The grade-separation serves two purposes. Firstly, it enables the junctions that form an inherent part of the EISL proposals to be adjacent to the station and to avoid any flat crossings. Secondly, by lowering the eastbound tracks, it ensures trains climbing from the future Fife line loop to the new station (past the west end of the airport runway under the EISL A3 proposals) will have a gradient no greater than 1:115.
The station will be 1700m south of the airport terminal and connected to it by a dedicated shuttle.
The EISL A1 route will require the acquisition of land from Easter Norton Farm, Norton Mains, the Gogarburn Golf Club and the new site of the RHC at Norton Park. In addition, some land within the grounds of the Norton House hotel will be acquired for the realignment of the tracks to the west of the new station.
The diversion will use only one face of each of the two island platforms and so will not enable any change to the running pattern of services. However, the rail layout will provide grade separation for the divergence of the Airdrie-Bathgate line from the E&G line and thereby improve operational flexibility. It replaces the current flat junction at Newbridge. With EISL A1, no train from Bathgate will be delayed awaiting a train towards Falkirk to cross its path.
Figure 6 shows the route diagram of stations served. Figure 7 is a diagrammatic representation of the track layout (not to scale). Appendix A1 shows a scale map of the proposed rail alignments. Figure 8 shows an aerial view of the route. Appendix A5 shows the track curvature and line speeds. Appendix A6 shows the rail gradients and elevations.
East of Ratho, the eastbound track from Bathgate will pass under the viaduct carrying the westbound track towards Falkirk.
East of the new station, both the eastbound and westbound tracks follow a curve of 1000m radius, allowing 80mph running. The eastbound line climbs from the station’s lower platform (elevation +43m) at a gradient of 1:250, initially in a deep cutting through the Gogarburn golf course, to rejoin the current alignment at Roddinglaw, west of the Edinburgh city bypass. The westbound line leaves the current alignment at Roddinglaw and climbs at 1:250 to reach the new westbound station platform on its viaduct (elevation +58m).
Figure 9 shows the stations served by EISL A2. Figure 10 is the track diagram (not to scale).
EISL A2 will bring into use the northern flanks of each of the two island platforms at Edinburgh International, such that the station will then have four operational platforms. This will greatly improve operational flexibility. Trains to and from Falkirk can use either the northern tracks through Gogar to Haymarket, or the southern pair of tracks through Edinburgh Park. With the projected high density of traffic on both the E&G line and the Airdrie-Bathgate line, this flexibility will be important to allow signallers to recover from train delays or other disruption.
Figure 11 shows an aerial view of the EISL A2 alignment. Appendix A2 shows the alignments in detail and to scale.
The eastbound track from the northern flank of the lower platform (elevation +43m) will also rise at about 1:150 passing through a new bridge under the A8 road to reach +50m at the Gogar burn, sufficient to clear the tram line as well as the burn. From here, the line will fall gently to the new Gogar junction.
The new eastbound line will diverge to the north of the E&G line immediately east of the Harvest Road bridge at Ratho Station. It will fall with a maximum gradient of 1:80 into a very deep cutting until it reaches an elevation of +40m. This is the point at which the future EISL A3 line from the Fife loop will join. It is possible that detailed analysis will show that a short section of tunnel would be more cost-effective over this 800m stretch than a deep cutting which will require a high retaining wall for the adjacent EISL A1 eastbound line which will be up to 5m higher. From the point of the future junction, the EISL A2 line rises steadily at about 1:300 to reach the northern flank of the eastbound platform (elevation +43m), passing under the passive box bridge providing for a future M8 link over the rail line.
The EISL A3 proposal is for a loop on the Fife line, not a diversion. It complements the existing line to the east of the runway. The flagship timings for services from Edinburgh to Aberdeen and Inverness will only be retained by maintaining the current line and skipping the airport stop. The EISL A3 loop will add about seven minutes to journey times (including a dwell time of 150 seconds at Edinburgh International station).
Figure 12 shows the route diagram of stations served. Figure 13 is a diagrammatic representation of the track layout (not to scale). Appendix A3 shows a scale map of the proposed rail alignments. Figure 14 shows an aerial view of the route. Appendix A5 shows the track curvature and line speeds. Appendix A6 shows the rail gradients and elevations.
