The Anonymous Widower

Could Three-Car Aventras Run Services On The Greenford Branch?

Services on the Greenford Branch Line between West Ealing and Greenford stations, are currently provided by a two-car Class 165 train.

Consider.

  • There are no plans to electrify the line.
  • West Ealing station has a recently-constructed bay platform to serve the branch.
  • The branch line is a 2.7 mile double-track line with three stations.
  • The intermediate stations at Drayton GreenCastle Bar Park and South Greenford have short platforms, that can only accept two-car trains.
  • The service frequency is two trains per hour (tph).
  • Each trip takes eleven minutes.

In an ideal world, the service would be electric and four tph.

Proposals For New Trains

Most proposals seem to suggest moving the branch line to the London Overground and using one of their Class 172 trains. But these trains are now being moved to West Midlands Trains, so that proposal would seem to be a non-starter.

Three-Car Aventras

Could three-car Aventras run services on the line using battery power?

I discussed such a train in A Detailed Look At A Three-Car Aventra, after West Midlands Trains ordered thirty-six of the trains.

These are my thoughts.

Capacity Increase

A three-car train would give a fifty percent increase in capacity on the line.

Is this capacity increase needed?

The Link With Crossrail

Under Services in the Wikipedia entry for Crossrail, it is indicated that twelve tph will pass through West Ealing station, although it is not yet known how many will stop.

Surely, when Crossrail opens fully, an integrated service with good connections will be created at West Ealing.

I believe Crossrail will work in one of two ways at West Ealing.

  1. In a London Underground-like manner, all trains will stop.
  2. Perhaps four or six tph will stop.

I suspect that Londoners won’t accept the second pattern, as they are used to the Underground and the Overground, where there are not many limited-stop services and a train comes along every few minutes.

So this would mean that there will be trains every five minutes in both directions at West Ealing station, creating a steady stream of passengers for the Greenford Branch Line.

Passengers will get fed up waiting thirty minutes for the branch line train.

As West Ealing will be a well-equipped station, waiting fifteen minutes for a train will probably be acceptable to passengers.

Anything less and there will be masses of complaints.

The Link With The Central Line

What applies at West Ealing with Crossrail, surely applies at Greenford with the Central Line.

Short Platforms

I feel that selective door opening on the Aventra could handle the short platforms on the branch.

Four Trains Per Hour

I think it be possible to work a four tph West Ealing to Greenford shuttle, as the branch line is double-track.

But it may need another cross-over to be installed.

Four tph would need two operational trains.

Charging The Trains

The trains could be charged at either end of the branch line, although for practical reasons, charging might use 25 KVAC overhead at West Ealing and 750 VDC at Greenford, as these are used on other tracks in the respective stations.

But as Aventras can be dual voltage, this could be handled by the trains.

As the line is only 2.7 miles long, charging could probably be done at one end only.

Other Alternatives

It would not be balanced to ignore other possibilities.

Refurbished Two-Car Diesel Trains

Two refurbished two-car diesel trains, like say Class 150 trains could also work four tph. on the branch.

But these would probably present services and refuelling problems.

Class 230 Trains

Two Class 230 trains could also work four tph. on the branch.

Consider.

  • They could work the branch on diesel or battery, or a combination of both.
  • Trains would be refurbished to a modern standard, with wi-fi and power sockets.
  • Two-car trains would fit the stations on the branch.
  • They are designed for remote servicing.

I think that a dedicated fleet of three two-car Class 230 trains would be a viable alternative.

Conclusion

Three-car Aventras could provide a good service on the Greenford Branch Line, but there are issues and it may be more complicated than anyone thinks to run a service, that is acceptable to passengers.

But three two-car Class 230 trains would be a viable alternative.

October 19, 2017 Posted by | Transport/Travel | , , , , , | 5 Comments

A Detailed Look At A Three-Car Aventra

In Bombardier and CAF To Make 413 Carriages For New West Midlands Franchise, I wondered if the three-car Aventras ordered by West Midlands Trains had a battery capability.

The Train Weight

I need a good estimate of the weight of a typical Aventra carriage.

Wikipedia gives the following values.

  • Bombardier Aventra – A nine-car Class 345  train weighs less than 350 tonnes, which gives a figure of 39 tonnes per car.
  • Siemens Desiro City – A twelve-car Class 700 train weighs 410 tonnes, which gives a figure of 34 tonnes per car.
  • Bombardier Electrostar – A five-car Class 378 train weighs 159.5 tonnes, which gives a figure of 32 tonnes per car.

Bombardier seem to play their weight figures close to their chest, so I’ll just use a figure of 35 tonnes per car. But it does appear that Aventras, could be heavier than Electrostars.

The Battery Weight

I tend to think in terms of New Routemaster hybrid bus batteries, which have a capacity of 75 kWh.  Surely hybrid bus batteries are fairly common and if you were needing a battery for a new application, it might be where you will start.

