Discontinuous Electrification For Valley Lines?
The title of this post, is the same as that of an article in the May 2018 Edition of Modern Railways.
The Valley Lines in question are the Cardiff Valley Lines, that fan out from Cardiff Central and Cardiff Queen Street stations in various directions.
- Some of the lines into the valleys are quite steep.
- The lines in the Cardiff area seem to be typical coastal lines and fairly flat.
- The lines are a mixture of single and double track.
- There are various plans to extend some of the branches.
According to the article, it would appear that the current diesel system would be replaced with a system, with these characteristics.
- Light rail vehicles
- Discontinuous electrification
- Use of stored energy.
- Street running is expected to be in the specification for the vehicles to be used, to allow extension in the Cardiff Bay area and perhaps other places.
The proposal would save costs against full electrification and heavy rail.
My observations follow.
Batteries
Batteries will be an integral part of the design of the new rail vehicles.
Powering The Trains
The article states that battery power will be used to power the trains on sections that are difficult to electrify, like the mile-long Caerphilly Tunnel.
Battery power could also be used on level and downhill sections of track up to a few miles, but I suspect on steep uphill sections, electrification will be needed.
Handling Regenerative Braking
I believe that regenerative braking will be employed on the rail vehicles and the energy generated will be stored in the batteries.
The main advantage of this is that it simplifies the power supply to the electrification, as it only has to handle power going to the train.
This less complex electrical system, saves construction costs.
Recovering The Train’s Potential Energy
A train travelling from Cardiff to one of the terminal stations at the heads of the valleys, will need to acquire an amount of potential energy, based on the train’s mass and the height involved. This will be provided by the train’s traction system powered by the electrification and the energy in the batteries.
Coming down the hill, the regenerative braking will control the speed of the train and store any energy generated in the batteries.
This will save on the cost of energy to operate the system.
Charging The Batteries
The batteries will be charged from both the overhead electrification and the regenerative braking.
Extensive simulations of the route on computers would be able to calculate the following, for a wide range of scenarios.
- The size of the batteries.
- The power of the traction motors.
- Where the electrification needs to be installed.
- The maximum power output of the electrification system.
These calculations could also lead to an energy-saving operating philosophy, that could be programmed into the train’s computer system.
I suspect the worst case scenario, would be a train full of the heaviest Welshmen after an important rugby match at the Millennium Stadium.
Electrification
My thoughts on how various sections of track would be electrified follow.
Tracks With A Significant Uphill Gradient
These would need to be electrified, as I doubt battery power on the steepest gradients, would be enough to take a fully-loaded train to the top of the hill.
Electrification would be lighter-weight 750 VDC overhead wires.
The picture shows some of the overhead wires in Birmingham, that are used by the Midland Metro’s Urbos 3 trams.
Tracks With A Downhill Gradient
These would not need to be electrified, as Newton’s friend gravity would do most of the work.
However, as batteries will be fitted, these can have three important functions on downhill stretches of track.
- Give the tram a nudge if needed.
- Restart the train after a stop at a station.
- Store any energy created by regenerative braking.
Note that we could have the unusual situation on a double-track section of line, where the uphill track was electrified and the downhill track was left without electrification.
Level Tracks
These would not need to be electrified, as battery power would be used to propel the train.
Selected Stations
Some stations could need to be electrified to ensure that the service was reliable. These might include terminal stations or those with tricky gradients on either side.
Tracks With 25 KVAC Electrification
Some of the tracks used by the trains on the Cardiff Valley Lines should be electrified with 25 KVAC, by the end of December 2018.
Class 399 tram-trains, that are used in Sheffield can use either 750 VDC and 25 KVAC overhead electrification.
it would probably be a good idea, if the new vehicles on the Cardiff Valley Lines could also use both voltages.
Automatic Pantographs
The pantographs on the vehicles would be raised and lowered automatically to access the electrification. This could even be GPS-controlled and able to be carried out at line speed.
Tram-Trains?
I very much feel, that tram-trains could be used to advantage.
- Some of the Valley Lines are also used by freight trains, so couldn’t be converted to trams-only.
- Tram-trains like the Class 399 tram-train, under test in Sheffield can work on both 750 VDC and 25 KVAC overhead wires.
- Tram-trains can use conventional railway signalling.
- Tram-trains could work on the South Wales Main Line to Newport.
- Modern tram-trains like the Class 399 tram-train have performance, that is about the same as a Class 142 train, which is a Pacer, that works the Cardiff Valley Lines, in large numbers.
- Tram-trains could run on the streets as trams, as they do in Sheffield.
Several manufacturers make tram-trains, which I believe could be suitablefor the Cardiff Valley Lines.
Stadler’s Class 399 Tram-Trains
Nothing is said about the vehicles, that would be used, but I think they need the following characteristics.
- Ability to climb the steepest section of the routes using 750 VDC overhead electrification.
- Ability to store energy.
- Regenerative braking to charge the batteries coming down the hills into Cardiff.
- A similar capacity to a Class 150 train, which is around 150 seats.
- It would be a bonus if they could use 25 KVAC overhead electrification, which will be available on part of some of the routes.
- Ability to raise and lower the pantograph quickly and automatically.
- Ability to run on the National Rail network.
- Ability to run on the street.
This specification is virtually the same as a Class 399 tram-train with the following additions.
- More seats and possibly an extra car.
- Batteries.
Class 399 tram-trains are a UK version of the Stadler Citylink tram-train. The German version is used in Karlsruhe to climb into the hills surrounding the city, on routes that are as challenging as the Cardiff Valley Lines.
So I have no worries about a version of the Class 399 train handling the Cardiff Valley Lines.
