The Anonymous Widower

HS2 Way Out In Front In Tunnel Design For High-Speed Rail

The title of this post is the same as that of this article on Rail Engineer.

The article describes how Arup and Birmingham University are using physical and computer modelling to obtain the ultimate profiles of both tunnel portal and train nose to both increase train performance and reduce train noise as the trains enter tunnels.

They are even using a huge shed at the former British Rail Research Centre in Derby!

The biggest problem, is that there are aerodynamic effects, as the trains enter the tunnels at very high speeds, which result in what are inevitably called sonic booms, that disturb the local residents.

Because the new trains and tunnel portals are being developed together, there must be a greater chance, they will meet the objectives.

Collateral Benefits

Get the design right and there will be other benefits.

Lower Power In The Cruise

In How Much Power Is Needed To Run A Train At 125 mph?, I said this.

I have found this on this page on the RailUKForums web site.

A 130m Electric IEP Unit on a journey from Kings Cross to Newcastle under the conditions defined in Annex B shall consume no more than 4600kWh.

This is a Class 801 train.

  • It has five cars.
  • Kings Cross to Newcastle is 268.6 miles.
  • Most of this journey will be at 125 mph.
  • The trains have regenerative braking.
  • I don’t know how many stops are included

This gives a usage figure of 3.42 kWh per vehicle mile.

This figure is not exceptional and I suspect that good design of the train’s nose will reduce it, especially as the design speed of High Speed Two will be 360 kph or 224 mph.

Reduced Noise

Stand on a Crossrail platform at say Southall or West Drayton stations and listen to the Class 801 trains passing.

They are only doing about 100 mph and they are certainly not quiet! Noise comes from a variety of sources including aerodynamics, overhead wires and running gear.

Could the nose and profile of high speed trains also be designed to minimise noise, when cruising at high speeds?

Reduced Pantograph Noise

Travelling at up to 360 kph, pantograph noise could be a serious problem.

The only way to cut it down, would be to lower the pantograph in sensitive areas and run the train on battery power.

But if the trains energy consumption could be cut to a much lower level, it might be possible for the cruise to be maintained on battery power alone.

Consider a journey between Euston and Birmingham.

  • The train would accelerate away from Euston and go in a tunnel to Old Oak Common.
  • Batteries could be charged whilst waiting at Euston and in the run to Old Oak Common.
  • Accelerating away from Old Oak Common would bring the train to 360 kph as fast as possible.
  • It would now cruise virtually all the way to Birmingham Interchange at 360 kph.
  • At the appropriate moment the pantograph would be lowered and the train would use the kinetic energy to coast into Birmingham Interchange.
  • There would probably be enough energy in the batteries to take the train into Birmingham Curzon Street station after the stop at Birmingham Interchange.

One technology that will massively improve is the raising and lowering of the pantograph at speed.

So could we see much of the long non-stop intermediate section being run on batteries with the pantograph down. If power is needed, it would raise to power the train directly. If the raising and lowering was efficient, then it might be able to use the pantograph only in tunnels.

Could It Be Possible To Dispence With Wires Outside Of Tunnels?

Probably not on the first phase of High Speed Two, but consider.

  • High Speed Two is designed to have a lot of tunnels.
  • Arup and Birmingham may come up with even better aerodynamic designs.
  • Pantograph raising and lowering will get faster and extremely reliable.
  • Battery technology will hold more electricity for a given weight and volume.
  • Dispensing with visible wires could reduce the problems of getting planning permissions.
  • Noise and visible intrision will be reduced.

I believe there will come a time, when high speed railways could be built without visible overhead electrification.

The only places, where electrification would be used would be in tunnels and stations.

Are There Any Other Applications Of This Research?

These are a few thoughts.

Hitachi Trains For The Midland Main Line

I’m suspicious, that the research or similar research elsewhere, might have already produced a very handy result!

In an article in the October 2019 Edition of Modern Railways, which is entitled EMR Kicks Off New Era, more details of the new Hitachi bi-mode trains for East Midlands Railway (EMR) are given.

This is said.

The first train is required to be available for testing in December 2021 with service entry between April and December 2022.

The EMR bi-modes will be able to run at 125 mph in diesel mode, matching Meridian performance in a step-up from the capabilities of the existing Class 80x units in service with other franchises. They will have 24 metre vehicles (rather than 26 metres), a slightly different nose to the ‘800s’ and ‘802s’, and will have four diesel engines rather than three.

Could the new nose have been designed partly in Birmingham?

Consider.

  • Hitachi’s bi-modes for EMR InterCity could be running at up to 225 kph in a few years.
  • The Midland Main Line between Derby and Chesterfield goes through a number of tunnels in a World Heritage Site.
  • Hitachi have collaborated with UK research teams before, including on the Hyabusa.
  • Hitachi and Bombardier are submitting a joint bid for High Speed Two trains, which is based in Birmingham.

It should be noted that when the Tōkaidō Shinkansen opened in 1964 between Tokyo and Osaka average speed was 210 kph.

So are Hitachi aiming to provide EMR InterCity with almost Shinkansen speeds on a typical UK main line?

Arup and Birmingham University, certainly have the capability to design the perfect nose for such a project.

Aventras

Did the research team also help Bombardier with the aerodynamics of the Aventra?

I’m pretty certain, that somebody did, as these trains seem to have a very low noise signature, as they go past.

Talgo

Tsalgo are building a research centre at Chesterfield.

Will they be tapping in to all the rail research in the Midlands?

Conclusion

It looks to me, that there is some world-class research going on in Birmingham and we’ll all benefit!

October 4, 2019 Posted by | Transport | , , , , , , , , , , | Leave a comment

The Texas Bullet Train

In the past, I have spent quite a few hours driving the long distances around Texas.

This article in Global Rail News is entitled Progress For Texas’ High-Speed Railway.

Texas Central Railway is proposing a high speed rail line between Dallas-Fort Worth and Houston, with the following characteristics.

  • 240 miles long.
  • Stations at Dallas-Fort Worth and Houston.
  • Routed along major infrastructure corridors like Interstate highways and freight railways.
  • Ninety minute journey time.
  • A train every thirty minutes.
  • Based on Japanese Shinkensen technology.
  • Wikipedia mentions, that the line could open as early as 2020.
  • Possibility of expansion to Austin and San Antonio.
  • Fluor Corporation, which is a very large engineering and construction company, headquartered in Texas, is involved in the design.

There’s more here on the Texas Central web site.

There’s also an appraisal of the line in this article in Dallas News, which is entitled Proposed Routes for Dallas-Houston High-Speed Rail Revealed.

Some points from the article.

  • Dallas would like the railway to connect to their extensive DART light rail system and perhaps even terminate at Dallas Union station.
  • A construction cost of $10 billion is given.
  • An in service date of 2021 is given.

Dallas certainly seems in favour of the project.

Conclusion

There certainly seems to be a degree of good will and support for this project.

Being Texas, they just had to label it a bullet train, but I’m more surprised that they seem to use railway instead of railroad.

 

August 23, 2017 Posted by | Transport | , , , , | 1 Comment