The Anonymous Widower

Could Reversing Sidings Be Used On The Chingford Branch Line?

Could The Hall Farm Curve Be Built Without Electrification?

Will Walthamstow Central Station On The Victoria Line Be Expanded?

September 8, 2016 Posted by AnonW | Transport/Travel | Chingford Branch Line, Class 710 Train, Electrification, Highams Park Level Crossing, Highams Park Station, Level Crossing, Remote Wake-up | 6 Comments

Crossrail 2 And The Chingford Branch Line

The Chingford Branch Line will be effected both during construction and after opening by Crossrail 2..

In Rumours Of Curves In Walthamstow, I said this.

But with the design stage of Crossrail 2 well underway, I do wonder, if connecting Chingford station and the related sidings to the West Anglia Main Line, might give Crossrail 2 better options to build the line or provide alternative services, whilst the West Anglia Main Line is rebuilt through the area.

I still think that the Chingford Branch Line will be an invaluable resource to help get the Northern end of Crossrail 2 built.

If the Coppermill Curve is built in the near future, I feel the main reason will be to help build Crossrail 2 and rebuild the West Anglia Main Line to four-tracks.

Once Crossrail 2 is open, I think that the two lines will be connected together at Seven Sisters/South Tottenham. There is a lot of scope for a major passenger-friendly interchange and as it will be a few years after Crossrail, the design will draw on the experience of theearlier line.

Conclusion

The Chingford Branch Line will end up being tightly linked to Crossrail 2.

Related Posts

Could Reversing Sidings Be Used On The Chingford Branch Line?

Could The Hall Farm Curve Be Built Without Electrification?

Will Walthamstow Central Station On The Victoria Line Be Expanded?

September 7, 2016 Posted by AnonW | Transport/Travel | Chingford Branch Line, Crossrail 2, Trains, West Anglia Main Line | 6 Comments

Could Reversing Sidings Be Used On The Chingford Branch Line?

In Improving The Chingford Branch Line, I showed how the new Class 710 trains and some adjustment to timetables could run eight trains per hour (tph) to Chingford, with 4 tph each going to Liverpool Street and Stratford, by getting the trains to cross at the level crossing at ighams Park station.

Several stations in London, including some on the Underground, have what is known as reversing sidings. In How Trains Reverse At West Croydon, I described the working of the reversing siding there, which London Overground trains use to swap tracks to get back to Dalston Junction station.

So could a strategically placed reversing siding be placed to turn back some services, before the Highams Park level crossing?

I don’t think a reversing siding would be needed until the Coppermill Curve was reinstated to allow trains to go to and from Tottenham Hale to Walthamstow, And even then, it would only be needed if more than eight tph were running to Walthamstow.

A reversing siding would allow the following.

More than eight tph to go to Walthamstow.
The creation of a triangular service from Tottenham Hale to Lea Bridge via Walthamstow.
Services between Chingford/Walthamstow and Seven Sisters/South Tottenham for a future Crossrail 2.
Services between Chingford/Walthamstow and Gospel Oak along the Gospel Oak to Barkjing Line.

This map from carto.metro.free.fr shows the railway lines around Seven Sisters station.

There are certainly a lot of possibilities.

The Seven Sisters Chord gives access to Seven Sisters, Enfield Town and Cheshunt.
The Gospel Oak to Barking Line gives access to Cricklewood, Gospel Oak, Richmond and West Hampstead.
The Gospel Oak to Barking Line gives access via Cricklewood to the Dudding Hill Line for Acton..
The Gospel Oak to Barking Line gives access via |Willesden Junction to the West London Line for Clapham Junction.

If another four tph service is created to Walthamstow, I suuspect it will be a third long East-West service, which will give eight tph on the busy part of the Gospel Oak to Barkling Line west of South Tottenham.

There are only three stations or four if you add in Forest Road, which I talked about in New Stations On The Chingford Branch Line.

St. James Street
Walthamstow Central
Wood Street
Forest Road.

I’ll look at each in detail.

St. James Street Station

This is probably too difficult and it’s the first station.

Walthamstow Central Station

This Google Map shows the station.

Walthamstow Central Station

I think it could be a possibility.

I think that the platforms are certainly able to accept eight car trains and might even take twelve, so there should be space for a reversing siding between the two lines to the East of the station.

Wood Street Station

This Google Map shows the station.

Wood Street Station

Again, I think this is a possibility.

Wood Street station will need a lot of rebuilding to make it step-free and there is space beyond the platforms towards Chingford to put in a reversing siding for a train.

These pictures show the station.

It is a station with potential.

Forest Road Station

This Google Map shows where Forest Road station will probably go.

Forest Road Station

It could be just too restricted a site.

How Would The Trains Be Organised?

I think that Walthamstow Central or Wood Street will be the station with a reversing siding.

Say there are going to be three 4 tph services. They could be.

Gospel Oak to Walthamstow Central or Wood Street
Liverpool Street to Chingford
Stratford to Chingford

The sequence at the reversing station would be.

The train from Gospel Oak arrives in the down platform, discharges passengers and goes into the reversing siding.
The two Chingford services arrive in the down platform, one after the other, pick up any passengers and go to Chingford.
The two Chingford services arrive in the up platform, one after the other, pick up any passengers and go to Stratford and Liverpool Street.
The train for Gospel Oak comes out of the reversing siding into the up platform, picks up passengers and goes on to Gospel Oak.

No passengers would have to change platforms to change trains.

Would It Be Sensible To Have A Reversing Siding Anyway?

I’m no expert, but I think the answer is Yes!

Crossrail have a reversing siding at Chadwell Heath station, that they say is for service recovery, in this page on their web site.

So perhaps, if say there was a problem on the highams Park level crossing, a train or two could be diverted to the reversing platform to await their slot on the return from Chingford.

Conclusion

A reversing siding at either Walthamstow Central or Wood Street would allow extra services to be developed around the Coppermill Curve and also be useful for service recovery.

Related Posts

Could Electrification Be Removed From The Chingford Branch Line?

Could The Hall Farm Curve Be Built Without Electrification?

Will Walthamstow Central Station On The Victoria Line Be Expanded?

September 7, 2016 Posted by AnonW | Transport/Travel | Chingford Branch Line, Gospel Oak And Barking Line, Walthamstow Central Station | 7 Comments

New Stations On The Chingford Branch Line

I have pulled this post out of What Might Have Been At Walthamstow And Woodford, as I want to have a series of linked posts that described the various ways that the Chingford Branch Line could be improved.

In the Future Developments section of the Wikipedia entry for the Chingford Branch, it is said that there may be a station at both Forest Road and Chingford Hatch, either side of Highams Park station.

This map shows the area.

Around Highams Park

The red arrow indicates Chingford Hatch, with the two stations shown being Highams Park in the middle and Wood Street at the bottom.

Chingford Hatch Station

This Google Map shows the location of Chingford Hatch between Highams Park and Chingford stations.

Chingford Hatch

Chingford station is at the top and Highams Park station is st the bottom.

I suspect if the station is built, it will be somewhere near the roundabout. The railway is a short distance to the East.

As the railway appears to be on a bridge, it won’t be a simple station to build.

Forest Road Station

This Google Map shows the probable location of a new station on Forest Road in Walthamstow.

Forest Road Station

The station would probably be built where Forest Road crosses the railway line.

I suspect that if the station was built, it would be a simple affair with platforms on either side of the current line.

At present there is no more information on either station.

Walthamstow Village Station

This Google Map shows the up-and-coming area of Walthamstow Village.

Walthamstow Village

The railway is in a deep cutting and I suspect despite what the locals might think a station wouldn’t be practical.

But I suspect, there would be space for a reversing siding, that could be used by trains reversing at Walthamstow Central station.

Conclusion

Both proposals look sound, but passenger statistics will define if new stations are built.

