£150 million in eight stages serving over 23 million passengers a year at Edinburgh Waverley

£150 million in eight stages serving over 23 million passengers a year at Edinburgh Waverley

04 Dec 2006

Rodger Querns is the Project Manager for the current works at Edinburgh Waverley, which includes remodelling, resignalling, platform works and structural alterations to the listed station structure. The fact that the imminent stages of this work necessitate major track possessions over the Christmas period, and in the run up to the Scottish General Election next May, both add to his job pressures! Transport Scotland is funding the infrastructure works with Network Rail managing the delivery. Westinghouse are the signalling contractor, Amec Spie are carrying out the construction work and Morgan Est the extension to the signalling centre.

576 trains a day and growing!

Edinburgh Waverley is the second largest station in terms of geographic area in Britain. With 23 million passengers using it every year, it is now operating at peak capacity. There has been a 50% increase in the number of trains using the station in the last fifteen years; it is now up to 576 trains each day.

Major projects including the Airdrie-Bathgate link, the new Borders railway, and the Edinburgh Airport Rail Link are all dependent on the redevelopment and increased capacity, which will result from the completion of the present works.

This year’s work

The contracts were awarded back in December 2005, and construction of the two Balmoral platforms together with re-signalling work began the following month. In April 2006 the contractors started work at Edinburgh Haymarket Station, and in May the link bridge to Princes Mall was erected. The extension of the Waverley signalling centre building was completed in August. During October the platform works at Haymarket reached substantial completion.

At Waverley the Balmoral and Klondyke platforms will be finished this month, together with new steps and escalators replacing the Princes Mall footbridge.

Disruptive weekend possessions 2006

The work this year has been divided into eight possession stages. Stage 1 saw the use of eight-hour nightly possessions for the construction of the two Balmoral platforms.

Stage 2 was the work on the Balmoral platforms, north loops and sidings. Possessions for this part of the works included 54 hours in week 48, 29 hours the next weekend, followed by a further 54 hours in week 52. These possession works continue with another 54 hours in week 8 and 29 hours the following weekend and finally 56 hours in week 39.

Stage 3 works centred on the Haymarket turn back platforms. Week 1 included a 54-hour possession of platforms 1 and 2 and 21.5 hours for platforms 3 and 4. Week 14 saw signal gantry work between Haymarket East and West junctions during a 54 hour block followed by OLE gantry work the next two weekends with 54 hours on the platform 1 and 2 lines and 26 hours on roads 3 and 4. Stage 4 saw the installation of new crossover 161 during an 88-hour possession in Mound Tunnel.

2007 works

January 2007 will see the commissioning of Slateford Depot and a start being made on the Waverley West Throat alterations, which are programmed for completion next November. The plan is for all infrastructure work to be finished by next December (although the signalling work will not be fully finished until June 2008).

Stage 5 includes a series of possessions, whilst work is carried out to the West Throat, north side. This work starts with the existing line Y blocked continuously from week 39 to 52 followed by a 54-hour possession of both lines Y and Z.

Stage 6 reconnects Line Z to the West Throat, South side with Line Z blocked continuously from week 1 to week 6 followed by another 54-hour possession of both Lines X and Z.

Stage 7 is a similar approach to the West Throat West side, with Line X blocked continuously from week 7 to 17, followed by a 45-hour possession for signal commissioning.

Stage 8 will see the reconnection of Line W to the West Throat South side with Line W being blocked continuously from week 18 to 34, with a 54-hour possession at the start in week 18 for signalling disconnections and two further 54-hour possessions in weeks 33 and 34 when Line W will be commissioned. At the end of each stage a twelve-hour ‘wheels free’ period has been planned for signalling testing.

The Waverley Steps

A scheme to re-design the Waverley Steps to provide escalator and lift access connections to the station obtained Planning and listed Building Consent early in 2006. Unfortunately the implementation of the works requires legal and commercial agreements to be agreed with adjoining neighbours and these negotiations are ongoing.

Klondyke and Balmoral

The current capacity improvement work will see four more trains using the West Throat approach to the station each hour. In stage one a new access and enclosure is being built at the Waverley Steps, new platform 10 is being built against the famous Klondyke Wall, with additional new platforms numbered 1 and 19 being built adjacent to the rear wall of the Balmoral Hotel.

