Heathrow Southern Railway will create a new route into central London from Heathrow Airport with an enormous increase in rail connectivity for the south west of the capital stretching as far as Waterloo.

Heathrow – Staines – Clapham Junction – Waterloo
This service is enabled by construction of a new connection with the Staines – Windsor line between Staines and Wraysbury.  Then the majority of HSR will run alongside the M25, minimising intrusion on the landscape. Services would be fully integrated with the South Western network via Staines, creating capacity for all kinds of rail users including non-airport passengers along the route to/from London and for local journeys. In addition, Clapham Junction and Waterloo/Waterloo East are key interchanges with high demand for airport access.

Network Rail’s modelling confirms that a service of four trains per hour is possible with current planned capacity enhancements, although this will require some adjustments to the service specification for the South Western franchise. We have already discussed these with both the Department for Transport and Network Rail.

The addition of a bay platform at Staines – deliverable within the existing railway boundary – would assist service resilience and potentially allow extension of Elizabeth Line services from Heathrow Terminal 5 to Staines. This would provide a highly attractive alternative route from Staines to central London, together with enhanced interchange with South Western services. Journey times from Staines to Paddington would be as fast as to Waterloo, with excellent central London distribution provided by the Elizabeth Line. We would expect the majority of Staines to central London passengers to transfer to the Elizabeth Line, with significant interchange from intermediate stations between Staines and Reading, thus relieving overcrowding between Staines and Waterloo.

Basingstoke/Guildford – Woking – Heathrow – Paddington
An exciting additional benefit of Heathrow Southern Railway is the scope to introduce half-hourly services from Basingstoke and Guildford to Heathrow and Paddington. These trains would provide a 15-minute frequency from Woking, with stops at Farnborough Main (Basingstoke services), Woking, Terminal 5, Terminal 2 and 3 and Old Oak Common, with the indicative journey times shown in the table below.

Whilst the Paddington times are 12-15 minutes longer than the current (fastest) services to Waterloo – which would still be quicker for most passengers – Paddington will be an attractive terminus for a significant minority of South Western passengers, particularly given the excellent connectivity provided by the Elizabeth Line. Our appraisal shows that there are major benefits as a result of combining the Woking service with Heathrow Express paths.