A Modern Electrified Metro Network Using IPEMU Technology
An IPEMU is an Independently Powered Electric Multiple Unit, which is a standard electrical multiple unit, which incorporates on-board energy storage, which can be charged on electrified lines and then used to power the train, where no electrification exists.
- At present a range on the on-board energy storage is typically fifty to sixty miles with adequate performance.
- The storage can be used to capture braking energy, which is then used to restart the train at a station.
- Every feature of a modern electric train can be provided.
The first IPEMUs to be delivered could be the Class 710 trains for the London Overground.
If you look at cities like Edinburgh, Glasgow, Liverpool, London, Leeds and Newcastle with comprehensive local metro networks of trains, they are mostly fully electrified, with perhaps the occasional line run by diesel trains.
Electric trains are preferable to diesel ones for several reasons.
- They have a better performance.
- They are quieter and don’t emit noxious fumes.
- They are easier to purchase.
But above all passengers like them better and they attract passengers and generate revenue and profits.
On the other hand.
- It is expensive to put up overhead wires and get power to the wires.
- Bridges need to be raised or track lowered to make space for the wires.
- Installation of electrification is disruptive.
- There are often heritage and/or environmental issues with the overhead wires or installing them.
But consider the cities or towns like Bristol, Cardiff, Norwich and Peterborough.
All have or will soon have the following.
- An electrified main line running through.
- A fully electrified central station.
- Branches and local lines fanning out from the central station, run by diesel multiple units.
- Most local services are less than eighty miles in total for an out and back journey from the central station.
- Other services go to another electrified central station, within the range of an IPEMU.
I think it goes without saying, that the current system in the town or city works after a fashion, even if the services are infrequent, too small and are worked using scrapyard specials.
Suppose the objectives for your new metro are as follows.
- Services are run by modern four-car electric trains, that meet all current and envisioned access and customer requirements.
- Services are run by a standard train, so if the network expands, more trains can be easily built!
- The ability to lengthen the trains, say for an important sporting or cultural event.
- Enough trains to run four trains per hour services on important lines and perhaps one per hour on lines that get much lesser use.
- Most services run out and back from the central station.
- As little disruption as possible, whilst creating the metro.
I believe that IPEMUs can be used to create such a metro, in the following manner.
- Get electricity to the central station.
- Check that all bridges, tunnels and stations on the lines can allow an IPEMU to pass.
- Upgrade and test the signalling for the new trains.
- Lengthen platforms on the lines to take the IPEMUs.
- Wire up the platforms in the central station and for possibly a few miles around the station.
- Test each line and convert them to IPEMU operation, as works are completed and IPEMUs become available.
One great advantage is that a lot of the testing can be done using a dummy IPEMU.
- It would be the same type of train as an IPEMU, but powered by a diesel engine.
- It would have the same cab as an IPEMU, so that all driver sight-lines and operations could be checked.
- It would have full signalling and other displays and instrumentation of an IPEMU.
- It would probably have a pantograph and a battery, so it could check all the overhead wires could charge the batteries of the IPEMU.
Real passengers could even be used for tests and asked for their opinions.
So where couldn’t this type of approach be used?
A Trip To Aylesbury Vale Parkway Station
Aylesbury Vale Parkway station is one of Chiltern Railway’s termini in Buckinghamshire.
It is on the London to Aylesbury Line with services to Marylebone via Amersham, with a journey time of five minutes over the hour.
Plans also exist for the station to be calling point on the proposed service between Marylebone and Milton Keynes. The plans for the station in Wikipedia say this.
East West Rail plans to extend passenger services northwards to Bletchley and Milton Keynes by 2019 using parts of the former Varsity Line. The platform has been built to accommodate a second track if ever implemented, which would create an island platform. At present trains (currently run only as specials onBank Holidays) between Aylesbury and Quainton Road cannot serve Aylesbury Vale as there is no platform on the through route.
The track between Aylesbury and the new station was upgraded to continuous welded rail with a maximum line speed for DMU passenger trains of 60 mph (97 km/h). It is proposed that when services are extended to the north, trains will run via High Wycombe and not Amersham. Trains currently serving the station will thereafter terminate at Aylesbury.
These are some pictures I took of the station.
It is just a simple affair with a bus stand, car parks and the usual facilities, that appears will be soon surrounded by houses.
Chiltern Railways And Electrification
Before discussing how services will link up and down the London to Aylesbury Line, I will look at Chiltern Railways and electrification.
Under Developments and Announcements in the Wikipedia Entry for the East West Rail Link, this is said.
On 10 January 2013 Network Rail announced its intention to construct the western section between Bedford and Oxford, Aylesbury and Milton Keynes, as part of their five-year strategic business plan (2014–2019). The target date for train services to be operational on this section is December 2017. Electrification of the line between Oxford and Bedford was also included in the budget and target completion date was March 2017.
So electrification of the East West Rail Link is included in the project, even if the dates in the announcement are very much out of date now.
Given the following facts about the Chiltern Main Line, I believe it is likely that at some point, everybody will look seriously at providing electric trains from Marylebone to Birmingham Snow Hill station.
- The line has a close relationship with the East West Rail Link and other electrified or soon-to-be electrified lines.
- Chiltern finds it difficult to acquire more diesel-powered trains to fulfil their ambitions.
- Chiltern would like to run faster, larger, more efficient and greener electric multiple units.
Under Electrification in the Wikipedia entry for Chiltern Railways, this is said.
No section of the line is electrified, but in 2010 the chairman of Chiltern Railways, Adrian Shooter, indicated that electrification is being considered, though not in the immediate future. He added: “We could do some very interesting things with high-acceleration EMUs and possibly some further infrastructure work.
