The Anonymous Widower

Bi-Mode Trains In Prospect As HS2 Northern Routes Confirmed

The title of this post is the same as that of this article on Railway Gazette.

Bi-Mode Trains On High Speed Lines

There are some, who believe that all trains should run on electrified lines.

But my belief is simpler – All trains should be electric, but they might be able to run on tracks with or without  electrification.

There are currently, four proven ways to provide traction power on board an electrically-driven train.

  • Diesel
  • Hydrogen
  • Gas Turbine
  • Stored energy – Battery and/or capacitor.

Each have their advantages and disadvantages.

Talgo who are on the short list to build trains for High Speed Two, already make a train called RENFE Class 730, which has the following specification.

  • 2.4 MW on 25 KVAC overhead electrification
  • 3.8 MW on diesel
  • Dual-gauge; Iberian and standard.
  • Eleven coaches
  • Maximum speed of 160 mph

High Speed Two is designed for 225 mph running, so the trains would need to be faster than these.

But suppose a train was to run say between Euston and Holyhead or any important place a hundred miles or so from High Speed Two.

It would be unlikely that the last part of the route without electrification, would be a high speed line, with a maximum speed in excess of 125 mph.

If it were a high speed line, then it would probably be electrified.

So a typical specification for a bi-mode for High Speed Two would probably be something like.

  • Maximum speed of 225 mph on High Speed Two using the electrification.
  • Maximum speed of 125 mph on the alternative power source.
  • Ability to go between at least Crewe and Holyhead (84 miles) and back without refuelling.

Effectively, the train has two performance regimes; one for electrified high speed lines and one for classic lines without electrification.

A Possible Design For A Bi-Mode High Speed Train

Eurostar’s Class 374 train, which is one of the latest high speed trains is described like this in Wikipedia.

The Velaro e320, named because of plans to operate at 320 km/h (200 mph), would be 16 cars long, to meet the Channel Tunnel safety specifications but would have distributed traction with the traction equipment along the length of the train, not concentrated in power cars at each end.

Note.

  • Distributed power gives better acceleration and smoother braking.
  • The trains also appear to have at least six pantographs, so does that mean that each feeds a number of cars?
  • I suspect there will be an electrical bus running the length of the train which will feed the traction motors.
  • In my design of train, each car would have batteries and/or capacitors to handle the regenerative braking.
  • The energy storage would give the train a limited range away from electrification.

For the required range between Crewe and Holyhead, there would probably be a need for diesel or hydrogen power.

I feel though, that in this day and age, no-one would build a new train that used diesel, if they could get the performance from hydrogen power or some other clean source.

Perhaps one of the middle cars of the train could be a power car fuelled by hydrogen.

This should be something that works, as British Rail and Stadler have both used this layout successfully.

On What Routes Would The Train Be Used?

I have used the service between London and Holyhead as an example and this is probably the longest route away from High Speed Two.

Any route that is in range from High Speed Two or a connected electrified route, could be served by these trains, if it was so desired and the train could be run on the route.

I wouldn’t be surprised to see one of these trains have the capability to go as far North as Aberdeen and Inverness.

Conclusion

Bi-mode high speed trains could be designed, if anybody needed them.

But for short extensions from High Speed Two, energy storage would probably suffice.

 

 

 

 

 

 

November 21, 2018 - Posted by | Transport | , , ,

No comments yet.

Leave a Reply

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

WordPress.com Logo

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

Google+ photo

You are commenting using your Google+ 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: