The Anonymous Widower

Mathematics Of A Stadler Flirt Akku Battery Train

In Stadler Receives First Flirt Akku Battery Train Order, I  quoted thia from as that of this article in Railway Gazette International.

Schleswig-Holstein transport authority NAH.SH has selected Stadler to supply 55 Flirt Akku battery multiple-units to operate regional services and provide 30 years of maintenance.

This is a substantial order for a large number of trains and many years of maintenance, and would appear to be structured similarly to deals in East Anglia, Glasgow and Liverpool in the UK.

Does The Train Have A Central Power-Pack Car?

Is the Flirt Akku, similar to Greater Anglia’s Class 755 trains and other of the companies products, in that it has a central power-pack car?

This picture shows a Class 755 train at Norwich.

 

Note that this four-car train has four full-size cars and a shorter one, that doesn’t appear to have any doors or proper windows.

This is the power-pack car, which in these trains has the pollowing properties.

  • The power-pack car is 6.69 metres long.
  • The power-pack car is identical in both the four-car and three-car versions of the Class 755 trains.
  • The four-car trains have four diesel engines.
  • The three-car trains have two diesel engines.

The number of engines possible, leads me to believe there are four slots for engines in the power-pack car.

Transport for Wales have ordered a number of Flirts, which are similar to those in use by Greater Anglia, but they are tri-mode trains, that can run on overhead 25 KVAC electrification, diesel or battery power.

I speculate that they have one diesel engine and three batteries in the four slots.

This is a picture of the Flirt Akku.

I have enlarged the image and it would appear that the trains do not have a central power-pack car, but they do seem to have a lot of electrical gubbins on the roof.

This video shows the Class 755 train being tested at Diss.

It looks to have a much smoother roof line.

Could this indicate that the batteries on the Akku are placed on the roof of the train, as there is certainly a lot of equipment up there?

 

 

 

June 22, 2019 Posted by | Transport | , , , | 10 Comments

Airport Plans World’s Biggest Car Parks For 50,000 Cars

The title of this post, is the same as that of an asricle in Wednesday’s copy of The Times.

This is the first two paragraphs.

The biggest car parks in the world will be built as part of a £14 billion expansion of Heathrow amid fresh claims that the scheme will be an “environmental disaster”.

Parking for almost 53,000 vehicles will be built as part of a 30-year masterplan, even though the airport insists that expansion can be achieved without any extra cars on the road.

This sounds to be contradictory, as why would you need to build extra car parking, if there were no more extra cars on the road?

Perhaps there is a clue later in the article, where this is is a paragraph.

Heathrow said that the overall number of parking spaces would “not change materially from today”, insisting that spaces were simply being consolidated on bigger sites. It pointed out that car parks would allow for 100 per cent electric vehicle usage in the future. In total, the number of parking spaces, including those for staff and spaces at nearby offices, will grow from 64,000 today to 67,000.

Admittedly, it only says allow, but Heathrow are future-proofing themselves for the day when everyone is driving electric cars.

Heathrow and others are also planning to do the following.

  • Charge a congestion charge of up to £15 a day will be imposed by 2026 to dissuade passengers from travelling to the airport by car.
  • A “green loop” — a 12-mile pedestrian and cycle network — will also circle the airport.
  • Finish Crossrail.
  • Improve Heathrow Express.
  • There will be a rail link to Reading.
  • There will be a second rail link to Waterloo via Clapham Junction.
  • There will be a rail link to Basingstoke, Guildford and Woking, possibly by extending Heathrow Express.

Will these measures nudge travellers in one of two positive directions?

  • Using public transport to get to the Airport.
  • Cycling or working to the airport.
  • Using an electric car to get to and from the Airport.

I am a Control Engineer, who spent a working life of nearly fifty years analysing data and doing mathematical calculations, hopefully to improve little bits of the world.

So what would I do?

It is absolutely essential that it is known, where all the vehicles to the airport are travelling to and from.