Related Posts

Could Electrification Be Removed From The Chingford Branch Line?

Could Reversing Sidings Be Used On The Chingford Branch Line?

Could The Hall Farm Curve Be Built Without Electrification?

Will Walthamstow Central Station On The Victoria Line Be Expanded?

Could Reversing Sidings Be Used On The Chingford Branch Line?

September 7, 2016 Posted by AnonW | Transport/Travel | Chingford Branch Line, New Stations, Stations | 8 Comments

Improving The Chingford Branch Line

The Chingford Branch Line has a four trains per hour (tph) service between Liverpool Street and Chingford via Hackney Downs and Walthamstow Central stations.

Those that I know who live in the area, have a few simple wishes.

New trains with wi-fi and other passenger-friendly features.
More trains to improve services and take the pressure off the Victoria Line.
A service from Chingford and Walthamstow to Stratford and Crossrail.
Perhaps some new stations.
Step-free access at St. James Street and Wood Street stations.

The following sections tackle these wishes in more detail.

New Class 710 Trains

The biggest change to the line will come with the new Class 710 trains in a couple of years time.

Thirty new four-car Class 710 trains will replace the same number of Class 315 and Class 317 trains, that currently work the Cheshunt and Chingford services.

As the number of trains and their length is the same, the service frequency and capacity will be no worse than at present.
The trains will be modern and have air-conditioning and all the features that passengers now expect.
The trains will be fitted with various driver aids to ensure accurate timekeepers.
Nothing has been said about wi-fi, but most other new Aventras will have free wi-fi fitted, so I suspect it will be fitted or there will be a big argument.
I am of the belief that all Class 710 trains will be fitted with enough onboard energy storage to handle regenerative braking and short movements not connected to the overhead wires.
Onboard energy storage would also mean the trains could be fitted with remote wake-up, so that trains stabled overnight at Chingford, can be driver and passenger ready before the driver arrives to start the service in the morning.

It should be noted that London Overground has taken an option for another twenty-four trains. So could some of these trains be added to the fleet on the Chingford Branch to increase capacity and service on the Branch?

The Highams Park Level Crossing

In an ideal world, more services would be provided on the Chingford Branch to Liverpool Street for the following reasons.

The Victoria Line from Walthamstow Central now has the trains to handle passengers to Central London, but the station doesn’t have the capacity to handle them, due to its cheapskate 1960s design.
The Chingford Branch has direct access to Crossrail at Liverpool Street whereas the Victoria Line doesn’t connect to London’s new train line.
The Chingford Branch has direct access to the North London Line at Hackney Downs and the new Class 710 trains, will mean that North London Line services will be increased.
Crossrail could release extra platform space at Liverpool Street for more London Overground services.

But there is one major problem to increased services on the current Chingford Branch. They must all go through the level crossing at Highams Park Station.

There is only long detours, if the crossing is closed.
Extra trains would cause significant traffic congestion.
Extra trains would mean the crossing would be closed for a large proportion of every hour.

As it is unlikely that the money could be found for a bridge or tunnel at Highams Park, the only thing that can be done, is make sure that all train services be at maximum length, which is probably eight cars.

Obviously, longer trains would help, but in the long term, I’m certain that London Overground would want to run more frequent services between Liverpool Street and Chingford.

I think it is true to say that the train frequency of the Chingford Branch through Highams Park is probably limited by a maximum of eight closures per hour of the Highams Park level crossing, unless the level crossing could be closed or by-passed.

But is maximum use being made of the level crossing closures now?

At present in the Off Peak.

Trains arrive at Highams Park from Chingford at 14, 29, 44 and 59 minutes past the hour.
Trains leave Highams Park for Chingford at 08, 23, 38 and 53 minutes past the hour.

I don’t think that this means that a Northbound and a Southbound train can share a single closure of the level crossing. This page on the National Rail web site, shows live departures at Highams Park.

