The Anonymous Widower

What Does High Speed Two Mean By Classic Compatible Trains?

The Classic-Compatible trains are described in this section in Wikipedia, by this sentence.

The classic-compatible trains, capable of high speed but built to a British loading gauge, permitting them to leave the high speed track to join conventional routes such as the West Coast Main Line, Midland Main Line and East Coast Main Line. Such trains would allow running of HS2 services to the north of England and Scotland, although these non-tilting trains would run slower than existing tilting trains on conventional track. HS2 Ltd has stated that, because these trains must be specifically designed for the British network and cannot be bought “off-the-shelf”, these conventional trains were expected to be around 50% more expensive, costing around £40 million per train rather than £27 million for the captive stock.

The Classic-Compatible trains will share these characteristics with the Full-Size trains.

  • Maximum speed of 225 mph.
  • Cruising speed of 205 mph on High Speed Two.
  • Length of 200 metres.
  • Ability to work in pairs.
  • A passenger capacity around 500-600 passengers.

But what characteristics will the Classic-Compatible trains share with other trains on the UK network?

The Classic-Compatible trains will share some tracks with other trains, according to High Speed Two’s latest plans.

  • On the East Coast Main Line, the trains will run between York and Newcastle.
  • On the Liverpool Branch between Weaver junction and Liverpool Lime Street station.
  • On the Midland Main Line between Clay Cross North junction and Sheffield.
  • On the Midland main Line between East Midlands Hub and Bedford.
  • On the West Coast Main Line, the trains will run between Crewe and Glasgow.
  • On the West Coast Main Line, the trains will run between Stafford and Macclesfield.

As High Speed Two develops, the Classic-Compatible trains could venture off the main routes to places like Aberdeen, Barrow-in-Furness, Blackburn, Blackpool, Cleethorpes, Holyhead, Huddersfield, Inverness, Middlesbrough, Redcar, Scarborough, Stirling and Sunderland.

They will need to be able to go anywhere, which is worthwhile to connect to High Speed Two.

The main restriction is the size of the train and so a Classic-Compatible train probably can’t be larger than the largest train on the UK network, with respect to width, height and to a certain extend length.

Widths of typical trains are as follows.

  • Class 319 train – 2.82 metres
  • Class 321 train – 2.82 metres
  • Class 387 train – 2.80 metres
  • Class 700 train – 2.80 metres
  • Class 710 train – 2.77 metres
  • Class 745 train – 2.72 metres
  • Class 800 train – 2.70 metres
  • Mark 4 coach – 2.73 metres

Heights of typical trains are as follows.

  • Class 319 train – 3.58 metres
  • Class 321 train – 3.78 metres
  • Class 387 train – 3.77 metres
  • Class 710 train – 3.76 metres
  • Class 745 train – 3.95 metres
  • Mark 4 coach – 3.79 metres


  • I find it odd, that the smallest width is one of the newest trains; Hitachi’s Class 800.
  • Length is fairly irrelevant as many trains in the UK are almost 240 metres long.

I suspect that Classic-Compatible trains will have width of between 2.70 and 2.80 metres and a height of around 3.80 metres.

Could A High Speed Two Classic-Compatible Train Go Through The Thameslink Tunnel?

I ask this question, as surely in a post-pandemic world, where we are all flying there may be a case to be made for a train service between the North of England and Gatwick Airport.

But when East Midlands Railway has their new Class 810 trains, it might be possible, if they didn’t use the diesel engines.

Signalling would not be a problem, as in a few years time, all trains will be equipped with the latest digital signalling systems.

If running a Class 810 train, through the tunnel is possible, given that a  Classic-Compatible train will not be larger than a Class 810 train, will High Speed Two’s trains be able to cross London in the Thameslink Tunnel?

As Midlands Connect are planning to run a Leeds and Bedford service using High Speed Two Classic-Compatible trains, could this service be extended through the Thameslink Tunnel to Gatwick Airport and Brighton?

I have a feeling that this will be physically possible.

  • It would be under the control of the signalling.
  • There’s no reason, why a high speed train can’t have a precise low speed performance.
  • It would stop at all stations.
  • It would use one of the Bedford and Brighton paths on Thameslink

Passengers would like catching a train at a station in Central London and like being whisked all the way to East Midlands Hub and Leeds.

Could A High Speed Two Classic-Compatible Train Go Through The Crossrail Tunnel?