The EISL A3 alignment crosses the centreline of the runway approximately 300m beyond its south western end. The line will traverse the airport grounds in a cutting such that no rail infrastructure (including future overhead line electrification) will be above current ground level. In line with the runway, the railway will be enclosed in a box, to allow airport lights and other instrumentation to be mounted above it, and to provide a safe overrun area for the runway. It also retains the option of westward lengthening of the runway. Figure 15 is an aerial view of the alignment.
Construction of this box will use the cut and cover method. This will require close co-operation with the airport authorities and some restrictions on aircraft activities for short periods to allow heavy lifting with cranes. The cost estimates reflect this requirement, assuming that lifting work is limited to night periods when the main runway can be closed or restricted. £38 million has been estimated for the cost of this box alone (£55 million with optimism bias). This is extremely high for a simple twin-track concrete box structure but the estimate has been inflated to reflect the highest possible complexity of project management, restricted site access, and working in unsocial hours. It also allows for the airport operator to be compensated for the cost of temporary relocation of airport lighting and communications and their subsequent reinstatement on the new railway box. It is likely that the box could be constructed for much less if the airport operator co-operates fully. 9
Other residents and local politicians are likely to press for the station to be reinstated at Kirkliston. However, the EISL A3 proposals presented here make no provision for a station and do not consider the effects on journey times for Fife trains of a stop at Kirkliston.
The trackbed includes a bridge over the River Almond just south of Kirkliston. This appears to be in reasonable condition but the costings include a sum of £3.5 million for possible restoration works on this bridge. Figure 16 shows an aerial view of the bridge.
A much more sophisticated arrangement is the monorail installed at Newark International airport in New Jersey. This extends for 3,000m serving eight stations around the airport terminals and parking lots as well as the railway station. This allows the flexibility of self-propelled vehicles and high capacity. However, its construction attracted great controversy and the final cost of US$600 million (~£300 million) was regarded as disproportionate.
Clearly this is much grander than the shuttle required at Edinburgh International. Nonetheless, the uncertainty about the optimum technology for the link causes significant uncertainty in the overall costings of the EISL A proposals.
We have adopted assumptions for Edinburgh International of a shuttle service with 24 shuttles per hour, initially each capable of carrying 60 passengers with luggage trolleys. Future expansion, by lengthening the shuttle trains, would enable each shuttle to carry 90 passengers, giving a capacity of 2,160 passengers per hour. For this arrangement, the central cost estimate is £135 million for a self-propelled automatically controlled shuttle service running on conventional elevated tracks, recognising that this is the most uncertain of all EISL costs.
In analysing future airport expansion, we have used the plans included in the 2003 DfT assessment 10 which considered options for expansion of Edinburgh Airport. The more recent BAA MasterPlan 11 for Edinburgh Airport is less specific about plans for the terminal building but the indicated footprint of the airport is similar to that used by the DfT assessment.
Plans are advancing to relocate the RHC to Norton Park, south of the A8 road. However, this move is not yet financed and it cannot be assumed that the move will occur. We have taken the sketch from the RHC’s 2006 Annual Report 12 as the best indication of the proposed plans for the new site.
Appendix A4 shows an overlay of the EISL A proposals on the drawings of the airport expansion and the relocation of the RHC to Norton Park.
|Newbridge - Ratho quadrupling||35|
|Rail junctions and viaducts||118|
|Road and tram bridges||30|
|Other civil works||14|
|Rail signalling and communications||30|
|Optimism bias (44%)||272|
However, if there were the political and economic imperative to construct all three phases simultaneously, there could be savings of about £46 million.
These costs have been prepared based solely on desk studies benchmarked against comparable projects. No site surveys have been conducted. The costs are generally likely to fall well within the optimism bias allowed for, but the costs of the airport shuttle remain very uncertain until the technology to be employed is determined.
The total benchmark costs for all three phases of the EISL A proposals, including 44% optimism bias, are £890 million. This is more than the EARL proposal but offers a major boost to the transport infrastructure of the central belt of Scotland with a transport hub that is future-proofed against a decline in aviation and would protect the economy of west Edinburgh and the central belt.