The main purpose is to provide a service to the new £3.5billion housing and commercial development project at Meridian Water, the developers of which will be rebuilding Angel Road station and renaming it to Meridian Water.
Brief details of the project are given in the March 2017 Edition of Modern Railways.
- STAR will involve laying a third track between Stratford and Angel Road, alongside the West Anglia Main Line and the Temple Mills Branch to Stratford.
- STAR will be completed at the end of 2018.
- STAR will run at a frequency of four trans per hour (tph)
- STAR will help in the four-tracking of the West Anglia Main Line.
More will certainly emerge in the next few months.
But I have a few questions about STAR.
What Type Of Train Will Be Used?
I think the route STAR will take, has a headroom problem at Tottenham Hale.
When I first saw this bridge and saw the height of the overhead electrification on the existing West Anglia Main Line under the far span, I immediately questioned if they could fit the electrification under either of the blue steel bridges, where STAR might pass, in a manner that would meet all the Health and Safety regulations.
So will this mean that STAR will be built without wires?
Diesel trains would work, but wouldn’t fit the profile of Meridian Water as an ecologically-sound development.
I think we could see IPEMUs or electric multiple units with onboard energy storage working the route.
Will STAR Share Platforms With The West Anglia Up Line?
The space for putting the third track for STAR is narrow as this picture at Tottenham Hale shows.
If STAR goes through in the space conveniently marked by green grass, the easiest way to create a platform would be to add a second face on the existing Platform 1.
- A step-free bridge is being built linking Hale Village to a new station building with step-free access to the existing Platforms 1 and 2.
- If STAR used the other face of Platform 1, it would share step-free access.
- STAR would have cross-platform access to Liverpool Street services.
- Passengers coming from say Stansted needing to get to Meridian Water would just wait on the shared Platform for the first Northbound STAR service.
- There would be step-free access between STAR and the Victoria Line.
It could be a very simple and affordable way of creating a new platform and interchange with full step-free access.
The technique could also be used at Northumberland Park station.
What Will Happen To STAR When The Great Anglia Main Line Is Four-Tracked?
STAR will only affect the West Anglia Main Line between Coppermill Junction and Angel Eoad, as this is the only section, where the STAR and the new lines will co-exist.
In How Many Fast Services Will Go Through Tottenham Hale Station?, I concluded that there will be between ten and twelve fast trains per hour in both directions between Tottenham Hale and Broxbourne stations.
I also think, that these trains will go non-stop along the new lines only stopping at Broxbourne, as the timings of the new slow trains could be the same as the current fast ones. See Timings Between Tottenham Hale And Broxbourne Stations for full details.
As the four-tracking will not take place for a few years, I think it is likely that Stadler and Bombardier will be able to fit onboard storage to their trains, so could we see the two new lines squeezed into the small space between STAR and the development at Tottenham Hale without electrification?
Signalling technology would also probably allow such a line to be bi-directional, with trains running alternatively in both directions.
It would certainly save space to have a bi-directional line without electrification handling the fast trains through Tottenham Hale!
The fast line would revert to a normal double track at Coppermill Junction and Angel Road.
As closing a rail route is often a difficult process, even after Crossrail 2 is providing a high frquency service between Tottenham Hale and Angel Road, STAR will continue into the future.
STAR is putting down some interesting markers for the future.
Marlborough once had a pair of stations, as this map of the railways in the town shows.
Note the various stations in an area, where Marlborough the largest town has a population of 8,395.
This railway map shows the important Reading to Taunton Line that passes to the South of Marlborough. This Google Map shows that line as it crosses the A346 road.
- The Reading to Taunton Line crossing the map in an East-West direction, generally following the Kennett and Avon Canal.
- Marlborough is to the North
- Pewsey station is to the West.
- Bedwyn station is to the East.
- Savenake Low Level station used to be somewhere to the South of what look like yellow field of Rape.
- The small town of Biurbage is to the South.
There would also appear to be tracks of disused railways leading North-Westerly from Bedwyn towards Marlborough.
If Marlborough and the surrounding area were to be given a better rail connection, I would think that a possible solution would be a parkway station, perhaps where the A346 crosses the railway and the canal.
It should be born in mind, that modern trains are designed to perform fast stops at stations, so the extra station at Marlborough would not be the time penalty, it was a few years ago.
Transition Marlborough’s Proposal
But a local action group called Transition Marlborough have their own plans for a Marlborough Rail Link, which as this graphic shows are more ambitious.
