The Anonymous Widower

Converting Class 456 Trains Into Two-Car Battery Electric Trains

Mark Hopwood is the interim Managing Director of South Western Railway and in Special Train Offers A Strong Case For Reopening Fawley Line, I quote him as saying the following about the trains for the Fawley Branch Line.

However, SWR’s Mark Hopwood favours a much bolder plan. “We’d have to take a decision, once we knew the line was going ahead. But my personal belief is that we should be looking for a modern environmentally-friendly train that can use third-rail electricity between Southampton and Totton and maybe operate on batteries down the branch line.”

Pressed on whether that would mean Vivarail-converted former-London Underground stock, Hopwood ads. “It could be. Or it could be a conversion of our own Class 456, which will be replaced by new rolling stock very shortly. But I don’t think this is the time to use old diesels.

Mark Hopwood is so right about using old diesels.

• Where possible new and refurbished trains should be zero-carbon.
• Diesel is to be banned by 2035 in Scotland and 2040 in England and Wales.
• Diesel trains and hydrogen trains for that matter need to refuelled.
• Get the diagrams right and battery electric trains can be charged on existing electrification or automatic Fast Charging systems, when they turn back at terminal stations.
• Electric trains attract passengers.
• Battery electric trains are mouse-quiet!

Who would use anything else other than electric trains with a battery option for sections without electrification?

The Class 456 Train

These pictures show some of the twenty-four Class 456 trains, that are in South Western Railway’s fleet.

This is the specification of a Class 456 train.

• Two cars
• Operating speed – 75 mph.
• Capacity – 152 seats – Although the plate on the train says 113!
• Built 1990-1991
• Ability to work in pairs.

Most trains seem to be used to lengthen trains from eight to ten cars, as some of the pictures shows. As these 4+4+2 formations will be replaced with new 10-car Class 701 trains or pairs of five-car Class 701 trains, the trains will be looking for a new role.

Does this explain Mark Hopwood’s statement?

It should be noted that the Class 456 trains are members of the Mark 3 family, and bare a strong resemblance to the Class 321 train, which are shown in these pictures.

Note that I have included the side view, as it shows the amount of space under these trains.

Some Class 321 trains are being converted to Class 600 hydrogen trains, by Alstom at Widnes. Others have been given a life-extending Renatus upgrade.

Are The Driver Cars Of Class 456 and Class 321 Trains Identical?

The trains may look similar, but does the similarity go deeper?

Could Alstom Use Class 600 Hydrogen Train Technology To Create A Class 456 Train With a Battery Capability?

Consider.

• Alstom are positioning themselves as Train Upgrade Specialists in the UK. They have already signed a near billion pound deal to upgrade and maintain Avanti West Coast’s fleet of Class 390 trains.
• Alstom are creating the Class 600 hydrogen train from withdrawn Class 321 trains.
• A hydrogen-powered  train is basically a battery electric train with a hydrogen tank and fuel cell to charge the batteries.
• The Class 600 train doesn’t appear to be making fast progress and is still without an order.
• One possible hydrogen route must surely be London Waterloo and Exeter, so I suspect Alstom are talking to South Western Railway.
• The Class 456 trains are owned by Porterbrook, who would probably like to extend the useful life of the trains.

Could it be that the battery core and AC traction package of Alstom’s hydrogen system for the Class 600 train can turn old British Rail-era electric multiple units into battery electric multiple units with a useful range?

It is certainly a possibility and one that is also within the capability of other companies in the UK.

Could The Class 456 Trains Receive a Class 321 Renatus Interior And Traction Package?

As Class 321 and Class 456 trains were built around the same time, the two trains must share components.

These pictures show the current interior of a Class 456 train.

This is excellent for a two-car electric multiple unit, built thirty years ago! Although, the refurbishment is more recent from 2014-15.

• Note the wheelchair space and the copious rubbish bins.
• I also spotted a stowed wheel-chair ramp on the train. It can be seen if you look hard in the picture that shows the wheelchair space.
• Some might feel that toilets should be provided.

These pictures show the interior of a Class 321 train, that has been given the Renatus upgrade.

What is not shown is the more efficient AC traction package.

I have been told or read, that the Renatus interior will be used in the conversion of a Class 321 train to an Alstom Class 600 or Breeze hydrogen train.

On the other hand, the current Class 456 interior would probably be ideal for a branch line, where one of initial aims would be to attract passengers.

Could A Class 456 Train Have a Lightweight Traction Package?

Consider.