I certainly believe after my experience in Karlsruhe, and looking at other Citylink variants, that Stadler can come up with a tram-train for Cardiff based on the Class 399 tram-train.
And Then There’s CAF!
CAF have provided the Urbos 3 trams for Edinburgh Trams and the Midland Metro.
These are modern trams, that will be doing the following in a few years in the Midlands.
- Running on stored energy in the centre of Birmingham and to Wolverhampton station.
- Sharing the South Staffordshire Line with heavy freight on a new route to Merry Hill Shopping Centre.
This sounds like a tram-train with stored energy.
Wikipedia also lists a version of the Urbos family, called an Urbos TT, which is described like this.
The Urbos TT series is built with tram-train technology, connecting existing heavy rail infrastructure directly to urban tramway systems.
This document on the CAF web site, gives more details of Urbos variants, including the Urbos TT.
Looking at the modular nature of the design, you could have a custom-built tram-train tailored to the rail network.
But surely, the major factor with CAF, is that they have recently opened a factory at Newport.
If CAF get the order for the Cardiff Valley Lines, they could do a substantial part of the train building in a factory connected directly to the lines.
Converting The Valley Lines
I think that there are advantages and cost savings to be had, by good design in this area.
Could The Rail Vehicles Be Designed To Fit The Existing Platforms?
The first thing to do would be to design, build and fully test the rail vehicles.
Could the tram-trains be built, so that they fitted all the existing platforms?
- Class 150 trains are 2.82 metres wide.
- Urbos 3 trams on the Midland Metro are 2.65 wide.
If the tram-trains could run without platform modifications, this would be a big cost saving and still allow diesel units to use the lines, at the same time.
Testing The Trains
If the tram-trains were being given a 25 KVAC capability, they could even be tested on the quadruple-track the South Wales Main Line after the line is electrified through Newport.
Electrifying The Lines
It could be that the only sections of the valley lines that will need electrification, are the steep lines into the hills, as all other sections could use stored power or the 25 KVAC, where it exists.
- It would probably be possible to put up the simpler 750 VDC overhead lines during weekend and perhaps longer possessions.
- The electrification could be designed so that it doesn’t interfere with existing services.
- The lines would be converted one at a time.
- ,Note that tram-trains could share track and platform with the current diesel trains working the lines.
If CAF were to get the order surely the Ebbw Valley Line, which could be connected easily to the factory would be the first to be converted.
Conclusion
Obviously, the devil will be in the detail, but it does look like a viable plan will emerge.
I think that if CAF get the order, that they could be big winners.
The Cardiff Valley Lines could demonstrate the following.
- Running on main lines with 25 KVAC electrification.
- Running on 750 VDC electrification.
- Running on batteries.
- Running on lines with steep hills.
- Street running.
- Sharing tracks with freight trains and other passenger services.
- The tram-trains could also connect to Cardiff Airport.
It is a world-class demonstration and test track for innovative tram-trains, designed to cope with challenging rail networks.
With a factory close by at Newport, the selling of the tram-trains to other operators would be a salesman’s dream.
I think there’s more to CAF coming to Newport, than was apparent, when the deal for the factory was signed.
Thoughts On The Sutton Loop Line
The Sutton Loop Line is a bit of a problem.
- It runs two trains per hour (tph) in both directions.
- Trains are eight-cars.
- It is not the most heavily-used of lines.
It is deeply political and difficult to make any changes.
Network Rail’s original plan is described under Political Developments in the Thameslink entry in Wikipedia. This is said.
Network Rail had planned to terminate Sutton Loop Thameslink trains at Blackfriars station, rather than have them continue through central London as at present. This would increase the capacity of the central core as the Sutton Loop could only accommodate shorter trains. This upset many residents in South London and their local politicians, who saw it as a reduction in services rather than an improvement. In response to pressure, government has ordered Network Rail to reverse the decision.
Was this design by those, who don’t understand the complexity of designing and running a train service?
On the other hand, the line has some strengths.
- It is a double-track railway.
- It is fully-electrified using 750 VDC third-rail.
- Stations have long platforms.
- There seems to be quite a bit of housing and other development.
But in some ways, the line’s biggest strength, is the wide margins at both sides of the tracks.
This section between Hackbridge and Carshalton stations is not untypical.
Adding extra platforms or complete stations would not be difficult.
What solutions are available to improve train services on the Sutton Loop Line, for both passengers and train operators?
Splitting And Joining Trains
In Has Thameslink Got The Wrong Length Of Train?, I proposed the following.
- Using twelve- and six-car trains on Thameslink.
- Allowing two six-car trains to work as a twelve-car unit.
- Trains would be able to join and split automatically, as Hitachi’s Class 395 trains are able to do.
I also proposed the following method of operation for the Sutton Loop Line.
The Sutton Loop Line could be run by using six-car trains that split and join in the area of Streatham station.
This map from carto.metro.free.fr shows the track layout at Streatham, at the start of the loop.
Note.
- Streatham South Junction is the gateway to the Sutton Loop, with the tracks to the West going via Tooting station and those to the South via Mitcham Eastfields station.
- There is a lot of spare land in this area.
- Transport for London keep talking about creating an interchange at this point.
I think, if and when the interchange is built, it could be designed, so that it increased traffic around the Sutton Loop Line.
- Two six-car trains running as a twelve-car could split at the interchange.
- One train would go round the loop clockwise and the other anti-clockwise.
- The trains would rejoin together at the interchange.
The same procedure could be done at Streatham, without creating the interchange, but it would block the station, if trains got delayed on the loop.
Currently, two trains per hour (tph) are proposed to run in both directions on the Sutton Loop Line.
This requires four eight-car trains and four paths through the central core.