Their plans would involve restoring and electrifying the line to Marlborough, where a well-positioned station will be built.
These are my initial thoughts.
- The route of the line appears feasible.
- Electrification may be a problem given Network Rail’s expertise in this area.
- Bedwyn would not appear to be the best terminus for a line to London.
- I’ve not been to Bedwyn station, but I suspect it could be a bleak place in some kinds of weather.
After I wrote this list, a kind soul in the area sent me this message.
You’ll find that Bedwyn station is a pretty bleak place, especially in Winter. To reach it by road from Marlborough involves a 7.5 mile road trip, at least 3 miles of which is on an unmarked road through a forest. Bedwyn station is almost inaccessible for people without cars, as the connecting bus service is poor and unreliable.
My Version Of The Proposal
I think the best solution could be to create a single-track railway without electrification to a simple station with adequate parking at the proposed Salisbury Road Business Park location.
The distance between Reading and Marlborough by train would be about 37 miles. Network Rail’s plans to electrify the line between Reading and Bedwyn are probably best described as fluid, but I suspect that electrification to Newbury could be possible, which would mean that only twenty miles between Paddington and Marlborough would be unwired.
So this would mean that when inevitably an electric train with onboard energy storage has a range of forty miles, Marlborough could get a modern electric service to and from Paddington.
The advantages of this strategy are as follows.
- No ugly overhead catenary marching across the country.
- Work would only include restoring a single track railway and building a simple no-frills station at Marlborough.
- Marlborough station would not have any electrification and could be designed like a tram stop.
- Fast Environmentally-friendly electric trains to and from Reading and Paddington.
- The route would be designed for six-car trains in case Marlborough College put on a free concert featuring the Rolling Stones.
- The route could be designed to allow two trains per hour (tph), as opposed to the current one tph service to and from Bedwyn.
- Marlborough to Paddington would have a maximum time of around 80 minutes.
But the biggest advantage is that the scheme is that it could be affordable.
This article on the BBC is entitled Marlborough £30m railway line restoration plan.
If this branch line is developed as I believe Network Rail are now thinking, there could be money left over for a good launch party!
With the next generation of electric train with onboard energy storage or IPEMUs, a Marlborough station on a new Marlborough Branch Line can be used to create a two tph service to and from Paddington to replace the current one tph service from Bedwyn.
So a new Marlborough station would be a win for all those using stations on the Reading to Taunton Line to the East of Pewsey.
I also wonder how many other similar services can be developed by extending a service past a main line terminal to a new or reopened branch line, which is built without electrification and run using trains with onboard energy storage.
This article in Rail Technology Magazine is entitled Further delays to GWML electrification as schemes deferred indefinitely.
The delayed schemes include.
- Bristol Parkway to Bristol Temple Meads
- Bath Spa to Bristol Temple Meads
- Oxford to Didcot Parkway
- Henley Branch
- Windsor Branch
The article also quotes the Rail Minister; Paul Maynard, as saying.
Introducing newer trains with more capacity in these areas could be done without costly and disruptive electrification,
Is this a meaningless platitude or is there substance behind it?
But this is said in the Wikipedia entry for the Class 800 train.
In July 2016, it was announced that GWR’s intended fleet of Class 801s were to be converted from pure EMUs to bi-mode units. Subsequently these were reclassified as Class 800s.
So will we see bi-mode trains working the Bristol Temple Meads routes, which are numbered 1 and 2 above?
That would certainly allow the Minister to bathe in the glory of a run to Bristol via Bath and back via Bristol Parkway.
Five-car Class 800 trains could also work route 3, thus giving Oxford trains, that would increase capacity and run on electric power between Didcot and Paddington.
But what about the four branch lines; Greenford, Henley, Marlow and Windsor?
- The Minister used the word newer not new.
- He also said capacity would be greater.
- When I passed the Marlow branch a few weeks ago, it appeared electrification had started.
- All branches are short, with the Marlow Branch the longest at 7.25 miles.
- The Henley Branch has a 50 mph speed limit.
So would it be possible to fit batteries to the Class 387 trains to fulfil the Minister’s statement?
- The Class 387 trains are very similar to the Class 379 trains used in the trial on the Mayflower Line.
- They are newer with greater capacity, than the current trains on the branch lines.
The answer could be yes! I reported on Rumours Of Battery-Powered Trains in August 2015. At that time Network Rail were calling the trains Independently Powered Electric Multiple Units or IPEMUs.