No-one is going to get out of their car, if there is no creditable alternative

The ultimate aim must be that, all transport within a certain distance of the Airport must be zero carbon.

  • All vehicles used by travellers and workers to get to and from the Airport.
  • All vehicles bringing supplies to the Airport.
  • All airside vehicles.

What will happen to those that lived in the zone?

This Google Map shows Hanwell Village to the South-West of the Airport.

Will all those residents pay the congestion charge?

But suppose Heathrow could get ninety percent of all cars travelling to  the Airport and using the car parks, to be electric vehicles.

This would be 45,000 vehicles, each with a battery of between 40-60 kWh. Let’s call it, 50 kWh.

This would mean that the total of energy storage on a typical day at the Airport would be 2.25 GWh.

Compare that to the 9.1 GWh capacity of Electric Mountain.

Electric Mountain would be bigger, but intelligent control of the batteries of these electric cars could create a massive electricity storage resource at the Airport.

  • Cars would be connected to a two-way charger, when the driver went about their business at the Airport, after telling the car when they would return.
  • On return to the car, it would have enough charge for the next journey.
  • The driver would also have an app on their phone, so they could alter their return times.
  • Whilst the driver was away, the grid would borrow electricity as required.

The grid might even pay for the use of your battery.

I suspect that all car parks for electric cars will work using something like this model.

Note the following calculation.

In December 2018, there were 31.5 million cars and four million light goods vehicles in the UK.

In a few years time, suppose half of these vehicles are electric with a 20 KWh battery.

That works out at an astronomical 355 GWh or nearly forty Electric Mountains.

  • Electric Mountain cost £425 million in 1984.
  • Applying a web inflation calculator means it would cost around £1350 million today.
  • So forty Electric Mountains would cost £54 billion.

That is a lot of money and we have no place to put them.

But we have this massive storage capability in the millions of electric vehicles, that will be on the roads in a few years.

Conclusion

All future large car parks must be built to be large storage batteries, when drivers plug in their electric cars.

If you were to be paid for the use of your car’s battery, would that ease the exense of owning an electric car?

 

 

 

June 21, 2019 Posted by | Transport | , , , | 3 Comments

Importance Of Battery Range: Stadler’s FLIRT BMU For Greater Anglia

The title of this post is the same as a sub-section of this article on Railway News, which is entitled Stadler Presents New FLIRT Akku For The First Time.

This is said.

By contrast, Stadler recently unveiled its bi-mode (electric-diesel) FLIRT for Greater Anglia (U.K.) at InnoTrans 2018. When asked why Greater Anglia went for a diesel-electric option rather than a battery-electric option to bridge the non-electrified gaps in the network, Railway-News was told that the non-electrified distances in the U.K. are currently too great for battery-operated trains to cope with. As battery technology improves, this will hopefully change, making diesel and the need for electrification obsolete

Does this infer the following?

  1. Greater Anglia would have preferred to use battery-electric trains.
  2. It is possible to swap the diesel engines in the power-pack for battery modules.
  3. It could be possible to swap a diesel generator for a hydrogen fuel cell.

Option three might be difficult, as you need somewhere to put the hydrogen tank within the limited UK loading gauge.

Conclusion

I think it is highly likely that as battery technology improves and Stadler are able to package it better for the Class 755 trains, that Greater Anglia will change some of their Class 755 trains to battery-electric operation.

June 20, 2019 Posted by | Transport | , , , , , | 4 Comments

Alice Promises Passengers A Pollution-Free Wonderland

The title of this post is the same as that of this article in The Times.

The Eviation Alice is a composite battery-electric aircraft, that has just been ordered by Cape-Air, who are based in Barnstaple, Massachusetts..

Currently, Cape-Air flies the following fleet of aircraft.

In addition, a hundred Tecnam P2012 Traveller are on order, which seat nine passengers.They will replace the Cessnas.

