The Minister instead proposed an alternative solution of adding an airport station at Gogar on the Fife railway line. This would provide an interchange with Edinburgh City’s trams for onward travel to the airport. He also said that the Government intends to build a rail link between the Fife and the Edinburgh & Glasgow (E&G) routes – the Almond chord – that would allow E&G trains to stop at the new airport station. (The terminology in 2007 was 'the Dalmeny chord' but that created confusion with the existing rail link between Winchburgh junction and Dalmeny junction which already carries that name so we refer to 'the Almond chord' throughout to refer to the proposed new link.)

The layout of the railway lines in 2007 and the assumed configuration of the proposed Edinburgh Gateway station and Almond chord are shown in Figure 1. There were no plans or documentation available in the public domain in 2007 that provided details or layouts of the Government’s proposals.

The station at Gogar later came to be named 'Edinburgh Gateway' and serves only the northern two of the four railway tracks that pass through Haymarket and Waverley. Trains to and from Fife use the northern pair of tracks; trains to and from Glasgow, Falkirk and Stirling use the southern pair. Therefore, trains to and from Glasgow that serve Edinburgh Gateway station via the proposed Almond chord would share the northern pair of tracks with Fife trains.

The requirement for the Almond chord appears unrelated to Edinburgh Airport. Prior to the Airdrie-Bathgate line being reopened in 2010, four trains per hour (tph) ran from Glasgow Queen Street, via Falkirk and Newbridge Junction to Edinburgh Waverley and a further two tph ran between Dunblane and Edinburgh. Network Rail has since electrified and increased the capacity of the E&G line as part of the EGIP project. With the addition of 4tph from Glasgow via Bathgate and a further 2tph from new services via Cumbernauld, there will be a total of twelve tph to be accommodated on the E&G line through Newbridge junction and Edinburgh Park.

The current track configuration cannot cope easily with this traffic. Newbridge junction is a flat junction and it would not be practicable to rebuild it as a grade-separated junction because it spans the M8 motorway, as shown in Figure 2. The initial technical feasibility report on the reopening of the Airdrie-Bathgate line noted (Section 3.1.1) “If EARL should proceed…it would ease the well-known capacity constraints at and east of Newbridge Junction into Haymarket Station.”

In the absence of EARL (or either EISL proposal), the Almond chord is required to provide the opportunity to divert some of the trains from Glasgow (via Falkirk) onto the Fife lines. The Fife lines carry only five or six tph and Network Rail has upgraded the signalling to improve their capacity. Diverting some of the Glasgow (via Falkirk) trains onto the Fife lines via Dalmeny would balance the loading on the E&G and the Fife lines more evenly and provide operational flexibility to cope with disruption to services. It would enable more trains to be timetabled to stop at Edinburgh Park. It is possible that the opening of the Almond chord would reduce the number of trains that could stop at Edinburgh Gateway because the tracks through that station would then be required by a greater density of traffic and trains that stop would delay following non-stopping trains.

All trains that use the Fife lines will pass through Edinburgh Gateway, regardless of whether they are stopping there. This is a different arrangement from that which was proposed for EARL, in which an extra set of tracks would have been provided forming a loop that would be used only by trains stopping at the airport station. EARL proposed only two platforms and proposed a timetable that allowed only about half the trains from the Fife lines and half from the E&G lines to be diverted through the EARL loop, because the EARL station’s two platforms could not have coped with all the trains that travel west from the four platforms at Haymarket.

Likewise, Edinburgh Gateway could never have more than about half the trains heading west from Haymarket passing through it, and fewer if many trains are to stop at Edinburgh Gateway. Because all Fife-bound trains must pass through Edinburgh Gateway, this will limit the number of trains that can use the proposed Almond chord. It is not obvious how many trains per hour could stop at Edinburgh Gateway but it appears unlikely that frequent services can be offered to any part of Scotland that is not served by a rail line through Fife.

With the Almond chord operational, the arrangements at Edinburgh Gateway and Edinburgh Park would be complex for passengers, especially infrequent travellers or tourists arriving at the airport. For example, it would be complex to advise passengers travelling from the airport where they should alight from the tram to board a train to Falkirk. The next train may leave from either Edinburgh Gateway or Edinburgh Park.

The station at Edinburgh Gateway directly benefits only passengers travelling from Fife, who are able to transfer to a tram at Edinburgh Gateway, rather than at Haymarket. It is unlikely to provide more than two trains per hour for passengers travelling to or from Glasgow. It will be unable to serve the Airdrie – Bathgate line to Glasgow. The Almond chord would offer benefits to the rail network but not directly to passengers travelling to or from Edinburgh Airport.

In 2007 we wrote: "If the option of developing EISL is to be taken forward, or at least preserved as a development option, it would be preferable for the Government to agree that:

1. The new station at [Edinburgh Gateway], providing a link for passengers on the Fife line to join the tram service to the airport, should be constructed south of the A8 road, adjacent to the Gyle shopping centre, to maximise the option for the future grade separated junction for EISL A2 or B2; and
   
   
2. The [Almond] chord should not be constructed because its function could be fulfilled better and more cost effectively by the proposed junction arrangements as part of the EISL A2 or EISL B3 proposals."