Due to location, foundation conditions are difficult and construction adjacent to the Klondyke wall required the drilling of no fewer than 31 bored piles down to depths of between 30 and 60 metres. This work will be completed by 27th December 2006, a key blockade date for the project. Adjacent to the New Street Car Park a design and build contract has resulted in the construction of an extended new Signalling Centre built by Amec Spie and being fitted out and commissioned by Westinghouse.

The temporary Mezzanine Bridge

The new platform adjacent to the Balmoral is due for completion by December 27th and the new scissors crossovers have already been installed. A temporary bridge link at Mezzanine level has been in use since May, routing passengers from Platform 19 through the Princes Mall Shopping Centre and onto Waverley steps and onto Princes Street.

‘We’re cutting it up most nights...’

By early October many kilometres of new track had already been laid in, nine new sets of S&C out of 29 were already in place and twenty more were in the pipeline. At £150 million Waverley is the biggest Scottish Railway Project at present, and the Project Manager was pleased to be able to say that it is going well. Rodger Querns went on to comment that “we are cutting it up most nights but putting it back together each morning” which sums up the normal possession working process.

Signalling matters

Edinburgh has been a major destination in Scotland since the early days of railways and its importance as a rail centre has continued to grow. The present signalling centre was the result of major improvements on the East Coast route during the 1970s and was commissioned in 1976. This ‘original’ installation comprised mainly GEC geographical interlockings at a number of sites, controlled from a Henry Williams Domino NX panel.

The control area eventually included the lines to the North to Ladybank, West to Linlithgow and south to the English border meeting up with Tweedmouth. This represented some 229 route miles and 523 main signals! Sometimes it seems that change is the only stability and changes were undertaken in the late 1980s in connection with East Coast Electrification.

Further significant changes followed in the mid 1990s when the entire interlocking at Haymarket was replaced with “interfaced SSI”. This was following discovery of severe insulation degradation within the interlocking cabling. [Interfaced SSI uses SSI TFMs (trackside functional modules) concentrated in a convenient place and connecting to the existing trackside cables.]

Wire degradation also led to the replacement of the entire relay interlocking at Waverley itself, this time by conventional 2 MHz SSI operating trackside functions via remote TFMs. Significant alterations to external signalling equipment were also undertaken, but without any track or layout changes.

The latter works were carried out by Westinghouse Rail Systems (who are also the signalling contractor for the present works), and were completed in January 2004. The work involved complex alterations to the original signalling panel and a temporary panel section was utilised to control part of the area whilst the main panel was modified. The panel had also to be electrically connected to the new SSI interlockings by means of a P-Mux arrangement (Panel-Multiplexer).

Enabling scheme

At the completion of these works there were six SSI interlockings controlling Waverley and Haymarket, with the Waverley SSI provision effectively serving as an “enabling scheme” for the current project. With the major alterations that are again underway with the present scheme, an additional SSI interlocking has been added to the original four at Waverley together with the associated works to provide new signals and point operations in the station area. The Haymarket ISSI installation had sufficient capacity to control the additional infrastructure at Haymarket.

“The complex SSI data associated with the changes, is being prepared and tested by Westinghouse Rail Systems Limited and this will be integrated into the new IECC.”

It was decided that the control of the area would be best accomplished by an electronic control system, which not only gives flexibility in undertaking alterations for the various stages of the track and layout alterations but also provides for the use of automatic route setting (ARS).

The new signalling will make use of standard straight post signals, where possible, and a new 5 track gantry which is being provided at Haymarket. Dorman LED searchlight signals are being used with an additional yellow for the fourth aspect. Point operation of new S&C is by a combination of Alstom HW2000 series point machines and mk 2 clamplocks, depending on layout and other constraints.

Alcatel AZLM axle counters are being used in all terminal/bay platform lines, the complex Waverley West Throat layout, and within the Mound Tunnel. All new and existing track circuits are standard High voltage DC - AC immune.

With the initial major commissioning at Christmas 2006, the planned work continues throughout 2007 and into 2008 and will see the control of all the present control area to the new IECC, as well as the staged remodelling at the west end of Waverley.

DeltaRail Group

The new Edinburgh control centre will feature the VDU-based Integrated Electronic Control Centre (IECC), supplied by DeltaRail Group Ltd. It will control not only the immediate area around Edinburgh, but also down to the Scottish border just north of Berwick-On-Tweed, towards Carstairs, Falkirk, Bathgate, and almost all of Fife, including the famous Forth Bridge.

