic town centre and attracting London-bound commuters to the new Rochester Riverside development. To cope with the expected rise in weekday travellers, there will be five additional morning rail services into London.

The station and its underpass allows residents to take a quick stroll between the riverside and town centre or hop on a train and be in London in 35 minutes.

David Statham, managing director of train company Southeastern, which operates the new station, spoke for all of the stakeholders at the opening: “The station is closer to the heart of Rochester than the old one used to be, which is great for residents, great for local traders and great for the hundreds of thousands of sightseers that visit the area each year for its festivals and amazing heritage.”

It was also a great success for Spencer Group, which had pioneered a new technique in installing the all- important subway.

Written by Simon Taylor