If they could, then that would cut the number of times the crossing closed in the Off Peak by half.

Things that will help, is that the Class 710 trains will have extensive driver aids and probably onboard signalling, so the precise timekeeping that would be required, so two trains shared a level crossing closure, could be a lot easier.

Eight trains per hour in the Off Peak in both direction through Highams Park station is a distinct possibility.

This 8 tph frequency could be continued through the Peak, as it’s probably better than the current timetable.

Eight Trains Per Hour From St. James Street To Chingford

So it looks like that modern Class 710 trains running to a precise timetable could mitigate the problems of the Highams Park Level Crossing and allow eight trains per hour between St. James Street and Chingford.

|As there is no other trains using the branch, except moving empty and some engineering trains to and from the sidings at Chingford, there is probably little to interfere with an 8 tph schedule.

South From St. James Street

South from St. James Street station, the trains go through the Coppermill Junction area and cross the West Anglia Main Line.

The Chingford Branch then joins the line from Tottenham Hale to Hackney Downs, as this map from carto.metro.free.fr shows.

Coppermill Junction

The map shows Coppermill Junction, where the Chingford Branch Line crosses the West Anglia Main Line, that runs North from Liverpool Street to Tottenham Hale, Bishops Stortford, Stansted Airport and Cambridge.

I suspect that there would be a problem fitting another four tph through Hackney Downs station and on to Liverpool Street.

In Rumours Of Curves In Walthamstow, I talked about how two curves would be rebuilt, based on information from an informant with detailed knowledge.

The Hall Farm Curve would be rebuilt as a bi-directional single-track connection between St. James and Lea Bridge stations.
The Coppermill Curve would be rebuilt to give a connection between St. James and Tottenham Hale stations.

The Hall Farm Curve is the significant one for passenger services on the Chingford Branch Line, as it would mean that the current service of 4 tph between Chingford and Liverpool Street would be augmented by a second 4 tph between Chingford and Stratford.

Waltham Forest would get an 8 tph metro service between St. James and Chingford stations.
There are extensive bus connections at Chingford, Walthamstow Central and Stratford.
The line has good connections to the Victoria Line, the Jubilee Line, the Central Line and Crossrail.

The only infrastructure needed would be the single-track Hall Farm Curve. If the Class 710 trains were to be fitted with onboard energy storage, this curve would not even need to be electrified.

Conclusion

By using the features of the new Class 710 trains, Chingford can be given four trains per hour to Liverpool Street and 4 trains per hour to Stratford, if a new single-track Hall Farm Curve without electrification is built between St. James and Lea Bridge stations.

Could The Hall Farm Curve Be Built Without Electrification?

Will Walthamstow Central Station On The Victoria Line Be Expanded?

September 7, 2016 Posted by AnonW | Transport/Travel | Chingford Branch Line, Class 710 Train, Electrification, Hall Farm Curve, Highams Park Level Crossing, Highams Park Station, Level Crossing, Remote Wake-up | 14 Comments

Comparing An Aventra IPEMU With An Electrostar IPEMU

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, which I discussed in Do Bombardier Aventras Have 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.

Four-car Electrostar

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 could be created from a train like a Class 377, Class 378, Class 379 or Class 387 train.

We know that in the demonstration using a Class 379 at Manningtree, that that train could do 18.2 km. on the Mayflower Line, just by the use of battery power.

Five-car Electrostar

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.

Four-car Aventra

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.

Five-car Aventra

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.

Conclusions

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.

September 6, 2016 Posted by AnonW | Transport/Travel | Aventra, Electrification, IPEMU, Remote Wake-up | Leave a comment

Slow Line Traffic Into Paddington

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.

September 5, 2016 Posted by AnonW | Transport/Travel | Class 387 Train, Crossrail, Great Western Railway, IPEMU | Leave a comment

How Big Would Batteries Need To Be On A Train For Regenerative Braking?

Let’s assume that we have a Class 710 train, trundling around North East London at up to 120 kph.

