The Anonymous Widower

Will Heathrow Southern Railway Use Trains Capable Of 125 mph?

If the Heathrow Southern Railway is built, by the time it opens, there will have been significant developments.

  • Digital signalling based on ERTMS, with the possibilities of a degree of automatic control will be commonplace.
  • Train manufacturers will offer 125 mph trains, that with the right interiors will be able to perform well on 100 mph routes with frequent stops.
  • 125 mph bi-mode trains will have arrived.
  • Great Western Railway services into Paddington, with the exception of local services will be run by 125 mph Class 800 trains.
  • The opening of Old Oak Common station with its connections to High Speed Two, may mean that some Great Western Railway services stop at that station.

These developments may mean that on the Western end of the Great Western Main Line, there will be a need for a train with a lot of acceleration, to avoid inducing delays in the complex schedule of trains serving Paddington and Old Oak Common stations.

The easy way to achieve the required acceleration, may be to use more powerful trains, which will probably be capable of 125 mph.

But would they offer advantages over other parts of the routes Heathrow Southern Railway will serve?

The following must be considered.

The Top Speed Of Third-Rail Trains

Currently, the Class 395 train, is the fastest train fitted with third rail shoes.

But the train only has a top speed of 100 mph, when on lines electrified using third-rail electrification.

The world record for a train powered by third-rail electrification was set by a Class 442 train at 108 mph.

As several trains in the UK can cruise at 125 mph, could it be that the dynamics of third-rail electrification impose a limit to top speed?

This article in Rail Magazine, is entitled Bombardier Bi-Mode Aventra To Feature Battery Power.

A few points from the article.

  • Development has already started.
  • The bi-mode would have a maximum speed of 125 mph under both electric and diesel power.
  • The trains will be built at Derby.

In Mathematics Of A Bi-Mode Aventra With Batteries, I analyse the train in detail.

This was my conclusion.

I am rapidly coming to the conclusion, that a 125 mph bi-mode train is a practical proposition.

  • It would need a controllable hydrogen or diesel power-pack, that could deliver up to 200 kW
  • Only one power-pack would be needed for a five-car train.
  • For a five-car train, a battery capacity of 300 kWh would probably be sufficient.

From my past professional experience, I know that a computer model can be built, that would show the best onboard generator and battery sizes, and possibly a better operating strategy, for both individual routes and train operating companies.

Obviously, Bombardier have better data and more sophisticated calculations than I do.

My calculation might be wrong, but it’s in the right area.

Using batteries with third-rail electric trains, may be an alternative way to overcome any problems with the dynamics of that method of electrification.

But I do suspect that if train manufacturers were asked to produce an electric train capable of running at 125 mph using third-rail electrification, they would take the money and build the trains.

Upgrading Track To 125 mph

Virtually all of Heathrow Southern Railway’s proposed or possible routes to the South and West of Heathrow are third-rail electrified

South Western Railway know that speed on these routes sells tickets, so much so that they are refurbishing the Class 442 trains for the Portsmouth route because of their higher performance.

Network Rail may get a lot of criticism for their performance with electrification, which work on new track layouts and improvements,seems not to attract.

They have also been very successful in designing and executing 125 mph track upgrades to the Midland Main Line.

So would it be possible to upgrade some of the routes to allow faster running?

Consider.

  • Fifty miles of line upgraded from 100 mph to 125 mph running saves six minutes.
  • Waterloo to Weymouth is 143 miles.
  • More powerful trains might save time on station stops.
  • The routes are four tracks to Basingstoke.
  • As modern digital signalling is applied to this route there will be further time savings.

At the moment there is no point, as South Western Railway only has trains with an operating speed of 100 mph.

But these trains will probably be replaced in the next few years or so and I wouldn’t be surprised to see them replaced with trains that are capable of 125 mph, which would make updating sections to the West of Woking possible.

South Western Railway

Surely faster services to Bournemouth, Poole, Portsmouth, Southampton and Weymouth will be of interest to South Western Railway, even if it means new trains.

The New Route Between Heathrow And Woking

Heathrow Southern Railway intends to build a new route between Heathrow Terminal 5 and Working stations.

  • A tunnel will connect  the Western end of Heathrow Terminal 5 station to new tracks running alongside the M25 to connect to the Chertsey Branch Line to the West of Chertsey station.
  • Trains would pass through Chertsey and Addlestone stations, before joining the South Western Main Line at Byfleet Junction.
  • Trains would pass through West Byfleet and Byfleet & New Haw stations to reach Woking station.

It is a well-designed route, that uses the M25 to minimise environmental damage.

From what I have said earlier about 125 mph third-rail trains, upgrading of routes to 125 mph and South Western Railways desire for faster services, I can see no reason, why this route shouldn’t be built for 125 mph operation.

125 mph trains would mean.

  • Removing level crossings at Chertsey and Addlestone stations.
  • Upgrading West Byfleet and Byfleet & New Haw stations.
  • Probably upgrading between Byfleet Junction and Woking station for 125 mph running.

But there would be about fifteen miles of high speed rail line, which for ease of operation would probably be electrified with third-rail.

Trains would switch electrification systems in Heathrow Terminal 5 station.

Conclusions

I am led to the following conclusions.

  • 125 mph third-rail trains will become a reality.
  • South Western Railway and Heathrow Southern Railway will look at them seriously.

I also feel that Heathrow Southern Railway will be a 125 mph railway.

 

August 19, 2018 - Posted by | Travel | , ,

1 Comment »

  1. […] discussed this in Will Heathrow Southern Railway Use Trains Capable Of 125 mph?, where I came the conclusion that the railway will be built to that […]

    Pingback by Heathrow Southern Railway And Woking Station « The Anonymous Widower | August 19, 2018 | Reply


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.