The Anonymous Widower

The Technology That Enables The Aventra IPEMU

It is worth stating why it looks like the Aventra IPEMU looks so promising.

Steel Wheel On Steel Rail

The dynamics of this are well known and mean the following.

  • There is a very low rolling resistance.
  • As more weight is applied, the rolling resistance goes down.
  • A fully loaded train might use less energy than an empty one.

You can’t ignore the laws of physics.


The air resistance of something like a train rises with the square of the speed.

But by careful aerodynamic design, you can reduce this energy loss substantially.

An Artist's Impression Of A Proposed Aventra

An Artist’s Impression Of A Proposed Aventra

The picture shows the clean lines of an Aventa

FLEXX-Eco Bogies

Boring but the design saves energy.

Low Energy Interiors

Air-conditioning and door and lighting systems have made great strides in recent years on reducing energy consumption.

Improved Energy Storage

The Class 379 Demonstrator used batteries, as nothing else was available. Better technology for this application like large capacitors and flywheels may be better suited to a train.

Because of the steel wheel on steel rail advantage weight is not a problem.

I think in a few years time, trains will use KERS. Like Formula 1, only bigger! It will be more affordable than batteries, as it’s purely electro-mechanical!

Regenerative Braking

Regenerative braking can save large amounts of energy, with Class 390 Pendolinos reportedly saving seventeen percent. But these trains give their generated energy to the overhead lines, whereas an Aventra IPEMU will keep the energy for itself in the storage device, if there is capacity.

From an electrical engineering point of view, I do wonder if energy storage is the best way to handle the electricity generated by regenerative braking, as otherwise it might have to be converted to transmit it back into the overhead wire or third rail.

I can see a time coming, when all electric trains have regenerative braking and energy storage!

Lightweight Construction

This only helps in the acceleration of the train, so it may not be as important as it would seem, because of the steel wheel on steel rail advantage.

Could it be that one of the reasons a High Speed Train rides so well, is that it is built out of steel and is strong and heavy?

Automated Systems

Things like pantograph deployment will be automatic, thus meaning when the train needs to add power and there is an overhead wire, this will be connected to power the train or top up the battery.

Automatic Train Control

But the biggest automation will be in the driving of the train. As on the Victoria Line the driver will tell the train to start and then it will go automatically to the next station. The train will collect information from the timetable, signals, GPS and sensors determining things like weather and passenger load and be driven accordingly.

Planes have been flown like this for many years.


The range of sixty miles quoted for the Demonstrator could be exceeded by a wide margin.

September 28, 2015 Posted by | Transport/Travel | , , , , | 1 Comment

Thoughts On Midland Main Line Electrification

I have been thinking about how the method of electrifying the Midland Main Line might change if the Aventra IPEMU was available.

These are thoughts in no particular order.

The Battery High Speed Train

An Aventra uses a modern version of the same bogies that are used in the Class 222 trains, which are capable of 200 kph. As the Class 387 train, which is a version of the Electrostar, can travel at 110 mph, I wouldn’t rule out that the more modern Aventra could run at 200 kph or 125 mph.

Acceleration on batteries would be the problem, not maintaining a high speed. that had been built up whilst running under the wires.

Also, when the train comes to the end of its northward journey at say Corby, it has to brake. With regenerative braking on the Aventra IPEMU, all of this energy would go back into the batteries.

So does this mean that no charging would need to be provided at say Corby?

I’m not totally sure of the mathematics and physics, but I’m certain that a battery electric train with regenerative braking, would put a significant part of the electricity it would need to accelerate away from a station, into the batteries as it stopped.

This would mean that stops at Wellingborough and Kettering would not stop Corby services from reaching their destination.

St. Pancras to Corby

I estimate that the distance from the end of the electrification at Bedford and Corby station is about thirty five miles.

This would mean that this route out of St.Pancras could be covered by an Aventra IPEMU.

Would this release a Class 222 train for use elsewhere? Or would the Aventra IPEMUs enable East Midlands Trains to offer more capacity or an increased frequency on this service?

St. Pancras to Leicester

I estimate that the distance from the end of the electrification at Bedford and Leicester station is about fifty miles.

This would mean that this route out of St.Pancras to Leicester could be covered by an Aventra IPEMU, especially if it were possible to recharge the train at Leicester, using the sort of short electrification, I wrote about at Rugeley Trent Valley station in Up And Down The Chase Line.

Leicester has problems as a station, as this extract from Wikipedia says.