To calculate the kinetic energy in the train, which will have to be transferred to the battery, we need the mass of the train and its velocity.

I’ll start with the velocity of the train.

As it approached a station, it will be at whatever is the appropriate line speed, which to make things easy I’ll assume is 100 kph or just under 28 metres per second.

In most cases after stopping and discharging and loading a few passengers, it will probably return to a similar line-speed to go to the following station.

The mass of each car of an Aventra, is found at several places on the Internet, including this entry in Wikipedia which gives it as 30-35 tonnes. So the four-car Class 710 train could have a mass of 130 tonnes. Add 100 passengers at an average of 80 kg. each and this would make the mass 138 tonnes

Applying the standard formula gives a kinetic energy of 53240741 joules or in common-or-garden units 14.8 kilowatt hours. So the energy of an Aventra going at 100 kph could power a one bar electric fire for fifteen hours.

To get a better handle on how much energy is involved let’s look at these specifications for a Nissan Leaf car.

Nissan talks about 24 and 30 kWh versions of the car, So if this is the battery size, then one of Nissan’s batteries could store all the braking energy of a four-car Class 710 train.

Even a fully-loaded Class 345 train would only need a 50kWh battery.

Assuming of course, I’ve got the maths correct.

I have a feeling that using batteries to handle regenerative braking on a train could be a very affordable proposition.

As time goes on, with the development of energy storage technology, the concept can only get more affordable.

September 5, 2016 Posted by AnonW | Energy Storage, Transport/Travel | Class 710 Train, Regenerative Braking | 5 Comments

A Low Key Launch Of New Electric Trains

This morning at 07:15, I was on the first Class 387 train out of Paddington for Hayes and Hsrlington.

It was a new train of eight coaches, complete with that smell that all new vehicles have for a few weeks.

At the moment GWR only have four Class 387 trains in service, which should be enough for a two trains per hour (tph) shuttle with eight coaches in each service.

But because the new bay platform for the Greenford Branch has not been completed yet at West Ealing station, there are only a few services a day.

This page on the GWR web site gives more details and says this about services in 2017.

From January, all Greenford trains will terminate at West Ealing; as we increase our electric service between Hayes & Harlington and London Paddington to every 30 minutes.

From May, these trains will start running to and from Maidenhead, as we replace our existing diesel fleet.

Does this mean that from January 2017, the Greenford branch will be served by a four tph shuttle? Or will that be later?

September 5, 2016 Posted by AnonW | Transport/Travel | Class 387 Train, Great Western Railway, Greenford Branch, Hayes And Harlington Station | 3 Comments

Could The Hall Farm Curve Be Built Without Electrification?

The Hall Farm Curve was a five-hundred metre curve that used to connect the Chingford Branch Line to the Lea Valley Line, thus enabling direct services between Stratford to Chingford via the new Lea Bridge, James Street and Walthamstow Central stations.

This map from carto.metro.free.fr shows the lines in the area around Coppermill Junction.

Coppermill Junction

It is a much-needed route, as anybody who has taken the bus between Walthamstow and Stratford can testify.

I have heard rumours that it will be rebuilt, but nothing has been published yet.

The last rumour said it would be a single-track bi-directional line, as I wrote in Rumours Of Curves In Walthamstow

If this were to be built, there would need to be appropriate cross-overs, so that the trains could go on the right lines to and from Chingford and Stratford.

As in a few years time, the Stratford-Chingford service would be likely to be run by Aventras and no other electric train would be likely to use the curve, would it not be possible to not electrify the curve.

In Bombardier’s Plug-and-Play Train, I showed that all Aventras will have a certain amount of onboard energy storage to handle regenerative braking and enable short movements using stored energy.

So could the Aventras use their onboard energy storage to navigate the curve? The pantograph could be raised and lowered appropriately in Lea Bridge and St. James Street stations.

Conclusion

Building the Hall Farm Curve without electrification is possible, if Aventras use the line exclusively for passenger services.

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