• The Class 456 train will access electrification that is only 750 VDC third-rail.
• Batteries work in DC.
• The new traction motors will work in AC, if they follow the practice in the Class 321 Renatus and the Class 600 train.
• Regenerative braking will charge the batteries in both trains.
• Air-conditioning and other hotel services can work in DC.

Some components needed to run from 25 KVAC like a transformer could be left out to save weight and improve acceleration.

I would suspect that a Class 456 train with batteries could use a slimmed-down traction system from the Class 600 train.

On both Class 456 and 600 trains a core system, that would power the train, might contain.

• The traction battery or batteries.
• The traction motors that both drive and brake the train,
• Third-rail electrification shoes, so that the batteries could be charged in a station, as required.
• A clever computer system, that controls the acceleration, braking and charging as required.

On the Class 600 train, there would also be the following.

• Hydrogen tanks and fuel cells to provide an independent power source to charge the batteries.
• A pantograph to access 25 KVAC overhead electrification.
• Extra electrical gear to access the electrification.

I think it would be possible to design the Class 456 train with batteries as the basic train and just add the extra  hydrogen and electrical gubbins to make it a Class 600 train.

Could A Class 456 Train Be Modified To Use 25 KVAC Overhead Electrification?

As I said, there are a lot of similarities between Class 456 trains and Class 321 trains.

As the Class 321 trains are equipped to use 25 KVAC Overhead Electrification, I suspect train modification specialists could create a Class 456 train, that could use overhead electrification.

What Battery Range And Size Would Be Needed In A Class 456 Train?

These are typical branch line lengths for South Western Railway.

• Fawley Branch – 8 miles
• Wareham and Swanage – 11 miles
• Lymington Branch – 5.6 miles
• Reading and Basingstoke – 15.5 miles

I would suspect that a range of thirty miles on battery power would be sufficient for a Class 456 train with batteries.

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, which is not very challenging.

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

So applying that formula gives battery capacity of between 180 kWh and 300 kWh.

In Issue 864 of Rail Magazine, there is an article entitled Scotland High Among Vivarail’s Targets for Class 230 D-Trains, where this is said.

Vivarail’s two-car battery units contains four 100 kWh lithium-ion battery rafts, each weighing 1.2 tonnes.

If 200 kWh can be placed under the floor of each car of a rebuilt London Underground D78 Stock, then I think it is reasonable that up to 200 kWh can be placed under the floor of each car of the proposed train.

This picture of the Driver Car of a Class 321 train, shows that there is quite a bit of space under those trains.

Are the Class 456 trains similar? This is the best picture I have got so far.

It does appear that space is similar to that under a Class 321 train.

If we assume that the Class 456 train can have the following specification.

• Battery capacity of 200 kWh in both cars.
• Regenerative braking to battery.
• Power consumption of 4 kWh per vehicle mile.

I think we could be approaching a range of fifty miles on a route without too many energy-consuming stops.

Charging The Batteries

I like the Vivarail’s Fast Charge concept of using third-rail equipment to charge battery trains.

This press release from the company describes how they charge their battery electric Class 230 trains.

• The system is patented.
• The system uses a trickle-charged battery pack, by the side of the track to supply the power.
• The first system worked with the London Underground 3rd and 4th rail electrification standard.

As the length of rails needed to be added at charging points is about a metre, installing a charging facility in a station, will not be the largest of projects.

Under How Does It Work?, the press release says this.

The concept is simple – at the terminus 4 short sections of 3rd and 4th rail are installed and connected to the electronic control unit and the battery bank. Whilst the train is in service the battery bank trickle charges itself from the national grid – the benefit of this is that there is a continuous low-level draw such as an EMU would use rather than a one-off huge demand for power.

The train pulls into the station as normal and the shoe-gear connects with the sections of charging rail. The driver need do nothing other than stop in the correct place as per normal and the rail is not live until the train is in place.

That’s it!

As an electrical engineer, I’m certain the concept could be adapted to charge the batteries of a conventional third-rail train.

Vivarail’s press release says this about modification to the trains.

The train’s shoe-gear is made of ceramic carbon so it is able to withstand the heat generated during the fast charge process.

That wouldn’t be a major problem to solve.

Class 456 Train With Batteries And Class 600 Train Compared

The following sub-sections will compare the trains in various areas.

Lightweight Design

As I suspect that the basic structure of the Class 456 and Class 600 trains are similar, systems like toilets, air-conditioning, traction motors and seats will be chosen with saving weight in mind.

Every kilogram saved will mean faster acceleration.

Operating Speed

The current Class 321 train is a 100 mph train, whilst the current Class 456 train is only a 75 mph train.

I wonder if applying the modern traction package of the Class 321 Renatus to the Class 456 train could speed the shorter train up a bit?