The specification of the Tecnam P2012 Traveller, was developed with input from Cape-Air,

  • Two Avco Lycoming piston engines.
  • 190 knot cruising speed.
  • Range of 950 nautical miles
  • Full certification.
  • Large passenger door.
  • Suitable for commuter, air taxi, medevac, troop transport and air cargo roles.
  • iSingle-pilot operations, a modern cockpit, an unpressurised cabin and a metal air-frame.
  • High -wing for visibility
  • Fixed landing gear for operation from rough landing strips.

It appears the Italians have designed a modern Islander.

This leads me to the impression, that the commuter airline operator are experienced, conservative and know what they want.

On the other hand, Cape-Air have just ordered ten Eviation Alice aircraft for air-taxi operations.

  • Nine passengers and two crew
  • Three 260 kW electric motors
  • 900 kWh Li-ion battery
  • 260 knot cruising speed.
  • Range of 565 nautical miles.
  • 95% composite air-frame.
  • Fly-by-wire control
  • Unpressurised cabin.
  • Retractable landing gear.
  • Automatic landing.

It is not a conventional aircraft.

If you want to learn more, this article on Aviation International News, which is entitled Eviation’s Alice To Fly This Year, gives a lot more details.

These are a few points.

Aerodynamic Design

It is to be expected,  that the composite structure has created a very aserodynamic design.

Battery Weight

The battery comprises sixty per cent of the weight of the aircraft.

Battery Charging

The Aviation International News article says this about charging.

The battery system on the Alice will be fully rechargeable in one hour and 10 minutes, using a half-megawatt charger on a mobile “bowser” truck that itself is charged up by plugging into the local electrical grid. This avoids having to build charging stations at airports, he said. Not all routes will require a full charge—the basic ratio is a half hour of charging time per hour of flight.

Given the 1:2 ratio between charging time and flight time, I suspect that Eviation are using similar tricks to those used by Vivarail with battery trains, that I wrote about in Vivarail Unveils Fast Charging System For Class 230 Battery Trains.

Landing Gear

Once the passengers and their luggage are on board, the weight of an electric plane will not change until the passengers disembark.

I suspect this gives advantages in the design of the landing gear, as it probably cycles through a narrower range of stresses, than the gear on a conventionally-powered plane.

Engine Failure

Engine failure in a twin-engined aircraft is every pilot’s nightmare and speaking from experience, there is no better moment in a flight in a piston-engined twin, than when the gear is raised and the plane is safely in the climb.

The Aviation International News article says this about controlling engine failures.

If power is lost in one wingtip-motor, the opposite motor will reduce power to prevent asymmetric thrust from causing a loss of control, while the rear motor can provide enough power to keep the Alice flying. In fact, Alice can continue a takeoff with loss of both tip thrusters at V2, according to Bar-Yohay.

This is how computer control should be used.

Take-Off And Landing Distance

The specification foe the Eiviation Alice,  does not give the take-off and landing distances, but it does give the approach speed as 100 knots.

The Eiviation Alice is replacing Cessna 401 aircraft at Cape-Air, so it must have a better performance.

The figures for the Cessna are.

Until, I’m told otherwise, I suspect that the Eviation Alice could use most seven-hundred metre runways, with a good surface.

Take Off Accidents

A lot of air accidents happen on take-off, when the plane is fully loaded with passengers and fuel and the engines are giving out maximum power. If the plane should crash, there is usually a large fire.

There have been fires in lithium=ion batteries in the past, but you don’t hear of hundreds of electric cars going up in smoke.

I would certainly like to see what Eviation are saying about the performance of Alice aircraft in an abandoned take-off, or one where an aircraft hits something large, that shouldn’t be there,  on the runway,. Thankfully, the latter doesn’t happen often, but read about the Tenerife Airport Disaster in 1977.

Fly-By-Wire

Fly-by-wire would not normally be expected on an aircraft of this size. But the Aviation Internation News article says the following.

  • The propellers can be managed using pitch and rpm to reduce noise.
  • Turbulence can be smoothed out.
  • Differential thrust can be applied to the two wing engines for crosswind landings.
  • The battery system can be fully controlled in sixteen strands to bring a high level of redundancy.
  • Autoland can be added.

