Wimbledon Line Enhancement
 

As part of the Wimbledon Line Enhancement Programme, Cleshar were appointed to undertake the design & construction of key infrastructure works comprising:

  • Twin tracking 790m of single line between Mitcham Junction flyover and Beddington Lane tram stop.

  • Remodelling Wimbledon Station Terminus to provide two platforms, a cripple siding and new track layout


Scope of works
1/2

Design – detailed design for the following disciplines:

  • Track layout

  • Civils works, including infrastructure for signals

  • Overhead line equipment

  • Electrical & communications services

 

Site Investigations – To provide the design with survey data and details of existing site conditions, including:

  • Topographical surveys

  • Civils, including ground investigations, structures, and drainage surveys

  • Services dilapidation, including cabling tagging and tracing surveys

  • OLE surveys

The design was produced & reviewed following the Network Rail GRIP stages and approved assurance processes, in conjunction with Tramlink & Network Rail Engineers & Project Managers. The design satisfied all relevant Network Rail and Tramlink standards.

Twin Tracking at Mitcham

The overall scope of works for the Mitcham twin-track project included design and construction activities as follows:

  • Shape embankment (1:3 slope) and install retaining walls to widen footprint for new eastbound track and footpath.

  • Track drainage in westbound cess and UTXs

  • Install cess path along length of site

  • Install multi-duct to length of site to facilitate diversion & installation of cables (fibre optic, UKPN pilot, signalling)

  • Remove existing track, excavate, and install sand blanket to new eastbound and westbound tracks.

  • Install geotextile, ballast, concrete sleepers and S49 rail, with welded joints to eastbound and westbound tracks

  • Install new S & C turnout unit

  • Tamp track to new alignment and stress track

  • Install OLE bases and cantilevered gantries, and transfer catenary wires from existing onto new

  • Remove redundant OLE masts and bases

  • Install OLE contact wire, register wires and new anchor to new eastbound track alignment,

  • Finalise OLE heights and staggers checks and adjustments after tamping

  • Install new golfers foot crossing and install PSR speed signage

  • Final shape embankment, topsoil, and seed.

 

Due to the amount of works required to the existing operational infrastructure, a 9-day blockade was agreed with Tramlink and utilised to allow continuous access to the work site. Weekend and weeknight possessions were also utilised.

Wimbledon Station Remodeling

​To carry out the construction of two new platforms, a cripple siding and installation of a completely new track layout within a fully operational Network Rail and Tramlink station, access and timing were key to the successful delivery of this project. The construction works were sequenced in two phases.

Phase 1 - New single track slab cripple siding, new platform 10b and new twin track slab constructed within a fenced non-operational zone. Works implemented during daytime normal working and within night possessions, but with ALO (Any Line Open) working

Phase 2 - New double track slab with S&C, new platform 10a and new re-aligned ballasted track single line approach. Works implemented within a 12-week blockade

Civils and Track Works:

  • Temporary & permanent relocation works of Network Rail HV power and signalling cables

  • Removal of the existing track slab, buffer stop, ballast, and platform structure

  • Install 200m of double- and single-line track slab

  • Install S&C turnout, points motor, expansion switches, buffer stops and realignment of the existing main line

  • Construct foundations for 10no OLE structures

  • Lay pits and ducts for electrical and signals cables, including posts and equipment plinths

OLE Works:

  • Temporary OLE alterations to maintain tram access to the station during the works

  • Install OLE structures, equipment & small parts steelwork for new track layout

 

Client

London Tramlink (TfL)

Location

Wimbledon & Mitcham

Contract Start and Completion

February 2014 – December 2015

 
Innovations

For the bespoke slab track design, materials and the Rhomberg track alignment system were used to construct a mock-up off site. This facilitated the critical refinement of the design detailing and construction methodology, to allow the new track and S&C to be installed to the required +/-2mm tolerance. This mock-up installation allowed valuable learning to take place, and this was utilised and of great benefit when construction was undertaken on site during periods of normal and blockade possessions

 

As access was only available from the north end of the site, a 130m long polydeck raised heavy duty temporary road and ramps structure was built over the newly constructed phase 1 track slab. This facilitated the movement of heavy plant, materials, and manpower into the phase 2 construction zone, and allow quick and efficient construction

 
Benfits / Project Outcome

The design & construction works had to be undertaken within fully operational station and track areas of the tram network. All the works had to be done whilst facilitating the running of a normal Network Rail train and Tramlink tram services timetable. For this to happen, the designs, methodology and techniques developed and implement allowed the new works to be fully integrated with minimum disruption.

 

Careful programming of the works allowed the majority of the works to be undertaken during normal working hours or standard night-time possessions. This all facilitated the major works being carried out with two key blockades. A 9-day blockade for the Mitcham twin-track works and a 12-week blockade for the complete remodelling of the Wimbledon station end of line terminus. The later timed to start immediately after the busy Wimbledon Tennis Tournament

 

We worked closely with the London Tramlink and Network Rail to deliver a complex project successfully, with minimum disruption to customers