If four six-car trains were to be used, running in pairs splitting at Streatham station or a new Streatham Common interchange, there would still be two tph in both directions round the Sutton Loop, but only two paths would be needed in the central core.
Travellers to and from stations on the loop would see six-car, rather than the current eight-car.
If the number of six-car trains were to be doubled and four paths used in the central core, the Sutton Loop Line would see four tph in both directions.
It sounds complicated but it would work and it has the following advantages.
- Train frequency could be increased as required.
- Paths are released in the central core.
- Twelve-car trains would go through the central core, where the capacity is needed.
The service would need a few more drivers and other staff.
Loop Only Services To A New Streatham Common Interchange
If a new interchange station is built at Streatham Common, then extra services could easily be run round the loop.
- Thameslink services could be reduced to perhaps one tph in each direction.
- These would be augmented by perhaps a four tph shuttle around the loop starting and finishing at Streatham Common.
- The shuttle trains could be any suitable unit, but surely a four-car would suffice.
I suspect that this wouldn’t work, as it would upset the natives.
The German Solution
I can’t help feeling that the Germans and especially those in Karlsruhe would look at the Sutton Loop Line and because there are both trams and trains, in the area, they would come up with a solution based on trains and tram-trains.
As fsr as I know, no-one has ever built a third-rail-powered tram-train!
But I don’t think that a tram-train powered by third-rail electrification, when running as a train is an impossibility. I lay out my ideas in The Third-Rail Tram-Train.
Safety
As to safety, look at this picture taken at Mitcham Junction station.
Note how the third electrified rails are in the middle away from the platforms. This is standard practice with this form of electrification.
So if it is deemed to be safe for trains now, it will surely be safe for third-rail train-trams.
When running as trams, the tram-trains will use 750 VDC overhead electrification.
Changing Networks
Tram-trains will need to change between the tram and rail networks.
This map from carto.metro.free.fr shows the track layout at Mitcham Junction station.
Note.
- Wimbledon is to the West and Croydon is to the East.
- With the addition of some extra tracks, it should be possible for tram-trains to pass between the networks.
- As trams can take tight curves, a chord could allow Westbound tram-trains from Croydon to turn South to Sutton.
- Tram-trains will probably change networks using a couple of ininutes of battery power.
I doubt any of the engineering will be too difficult.
Adding The Sutton Loop Line To Tramlink Using Tram-Trains
Tram-trains would take the following route.
- Arrive from Croydon at Mitcham Junction, where they would turn South onto the Sutton Loop Line.
- Pass through Hackbridge and Carshalton stations.
- Call in Sutton station for interchange with trams and National Rail.
- Continue to Wimbledon station calling in Platform 9 for interchange with trams in Platform 10 and 10b and National Rail.
- Pass through Hatdons Road and Tooting.
- Take new chord to cross to the other leg of the Sutton Loop Line.
- Pass through Itcham Eastfields station.
- Rejoin the tram route at Micham Junction station.
Tram-trains could also travel in the reverse direction.
Trams And Tram-Trains At Wimbledon
This map from carto.metro.free.fr shows the track and platform layout at Wimbledon station.
Note.
- Currently, Thameslink services on the Sutton Loop Line use Platform 9 in both directions.
- Hayons Road station is to the North-East and |Wimbledon Chase station is to the South.
- Tram-trains on the Sutton Loop Line would do the same.
- Platform 9 probably defines the capacity of the Sutton Loop Line.
Access to the trams in Platforms 10 and 10b, is just a walk across the platform.
The picture was taken from a Thameslink train.
There might even be space for another tram platform, that can be accessed from the Haydons Road direction.
Trams And Tram-Trains At Sutton
This map from carto.metro.free.fr shows the track and platform layout at Sutton station.
Note.
- The Sutton Loop Line is the Northernmost pair of tracks.
- Carshalton station is to the East and West Sutton station is to the West.
- It could be possible for tram-trains to by-pass Sutton station and run on the streets of Sutton.
This picture shows Sutton High Street.
Is it going to be easy to bring the planned tram extension from Wimbledon to Sutton?
Dual Platform Issues
Platforms at the stations on the Sutton Loop Line are long and are certainly capable of taking eight-car trains.
But are they long enough to have a lower section of platform, so that tram-trains can have step-free access?
This is one of the problems, that should be solved in the tram-train trial in Sheffield.
The Split At Streatham Common
This Google Map shows, where the two routes of the Sutton Loop Line meet near Streatham Common station.
This picture shows a train going towards Mitcham, from one having passed through Tooting station.
I don’t think it would be the most difficult engineering project to create a chord, that would allow tram-trains to go directly between Tooting and Mitcham Eastfields stations.
A Possible Service
As I said earlier, Platform 9 at Wimbledon station. is probably the limiting factor on services round the Sutton Loop Line.
Thameslink is planning two tph in both directions.
I suspect that this could be supplemented by two tph services run by tram-trains, if a signalling solution can be implemented to allow four tph in each direction, through the platform.
Conclusion
There are several ways to improve the Sutton Loop Line.
A Trip To Baden-Baden By Tram-Train
These pictures show how I caught a tram-train in the Centre of Karlsruhe and went to Baden-Baden both to have a look and an early supper.
It was a good illustration about how tram-trains widen the transport possibilities of a city or large town.
- I caught the tram-train in the middle of the main street of Karlsruhe.
- It used the tram lines to get to Karlsruhe station.
- From there it became a train anmd went all the way to Baden-Baden station.
- I then caught a bus to the centre of Baden-Baden using the same ticket.
The only problem was that the service frequency was only one tram-train every half-hour.
But then German trains and trams aren’t as frequent as those in the UK.