This is a commuter aircraft with all the flight control features of a full size airliner, that has been designed to be flown by a dumb well-programmed computer.

Those that have designed advanced fighter aircraft would certainly approve.

Happy Landings

In the Wikpedia entry for the Eviation Alice, this is said.

It will be built with existing technology, including a composite airframe, distributed propulsion with Siemens electric engines and Honeywell flight control systems, including automatic landing.

The approach speed is also stated on the plane’s specification to be a very reasonable and pilot-friendly; 100 knots.

Once, I flew an approach in a Piper Arrow into Dublin Airport faster than 100 knots as Air Traffic Control, said there was a Jumbo on my tail and could I hurry up! They then asked if I could clear the runway fast, which I did, to be greeted by “We’ll give you ten out of ten for that!” The Irish are gloriously different!

Under Fly-By-Wire, I said this was possible.

Differential thrust can be applied to the two wing engines for crosswind landings.

This I like, as I was not good at crosswind landings.

Once, I landed my Cessna 340 in very heavy rain and strong crosswinds at Cardiff Airport. I landed safely, but it was lucky I was wearing appropriately-coloured underwear.

Cost Of Ownership And Operation

The Aviation International News article gives full details.

The Future

The one thing that can be said about the design of electric planes, is that the batteries will hold more power for a given weight in a few years.

In addition.

  • Composite structures will get lighter and stronger.
  • Aerodynamics of the air-frame and the propellers will get better and more efficient.
  • Fly-by-wire will use better algorithms and add more features.

Range and/or payload will increase.

I also think that, if they can be almost silent, then they could fly very different routes and perhaps even use runways reserved for electric aircraft.

Conclusion

This project might appear to be a total fantasy, but having flown over a thousand hours in a small twin-engined aircraft, I can see where Eviation are coming from.

  • They have also convinced Cape-Air, top class suppliers like BendixKing, Hartzell, Honeywell and Siemens to be part of the project.
  • If nothing else, Eviation have proven, that they can design and build a nine-seat commuter aircraft.

I feel, I can look forward one day to flying in an electric aircraft. Even if it is not the Eviation Alice.

Aircraft like Alice will revolutionise aviation, for distances up to perhaps two thousand miles.

June 19, 2019 Posted by | Transport | , , , | 1 Comment

Scottish Government Is Considering Plans To Electrify The Borders Railway

The title of this post is the same as that of this article in The Scotsman.

These reasons are given for the electrification, of the Borders Railway.

  • Electric trains would shorten journey times.
  • New Class 385 trains would be more reliable than the current elderly diesel trains.
  • It would be an easy line to electrify, as the line was built so that overhead electrification could be added without any gauge enhancement.

I would add a few reasons of my own.

  • The route is already electrified as far as Newcraighall station. This would probably ease the grid connection  to the new electrification.
  • I believe that electrification of a new railway, where everything is known an well-documented has a higher change of being delivered on time and on budget.
  • Running Class 385 trains may also produce operating and maintenance savings.
  • The Class 385 trains are serviced at the convenient Millerhill Depot.
  • Electrification might help running trains across Edinburgh.

If and when the Borders Railway is extended to Carlisle, there could be very good reasons to electrify the whole route.

I will answer a few questions.

How Much Time Would a Class 385 Train Save?

Currently, trains between Edinburgh and Tweedbank currently take fifty-five minutes with seven stops.

The Class 385 trains will probably save a few minutes at each stop, so this will make the journey time a bit shorter and turnround at each end of the route will be more relaxed.

How Long Is The Section Without Electrification Of The Borders Railway?

The distance between Newcraighall and Tweedbank stations is 30.75 miles.

How Challenging Is The Borders Railway?

It is not the easiest of routes, but it is not the most difficult either. It also has a high summit.

The current diesel trains don’t seem to be working that hard, when I’ve used the railway.

Would Electrification Be Difficult?