The possibility also exists that Class 387 trains with batteries could also work the lines between Didcot Parkway and Oxford, Reading and Basingstoke and Reading and Bedwyn.
Network Rail needs to convert a serious loss of face into at least a score-draw!
If the Great Western does use this approach, they’ll only be taking a similar route to the Germans, as I wrote about in German Trains With Batteries.
This article in the Oxford Mail is entitled Train timetable released for new Oxford to London Marylebone route.
This is said.
The new timetable shows services running every 30 minutes, starting at 6.02am from Oxford and returning at 23.10pm.
The line will open on Monday, December 12.
That is certainly a passenger magnet of a timetable.
Looking at the timetable of both Chiltern and Great Western,
- Both services run at least two trains per hour (tph) all day.
- Both services run fairly late in the evening.
- Great Western has the fastest trains, with some doing the journey in under an hour.
It will certainly be interesting to see how these two heavyweights slug it out.
But this is only Round 1One.
- In December 2018, Crossrail services between Paddington and Abbey Wood, via Liverpool Street and Canary Wharf start.
- In May 2019, Crossrail services between Paddington and Shenfield start.
- In December 2019, full Crossrail services start.
- The East West Rail Link will open.
- Oxford to Didcot should be electrified, allowing electric trains to Oxford.
These developments may appear to favour Great Western services over Chiltern, but I doubt that Chiltern will sit back and do nothing.
So what will Chiltern do?
- Will the Marylebone to Oxford route be improved to allow services to run faster and more frequent services? There are certainly some possible plans for this on Wikipedia.
- Will the West Hampstead Interchange be created?
- I doubt that it would be easy to shoehorn more services between High Wycombe and Marylebone, so this route will probably be limited to 2 tph.
- The Oxford to Marylebone trains will go to Class 68 locomotives and rakes of Mark 3 coaches, as Chiltern use to Birmingham at the present time.
- Greater Anglia could be releasing some high-quality Mark 3 coaches in 2019-2020.
- There has been speculation that Chiltern could open a second London terminus at Old Oak Common for Crossrail. I wrote about it in Will Chiltern Railways Get A Second London Terminus At Old Oak Common?.
- Will electrification come to the Chiltern Line? Or at least enough to run modern bi-mode or battery-electreic trains.
- The Guardian says that Bicester Village is one of the top tourist destinations in the UK.
What is needed is a comprehensive plan for Chiltern’s future.
I can’t believe that they’re not working on one!
It could include the following.
- Line improvements to reduce journey times between Marylebone and Oxford.
- Improvements to allow the longest possible locomotive-hauled sets to run the route.
- Development of West Hampstead Interchange.
- Creation of a second terminus at Old Oak Common.
One or both of the last two options will have to be implemented, due to the lack of capacity at Marylebone and that station’s bad connectivity.
But what would I do?
The Southern end of the Chiltern Main Line needs better connectivity and the best way to do this would be to link it to Crossrail.
When Crossrail opens to Paddington in December 2018, the direct link I wrote about in Paddington Is Operational Again, will enable passengers taking the Bakerloo Line from Marylebone to change easily to Crossrail.
Together with line improvements and longer trains, this should handle the traffic for a few years.
It is interesting to look at a few journey times.
- Chiltern has trains scheduled between Marylebone and High Wycombe in around 24-28 minutes.
- Crossrail services from Paddington will take 27 minutes to Sloughbold step of creating a Crossrail .
- Crossrail services from Paddington will take 45 minutes to Reading.
I would take the bold step of creating a Crossrail branch to High Wycombe.
- High Wycombe would receive 4 tph from Crossrail.
- There could be cross-platform interchange between Crossrail and Chiltern services to Oxford and Birmingham.
- The Acton-Northolt Line would be double-tracked and electrified to connect Crossrail at Old Oak Common to the Chiltern Main Line at Northolt Junction.
- The Chiltern Main line would be electrified from Northolt Junction to High Wycombe.
- Chiltern’s Oxford and Birmingham services could use Class 88 electro-diesel locomotives, to take advantage of the limited electrification.
- Extra services could run from High Wycombe to Oxford and Birmingham, if traffic required more capacity.
Except for the electrification and some track layout changes, there is no substantial investment required in new lines and stations.
If this approach is taken, there will probably be eough eletrification on the Chiltern routes to use Aventra trains with an IPEMU-capability to provide the services out of Marylebone.