Is The West Midlands Going To Get A Tram-Train Line?
This article on Global Rail News is entitled Midland Metro Extension Receives £200m Boost From UK Government.
This is the first paragraph.
West Midlands mayor Andy Street has confirmed that £200 million from the UK government’s new ‘Transporting Cities Fund’ will be used to extend the Midland Metro to Brierley Hill.
The Brierley Hill Extension would use the currently disused South Staffordshire Line. It would link Wednesbury to Stourbridge, via Dudley, Brierley Hill and the Merry Hill |Shopping Centre.
Wikipedia says that ten trains per hour would run South of Wednesbury and five services would go to each of Birmingham and Wolverhampton.
The Need For Tram-Trains
The South Staffordshire Line is also wanted by Network Rail for use as a freight line.
Tram-trains would be the solution for a line-share.
- The extension could be configured to suit Class 399 Tram-trains.
- Class 399 tram-trains seem to be working well in Sheffield as trams.
- In Rotherham the Class 399 tram-trains will co-exist with the heaviest of freight trains.
- Dual-voltage tram-trains would allow electrification of the South Staffordshire Line with 25 KVAC at a later date if required.
The biggest advantage would be the cost savings, as both the tram-trains and the freight trains could use the same standard of track.
But I also feel that all the design problems for the extension will have been explored in a practical way in the Sheffield-Rotherham trial.
Should the Tram-Trains Terminate At Stourbridge?
The Global Rail News article doesn’t mention Stourbridge, but Wikipedia indicates it could be the terminus of the tram route.
If tram-trains are used on the route, then to run them as trains to Stourbridge Junction station may be a good idea.
Conclusion
This extension of the Midland Metro has a lot of possibilities.
I think that like the Midland Metro’s proposed use of battery trams, it shows that the West Midland Combined Authority is not afraid to be innovative.
Authorities Plan Joint Tram-Train Procurement
The title of this post is the same as that of this article in Global Rail News.
This is the first paragraph.
Several European transport authorities are planning to work in partnership to procure new tram-trains in order to bring down the cost enough to make the transport mode more commercially viable.
This later paragraph gives the members.
The new association includes Karlsruhe’s transport authorities, Albtal-Verkehrs-Gesellschaft (AVG) and Verkehrsbetriebe Karlsruhe (VBK), Saarland tram-train operator Saarbahn Netz, Kassel operator Kasseler Verkehrs-Gesellschaft, Upper Austria’s Schiene Oberösterreich, Erms-Neckar-Bahn and Regionaltangente West in Germany’s Rhine-Main area.
I hope Network Rail keeping a watching brief!
After all, the Class 399 tram-train being trialled in Sheffield is a 25 KVAC version of the tram-trains used in Karlruhe, where the main line voltage is 15 KVAC.
This picture shows a Class 399 tram-train in Sheffield.
This is one of Karlsruhe’s similar tram-trains.
There are some cosmetic differences and the German tram-trains have a coupler for multiple working.
Surely, any initiative for a standard European tram-train, that could work all over the Continent would bring benefits.
- Prices would probably be more reasonable.
- Solutions and problems could be shared.
- \setting up a new tram-train line should become easier and more affordable.
Having travelled extensively on Karlsruhe’s tram-train network, it would appear that they are using not only the tram-trains, but several other ideas in Sheffield.
Different Voltages
Overhead line voltages vary across Europe.
- 15 KVAC is used in Germany
- 1,500 VDC is used in The Netherlands and for some local networks.
- 25 KVAC has become an international standard and is generally used for high speed lines.
Surprisingly, all our overhead electrification used on railways is 25 KVAC. All other systems have been either replaced or closed.
All these different voltages can be handled by a good electrical system on the tram.
This will handle the problem ehere a route runs between two areas or countries with different voltages.
Changing From Tram To Train Mode And Vice-Versa
In Karlsruhe this is performed by connecting the two systems together with a cermaic rod in the catenary to separate the voltages.
Tram-trains just drive across, with perhaps some battery assistance.
I suspect Sheffield are using a similar method to Karlsruhe.
Platform Height
If the tram-trains are to have level access, as most low floor trams do these days, then platform height can be a problem.
Trams generally have low platforms as this picture from Tramlink shows.
On the Continent, the main line platform heights are often simiar, so level access can be easy.
But in the UK, platform heights are generally higher. The problem appears to be being solved at Rotherham Central station by means of dual height platforms. This technique is used in Karlsruhe.
The article says this about platform height.
VDV has said the tram-trains will be available as two or four-door vehicles and will be able to meet different platform heights and maximum axle loads.
So hopefully, it will be one size fits all!
Karlruhe
This is a paragraph from the article.
AVG and VBK would receive more than half of the new vehicles under the arrangement. AVG said it had already been approached by other transport companies interested in adopting the so-called Karlsruhe model tram-train system.
Karlsruhe certainly seem to be leading this project, in more ways than one.
The Sheffield tram-train trial could be said to use the Karlsruhe model.
Conclusion
I believe that nothing I have seen on the various tram-train systems, I have visited, would stop a common tram-train that worked being developed.
This must lead to the development of a lot more tram-train systems.
The Penistone Line And Rotherham Tram-Train Trials
The Penistone Line Tram-Train Trial
The Penistone Line from Sheffield to Barnsley, Penistone and Huddersfield was the line originally selected for the tram-train trial.
In the Wikipedia entry for the line, this is said about the tram-train trial.
On 18 March 2008, the Department for Transport released details of a proposal to trial tram-trains on the Penistone Line, the first use of such vehicles in the UK. The trial was to start in 2010 and last for two years. Northern Rail, the operator of passenger services on the line, asked potential manufacturers to tender for the design and construction of five new vehicles, which Northern Rail would subsequently lease. In addition, Network Rail planned to spend £15m modifying track and stations to make them compatible with the new vehicles.
