Quakers Yard station - expert track design

30 March 2022
Quakers Yard railway station.
Unexpected problems required a flexible response when Amey Consulting undertook the design of a new track layout at Quakers Yard station in Wales

The renewal of the Core Valley Lines (CVL) is an important part of the ongoing programme to transform the Wales & Borders rail network. With the number of trains running set to double, various projects have been undertaken to upgrade the ageing CVL infrastructure and ensure it is able to cope.

Sophisticated railway modelling revealed that Quakers Yard in the Taff valley would be a potential bottleneck when the new timetable was introduced. Amey Consulting's task was to design a new track configuration that would keep the trains moving on that part of the network.

Quakers Yard had a single track served by one working platform, with a second platform lying derelict since the Dr. Beeching cuts of the sixties. The plan was to add a passing loop to accommodate northbound trains, served by a new platform, while the current platform would serve trains heading south on the mainline. The derelict platform would be demolished. The scope of works included new sets of points and a footbridge to replace an existing foot crossing.

However, in practice the comparatively narrow, curving rail corridor and the geometry of the terrain posed several challenges. Quakers Yard is on a sloping site above the Taff river, adjacent to Brunel’s 180-year-old Goitre Coed viaduct. These conditions impacted on the design in various ways.

For example, an early iteration of the plan placed the loop and a set of points on the viaduct itself, but the designers calculated the venerable structure would not bear the weight of the train-mounted crane necessary to lay the new track. In addition, the higher risk of derailment presented by the points would require the installation of guard rails on the track to protect trains, adding to the load. The solution was to redesign the track layout to shorten the loop and move the points off the viaduct.

In fact, this was fortuitous as it provided an opportunity for Amey Consulting to add value by improving the S&C (switches and crossings) design. The original proposal for a mechanical system to move the rails was changed to a more modern hydraulic system, which offers various benefits including greater efficiency and reliability, reduced need for maintenance, and cheaper whole-life cost.

Curvature of the track impacted on the design of the new platform. In order to reduce the gap between train door and platform, railway standards restrict the radius of curvature permissible. The initial location of the platform would have resulted in a non-compliant curve, which meant it had to be moved north where the curve could be flattened as much as possible. The accompanying footbridge also had to move.

The footbridge itself was due to replace a foot crossing that had been in use for many years. The foot crossing was not only non-compliant with current standards but posed a real risk due to the planned increase in the frequency of trains – especially when noisy diesels replaced silent electric rolling stock. The Amey team, recognising that people’s habits are hard to change, introduced fencing and other methods to ensure people walked the longer distance to the footbridge rather than attempting to cross the tracks in the old way.

Quakers Yard is an excellent example of Amey Consulting's ability to think and react flexibly when faced with unexpected situations. Every design change can have a knock-on effect – for example, the redesigned track geometry resulting from the speed issue affected braking distances and the placement of signalling equipment. Accommodating this involved a further change to the track layout that required the removal of an old bridge abutment. Since there was a possibility that bats roosted there, a survey had to be commissioned to find out if this was the case. Tree protection orders in the vicinity of the works were another complication that had to be resolved.

Amey Consulting succeeded in producing an approved track design on time which was a significant win for the team.