Bombardier’s New Talent 3 Electrical Multiuple Unit
This is the data sheet on Bombardier’s web site announcing the new Talent 3 EMU, which has recently been announced at Innotrans 2016. It is the successor to the Talent 2.
These are some phrases picked from the sheet.
- Flexible and efficient when operating as commuter, regional, or intercity train.
- The use of proven and optimized components, recognized in operation in several European countries,
- For the first time a TALENT EMU train is compatible with the BOMBARDIER PRIMOVE Li-ion battery system.
Reading the data sheet the train seems very similar to the Aventra, except that in the case of the Talent 3, they mention batteries.
This Bombardier press release is entitled New PRIMOVE battery for rail presented at InnoTrans exhibition.
This is said.
The TALENT 3 EMU with PRIMOVE battery system will provide an environmentally friendly alternative to diesel trains operating on non-electrified lines. The results will significantly reduce noise pollution and emissions while making rail passenger transport cleaner and more attractive. Operators and passengers will also benefit from a battery technology that eliminates the need to change trains when bridging non-electrified track sections.
Other documents and web pafes emphasise how Primove is for all tranport applications. Thjs is the Primove web site.
In their data sheet, Bombardier said this.
For the first time TALENT EMU train is compatible with the BOMBARDIER PRIMOVE Li-ion battery system.
Reading about Primove, it would appear to be various standard modules.
Supposing you fit a train with the a standard Primove battery. This will give a defined range and performance to a p[articular train or tram with a specfic size battery.
As an electrical engineer and a control engineer in particular, I would suspect that the connections and the control system are the same for all batteries and that provided the battery can fit within the space allocated, all sizes will fit all trains.
So a suburban trundler would probably have less battery capacity, than a fast regional express, that stopped and started quickly all the time.
If you want more range and performance, you just fit a bigger or more efficient battery.
I suspect too, that if an innovative company came up with another battery design, perhaps based on something like several miles of strong knicker elastic, so long as the plugs fit and it goes in the standard space, Bombardier would at least look at it.
So it looks like the fitting of batteries could be totally scale-able and future-proofed to accept new innovative battery technologies.
Aventras And Batteries
There has been no direct mention of batteries on Aventras
This is the best information so far!
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-Iron batteries if required.
Bombardier have confirmed the wiring for onboard power storage to me.
But you have to remember that the Talent 3 is for the more generous European loading gauge.
So could it be that Bombardier’s standard Primove system fits the Talent 3 and it’s too big for an Electrostar and an Aventra designed on standard lines?
But possibly, splitting the various heavy electrical components between two cars, as indicated in the Global Rail News article, gives more space for fitting a standard Primove battery and distributes the weight better.
Perhaps they can even fit a standard Primove battery into an Aventra, if it has the underfloor space to itself!
Obviously, using the same batteries in a Talent 3 and an Aventra must have cost and development advantages. Especially, if you can size the battery for the application.
Electrostars And Batteries
It has always puzzled me, why some Electrostars with an IPEMU-capability have not appeared. Could it be, that the amount of electrical equipment required is too much for a standard design of train running on a UK loading gauge?
Bombardier must have a target range for a train running on batteries. Perhaps, the Electrostar can’t get that range, but the Aventra with its twin power-car design can!
I wonder if the Electrostar with batteries and an IPEMU-capability will borrow from the Aventra design and have twin power-cars. That could be a much more major modification than that performed on a Class 379 train to create the BEMU denonstrator early last year.
But it could enable the use of a standard Primove battery and obtain the range needed for a viable Electrostar with an IPEMU-capability.
Crossrail And Energy
Crossrail is unlike any other railway, I’ve ever seen, with the exception of the RER under Paris.
- Crossrail will be deep and all stations will have platform edge doors.
- Crossrail will have twenty-four trains per hour.
- A fully loaded Crossrail train going at the design speed of 145 kph has an energy of 105.9 kWh.
All of these and other factors will lead to lots of energy and heat being introduced into the stations, trains and tunnels.
One way of minimising problems is to design the the tunnels, trains, stations and electrical systems together.
As an example of how systems interact consider this. A train pulling away from the station needs a lot of energy to get to line-speed. In a traditional design, there could be a lot of energy wasted as heat in the overhead wires getting the electricity to the train. This heat would then need more air-conditioning to cool the platforms and the train.
So in this and many ways, saving energy, not only saves costs, but leads to further energy saving elsewhere.
Because of enegy problems, railways like Crossrail have to be designed very carefully with respect to energy usage.