However, it was announced on 15 September 2009 that a city tram-train trial between Rotherham and Sheffield would replace the Penistone Line scheme.
More about the trial is said in this article on Rail News, which is entitled Penistone Line Is Chosen For £24m Tram Trains Trial. In particular, this is said.
One of the biggest initial tasks is to set a specification for the building of the five diesel-electro hybrid tram trains at a cost of £9 million. The trains will have to be equipped with braking systems suitable for on-street running and a Train Protection Warning System which is required for running on lines with ‘heavy’ rail passenger and freight trains.
The article was written in 2008 and Chemnitz hybrid Citylink tram-trains didn’t enter service until 2016.
So was the trial on the Penistone Line a disaster before it even started?
It had the following problems.
- It was expecting a diesel-electric hybrid tram to be designed and built before 2010.
- A long distance was involved.
- The track-work needed to connect to the Sheffield Supertram could have been incredibly complicated.
- The first all-electric Citylink tram-trains weren’t delivered to Karlsruhe until May 2014, which was seven months late.
For these and other reasons, I think that the decision of the trial to be delayed and to use Rotherham, was a prudent decision.
The Rotherham Tram-Train Trial
Consider these characteristics of the current trial, between Cathedral and Rotherham Psrkgate.
- The tram-trains are virtually standard Karlsruhe Citylink tram-trains, adapted for UK 25 KVAC and painted blue!
- A simple chord connecting the two systems.
- A few miles of electrification, that could be powered by either 750 VDC or 25 KVAC.
- Modification of the recently-built Rotherham Central station.
- Building of a new terminal tram stop at Rotherham Parkgate.
It’s a simple plan, but one that covers a lot of design possibilities and has few, if any, risky elements, that haven’t been done in the UK or Karlsruhe.
The following can be tested.
- The Class 399 tram-trains on the Sheffield Supertram network and an electrified main line.
- Passenger entry and exit at Rotherham Central station and all over the Supertram network.
- Operation under both 750 VDC or 25 KVAC.
- Signalling systems on both tram and main line networks.
The one thing that can’t be tested is a diesel hybrid tram-train as they have in Chemnitz, as they haven’t ordered any!
But if they did want to order some, they could easily be tested between Cathedral and Rotherham Parkgate.
Conclusion
The original plan to use the Penistone Line and diesel-electric tram-trains was impossible.
Network Rail might have got this one right at the second attempt.
They could even run a UK version of the Chemnitz hybrid tram-train on the test route between Sheffield and Rotherham.
Class 399 Tram-Trains In Service
On my two day trip to Sheffield, I reckon that I saw six of the seven Class 399 tram-trains in service on the Supertram.
These pictures were taken on a quiet Saturday morning trip from the station to Herdings Park.
Current Service
Currently, the Class 399 tram-trams are running on the Purple Route from Cathedral to Herdings Park, which is generally tun at a frequency of two trams per hour.
If you arrive in Sheffield station and don’t feel like walking up the hill, you take any of the trams from the stop on the station side of the tracks.
But take a tram going to Cathedral and over the two and a bit days I was in Sheffield, it was always a Class 399 tram-train.
Comparison With Current Fleet
The Class 399 tram-trains and the existing Siemend-Duewag Supertram are surprisingly similar in several ways.
- Both have three sections and four doors on either side.
- The Siemens tram is 34.8 metres long, whereas the Class 399 is 37.2 metres long.
- The Siemens tram weights 46.5 tonnes, whereas the Class 399 is a lot heavier at 66.1 tonnes.
- The Siemens tram has installed power of 1108 kW, whereas the Class 399 has just 870 kW.
- The Siemens tram has room for 86 sitting and 155 standing passengers, whereas the Class 399 has room for 88 and 150 respectively.
- The seats and their arrangement are vaguely similar.
- Neither tram has wi-fi.
The big difference other than the tram-train capability and what that entails, is that the Class 399 tram-train is faster with a 100 kph top speed, as against the 80 kph of the Siemens tram.
Other differences are detailed in the next sub-sections.
Step-Free Access
Getting on and off both trams is step-free and I saw people in wheel-chairs on both vehicles. One was easily pushed into a Class 399.
These pictures show the steps inside the two trams.
There is only a single-step on the Class 399 tram-train, whereas the Siemens tram has more.
Neither tram is a hundred percent step-free.
Weight
Note that the weight of the Class 399 tram-train is more than that of the Siemens tram.
As the two vehicles are of a similar size, could this mean that any of the following causes the weight increase.
- The electrical equipment needed to handle 15/25 KVAC power.
- The weight of the two extra traction motors.
- Strengthening for main line operation.
As someone, who has ridden for a few hours in both the Karlsruhe and Sheffield variants of the Citylink tram-train, they certainly don’t ride badly.
Performance
The current Siemens tram has 1108 kW of power and a weight of 46.5 tonnes, which gives an installed power/weight ratio of 23.8 kW/tonne.
The Class 399 tram-train has 870 kW of power and a weight of 66.1 tonnes, which gives an installed power/weight ratio of 13.1 kW/tonne.
So it would appear that the Class 399 tram-trains may not have the acceleration and hill-climbing capability of the Siemens trams.
However look at this data sheet on the Stadler Rail Espana web site for the Class 399 tram-train.
It clearly shows that the tram has four bogies and the text says that three are motored and one is a trailer. So this means that the central car is not a trailer and that power must be distributed along the tram, which probably puts the power to the rail in a more efficient way.
