Geographical Map

Connecting Windsor to HeathrowGeographical map key 3

The above map shows phases 1 and 2 of the Windsor Link Railway. Existing rail links are in black and the proposed new ones in red. These are as follows:

Phase 1 of the Windsor Link Railway connects the two branch lines that already serve the town. These were built by different railway companies at the height of their competition. Unlike in other towns, such as Reading, the lack of connectivity between the two was never corrected and we are left with an historical anomaly.


To correct this, phase 1 of the Windsor Link Railway proposes a new tunnel to connect the two lines. Connecting these had been proposed before but failed to resolve the problem of the two existing stations being at such different levels. The Windsor Link Railway resolves this by ignoring the two existing stations and proposing a new station in between the two with a tunnel connecting them. As the two lines enter the town at similar levels this results in less steep gradients than on the existing lines. Also, by proposing a cut-n-cover tunnel under an existing road, construction time and cost are minimised, as is the environmental impact. This new tunnel is shown in red in the phase 1 circle on the above map. This is the tunnel in Windsor (shown in red in the phase 1 circle). For aerial photos on this route through Windsor, have a look at the Windsor page.


Whilst the lines in and out of London in the area are quite good, orbital links are almost non-existent. This new line route would therefore be a major addition to the rail infrastructure of the region and allow many more journeys and more frequent services.


The capital cost of this phase has been assessed by Network Rail and found to be in-line with WLR’s estimates, putting the cost at between £75-150 million, excluding contingency and property returns.

This is the link to Heathrow (shown in red in the phase 2 circle on the above map).

It takes advantage of the fact that the existing Windsor Line (shown in black) goes within a few miles of Heathrow Terminal 5. It is therefore a relatively simple engineering challenge to connect the two. Rather than use an expensive tunnel, as proposed by Slough BC (the blue dotted line to the north, called WRAtH) or by BAA (the grey dotted line to the south), the WLR preferred solution is for an alignment that exits the station under terminal 5 and then climbs to a bridge over the M25. West of the motorway, there are several route options that could be designed to minimise the environmental impact, e.g. by hugging the side of the reservoir and following the route of an existing quarry. The red line shows one such possibility although the precise route is to be finalised.


Another option is a modification of BAA’s Airtrack proposal with a small additional chord allowing trains via Windsor to reach Heathrow direct. This is more expensive but has the advantage that it has been through a detailed design and is therefore less risky at this stage. WLR doesn’t expect to use this route but it is a useful fall-back if for any reason the bridge route is not possible or turns out to be more expensive than expected.


The cost of the northerly and southerly direct connections are estimated at about £500 million each (by Slough Council and BAA respectively). The cost of the bridge option over the M25 is estimated by WLR to be about £250 million excluding contingency. This cheaper price combined with a many more journey options provided by phase 1 and future phases means that although the slightly longer route will add a few minutes to journey time (plus 6 minutes from Slough, for example) the business case is many times stronger. That is, it will bring more net benefit and to many more people.

Integration with Crossrail
This phase would also allow Crossrail to be easily extended to both Slough and Staines (and beyond) bringing the advantages of this massive investment to millions more people in this economically important area.

Integration with HS2

The Windsor Link Railway improves connectivity throughout the region. One of the nice results of this is that it makes HS2 accessible to many more people. Without the WLR, people from the south-west of London wishing to travel on HS2 would have to go via London using already overcrowded trains and tubes. With the WLR, they can go via the new track to Heathrow to connect with HS2 at Old Oak Common. This would reduce journey times from this important economic area by over one hour.

Future phases are also planned, such as a new chord at Staines, allowing direct connections to Heathrow from Ascot and the south (shown by the number 8 above). Other possibilities include a direct connection from High Wycombe, by re-opening the line to Maidenhead, and rebuilding the chord at Farnborough, which would allow direct trains from Basingstoke and the south to Heathrow.


These future phases also enable further better integration with the road network. Just as phase 1 enables a park-n-ride and parkway station of the M4, future phases could allow similar facilities off the M3 and M40.


Each new link gives cumulative returns, building on the advantage of the previous additions. Thus, whilst the individual phases are relatively small compared with some of the other engineering projects undertaken by Network Rail, taken as a whole they would have very substantial economic benefits.

NB This information is preliminary and may change as plans are developed