Class 345 Trains
- They have been specifically designed for Crossrail.
- Regenerative braking is standard.
- High energy efficiency.
- Acceleration is up to 1 m/s² which is more than an |Electrostar.
- Maintenance will be by the manufacturer in purpose-built depots.
From this I conclude that it is in Bombardier’s interest to make the train efficient and easy to service.
I also founds this snippet on the Internet which gives the formation of the new Class 345 trains.
When operating as nine-car trains, the Class 345 trains will have two Driving Motor Standard Opens (DMSO), two Pantograph Motor Standard Opens (PMSO), four Motor Standard Opens (MSO) and one Trailer Standard Open (TSO). They will be formed as DMSO+PMSO+MSO+MSO+TSO+MSO+MSO+PMSO+DMSO.
As the article from Global Rail News said earlier, the power system of an Aventra is based on two cars, with the heavy equipment split. So as each half-train seems to have be DMSO+PMSO+MSO+MSO in a Class 345 train, could the trains be using a three-car power system, with one car having the converter and batteries in the other two, all connected by a common bus.
It should also be noted that most Electrostar pantograph cars, don’t have motors, but the Class 345 trains do. Thus these trains must have prodigious acceleration with thirty-two diving axles in a nine-car formation.
There are also sound engineering and operational reasons for a battery to be fitted to the Class 345 trains.
- Handling regenerative braking in the tunnels. As a train stops in a tunnel station, the regenerative brakes will generate a lot of energy. It would be much more efficient if that energy was kept in batteries on the train, as the tunnel electrical systems would be much simpler. There could also be less heat generated in the tunnels, as the overehead cables would be carrying less power to and from the trains.
- Remote wake-up capability. Trains warm themselves up in the sidings to await the driver.
- The depots could be unwired. I’ve read that the main Old Oak Common depot is energy efficient. Batteries on the trains would move the trains in the depots.
But the biggest advantage is that if power fails in the tunnel, the train can get to the next station using the batteries. In a worst case scenario, where the train has to be evacuated, the batteries could keep the train systems like air-conditioning, doors and communication working, to help in an orderly evacuation via the walkway at the side of the track.
How do you open the doors on a boiling train with fifteen hundred panicking passengers and no power? An appropriately-sized battery solves the problem.
Incidentally, I have calculated that a Class 345 train, loaded with 1,500 80 Kg people travelling at 145 kph has an energy of 105.9 kWh. As s Nissan Leaf electric car can come with a 50 kWh battery, I don’t believe that capturing all that braking energy on the train is in the realm of fantasy.
One big problem with regenerative braking on a big train with these large amounts of energy, must be that as the train stops 105.9 kWh must be fed back through the pantograph to the overhead line. And then on starting-up again 105.9 kWh of energy must be fed to the train through the pantograph, to get the train back up to speed.
As this is happening at a crowded station like Bond Street, twenty-four times an hour in both directions, that could mean massive amounts of energy flows generating heat in the station tunnels.
Remember that London’s tube train are smaller, have similar frequencies and have regenerative braking working through a third-rail system.
Surely, if the train is fitted with a battery or batteries capable of handling these amounts of energy, it must be more efficient to store and recover the energy from the batteries.
Batteries also get rid of a vicious circle.
- Feeding the braking energy back to the overhead wire must generate heat.
- Feeding the start-up energy to the train from the overhead wire must generate heat.
- All this heat would need bigger air-conditioning, which requires more energy to be drawn by the train.
Batteries which eliminate a lot of the high heat-producing electricity currents in the tunnels at stations, are one way of breaking the circle and creating trains that use less energy.
After writing this, I think it is obvious now, why the trains will be tested in short formations between Liverpool Street and Shenfield.
The trains could be without any batteries during initial service testing, as all the reasons, I have given above for batteries don’t apply on this section of Crossrail.
- Regenerative braking can either work using two-way currents on the upgraded overhead wiring or not be used during testing.
- Remote wake-up is not needed, as the trains will be stored overnight at Ilford depot initially.
- Ilford depot is still wired, although the jury may be out on that, given the depot is being rebuilt.
- There will be no need to do rescues in tunnels.
Once the trains have proven they can cope with herds of Essex girls and boys, batteries could be fitted, to test their design and operation.
You have to admire Bombardier’s careful planning, if this is the way the company is going.
Could the following be the operating regime for Crossrail going from Shenfield to Reading?