The best estimate I can make is that a 75 kWh battery weighs about 600 Kg. I will use this until I find a better figure.

Could the weight of the battery explain the increase in weight between an Electrostar and an Aventra?

The Gangway Weight

One thing that could add to the weight of the Aventras of West Midlands Trains, is the fact that they will be built with a gangway.

Will they be able to split and join automatically in a couple of minutes?

Aventras Have A Lot Of Traction Motors

From what I’ve seen on the Internet, it appears that Aventras have a lot of powered bogies.

A Three-Car Aventra

I think that a three-car Aventra would have a formation something like.

  • DMSLW – Driver Motor Standard – Wheelchair and Universal Access Toilet
  • PMS – Pantograph Motor Standard
  • DMS – Driver Motor Standard

Note.

  1. I estimate it would have about 230 Standard Class seats in a traditional layout. or perhaps 150 in a Metro layout.
  2. There would be a couple of wheelchair spaces.
  3. Would a toilet be provided on the train? Crossrail puts them in the stations! Does Birmingham?
  4. Each car would be fully motored.
  5. Could each car have its own battery, so they handled their own regenerative braking efficiently?
  6. All the cars would be connected together by an electrical bus fed from the pantograph car.
  7. West Midlands Trains have said the new trains will be 90 mph units.

The capabilities are not unlike the current Class 323 trains.

The Aventras have advantages over the older trains.

  • They are articulated, which gives more space.
  • They are wider inside due to thin, strong car sides and underfloor heating.
  • Design of lobbies has improved.
  • A mixed traditional/metro interior can be used as in Crossrail’s Class 345 trains.

They could also be designed to a slightly longer length if required. But this might have operational and depot issues.

I expect Bombardier will have used every trick and dodge to get this order.

What Size Of Battery Is Needed To Handle Regenerative Braking?

I’ll do the calculation for one car with perhaps a hundred passengers running at 90 mph or 145 kph.

I’ll assume each passenger weighs 80 Kg with all their baggage, which gives a one-car mass of 43 tonnes.

The amount of energy in that one car is a very surprising figure of just 10 kWh.

How Far Could A Three-Car Aventra Go On Battery Power?

In an article in the October 2017 Edition of Modern Railways, which is entitled Celling England By The Pound, Ian Walmsley says this in relation to trains running on the Uckfield Branch.

A modern EMU needs between 3 and 5 kWh per vehicle mile for this sort of service.

The three-car Aventra will be an efficient train, but it will have features like air-conditioning, so I suspect that a figure of 4 kWh per car-mile will be achievable, if the following is done.

  • Air-conditioning is very intelligent and efficient.
  • The train is very well insulated.
  • All electrical equipment on the train like lights, toilets and doors are efficient.
  • Operation ensures batteries are fully charged before entering battery sections.
  • Pantograph operation will be intelligent to snatch a sneaky charge on a short length of electrification.
  • Regenerative braking energy is stored on the train.

3 kWh per car-mile may even be possible.

Suppose the battery in each car had a capacity of 75 kWh. This would give the following ranges with various energy consumption rates.

  • 3 kWh – 25 miles
  • 4 kWh – 19 miles
  • 5 kWh – 15 miles

It certainly is important to get the train as energy efficient as possible.

Increasing the battery capacity will increase the range proportionally.

This would mean that a very efficient train with a double-size battery could go fifty miles without wires.

Where Practically Could These Trains Run?

There are several possibilities.

Camp Hill Line

The Camp Hill Line is an obvious possibility.

A lot is said about the reopening in Future Plans in the Wikipedia entry for the line.

This is the latest part of the section.

In August 2017, West Midlands Trains announced plans as part of their franchise deal that the line would reopen by December 2019 as part of a £1 billion investment in the West Midlands. This included a new station at Moseley.

There has also been speculation in the railway press, that chords will be created to allow trains on the line to run directly into Birmingham Moor Street station.

Moor Street Station

If these trains were to run into Birmingham Moor Street station would the bay platforms at the station be electrified?

This would allow the trains batteries to be charged before returning along the Camp Hill Line.

But it would open up interesting possibilities.

With electrification at stations like Stratford-upon-Avon and Leamington to charge the batteries, could services South of Birmingham be run by three-car Aventras running on batteries?

Both |Stratford-upon-Avon and Leamington Spa are under forty miles by road from Birmingham,

I think it could be theoretcally possible, but West Midlands Trains are acquiring a lot of diesel trains.

Extending Existing Electric Services

From May 2018, the electric services on the Cross City Line will run between Bromsgrove and Lichfield Trent Valley stations.

Could trains running on batteries extend services?

Conclusion

Three-car Aventras are an interesting possibility.

I think we’ll be seeing a lot of them around the UK.

October 19, 2017 Posted by | Transport/Travel | , , , | 1 Comment