When commissioned, the IECC will consist of seven signaller’s workstations, two supervisor’s workstations, and various subsystems which will provide comprehensive fault diagnostics and monitoring, automatic route setting (ARS), interfacing with adjacent signalling centres and other equipment, and timetable editing facilities.

Rigorous process

The essential requirements for the selection of the IECC for the Edinburgh Waverley Phase 1 railway enhancement project were:

  • • availability of a proven tried and tested control system
  • • the necessity that the system be flexible enough to enable infrastructure changes to be accommodated on a multi stage basis
  • • the ability to enable infrastructure changes without reduction in operational performance (the requirement to do that with the attendant benefit of ARS)
  • • the capability of the system to interface with Solid State Interlockings, together with a multitude of existing relay interlockings.

Through a rigorous process of feasibility and Design & Development, DeltaRail working with Network Rail and Transport Scotland demonstrated compliance with these requirements and through competitive tendering are now providing an optimal solution to the projects signalling control needs.

Delivery is being made via the Project Signalling Contractor Westinghouse Rail Systems Limited and the signallers’ workstations will be commissioned on the new control room floor which has been built onto the existing Edinburgh Waverley signal box.

Remote Interlocking Interface

The biggest technical challenge is interfacing the IECC to twenty-four relay interlockings, which date from around 1980, and which are to be retained. Interfacing to relay interlockings has been done before, but never on such a scale (the largest previous application at Leeds involved only seven interlockings). For interfacing purposes, DeltaRail Group Limited provide a special IECC subsystem known as the Remote Interlocking Interface (RII). The RII appears to the IECC as a standard Solid State Interlocking (SSI), but to the interlocking it appears as a set of buttons, switches and lamp indications, i.e. a conventional control panel.

There are two types of relay interlocking in the Edinburgh area. One type, supplied by the General Electric Company (GEC), is known as the GEC Geographical system, and is in place at twenty-three of the twenty-four sites. The remaining interlocking, at Portobello, was built to a design produced by the former British Rail’s Scottish Region, and is known as Scottish Region Geographical. (The term ‘geographical’ refers to the fact that in both types of interlocking, the relays and cabling in the relay rooms are laid out in an arrangement which mirrors the physical layout of the actual signals, points and track).

Neither type of relay interlocking had previously been interfaced to an IECC, so the first task for DeltaRail Group Limited was to evaluate the circuits thoroughly to ensure that their operation was completely understood. The next stage was to produce a functional specification for each type of interlocking, recording what the RII was required to do to interface correctly. From these functional specifications, a data preparation guide was written and tested against a sample layout in the laboratory.

Site trial

After this, the data for one interlocking of each type has been written and will shortly be taken to site for a site trial, which involves connecting the RII to the actual relay interlocking and undertaking a functional test of each type of function, e.g. setting a route, cancelling a route, moving points etc. The purpose of the site trial is to validate the data structures developed in the data preparation guide, and thus to ensure that everyone involved has confidence that the RII will work correctly when commissioned.

Once the data has been produced, independently checked and tested, it will be installed on the RII on site, and one or more site rehearsals will be carried out. At that stage, every function will be tested, and any final adjustments made. Finally the RII will be commissioned, and control of the relay interlocking will pass from the existing panel to the new IECC control system.

Demanding timescales

The other major challenge has been the extremely demanding timescales, with the first commissioning (at Christmas 2006) taking place just one year after the order was placed. The Christmas 2006 commissioning covers the Edinburgh Waverley and Haymarket areas, and is the only major commissioning which does not involve relay interlockings, all the existing interlockings being solid-state. The first relay interlocking will be transferred to IECC control in May 2007, the remainder being transferred in groups until the final commissioning in July 2008. The last stage involves the transfer of no less than seven relay interlockings - the previous ‘record’ was two relay interlockings at a single commissioning.

Since its introduction in 1989 IECC has been subject to continued development to enhance functionality as it evolves to suit future requirements for control systems in the UK and in this instance it will be the first application of the extended axle-counter control functionality now provided by IECC.

With Transport Scotland looking to maximise the benefits from such a significant investment, it is anticipated that the future signalling control needs of the Airdrie Bathgate line reopening, the Edinburgh Airport Rail link, and the Borders Rail link, together with several smaller Network Rail signalling work programmes, may be catered for at the new Edinburgh Control Centre.

Reported in the rail engineer December 06 edition.

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