- The train runs normally between Shenfield and Stratford, using regenerative braking through the overhead wires or batteries.
- The train arrives at Stratford with enough power in the batteries to come back out or get to a station, if there was a total power failure.
- The train uses regenerative braking with the batteries between Whitechapel and Paddington.
- In the tunnels, the power levels in the batteries, are kept high enough to allow train recovery.
- Once in the open, regenerative braking could use overhead wires or batteries as appropriate.
- The train even handles complete power failure and perhaps a problem with one pair of power cars, as the train is in effect two half-trains coupled together, with at least two of everything.
Has there ever been a train design like it?
It looks to me, that the Aventra and Talent 3 trains are just different-sized packages for the same sets of components like Flex-Eco bogies and Primove batteries.
One train is for the UK and the other for Europe and the rest of the world.
But have the two design teams been borrowing ideas and components from both sides of the Channel?
You bet they have!
Brexit? What Brexit?
The engineers of Crossrail, have not only dug one of the biggest holes in Europe for a long time, but with Bombardier’s engineers, they could also have designed a very efficient and different way of getting passengers through it.
I am very strongly of the opinion, that putting batteries on the trains to handle regenerative braking in tunnels, is almost essential, as it is simpler, possibly more affordable and cuts the amount of heat generated in the tunnels.
If Bombardier in Derby and the Germans in Chemnitz (Karl Marx Stadt to Jeremy and the Corbedians) are addressing battery technology, you could be sure that the Japanese would have ideas and there is this article in Railway Gazette, which is entitled Emergency batteries for Tokyo Metro trains.
This is said.
Nippon Sharyo Series 1000 trainsets operating on Tokyo Metro’s Ginza Line have been fitted with Toshiba onboard emergency batteries so that they can reach the next station under their own power in the event of a traction supply failure.
Toshiba says the SCiB lithium-ion battery is well-suited to emergency use, being resistant to external shock, internal short circuits and thermal runaway. It recharges rapidly, has a long life and a high effective capacity over a wide range of environmental conditions.
The battery draws power from the third rail during normal operation, and can supply the traction system in the event of power outage or other emergency. It can also be used for train movements within depots.
I also said this in Bombardier’s Plug-and-Play Train,
I wouldn’t rule out that all Class 345 trains were fitted with some form of onboard energy storage.
The main reasons are all given in the article about Japanese trains.
One of my Google alerts found this article on Rail Journal, which is entitled DB to convert DMUs to bi-mode hybrid trains.
This is said.
GERMAN Rail (DB) has announced it is working with technical universities in Chemnitz and Dresden to develop bi-mode (diesel and electric) trains with lithium-ion battery storage. Between 2017 and 2021 DB intends to convert 13 existing Siemens class 642 Desiro Classic DMUs to hybrid bi-mode configuration.
It seems the Germans share my belief that trains with batteries are the future.
The Concept Of An IPEMU
This article in Rail Engineer, which is entitled An Exciting New Aventra, quotes Jon Shaw of Bombardier on onboard energy storage.
As part of these discussions, another need was identified. Aventra will be an electric train, but how would it serve stations set off the electrified network? Would a diesel version be needed as well?
So plans were made for an Aventra that could run away from the wires, using batteries or other forms of energy storage. “We call it an independently powered EMU, but it’s effectively an EMU that you could put the pantograph down and it will run on the energy storage to a point say 50 miles away. There it can recharge by putting the pantograph back up briefly in a terminus before it comes back.
I believe that once the concept of onboard energy storage is accepted, that Bombarduier’s engineers have found other ways to use it to the benefit of passengers, operators and Network Rail.
- Regenerative braking energy can be stored on the train and used for a restart or other purposes, rather than just burning it off or returning it to the grid, through complicated transformers.
- Onboard energy can be used to move a train to the next station, if the overhead or third rail power should fail.
- Depots and stabling sidings don’t need to be fully electrified.
- Onboard energy storage enables train features like remote wake up.
- Trains can safely pass over short sections without electrification. Third rail trains can do this with contact shoes at both ends of the train.
Trains with onboard energy probably need to have intelligent current collection, so that pantographs and contact shoes can be intelligently deployed and retracted.
Take the simple example of a passing loop on a single track electrified branch line, which is needed for two trains per hour. The passing loop could be built without electrification and without altering the existing electrification, with just a set of points and appropriate signalling at each end.
- Trains using the existing line and electrification would travel as now.
