Superlink (railway network)

In a 2005 report, CLRL examined the proposal and rejected it on the following grounds:[3]

• The large number of branches and long distances would not be compatible with short and regular train intervals through the central tunnel, leading to performance problems and transmission of delay between parts of the network.
• Although increased demand for commuting into London is predicted in the regions served, these are already planned to be catered for with less costly train lengthening. Also, development and planning policy in these regions seeks to achieve sustainable growth and local employment, with less reliance on long distance commuting.
• CLRL found the cost estimates of Superlink to be unreliable, eroding a key claim that it would be easier to finance than Crossrail. The estimated construction cost is 55% greater.
• Superlink would require construction of new track and possibly a depot and stations in the green belt between Barkingside, Shenfield and Harlow. This causes environmental and planning issues.

Superlink was rejected in favour of the Crossrail scheme (currently under construction)

Superlink responded in detail to each of the criticisms.

• It pointed out that Thameslink, as being gradually expanded, would likely have more branches than Superlink. Moreover, all Superlink connections to existing railways have been designed to allow strict isolation of delays to any branch.
• It said Crossrail had greatly overstated the costs of Superlink, and that Superlink would offer faster and more reliable services and additional capacity. While the capital costs would be about £3 billion higher, Superlink forecast supplementary 5-to-10-year net present value returns spread across less spending in rail subsidies, building contributions to councils by developers and the taxes, including indirect taxes such as stamp duty, from indirect new or higher-paid job creation areas and booming London employment. It estimated as to all these complex anticipated government revenues around £6 billion over 10 years from the extra £3 billion cost.
• It said that many recent further lanes of motorways, service stations and a few railways built, including High Speed 1 and 2, went through the Metropolitan Green Belt, legal precedent thus implying such impacts can be mitigated to acceptable.
• While Superlink sympathised with the objective of reducing reliance on long-distance commuting, it argued that growth is inevitable – Superlink will help more of it go by rail, not road.
• It published a detailed critique of the Crossrail and scenarios in which the benefits may be over-stated.

In any case, Crossrail was modified per some of Superlink experts' suggestions:

• a likely depot at Romford in east London has been aborted in favour of North Pole depot west London, recently vacated by Eurostar.
• Plans for a branch to Kingston and Richmond were dropped.

In its 2011 Route utilisation strategy for London and the southeast, Network Rail favoured the experts' proposal that Crossrail take over the Northampton to London trains via a new connection at Old Oak Common. This would add to the possible intersection of High Speed 2 there.

• Heathrow Airport transport proposals