If I look at electrification projects over the last few years in the UK, they have been delayed and suffered cost increases because of the following.

  • Difficulty of raising bridges over the route.
  • Connecting to the electricity grid.
  • Surprises like unexpected sewers and mine workings, when installing the electrification.

Hopefully, as the Borders Railway is new railway, that is already partially electrified, this will not be a difficult electrification.

Could the Current Route Be Served By A Battery-Electric Train?

This is the big question, as it were possible, then the current Borders Railway may not need to be electrified.

In Hitachi Plans To Run ScotRail Class 385 EMUs Beyond The Wires, I talked about Class 385 trains with batteries, that #Hitachi are proposing.

Hitachi have said this.

  • It would be straightforward to add batteries to give a range of twenty miles on batteries.
  • Sixty miles would be possible but more difficult.

I believe that a safety-first way to run a battery-electric Class 385 train on the Borders Railway would be to do the following.

  • Procure a sin-fleet of Class 385 trains, with a range of forty miles on onboard batteries.
  • The trains would handle regenerative braking to the onboard batteries.
  • A charging station would be provided at Tweedbank station.

The only new infrastructure would be the charging station, which I believe should be based on Vivarail’s design, which I wrote about in Vivarail Unveils Fast Charging System For Class 230 Battery Trains

  • Currently, trains take just under ten minutes to turn round at Tweedbank station, which would be time enough to charge the battery.
  • Vivarail’s system is fully automatic, after the driver stops the train over a length of third-rail electrified track, which is only live, when a train is connected.

Hitachi would need to fit third-rail shoes to the trains, but then they could use the design from their Class 395 trains.

Conclusion

There is currently no need to electrify the Borders Railway, if Hitachi can do the following.

  • Fit batteries to a Class 385 train, to give a range of forty miles.
  • Design a fast charging system and install it at Tweedbank station.

I also believe that if and when the Borders Railway is extended to Carlisle, that there could be a strong case for electrification of the whole route.

Running battery-electric Class 385 trains on the Borders Railway would be a project with a lot of winners.

  • Hitachi would have a scenic demonstration route, close to a major well-connected international city.
  • The Borders would get a better and more environmentally – friendly train service to Edinburgh.
  • Scotrail would have a higher proportion of one class of electric trains.

But the biggest advantage could be the possibility of terminating Borders Railway services on the other side of Edinburgh, at perhaps Stirling or Dunblane.

 

 

 

June 19, 2019 Posted by | Transport | , , | Leave a comment

‘Empty’ Uber Cabs Driving Pollution And Congestion

The title of this post is the same as that of an article in today’s Sunday Times.

This is the first paragraph.

Uber cab drivers carry a paying passenger for less than half their shift, according to new data that raises serious concerns that the ride-hailing giant is adding to congestion and pollution.

The article also says that Uber cabs are carrying a paying passenger only 42% of the time.

This fits with my observation around busy points in London like Kings Cross station, where you see lots of Toyota Prius card with just a driver in them.

Only an hour ago, one such car, did a U-turn at Highbury Corner causing delay to everybody else. I can’t be sure it was an Uber cab, but it very much looked like one.

On a related point, a couple of months ago, my son paid for me to have an Uber cab from Walthamstow to Dalston. The cab had come all the way from Ealing around the North Circular Road, to pick me up.

How environmentally-friendly is that?

Conclusion

We need to cut pollution and non-electric cars crawling around waiting for business or driving half-way across London for a fare, is not a good idea.

  • Perhaps, Uber and other non-electric cabs should only be licensed to pick up in one London Borough.
  • All cabs should also be clearly marked with their company.

The sooner though, all vehicles inside the North Circular Road are zero-carbon the better..

 

June 9, 2019 Posted by | Transport | , , , | 2 Comments

Toshiba Unveils Tri-Mode Locomotive Demonstrator

The title of this post is the same as that of this article on Railway Gazette.

This is the first two paragraphs.