  • It would surely be possible to arrange tracks at Old Oak Common to allow High Speed Two Classic-Compatible trains to go between High Speed Two and Crossrail.
  • Crossrail is considering running to Ebbsfleet.
  • It might even be possible to connect in East London.
  • The High Speed Two Classic-Compatible trains would be digitally-signalled and controlled through Crossrail without stopping.
  • Platform edge doors would ensure safety, but also prevent the trains from stopping at the existing stations.

I have just looked at the London railway map on carto metro, there are stretches of Crossrail under London, where there is space for a station with 200 metre, if not a 400 metre platforms, to the West or East of current Crossrail stations.

  • To the West of Bond Street
  • To the East of Tottenham Court Road
  • To the West of Farringdon
  • To the East of Liverpool Street
  • To the West of Canary Wharf
  • To the East of Canary Wharf

Would all appear to have the required space and be possibilities for extra High Speed Two platforms.

Effectively, some stations would have two sets of platforms on the tracks beside each other.

  • One pair of platforms would be the existing station, with platform edge doors compatible with Crossrail’s Class 345 trains.
  • The other pair of platforms would be the High Speed Two station, with platform edge doors compatible with High Speed Two Classic-Compatible trains.
  • The signalling and train control systems would automatically stop trains in the appropriate platform.
  • Extra passageways would link the new platforms to the existing station.

I suspect when Crossrail was designed, the possibility of adding extra stations to the underground section was considered and there is a method of adding extra platforms in Crossrail’s book of cunning engineering ideas.


I don’t rule out a High Speed service between Birmingham and stations in the North of Great Britain and major cities on the Continent.

  • Crossrail would be used to link High Speed One and High Speed Two.
  • High Speed Two Classic-Compatible trains would be used.
  • Stops in London could be Old Oak Common, Bond Street, Liverpool Street, Canary Wharf and Ebbsfleet

It may sound to be a fanciful idea, but I believe it is possible.




August 23, 2021 - Posted by | Transport/Travel | , , , , , ,


  1. Your second set of dimensions refers to heights not widths

    Comment by fammorris | August 23, 2021 | Reply

    • I spotted it earlier.

      Comment by AnonW | August 23, 2021 | Reply

  2. You’ve not addressed individual car lengths nor the 6 UK loading guage profiles associated with the ability of a vehicle to get route clearance. They’re often the determining factor
    RSSB published guidance (GERT8573) on gauging, and associated railway safety principles as well as advice on the installation of pantographs and their impact on vehicle gauges, platform stepping distances (not all platforms were the same height), and the effects of cross-wind loading, which also affect a trains ability to negotiate a route.
    Everything is possible at a price, I’m afraid this one really has the devil in the detail.
    BTW good to see the Stadler retractable step, although I thought I’d seen this somewhere else. It might need to get more complicated the more variations of platform/train interfaces you encounter.

    Comment by fammorris | August 23, 2021 | Reply

    • Common sense says they’ll have to pass the longest freight trains on a bendy section of track!

      Comment by AnonW | August 23, 2021 | Reply

  3. The class 800 maybe narrower as they are longer at 26m and thus more of a mid overhang on curves which is countered by a narrower body.

    Classic compatibles can run in pairs. HS2 only trains can run in pairs.

    Can you run a mixed pair? Would be useful for ‘rescue’ purposes and also to share train paths.

    Comment by chilterntrev | August 23, 2021 | Reply

  4. AS the eastern leg is near enough dead, the speculation is that dedicated HS2 trains will be dropped in favour of classic compatible ’tilting’ trains

    Classic compatible trains are SLOWER on existing track as they do not tilt.

    Comment by John | August 23, 2021 | Reply

  5. If conventional trains on existing track are slower, than those that tilt, why are Avanti replacing Pendelinos with Class 807 trains. It has been stated in Modern Railways, that the 807s are as fast if not faster than the 390s.

    I suspect that the tilt mechanism is so heavy it buggers the acceleration!

    Tilting trains are usually so cramped, I will not be sad, when they are confined to history in the UK, with its small loading gauge.

    Comment by AnonW | August 23, 2021 | Reply

    • Avanti are not replacing Pendelinos with Class 807 trains, they are replacing 221s running to Liverpool “It has been stated in Modern Railways, that the 807s are as fast if not faster than the 390s.” I generally respect Modern Railways journalism but without agreed modelling comparison or actual side by side operation why should I put any credit to this remark.
      The tilt mechanism will not be so heavy it impacts on the acceleration nor will the power requirements to operate it have a significant affect, in any case the tilt is still required north of Oxenholme to maintain route speed.

      Comment by fammorris | August 23, 2021 | Reply

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: