The Anonymous Widower

Could Some of Hitachi’s Existing Trains In The UK Be Converted To Battery-Electric Trains?

The last five fleets of AT-300 trains ordered for the UK have been.

Each fleet seems to be tailored to the needs of the individual operator, which is surely as it should be.

I can make some observations.

Fast Electric Trains

Both all-electric fleets on the list, will run on routes, where speed will be important.

  • The Avanti West Coast Class 807 trains on the West Coast Main Line, will have to be able to keep up keep with the Class 390 trains, that have the advantage of tilt for more speed.
  • The East Coast Trains Class 803 trains on the East Coast Main Line, will have to work hard to maintain a demanding schedule, as I outlined in Thoughts On East Coast Trains.

Any reduction in weight will improve the acceleration.

  • The seven tonne MTU 12V 1600 R80L diesel engines can be removed to reduce the weight.
  • As a five-car Class 800 train with three diesel engine weighs 243 tonnes, this could save nearly 9 % of the train’s weight.
  • East Coast Trains feel they need an appropriately-sized battery for emergency hotel power. Could this be because the catenary is not as good on the East Coast Main Line as on the West?
  • Perhaps, Avanti West Coast feel a battery is not needed, but they could obviously fit one later. Especially, if there was already a ready-wired position underneath the train.

The extra acceleration given by 100% electric operation, must make all the difference in obtaining the required performance for the two routes.

Why Four Diesel Engines In A Class 810 Train?

The Class 810 trains are an update of the current Class 800/Class 802 trains. Wikipedia described the differences like this.

The Class 810 is an evolution of the Class 802s with a revised nose profile and facelifted end headlight clusters, giving the units a slightly different appearance. Additionally, there will be four diesel engines per five-carriage train (versus three on the 800s and 802s), and the carriages will be 2 metres (6.6 ft) shorter due to platform length constraints at London St Pancras.

Additionally, in this article in the October 2019 Edition of Modern Railways, which is entitled EMR Kicks Off New Era, this is said.

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.

The four diesel engines would appear to be for more power, so that these trains will be able to run at 125 mph on diesel.

In How Much Power Is Needed To Run A Train At 125 mph?, I calculated that a Class 801 train, which is all-electric, consumes 3.42 kWh per vehicle mile.

  • At 125 mph a train will in an hour travel 125 miles.
  • In that hour the train will need 125 x 5 x 3.42 = 2137.5 kWh
  • This means that the total power of the four diesel engines must be 2137.5,
  • Divide 2137.5 by four and each diesel must be rated at 534.4 kW to provide the power needed.

The MTU 12V 1600 R80L diesel engine is described in this datasheet on the MTU web site.

Note on the datasheet, there is a smaller variant of the same engine called a 12V 1600 R70, which has a power output of 565 kW, as compared to the 700 kW of the 12V 1600 R80L.

The mass of the engines are probably at the limits of the range given on the datasheet.

  • Dry – 4500-6500 Kg
  • Wet – 4700-6750 Kg

It would appear that the less-powerful 12V 100 R70 is about two tonnes lighter.

So where will four engines be placed in a Class 810 train?

  • The five-car Class 800 and Class 802 trains have diesel-engines in cars 2, 3 and 4.
  • The nine-car Class 800 and Class 802 trains have diesel-engines in cars 2,3, 5, 7 and 8.
  • It appears that diesel-engines aren’t placed under the driver cars.
  • Five-car AT-300 trains generally have a formation of DPTS+MS+MS+MC+DPTF.
  • The car length in the Class 810 trains are two metres shorter than those in other trains.

Could it be that the intermediate cars on Class 810 trains will be an MC car, which has both First and Standard Class seating and two identical MS cars both with two smaller diesel engines?

  • The two smaller diesel engines will be about 2.6 tonnes heavier, than a single larger engine.
  • Only one fuel tank and other gubbins will be needed.
  • The shorter car will be lighter in weight.
  • MTU may have designed a special diesel engine to power the train.

I would suspect that a twin-engined MS car is possible.

Could The Battery And The Diesel Engine Be Plug-Compatible?

I found this document on the Hitachi Rail web site, which is entitled Development of Class 800/801 High-Speed Rolling Stock For UK Intercity Express Programme.

The document may date from 2014, but it gives a deep insight into the design of Hitachi’s trains.

I will take a detailed look at the traction system as described in the document.

This schematic of the traction system is shown.

Note BC is described as battery charger.

This is said in the text, where GU is an abbreviation for generator unit.

The system can select the appropriate power source from either the main transformer or the GUs. Also, the size and weight of the system were minimized by designing the power supply converter to be able to work with both power sources. To ensure that the Class 800 and 801 are able to adapt to future changes in operating practices, they both have the same traction system and the rolling stock can be operated as either class by simply adding or removing GUs. On the Class 800, which is intended to run on both electrified and non-electrified track, each traction system has its own GU. On the other hand, the Class 801 is designed only for electrified lines and has one or two GUs depending on the length of the trainset (one GU for trainsets of five to nine cars, two GUs for trainsets of 10 to 12 cars). These GUs supply emergency traction power and auxiliary power in the event of a power outage on the catenary, and as an auxiliary power supply on non-electrified lines where the Class 801 is in service and pulled by a locomotive. This allows the Class 801 to operate on lines it would otherwise not be able to use and provides a backup in the event of a catenary power outage or other problem on the ground systems as well as non-electrified routes in loco-hauled mode.

This is all very comprehensive.

Note that the extract says, that both the Class 800 trains and Class 801 trains have the same traction control system. A section called Operation in the Wikipedia entry for the Class 802 train, outlines the differences between a Class 802 train and a Class 800 train.

The Class 802s are broadly identical to the Class 800 bi-mode trains used in the Intercity Express Programme, and are used in a similar way; they run as electric trains where possible, and are equipped with the same diesel generator engines as the Class 800. However, they utilise higher engine operating power – 700 kW (940 hp) per engine as opposed to 560 kW (750 hp) – and are fitted with larger fuel tanks to cope with the gradients and extended running in diesel mode expected on the long unelectrified stretches they will operate on.

I would assume that the differences are small enough, so that a Class 802 train, can use the same traction control system, as the other two train classes.

The Hitachi document also describes the Train Management and Control System (TCMS), the function of which is described as.

Assists the work of the train crew; a data communication function that aids maintenance work; and a traction drive system that is powered by the overhead lines (catenaries) and GUs.

Several trains have been described as computers on wheels. That could certainly be said about these trains.

There would appear to be a powerful Automatic Train Identification Function.

To simplify the rearrangement and management of train configurations, functions are provided for identifying the train (Class 800/801), for automatically determining the cars in the trainset and its total length, and for coupling and uncoupling up to 12 cars in normal and 24 cars in rescue or emergency mode.

Now that would be a sight – One nine-car train rescuing another!

I would assume that this Automatic Train Identification Function has already been updated to add the Class 802 trains and it would appear to me, as a very experienced computer programmer, that in future it could be further updated to cater for the following.

  • New classes of trains like the future Class 803 and Class 810 trains.
  • The fitting of batteries instead of diesel engines.

Could the Function even be future-proofed for hydrogen power?

There are two main ways for trains to operate when the diesel engine in a car has been replaced by a battery.

  1. A plug-compatible battery module is designed, that in terms of function looks exactly like a diesel engine to the TCMS and through that the train crew.
  2. The car with a battery becomes a new type of car and the TCMS is updated to control it, in an appropriate manner.

Both methods are equally valid.

I would favour the first method, as I have come across numerous instances in computer programming, engineering and automation, where the method has been used successfully.

The method used would be Hitachi’s choice.

What Size Of Battery Could Be Fitted In Place Of The Diesel Engine?


  • The wet mass of an MTU 16V 1600 R80L diesel engine commonly fitted to AT-300 trains of different types is 6750 Kg or nearly seven tonnes.
  • My engineering knowledge would suggest, that it would be possible to replace the diesel engine with an inert lump of the same mass and not affect the dynamics of the train.

So could it be that a plug-compatible battery module can be fitted, so long as it doesn’t exceed the mass of the diesel engine it replaces?

For an existing Class 800 or Class 802 train, that limit could be seven tonnes.

But for East Coast Train’s Class 803 train, that size would probably be decided by the required train performance.

How much power would a one tonne battery hold?

This page on the Clean Energy institute at the University of Washington is entitled Lithium-Ion Battery.

This is a sentence from the page.

Compared to the other high-quality rechargeable battery technologies (nickel-cadmium or nickel-metal-hydride), Li-ion batteries have a number of advantages. They have one of the highest energy densities of any battery technology today (100-265 Wh/kg or 250-670 Wh/L).

Using these figures, a one-tonne battery would be between 100 and 265 kWh in capacity, depending on the energy density.

This table can be calculated of battery weight, low capacity and high capacity.

  • 1 tonne – 100 kWh – 265 kWh
  • 2 tonne – 200 kWh – 530 kWh
  • 3 tonne – 300 kWh – 895 kWh
  • 4 tonne – 400 kWh – 1060 kWh
  • 5 tonne – 500 kWh – 1325 kWh
  • 6 tonne – 600 kWh – 1590 kWh
  • 7 tonne – 700 kWh – 1855 kWh

As energy densities are only going to improve, the high capacity figures are only going to get larger.

If you look at the design of the Class 803 trains, which could have three positions for diesel engines or batteries, the designers of the train and East Coast Trains can choose the battery size as appropriate for the following.

  • Maximum performance.
  • Power needs when halted in stations.
  • Power needs for emergency power, when the wires come tumbling down.

I suspect, they will fit only one battery, that is as small as possible to minimise mass and increase acceleration, but large enough to provide sufficient power, when needed.

Conversion Of A Five-Car Class 800/Class 802 Train To Battery-Electric Operation

If Hitachi get their design right, this could be as simple as the following.

  • Any of the three MTU 12V 1600 R80L diesel engines is removed, from the train.
  • Will the other diesel related gubbins, like the fuel tank be removed? They might be left in place, in case the reverse conversion should be needed.
  • The new battery-module is put in the diesel engine’s slot.
  • The train’s computer system is updated.
  • The train is tested.

It should be no more difficult than attaching a new device to your personal computer. Except that it’s a lot heavier.

As there are three diesel engines, one, two or three could be replaced with batteries.

Trains would probably be able to have a mixture of diesel engines and battery modules.

A Class 802 train with one diesel engine and two five-tonne batteries would have the following power sources.

  • 25 KVAC overhead electrification.
  • A 700 kW diesel engine.
  • Two five-tonne batteries of between 500 kWh and 1325 kWh.

With intelligent software controlling the various power sources, this train could have a useful range, away from the electrification.

Conversion Of A Five-Car Class 810 Train To Battery-Electric Operation

The process would be similar to that of a Class 800/Class 802 Train, except there would be more possibilities with four engines.

It would also need to have sufficient range to bridge the gaps in the electrification.

Perhaps each train would have the following power sources.

  • 25 KVAC overhead electrification.
  • Two 565 kW diesel engines.
  • Two four-tonne batteries of between 400 kWh and 1060 kWh.
  • Batteries might also be placed under the third intermediate car.

I estimate that with 400 kWh batteries, a train like this would have a battery range of sixty-five miles.


The permutations and combinations would allow trains to be tailored to the best compromise for a train operating company.

June 8, 2020 - Posted by | Transport/Travel | , , , , , , ,

1 Comment »

  1. […] Could Some of Hitachi’s Existing Trains In The UK Be Converted To Battery-Electric Trains?, I indicated that as Middlesbrough station is only 21 miles and 29 minutes from Northallerton and […]

    Pingback by £35m Station Transformation Launched By Tees Valley Mayor « The Anonymous Widower | June 10, 2020 | Reply

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