I did speak to a driver and he told me that on some of the hills the Siemens trams will strruggle with a full load, but the Class 399s can go up the hills at 40 mph.
The Class 399 tram-trains are very similar to the Stadler tram-trains in Karlsruhe, where the hills are much stiffer than Sheffield.
So it would appear that the layout of six smaller motors in a more modern vehicle probably does the trick.
Energy Efficiency
The question has to be asked if, as the Class 399 tram-trains have twenty-one percent less installed power, does this result in a saving of electricity use?
Comparison With Karlsruhe’s Tram-Trains
The Karlsruhe and Sheffield tram-trains are both variants of the Vossloh Citylink tram-train, that is now built by Stadler at Valencia in Spain.
The tram-trains in Karlruhe would appear to be very similar to the Class 399 tram-train, with a few small technical differences.
- They work on 750 VDC and 15 KVAC overhead wires, whereas the Class 399 can work on 750 VDC and 25 KVAC.
- As an electrical engineer, I wonder if the electrical systems are the same in both tram-trains and both can work 750 VDC and 15-25 KVAC, so they could work cross-border routes between say Germany and France.
- They have couplers to work in multiple.
- They have different passenger door arrangements.
- The driver’s cab windows have different arrangement.
These pictures show Karlsruhe’s tram-trains.
Imagine these trams in Supertram colours on the streets of Sheffield.
Take a close look at picture 4.
You will notice that the Karlsruhe tram-trains have an obvious coupling and it can be assumed that they can work in ,multiple, although I don’t seem to have seen it happening.
Picture 4, also shows passengers apparently sitting in the back cab of the tram-train.
The fifth picture was taken from sitting inside the tram-train looking backwards, over the folded-down driver’s desk.
This feature wasn’t being used in Sheffield and this could be for one the following reasons.
- The Class 399 tram-trains don’t have the feature installed.
- There has been a Health and Safety decision.
- It takes perhaps ten minutes to fold up the driver’s desk and this would slow the timetable.
It’s a pity , as this feature of German trams is very common and popular.
Comparison With Class 144 Train
The Class 399 tram-trains and Northern’s Class 144 train will share routes and on some routes the tram-trains may even take over from the Pacers.
So how do the two trains compare?
- The Class 399 has room for 88 sitting and 150 standing passengers, whereas the Pacer has 99 seats in a two-car and 157 in a three-car train.
- The Class 399 weighs 66.1 tonnes, whereas a two-car Pacer weighs 49.2 tonnes and a three-car weighs 72 .7 tonnes.
- The Pacer has a toilet.
- The Class 399 is air-conditioned, whereas the Pacer relioes on waste heat from the engine.
- The Pacer is a 75 mph train, but seems to operate most of the time at 60 mph
- The Class 399 has installed power of 870 kW, whereas the Pacer has just 336 kW.
- The Pacer is thirty-year-old crap, that should have been strangled at birth, whereas the Clas 399 is a modern unit.
You could argue, that I’m being biased, as the tram-train can’t operate without electrification.
But it can!
Chemnitz or Karl Marz Stadt as the East Germans renamed it. also runs Stadler Citylink tram-trains, which are similar to the Class 399 tram-trains.
But the tram-trains in Chemnitz are different in that instead of being dual-voltage like Sheffield and Karlsruhe, they have a diesel-generator to power them away from the 750 VDC overhead wires.
This data sheet gives a few details of the Chemnitz Hybrid tram-train. The data sheet doesn’t specify the power of the diesel powerpack, but the much heavier Class 769 train uses two rail-proven MAN diesel engines of 390 kW each.
In this article on Rail News, which is entitled Penistone Line Is Chosen For £24m Tram Trains Trial, the original trial is described and this is said.
One of the biggest initial tasks is to set a specification for the building of the five diesel-electro hybrid tram trains at a cost of £9 million.
The article was written in 2008 and hybrid Citylink tram-trains didn’t run in Chemnitz until 2016.
So the original proposal envisaged using hydrid diesel tram-trains.
Why not use them in Sheffield?
Operational Details
The Class 399 tram-trains have other features that became apparent on my observations.
Battery Use
Passing a Class 399 tram-train, I took this picture.
I hadn’t thought about it before, but batteries on a tram must have similar uses to those in any vehicle.
- Starting up the vehicle.
- Raising the pantograph, on an electric tram, train or locomotive.
- Opening the powered doors.
- Providing lighting and other important services in a power failure.
- Being able to move the vehicle a short distance in case of a complete overhead power failure.
- With a dual-voltage vehicle, it must be there in case the changeover isn’t successful.
But with a tram-train, battery operation surely opens up the possibility of changing between the tram and heavy rail lines using very simple track without electrification, points and cross-overs.
The driver would do the following.
- Pan down on one network.
- Use battery power to move perhaps fifty or a hundred metres to the other system.
- Raise the pantograph on the other network.
Provided the driver obeys the rules and the signals, it should be a safe transfer.
Regenerative Braking
This article on the Railway Gazette is entitled Karlsruhe orders Vossloh tram-trains.
These tram-trains were the first of the Citylink family of tram-trains, of which the Class 399 tram-trains are a member.
This is said.
The three-section steel-bodied tram-trains will incorporate extensive crashworthiness design elements and provision for regenerative braking. Top speed will be 80 km/h, with the four bogies having pneumatic secondary suspension. The air-conditioned interior will have 104 seats cantilevered from the sides for easy cleaning.
How do the Citylink tram-trains handle the regenerative braking?
Two methods are possible.
- They return the braking energy to the overhead wires.
- They store it in their battery for reuse.
In the Wikipedia entry for the Supertram, there is a section called Overhead Wiring. This is said.