Toshiba Railway Europe unveiled a electric-diesel-battery hybrid traction technology demonstrator locomotive at the Transport Logistic trade show in München on June 4.

The company has a contract to supply 50 diesel-battery centre cab locomotives to DB Cargo from 2021, TRE Managing Director Hinrich Krey told Railway Gazette. The demonstrator is intended to showcase the company’s design work to date as well as highlighting future development options.

It is based on the frame and bogies of a heavy shunting locomotive.

  • There are two MAN 471 kW gensets.
  • The diesel engines are compatible with EU Stage V emissions regulations.
  • There are two SCiB 62 kWh lithium titanate oxide traction batteries.
  • Battery life is quoted as up to ten years.
  • The design is modular, so that a diesel engine can be replaced with another battery pack.
  • A pantograph working with common European voltages can provide electric power.

The locomotive is aimed at heavy shunting and light freight.

Conclusion

The power of the locomotive is probably about 1MW, which is less than half the power of a Class 66 locomotive. But locomotives like the Class 66 are often used for tasks, where a smaller locomotive could do an excellent job.

The low pollution of the Toshiba locomotive probably means it could work in sensitive areas or close to a workforce.

The locomotive appears to be a well-designed locomotive for an important niche market.

If this design and others like the Stadler Class 93 locomotive succeed it will lead nearer to the ultimate goal of a high performance heavy freight zero-carbon locomotive to replace the polluting diesel locomotives, that are so common on the railways of the world.

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

Chester To Liverpool Via Runcorn

This new service between Chester and Liverpool Lime Street stations via Runcorn station and the Halton Curve, started a couple of weeks ago.

I took these pictures of the journey.

Note.

  1. The service was busy, as everybody seemed to be going to Liverpool to prepare for the evening’s match.
  2. The Class 150 train kept up a good speed, which indicates that Network Rail didn’t cut quality on the link.
  3. Runcorn is about the halfway point of the journey.
  4. The route is electrified between Runcorn and Liverpool Lime Street stations.
  5. The Class 150 train was a bit tired.

I wouldn’t be surprised to see a hybrid train working this route.

Operation would be as follows.

  • All these trains work be capable of 100 mph using 25 KVAC overhead electrification between Liverpool Lime Street and Runcorn stations.
  • Power changeover would be at Runcorn station.
  • Between Runcorn to Chester stations is only about fourteen miles.. This will be well within battery range in a few years.

Transport for Wales will be obtaining trains from a crowded market.

More Halton Curve Services

Under Planned Improvements in the Wikipedia entry for Transport for Wales, this is said.

Introduction of a new hourly Liverpool to Llandudno and Shrewsbury service, and a new two-hourly Liverpool to Cardiff Central service from December 2022.

Adding these to the current hourly service, this would mean that two trains per hour (tph) would normally run between Liverpool Lime Street and Chester stations, with three trains in every alternate hour.

I think that, there would be a marketing advantage in running hybrid trains on these routes. Hydrogen would be ideal, as these would not need recharging like battery trains after a long trip.

To go through the single-track Halton Curve appears to take trains about five minutes, so up to eight tph could probably be feasible, which would mean four tph between Liverpool and Chester via Runcorn in both directions.

If Trains for Wales are going to compete with the Merseyrail electric services, they need a four tph frequency in both directions.

Flexible Ticketing

Currently, if you want to buy a ticket between the Chester and Liverpool Lime Street, you have to buy an appropriate ticket for your chosen route.

Surely, tourists and others might like to do the out and back journeys by a different route.

If London Underground and some train companies can share ticketing, then surely Merseyrail and other train companies can do the same.

Conclusion

This new service will be surprisingly well-used and needs an iconic hybrid train.

  • Diesel is not appropriate for the long term, although in Northern Connect Between Chester And Leeds To Start In May, I did report a rumour that Class 769 trains might be running between Chester and Leeds.
  • Hydrogen is non-polluting and has a longer range, that could make services between Liverpool and Holyhead possible.
  • Battery will probably need a charging infrastructure.