Range Away From Electrification

Alstom have quoted ranges of hundreds of miles for the Class 600 train on one filling of hydrogen, but I can’t see the Class 456 train with batteries doing much more than fifty miles on a full charge.

But using a Fast Charge system, I can see the Class 456 train with batteries fully-charging in under ten minutes.

Fast Charge systems at Romsey and Salisbury stations would surely enable the Class 456 trains with batteries to run the hourly service over the thirty-eight mile route between the two stations.

Passenger Capacity

The current Class 456 trains have a capacity of 152 seats.

In Orders For Alstom Breeze Trains Still Expected, I said this.

The three-car Alstom Breeze is expected to have a similar capacity to a two-car diesel multiple unit.

But until I see one in the flesh, I won’t have a better figure.

If South Western Railway were wanting to replace a two-car diesel Class 158 train, they’d probably accept something like 180 seats.

Increasing Passenger Capacity

There are compatible trailer cars around from shortening Class 321 trains from four to three cars and there may be more from the creation of the Class 600 trains.

I suspect that these could be added to both Class 456 and Class 600 trains to increase capacity by fifty percent.

As a two-car train, the Class 456 train might be a bit small, but putting in a third car, which had perhaps slightly more dense seating and possibly a toilet and even more batteries could make the train anything the operator needed.

Suitability For London Waterloo and Exeter via Salisbury

This is South Western Railway’s big need for a zero emission train.

1. It is around 170 miles
2. Only 48 miles are electrified.
3. It is currently worked by three-car Class 159 trains working in pairs.
4. Class 159 trains are 90 mph trains.

I have believed for some time, that with fast charging, a battery electric train could handle this route.

But, I would feel that.

• Class 456 trains would be too slow and too small for this route.
• Class 600 trains would be too small for this route.

On the other hand, I believe that Hitachi’s Class 800 train with a battery electric capability or Regional Battery Train, which is described in this infographic from the company, could be ideal for the route.

The proposed 90 km or 56 mile range could even be sufficient take a train between Salisbury and Exeter with a single intermediate charge at Yeovil Junction station, where the trains wait up to ten minutes anyway.

There are other reasons for using Hitachi’s Regional Battery Train rather than Class 600 trains.

• First Group have a lot of experience of running Hitachi Class 80x trains, through their various subsidiaries.
• They could share depot facilities at Exeter.
• No specialist facilities would be needed.
• A five-car Class 801 with batteries would have a convenient 300 seats.
• I suspect they could be delivered before Alstom’s Class 600 train.

As the only new infrastructure required would be Fast Charge facilities at Salisbury and Yeovil Junction stations, I feel that Hitachi’s Regional Battery Train, should be a shoe-in for this route.

First Delivery

The Wikipedia entry for the Class 600 train, says introduction into traffic could be in 2024. Given, the speed with which Greater Anglia’s Class 321 trains were updated to the Renatus specification, we could see Class 456 trains with a battery capability and new interiors running well before 2024.

A Few Questions

These questions have occurred to me.

Could The Technology Be Used To Create A Class 321 Battery Electric Train?

I don’t see why not!

I believe a Class 321 battery electric train could be created with this specification.

• Three or four cars. Remember the Class 320 train is a three-car Class 321 train.
• 100 mph operating speed.
• Regenerative braking to the batteries.
• Renatus or operator-specified interior.
• Toilet as required.
• Electrification as required.
• Battery range of around sixty miles.
• Ability to use a Fast Charge system, that can easily be installed in a terminal platform.

Trains could be tailored to suit a particular route and/or operator.

Any Other Questions?

If you have any other questions, send them in and I’ll add them to this section.

Conclusion

It does appear that if the Class 456 trains, were to be fitted with a battery capability, that they would make a very useful two-car battery electric train, with the following specification.

• Two cars
• Operating speed – 75 mph. This might be a bit higher.
• Capacity – 152 seats
• Ability to work in pairs.
• Modern interior
• Range of 45-50 miles on batteries.
• Ability to charge batteries in ten minutes in a station.
• Ability to charge batteries on any track with 750 VDC third-rail electrification.

This is the sort of train, that could attract other operators, who don’t have any electrification, but want to electrify short branch lines.

August 12, 2020 Posted by AnonW | Energy Storage, Hydrogen, Transport/Travel | Alstom, Class 321 Hydrogen/Alstom Breeze, Class 456 Train, Class 600 Train, Exeter, Hitachi Regional Battery Train, Porterbrook, Regenerative Braking, Salisbury, South Western Railway, Vivarail Fast Charge | 14 Comments