Train operators using the station include CrossCountry and East Midlands Trains. Due to a 15 mph maximum speed to the south of the station, all passenger trains stop at the station. Up until the winter 2008 timetable, the morning southbound The Master Cutler express from Leeds to London St Pancras was an exception although this now also calls.

Leicester is a bottleneck station as it has only four platforms. All platforms are well utilised, especially platforms two and three which receive freight as well as passenger trains. A freight loop goes to the east of the station alongside the carriage sidings which run adjacent to platform four.

This Google Map of the station shows the platforms and the freight loop.

Leicester Station

Leicester Station

It does look that there would be space to expand the station and from this section in Wikipedia, I’m sure Network Rail are working on an upgrade to the area to address all the problems.

It would appear to be stating the obvious to say, that Leicester station must be sorted first before any electrification in the area.

An extra bay platform would probably allow Aventra IPEMUs to run an electrified service to St. Pancras, if East Midlands Trains felt this was needed. Because of the regenerating braking of the train, it might not be necessary to provide a means of charging the trains at Leicester.

Creating A High Speed Route To Chesterfield and Sheffield

A few years ago, much of the Erewash Valley Line was upgraded ready for electrification and high speed running. On the Future of this line, Wikipedia says this.

Network Rail as part of a £250 million investment in the regions railways has proposed improvements to the junctions at each end, resignalling throughout, and a new East Midlands Control Centre.

As well as renewing the signalling, three junctions at Trowell, Ironville and Codnor Park will be redesigned and rebuilt. Since the existing Midland Main Line from Derby through the Derwent Valley has a number of tunnels and cuttings which are listed buildings and it is a World Heritage Area, it seems that the Erewash line is ripe for expansion. As the new signalling is rolled out, train detection is moving away from the traditional Track circuit detection of trains to Axle counting.

So could we see all of the very fastest services from St. Pancras to Chesterfield and Sheffield using this route?

Is the route from Trent Junction in the South to Chesterfield and Sheffield in the North ready for electrification?

Network Rail must ensure that as much of the line is capable of 125 mph running and that all bridges and tunnels have sufficient clearance from London to Sheffield via Chesterfield.

Creeping The Electrification North

From Bedford the electrification would be crept north at a sensible pace, which would be designed to cause minimum disruption to services.

Every mile it went north would increase the reach of the new electric trains, but only after the bottleneck of Leicester was eased to allow high speed running through the station.

The Electric Spine

If the Electric Spine was to be implemented in full from Southampton to Sheffield and Doncaster, then the electrification must be completed North of Bedford.

But as there are a lot of places where the electrification will not be completed elsewhere, will we see a shift towards electro-diesel freight locomotives like the Class 88.

So although freight would take advantage of an electrified Midland Main Line, it may not be as important as many think.

Completing The Electrified Routes to Sheffield, Nottingham and Derby

These three important cities all have extensive local rail networks, that could benefit from an electrified hub, so that Aventra IPEMUs could be used to bring benefits to all the communities served by diesel multiple units and in Sheffield’s case, quite a few Pacers.

So as a minimum, this electrification must be completed.

  • East Midlands Parkway to Derby
  • East Midlands Parkway to Nottingham
  • East Midlands Parkway to Chesterfield and Sheffield via the Erewash Valley Line.

Chesterfield to Derby would probably be filed in the Too Difficult box, but would be an easy run for an Aventra IPEMU.

Note that I would start the electrification from East Midlands Parkway, as this station and the Airport are talked about as destinations for tram-train services.

Obviously to complete the Electric Spine, the following electrification would also need to be done.

  • Complete the electrification between Bedford and East Midlands Parkway.
  • Sheffield to Doncaster.

But once Sheffield station is electrified none of the many local lines reaching out from the city would need to be electrified, as most services could be run using Aventra IPEMUs. Obviously, if there was a special reason like freight or tram-trains, this wiring would only help the Aventra IPEMUs.

New Elecric Services

Once electrification has been installed up the Erewash Valley Line to Sheffield, lots of important places become within range of Aventra IPEMUs running from St. Pancras.

  • Barnsley
  • Bradford
  • Huddersfield
  • Leeds
  • Manchester

It would also mean that several existing cross-country services could be run using electric trains.

  • Liverpool to Norwich
  • Nottingham to Cardiff
  • Bristol to Newcastle

Remarkable in some ways as a lot of electrification has been dropped.

September 28, 2015 Posted by | Transport/Travel | , , , , , , , | 1 Comment