At some time in the next ten years, we’ll probably see electric trains between Marylebone and Birmingham Snow Hill.
But there will not necessarily be full electrification, as I believe IPEMU technology will change the way electrification is carried out.
Consider as well that the Chiltern Main Line is just one hundred and eighty kilometres long and the current maximum range of an IPEMU is being quoted as about sixty miles or just under a hundred kilometres, so with the following electrification.
- Marylebone and for perhaps twenty miles or so to handle local metro services.
- Birmingham Snow Hill, Birmingham Moor Street and the Snow Hill Lines, where there are local metro services.
- Banbury to Leamington Spa and other places, so that freight trains powered by bi-mode Class 88 locomotives, could use the line efficiently.
The Local lines from Marylebone and the Snow Hill Lines would be electrified using the techniques in A Modern Electrified Metro Network Using IPEMU Technology
IPEMUs would be able to run the full length of the line without the need for full electrification in an environmentally-sensitive area, inhabited by touchy people.
Northward To The East West Rail Link And Milton Keynes
Northward from Aylesbury Vale Parkway station, the Wikipedia entry for East West Rail Link, says that the line will be single track and allow 90 mph working. But as my pictures and a quick gander on Google Maps show, there is quite a bit of space available around the current single track. So as the East West Rail Link seems to be being designed as a double-track 100 mph railway, with full electrification, I think there are three possible options between the East West Rail Link and Aylesbury Vale Parkway and Aylesbury stations.
- Double-track 100 mph with electrification.
- Single-track 90 mph with electrification.
- Single-track 90 mph without electrification.
I think the line will be built with some form of electrification, so that electric trains can run from Aylesbury to Milton Keynes.
The line is also used by some freight trains, so double-track might be a good idea.
Aylesbury To London Via Amersham
Returning from Aylesbury today, I was surprised to see that the train ran from Amersham to Harrow-on-the-Hill on the same tracks as the Metropolitan Line. In fact for sixteen of the thirty-nine miles of the line from Marylebone to Aylesbury Vale Parkway, the line has full London Underground electrification.
Amersham to Aylesbury is about fifteen miles, with the distance between the two Aylesbury station being four miles, which means that Harrow-on-the-Hill to Marylebone is just a few miles.
So if an IPEMU could use the London Underground’s rail-based electrification, starting at Milton Keynes the train would easily arrive at Harrow-on-the-Hill with a full battery, that would take the train to Marylebone and back.
I don’t believe that the technical problems of an IPEMU starting at any station between Aylesbury and Milton Keynes and going to Marylebone and back are insurmountable.
Aylesbury To London Via High Wycombe
This uses the single-track Aylesbury to Princes Risborough Line, which is about a dozen miles long, before running to Marylebone along the Chiltern Main Line, which is another forty miles or so.
So some electrification will be needed.
According to Wikipedia, Chiltern have various plans to improve their network.
- The restoration of the quadruple track between South Ruislip (Northolt Junction) and West Ruislip, allowing trains to call at both stations without blocking the line. Triple track currently exists at West Ruislip, with the up platform loop still in situ, and at South Ruislip, with the Down Main through line also in situ. This would involve the reconstruction of the new down platform at West Ruislip, and the reconstruction of the up platform at South Ruislip. This ‘Chiltern Metro’ service was not programmed into the last round of franchising agreements.
- Restoration of fast through lines at Beaconsfield as part of a longer-term aspiration for a 90-minute journey time between London and Birmingham
- Double-track the line from Princes Risborough to Aylesbury.
- New Chiltern Metro Service that would operate 4+tph for Wembley Stadium, Sudbury & Harrow Road, Sudbury Hill Harrow, Northolt Park, South Ruislip and West Ruislip. This would require a reversing facility at West Ruislip, passing loops at Sudbury Hill Harrow, and a passing loop at Wembley Stadium (part of the old down fast line is in use as a central reversing siding, for stock movements and additionally for 8-car football shuttles to convey passengers to the stadium for events)
Some would also fit well with adding electrification, so I think that enough electrification can be added to allow an IPEMU to go from Aylesbury to Marylebone.
Oxford To London
Given that there will be electrification between Oxford and Bicester Village stations courtesy of the East West Rail Link, IPEMUs could start at Oxford and reach Princes Risborough, from where they used the same methods as Aylesbury and Birmingham services to get to London.
This article on the BBC, which is entitled Cowley line passenger train service planned for Oxford, says this.
Chiltern Railways has revealed plans for a passenger service to run on the Cowley branch in Oxfordshire.
The line, currently only used for freight, would see two new stations on the route at Oxford Science Park and Oxford Business Park.
So if this service goes to London, it would certainly be another job for an IPEMU.
Watford Junction To Amersham And Aylesbury
The Croxley Rail Link has been designed so it can have a link to Amersham. Wikipedia says this about the link.
A further proposal is to use the existing but seldom-used Metropolitan line chord which allows trains to run from Watford towards Amersham via Rickmansworth. In conjunction with the Croxley Rail Link, this route would allow direct services between Watford Junction and Amersham, thus improving local public transport in Hertfordshire and Buckinghamshire.
These are pictures I took, as the train passed the junction of the branch line to Watford.
It would certainly be a new use for a substantial piece of infrastructure, but would it do much more than link Amersham to Watford Junction.
Chiltern Trains could run an IPEMU from Watford Junction to Aylesbury Vale Parkway calling at all stations, but as passengers could also get to Aylesbury from Milton Keynes, I wonder if it would be well used.
The Anonymous Widower 