- Electric trains using the loop would lower the pantograph a safe distance before the loop, go along the passing loop using onboard energy and then once on the main line, raise the pantograph.
This technique could probably be used to simplify building of new stations or adding new platforms to existing ones.
Network Rail are going to love trains with onboard energy storage.
Electrostars and Aventras
Bombadier have shown that onboard energy storage is possible in an Electrostar and there is various articles on the web saying it can be fitted to the new Aventra.
As both Aventras and Electrostars seem to come in four- and five-car versions, I’ll do the calculations for both lengths of trains.
I’ll use these assumptions.
- Electrostar cars weigh 40 tonnes and Aventra cars 32.5 tonnes.
- Each car has 50 passengers weighing an average of 80 kilos.
The various types of IPEMU are shown in the next four sections.
This would have the following characteristics.
- A mass of 160+16 = 176 tonnes.
- A formation of DMOS+MOS+PTSO+DMOS
- Braking from 100 kph would release 18.9 KWH.
- Braking from 200 kph would release 75.5 KWH.
- Onboard energy storage could be placed in probably the MSO or PTSO cars.
This would have the following characteristics.
- A mass of 200+20 = 220 tonnes.
- A formation of DMOS+MOS+PTSO+MOS+DMOS
- Braking from 100 kph would release 23.6 KWH.
- Braking from 200 kph would release 94.3 KWH.
- Onboard energy storage could be placed in probably the MSO or PTSO cars.
This would have the following characteristics.
- A mass of 130+16 = 146 tonnes.
- A formation of DMOS+MOS+PMSO+DMOS
- Braking from 100 kph would release 15.6 KWH.
- Braking from 200 kph would release 62.6 KWH.
- Bombardier have stated that the MOS car is ready for onboard energy storage.
This could be created from a train like a Class 710 train.
This would have the following characteristics.
- A mass of 162.5+20 = 182.5 tonnes.
- A formation of DMOS+MOS+PMSO+MSO+DMOS.
- Braking from 100 kph would release 19.6 KWH.
- Braking from 200 kph would release 78.2 KWH.
The five-car Aventra could have two sets of batteries or onboard energy storage.
Note this about all Aventras.
Bombardier have stated that the MSO car is ready for onboard energy storage, if the customer desires.
The MSO and PMSO cars can be considered a fixed pair of cars handling the electrical power for the train.
Can a PMSO and two MSOs be considered a trio on the five-car Aventra?
Aventras have a lot of motored cars, with lots of traction motor/generators.
The trains can have a remote wake-up feature, that would probably need some form of onboard energy. After all, your smart-phone doesn’t work if the battery is not fitted.
Can I draw any conclusions?
- The Aventra with its pair of electrifical cars has been designed to have onbosrd energy storage.
- The energy that needs to be handled is less with the lighter weight Aventra.
- Stopping from 200 kph releases a lot more energy. Four times more than from 100 kph in fact.
- The energy storage needed for 100 kph stop and restart operation, are within the battery size range of the battery in an electric car like a Nissan Leaf.
- There could be advantages concerning reliability and battery size with the five-car Aventra with its possible two sets of energy storage.
Obviously, the weight of the battery would need to be factored into the calculations, but if say it was a tonne, it would only increase energy figures by less than one percent.
The Definitive IPEMU
I said that two two sets of energy storage in the five-car Aventra could give advantages.
- Each set could be smaller.
- Two sets will be more reliable than one.
- The weight of the storage is shared between two MSO cars.
- The two MSO cars in the five-car Aventra IPEMU would probably be identical.
In the extract from the Rail Engineer article that started this post Jon Shaw of Bombardier is quoted as saying this.
it will run on the energy storage to a point say 50 miles away.
Two sets of onboard storage would obviously help this, with each set needed to keep the train going for 25 miles. This is not the onerous task it could appear. Especially in an Aventra.
- The train is designed to minimise aerodynamic losses.
- The train is designed to minimise the very small rolling losses of steel wheel on steel rail.
- All passenger systems like wi-fi, lighting and air-conditioning are designed to use minimum electricity.
- Driving aids on the train will help the driver to drive in an energy efficient way.
- When the brakes are applied, the energy is recovered and stored in the onboard energy storage.
- The train will stop at a station using much less energy than a conventional train.
But the most important thing, is that the train has been designed from the wheels up as an efficient package.
I believe the following.
- Five cars will be one of the most common lengths for Aventras. Abellio have already ordered eighty-nine.
