Featured in the Future Transport London Newsletter January 2024
HS2 is supposed to be about ‘capacity not speed’. However, so long as Old Oak Common is its London terminus, only six trains per hour are planned to run along the rump of HS2: three trains to/from Birmingham and three trains beyond. A 400-metre HS2 train will have 1,100 seats, so the hourly capacity along that line will be 6,600 in each direction. That seems a very modest increase after all that expense and disruption, especially if HS2 never gets to Euston. Could more capacity and public benefit be achieved at much less cost?
Yes, if the infrastructure built for HS2 between Old Oak Common and Birmingham, Curzon Stret is repurposed as, mostly, a new branch of the Elizabeth line. Stations could be added to serve intermediate towns and cities, eg, Aylesbury Parkway, Calvert (for interchange with East-West Rail), Brackley, Coventry/Kenilworth Parkway as well as Birmingham Interchange. Some would be good locations for new towns.
Commuters into Birmingham from those places would have a new, high-quality train service, helping to balance demand in both directions.
London passengers, instead of waiting for an infrequent HS2 departure and having to change trains at Old Oak Common, would have a high-frequency service direct to/from all existing Elizabeth line stations/interchanges in Central London including Paddington (with its existing Great Western interchange) and both eastern branches: Stratford station is close to Stratford International and there are calls for the Abbey Wood branch to be extended to the vicinity of Ebbsfleet International. Both have potential for interchange with HS1, which HS2 always lacked.
The enormous Old Oak Common interchange/terminus need not be built, operated, or maintained. Nor would Great Western trains be delayed by stopping there (a modest, surface-level station could be added on the existing Elizabeth line tracks to serve local developments).
The costs and technical difficulties of extending HS2 into Euston and of dispersing passengers from there (especially if that ‘requires Crossrail 2’) would vanish. A much more frequent and direct Elizabeth line service would help offset it having slower trains than HS2.
At present, 24 trains are scheduled between Whitechapel and Paddington during the peak hour, but 14 of those reverse at Paddington. reflecting much higher demand to/from the Elizabeth line’s eastern branches. Maintaining 24 trains per hour through Central London but extending some of or all those14 reversing trains per hour towards Birmingham, would provide more frequency and capacity between the UK’s first and second cities. The current Elizabeth line trains have a top speed above 100 mph and stated maximum capacity of 1500. Fourteen of those to/from Birmingham would give an hourly capacity of 21,000 compared with HS2’s planned 6,600 to/from Old Oak Common.
Birmingham trains would need to have the same door configuration and floor height and the same length as existing Elizabeth line trains: perhaps a faster version could be developed. The addition of accessible toilets and of more seating would marginally reduce train and hourly capacity, but line capacity would still be at least double that planned for HS2.
A lower maximum speed than HS2 means the train wheels need not dissipate so much heat when braking and can be smaller, giving more flexibility about train floor height.
If the platforms at the intermediate Acton-Aston stations can be built on side tracks, they could provide step-free gap-free boarding and alighting just as Elizabeth line trains do in Central London while faster trains pass on the main line.
At Old Oak Common, the tracks designed for HS2 are 18 metres below the surface. Instead of being extended from there all the way to Euston in tunnel (at great expense and technical difficulty) they could be extended a short distance to provide a grade-separated junction with the existing Elizabeth line tracks, which are parallel to HS2’s and nearby.
That new junction would also connect the HS2 tracks with the existing National Rail terminus at Paddington. The trains currently on order for HS2 are too big, but Pendolinos could reasonably terminate there, and they could exploit their design top speed of 140 mph between Old Oak Common and Birmingham Interchange.
North of Birmingham, being able to tilt through West ~Coast Main Line curves, Pendolinos would outpace the non-tilting trains ordered for HS2. Perhaps three Pendolinos per hour could be scheduled for the services between Paddington and Manchester/Liverpool/Glasgow, while the Elizabeth line serves passengers between London, intermediate stations, and Curzon Street.