The contact wires are twin cadmium copper ones, twin wires being necessary because of the high installed power rating of the trams (1 megawatt). The regenerative braking on the tram feeds current back into the wires.
So any braking energy can be returned to the wires.
But as the Railway Gazette article dates from 2011, I wonder if the trams have been developed to use battery storage?
How Far Could The Tram-Train Go On Battery Power?
I’ll assume the following.
- A New Routemaster bus battery of 75 kWh can be fitted to the Class 399.
- Running on an easy track, the Class 399 could need 5 kWh for each car-mile.
This would give a range of five miles.
Note.
- The stiffer the route the smaller the range.
- Battery capacity should increase through the years.
- Battery cost should decrease through the years.
- Charging stations can be fitted at station stops.
The only certainties are that practical battery range will increase and battery cost will decrease.
Conclusions
These tram-trains have been well worth waiting for.
If I was in charge of the Sheffield Supertram and a decision was made to replace the original Siemens trams, I would think seriously about going to Stadler for a replacement fleet.
If the fleet was all Class 399 tram-trains, this could offer other savings.
- The lower-power of the Class 399 tram-trains might cut electricity use.
- Regenerative braking using onboard batteries saves electrification costs.
- Would expensive twin cadmium copper contact wires still be needed?
- One tram type would save costs in maintenance and staff training.
New must-have features like wi-fi and 4G boosters could be added, as the technology has now been developed, since the Siemens trams were built.
Why Can’t A Train Be More Like A Tram?
This is the title of a two-part article by Ian Walmsley in the May 2017 edition of Modern Railways.
Part 1 – How Hard Can It Be?
In the First Part, which is entitled How Hard Can It Be?, he contrasts tram operation with typical heavy rail operation.
He starts the First Part with this paragraph.
After a career in trains, I wish they could be more like trams, at least for the short-distance commuting market. Big windows, low-back seats, super-cool looking front ends, terrific acceleration and braking, all at half the price. Meanwhile commuter trains are bogged down with legislation, defensive driving and restrictive practice.
He also compares trams and heavy rail with the London Underground, which has the frequency and speed of a tram to get the needed capacity. This is another quote.
Heavy-rail’s answer to capacity is to take a few seats out or declassify a First Class compartment, going faster is too difficult.
These points are also made.
- A turn-up-and-go frequency is made possible by a continuous stream of trams doing the same thing, uninterrupted by inter-city or freight intruders.
- Frequent stops on a tram mean rapid acceleration is essential, so a high proportion of axles must be motored.
- In many heavy rail services, the culture of caution has removed any urgency from the process.
- Separation of light from heavy rail is essential for safety reasons.
- Trams can take tight corners which helps system designers.
- Trams save money by driving on sight.
- Lots of safety regulations apply to heavy rail,but not trams.
He also uses a lot of pictures from the Bordeaux trams, which I wrote about in Bordeaux’s Trams. These trams run catenary-free in the City Centre.
High-Cacapity Cross-City Heavy Rail Lines
It is interesting to note that cross-city heavy rail lines are getting to the following ideals.
- High frequency of upwards of sixteen trains per hour (tph).
- High-capacity trains
- Heavy-rail standards of train and safety.
- Slightly lower levels of passenger comfort.
- Step-free access.
- Several stops in the City Centre.
- Interchange with trams, metros and other heavy rail services.
- Separation from freight services.
- Separation from most inter-city services.
Have the best features of a tram line been added to heavy rail?
Worldwide, these lines include.
- Leipzig – S-Bahn Mitteldeutschland
- Liverpool – Merseyrail Northern Line
- London – Crossrail
- London – East London Line
- London – Thameslink
- Paris – RER
There are obviously others.
Crossrail with up to 30 tph, platform edge doors, fast stopping and accelerating Class 345 trains, and links to several main lines from London could become the world standard for this type of heavy rail link.
30 tph would be considered average for the London Underground and modern signalling improvements and faster stopping trains, will raise frequencies on these cross-city lines.
All of these lines have central tunnels, but this isn’t a prerequisite.
Manchester is achieving the same objective of a high-capacity cross-city rail link with the Ordsall Chord.
Part 2 – Tram-Train, Are You Sure You Really Wnt |To Do This?,
In the Second Part, which is entitled Tram-Train, Are You Sure You Really Wnt |To Do This?,
Ian starts the Second Part with this paragraph.
Anyone with a professional interest in public transport must have been to Karlsruhe in Germany, or at least heard of it.
He then wittily describes an encounter with the diesel tram-train in Nordhausen, which I shall be visiting within a week or so.
He was not impressed!
I like the concept of a tram-train, where the same rail vehicle starts out in the suburbs or the next town as a train, goes through the City Centre as a tram and then goes to a destination on the other side of the city.
But you could also argue that Merseyrail’s Northern Line and London Underground’s Piccadilly and Central Lines achieve the same purpose, by running at all times as a rail line, with the centre section in a tunnel under the City.
The Sheffield Tram-Train Project
Ian then goes on to talk about the Sheffield Tram-Train Project. He says this about the route extension from Meadowhall to Rotherham.
This route extension runs just over three miles and after a series of delays, it will not open until 2018, 10 years, after the first proposal, six after the scheme approval. The cost is £58million. That’s 21 million Rotherham – Meadowhall single fares, for which the existing journey time is six minutes. Bargain.
He also says that because Nick Clegg was a Sheffield MP, the project should stay in Sheffield.
I will add some observations of my own on the Sheffield -Rotherham tram-train.
- The Class 399 tram-train is a variant of the tram-trains used in Karlsruhe – Good
- The route, doesn’t connect to Sheffield station – Bad
- The frequency is only a miserly three tph – Bad
- The route is too short – Bad
Hopefully, the bad points don’t result in a system that nobody wants.