My money is on hydrogen power.

 

 

June 2, 2019 Posted by | Transport | , , , , , , , , , , , | 2 Comments

Better Storage Might Give Hydrogen The Edge As Renewable Car Fuel

The title of this post is the same as that of this article on an Australian blog called Create.

This paragraph summarises the article.

Professor David Antonelli from Lancaster University has recently discovered a material that he says could allow existing tank sizes to fuel four times their current range.

Take the time to read the article in full!

If this is developed successfully, then coupled to improved battery technology, that will surely increase the practical range of hybrid hydrogen-battery cars, trucks, buses and trains.

Whilst politicians vanish up their backsides discussing the irrelevant Brexit, engineers and scientists will get on developing ideas, that will make everybody’s lives better.

May 29, 2019 Posted by | Transport | , , , | 1 Comment

What Is The Kinetic Energy Of A Class 710 Train?

I finally got a good look at a Class 710 train at Gospel Oak station this morning.

The picture shows the plate on the end of a DMS car.

  • The weight of the train is 157.8 tonnes. Note that the four-car Class 378 trains weigh 172.1 tonnes.
  • 700 passengers at 90 Kg each with baggage, bikes and buggies would be 63 tonnes.
  • That would be a total weight of 220.8 tonnes.
  • The operating speed is shown as 75 mph., which is the same as the Class 315 train, that many Class 710 trains will replace.

Using the Omni Kinetic Energy Calculator gives a kinetic energy of 34.5 kWh.

For completeness these are the figures for different speeds.

  • 90 mph – 49.4 kWh – Operating speed of a Crossrail Class 345 train.
  • 100 mph – 61.3 kWh – Operating speed of many electric multiple units.

Note that the amount of energy is proportional to the square of the speed.

What Do The  Kinetic Energy Figures Show?

These are a few of my thoughts.

What Is Regenerative Braking?

A full Class 710 is travelling along at 75 mph, ihas 34.5 kWh of kinetic energy. Whenit needs to stop at a station, this energy has to be dissipated.

With normal friction brakes, the energy will be converted into heat and wasted.

But with regenerative braking, the traction motors are used in reverse to generate electricity.

This electricity is generally handled in one of three ways.

  • It is passed through resistors on the roof of the train and turned into heat and wasted.
  • It is fed back into the electrification and used by nearby trains. This needs special transformers feeding the electrification.
  • It is stored in a battery or other energy storage device on the train.

The last method is the most efficient, as the stored energy can be used to help restart the train and regain line speed.

Can The Lea Valley Lines Electrification Handle Regenerative Braking?

This question must be asked, as if the lines can’t then running trains with batteries could be the best way to handle regenerative braking and improve efficiency and reduce the electricity bill.

It should be noted, that the Chingford and Enfield Town routes are not shared with any other trains, so running Class 710 trains on these routes may have advatages in the maintenance of the electrification, if the trains handle the regenerative braking.

On the Cheshunt route, there are also some Greater Anglia services, but these will generally be run by Class 720 trains, which are also Aventras.

On the other hand, the electrification on the Gospel Oak to Barking Line has probably been installed to handle the reverse currents.

Do Class 710 Trains Have Regenerative Braking?

Search the Internet for “Class 710 train regenerative braking” and you find little in addition to my ramblings.

But other Aventras, like Crossrail’s Class 345 trains have been stated to have regenerative braking.

I also repeated my views in an article in Rail Magazine, which I described in I’ve Been Published In Rail Magazine.

No-one has told me that they disagree with my views and I was talking rubbish!

So I will assume that Class 710 trains do have regenerative braking!

The Aventra’s Electrical Systems

In this article in Global Rail News from 2011, which is entitled Bombardier’s AVENTRA – A new era in train performance, gives some details of the Aventra’s electrical systems. This is said.

AVENTRA can run on both 25kV AC and 750V DC power – the high-efficiency transformers being another area where a heavier component was chosen because, in the long term, it’s cheaper to run. Pairs of cars will run off a common power bus with a converter on one car powering both. The other car can be fitted with power storage devices such as super-capacitors or Lithium-ion batteries if required.