- The range on energy storage of a five-car Aventra with two sets of energy storage will be at least fifty miles.
- Aventras with an IPEMU-capability will be used to reduce electrification work.
- Aventras with an IPEMU-capability will be used to develop new electrified routes.
- As the IPEMU technology develops, Bombardier will develop a solution, so that later Electostars will be able to store their own braking energy and travel a limited distance away from electrification.
- All train manufacturers will look seriously at energy storage on trains.
If I was asked what would be the ultimate range of a train using this technology, I would say, that trains with an IPEMU-capability will within a few years be running the whole route between Waterloo and Exeter.
I was thinking today, as I came back from my trip from Paddington, that I described in A Low Key Launch Of New Electric Trains, that when all of the new trains are running on Crossrail and the GWR, the slow lines will be very busy.
According to Wikipedia, Crossrail will be running.
- 4tph Abbey Wood – Heathrow Terminal 4
- 2tph Abbey Wood – West Drayton – Peak Hours Only
- 2tph Shenfield – Reading
- 2tph Shenfield – Maidenhead
In addition there will be non Crossrail services on the line.
- 4 tph Heathrow Express
- 2 tph Paddington Main Line – Bedwyn
- 2 tph Paddington Main Line – Oxford
- 2 tph Paddington Main Line – Hayes and Harlington
So that gives eighteen services an hour, with probably all except the Heathrow Express on the slow lines.
As the Shenfield Branch of Crossrail is going to handle 16 tph, 14 tph would seem to be within the capacity of the slow lines to Reading, even leaving some space for freight.
I do wonder that as GWR has ordered forty-five Class 387 trains, which in view of today will probably be run mainly as eight-car trains, for where they are going to add services to the network.
So how many trains will they need for current services?
- 2 tph to Hayes and Harlington – Under half an hour, so 2 trains, or 4 if running as a pair.
- 2 tph to Oxford (stopping) – Two hours, so 8 trains or 16 if running as a pair.
- 2 tph to Bedwyn – 90 minutes, so 6 trains or 12 if running as a pair.
Oxford and Bedwyn will also be served by fast Class 800 long distance trains.
This gives a total of 32 Class 387 trains.
So what happens to the other thirteen trains?
There has been talk of giving some of the trains an IPEMU-capability, which I reported in Rumours Of Battery Powered Trains to run the branch lines to Henley, Marlow and Windsor and the Reading to Gatwick service.
I just wonder, if the Electrostar might have made a good demonstrator for the IPEMU technology, but that an IPEMU based on an Aventra is so much better, that there is little point in creating an Electrostar IPEMU.
Or are Bombardier wanting to get the Aventra fully designed in all its variants before they tackle creating an Electrostar IPEMU?
So how many trains with an IPEMU-capability would be needed for the branch lines and Reading to Gatwick?
- Gatwick to Reading takes 90 minutes, so 6 trains could provide 2 tph.
- 4 tph on the Greenford Branch, would need 2 trains charging at West Ealing.
- 2 tph on the Henley Branch, would need 1 train charging at Twyford.
- 2 tph on the Marlow Branch would need 2 trains charging at Maidenhead. – By a bit of fiddling, the trains might pass at Bourne End or there could be a passing loop.
- 2 tph on the Windsor Branch, would need 1 train charging at Slough.
This adds up to the missing thirteen trains, if you add in a spare. In Modern Railways for June 2016, one paragraph in a larger article gives some news about the progress of Bombardier’s IPEMU technology. This is said.
Industry sources confirm that options for some of the GWR order to be produced as independently powered EMU (IPEMU) variants fitted with batteries for operation away from electrified routes are still being explored. This would enable GWR services to Gatwick Airport and on some of the Thames Valley branches to be worked by ‘387s’ prior to electrification. Any decision to look seriously at this proposal will depend on final electrification timescales being confirmed by Network Rail.
Ordering the number of trains they have means that GWR can offer a workable solution on all routes in the Thames Valley, depending on what Network Rail deign to deliver and if Bombardier come up with an affordable IPEMU solution.
- No electrification, no IPEMU – Use refurbished diesel multiple units.
- Electrification – Use Class 387 trains as electric multiple units.
- No electrification, IPEMU – Use Classs 387 trains in IPEMU mode.
Obviously, if Network Rail decide to electrify any part of the network later, the trains can be driven and controlled accordingly.
I’m also sure, there will be routes in the Bristol area, where a Class 387 train with an IPEMU-capability could be very useful.