This was published eight years ago, so I suspect Bombardier have refined the concept.

But even in 2011, Bombardier were thinking about energy storage on the train.

How Much Storage Would A Class 710 Train Need?

As I said earlier, I train would need sufficient energy storage to store the kinetic energy of a train.

As my calculations show that a full train travelling at the maximum speed of 75 mph, then the energy storage for this version of a Class 710 train must be able to store at least 34.5 kWh, at all times.

The size of the on board energy storage could be around 40-50 kWh, which is readily available in a lithium ion battery, that has been designed for transport use.

Where Would The Energy Storage Be Placed?

The extract above says that two cars hold the electrical systems.

These pictures show the pantograph car and driver car next to it.

Note that underneath the pantograph car is a transformer.

So are these, the pair of cars, the extract describes? They certainly could be!

This is a selection of pictures of the underneath of the driver car.

Note.

  1. There are two large boxes with latches under both driver cars.
  2. Next to these boxes is a smaller box. At the pantograph end of the train, it is open and looks like a cooling system for the two boxes
  3. At the other end of the train, the smaller box appears to have a blanking plate, so perhaps the boxes are empty.

The only sensible use I can think of for the boxesis to store the batteries or capacitors.

I

I would estimate that each of the four large boxes.

  • Is about a metre wide.
  • Is about 0.3 metres high.
  • Is sized to fit within the 2.7 metre width of the train. Perhaps 2.5 metres.

These give a column of 0.75 cubic metres.

Bombardier used to manufacture a Primove 50 kWh battery, which was built to power trams and trains, that had the following characteristics.

  • A weight of under a tonne.
  • Dimensions of under two x one x half metres.

Were these boxes under the floor of the driver cabs of the Class 710 train designed to hold a Primove 50 kWh or similar battery?

Four batteries could give the train as much as 200 kWh of energy storage.

But surely for trundling along the Gospel Oak to Barking Line. a smaller battery capacity would be sufficient. I suspect that you fill the boxes with how many batteries you need and the computer does the rest.

Perhaps, just one 50 kWh battery would be enough! This could explain, why the cooling system appears to be blanked off at one end of the train.

Could The Batteries Be Used To Power The Class 710 Train?

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 a 50 kWh bsttery would give the following ranges with these consumption rates for a four-car Class 710 trains.

  • 3 kWh – 4.2 miles
  • 4 kWh – 3.1 miles
  • 5 kWh – 2.5 miles

It looks to me, that battery power would be possible over the extension to Barking Riverside station, which is about a mile long.

Battery power would also other uses.

  • Moving the train to a safe place for passenger evacuation, when the overhead electrification fails.
  • Moving the train in a depot or sidings, without overhead power.
  • Running innovative on-board services for maintenance and train preparation, when the train is parked overnight.

Reliable battery power has a lot of uses on a train.

West London Orbital Railway

The West London Orbital Railway would have less than ten miles of lines without electrification, with several electrified miles on either side.

I believe that Class 710 trains with the right amount of batteries could bridge the gap and make a massive difference to rail transport in North and West London.

I think that jumping a gap of a few miles on battery power, may well be easier than doing an Out-and-Back service..

A Flexible System

As it appears, each Class 710 train has got four battery boxes, I suspect that batteries can be installed as to the needs of the route.

  • Standard operation on Gospel Oak to Barking, Watford DC Lines and Lea Valley Lines could be one or two batteries to handle regenerative braking.
  • Out-and-Back to Barking Riverside station ,might need two batteries.
  • West London Orbital services might need three or four batteries.

These battery boxes also could be designed to allow an easy and quick change of battery, as batteries on buses have given Transport for London trouble in the past.

Conclusion

Bombardier’s design of the Aventra has been designed with battery operation in mind, which opens up lots of possibilities!

May 25, 2019 Posted by | Transport | , , , , | 2 Comments