The Expert View Of Rotherham’s Problems
There is an article in the Yorkshire Post, which is entitled Rotherham could get new rail station, which gives detail from a consutant’s report of how to improve services in the town.
- Rotherham Parkgate station should be developed as an inter-regional station, at a cost of up to £53.2 million
- Rotherham Central station would be be more about local services.
- Rotherham should have one tph to Leeds and Manchester, three tph to Doncaster and six tph to Sheffield.
The consultant’s estimate was that this investment could benefit the area by up to £100million.
Ian’s Conclusion
Ian says this and I am coming to agree with him.
I, like many others, have been a fan of tram-train, but a little knowledge is a dangerous thing.
The more I think about it, the more I think trams and trains have their place and mixing them up is fraught with problems.
As I said earlier, I’m off to Karlsruhe ad I’ll see how they’re getting on with the enormous hole in their budget; the new tunnel on the Karleruhe Stadtbahn.
Imagine building a cut-and-cover down Oxford Street in London.
Train Like A Tram
Ian finishes with two further sections, the first of which is Train Like A Tram.
He says this.
Heavy rail needs to recaspture a sense of urgency and realise that more speed = more trains = more capacity. Risk analysis should allow the use of low-back seats and plastics; based on the lower average speeds. All axles need to be motored for tram-like acceleration and lots of regenerative braking.
I agree with what he says, but I’m surprised that he doesn’t mention Zwickau.
In that German town, an extension was built from the Hauptbahnhof to a new station in the town centre. I wrote about Zwickau’s unique system in Riding The Vogtlandbahn
Standard two-car diesel multiple units, run alongside Zwickau’s trams on a dedicated route according to similar operational rules on the three kilometre route.
Surely, there is scope to do this in the UK, on existing and new branch lines or spurs.
- The route must be short.
- All stops would be built like tram stops.
- Trains would be independently-powered by diesel, battery or fuel cell.
- Signalling would be heavy-rail.
In my view this sort of system would be ideal for serving Glasgow, Leeds-Bradford and Liverpool Airports, where off main line running would be done across open country that could be appropriately fenced.
Tram Like A Train
Ian finishes his final section, where he talks about the likelihood of more tram-train systems following Sheffield, with this.
I suspect that the number of follow-on vehicles in the foreseeable future will be about the same as the number of battery EMUs based on the last research trial.
Don’t feel too bad though; do we really want the national rail system full of 50 mph-limited trams?
I feel that Ian and myself would have different views about battery EMUs.
What Do You Do With A Problem Like Rotherham?
I mentioned a consultant’s report earlier and the easiest way to get their recommended frequency of trains through Rotherham would be to expand the electrification network, by wiring the following lines.
- Sheffield to Doncaster
- Leeds to Colton Junction
- Leeds to Selby
- Fitzwilliam to Sheffield
As some of these lines were built or rebuilt recently for the Selby Coalfield, I suspect electrification would be starting from decent documentatyion.
Until the electrification is complete Class 319 Flex trains could work the routes.
Electrification At Rotherham
These pictures show some of the electrification gantries around Rotherham Central station.
The overhead gantries would appear to be Network Rail’s standard for 25 KVAC, rather than the lighter-weight structures used on the Sheffield Supertram for their 1500 VDC.
So are Network Rail future-proofing the gantries for later conversion to 25 KVAC or are they being wired to that voltage, so that the tram-trains can be tested on the 25 KVAC as well?
The latter would be prudent, so that the problems and strengths of dual-voltage 25 KVAC/1500 VDC tram-trains can be assessed.
However, as I returned to Sheffield later, it appeared that the line connecting Rotherham and Sheffield had both heavy-weight and light-weight gantries in place.
Could there be a last minute change of project scope to include 25 KVAC running in the Sheffield tram-train trial, which also explains the timing of the rebuilding of the College Road Bridge?
This is said under Future in the Wikipedia entry for the Sheffield Supertram.
A tram-train extension to Rotherham is currently under construction and is scheduled to open in 2018, with a fleet of seven Vossloh Citylink Class 399 tram-trains in a UK first. This will involve trams operating on Network Rail’s Dearne Valley Line from Meadowhall Interchange to Rotherham station with a short extension to Rotherham Parkgate Shopping Centre. The proposed station will be a combined tram stop and railway station.[10] It is also planned that Rotherham Parkgate will be the hub for longer distance inter regional services,[11] while Central station will be the hub for local, Yorkshire based services. To cater for the tram train services, Rotherham Central will have a third platform built. It is thought that constructing the station will cost around £14 million (£53 million including the railway service to Leeds) and deliver economic benefits worth over £100 million. A study has concluded that it is not worth expanding Rotherham Central railway station because it would cost £161 million to expand the station but only deliver benefits worth £76 million. This is why constructing a new station is considered more viable.
That explains a lot, especially as it is a big change from what was being said perhaps a year ago.
There is an article in the Yorkshire Post, which is entitled Rotherham could get new rail station, which gives a lot more detail.
- Parkgate station could cost up to £53.2 million
- Parkgate would be the inter-regional station.
- Central would be more local
- Rotherham should have one train per hour (tph) to Leeds and Manchester, three tph to Doncaster and six tph to Sheffield.
As I came through the Rotherham Parkgate area on my train between Leeds and Rotherham earlier, I didn’t see any evidence of station construction.
I think that Network Rail by putting up gsntries that can accept 25 KVAC electrification have made sure that they can fit any future plans.
So long as they can get some sort of wiring along the route and a reversing facility somewhere in the Rotherham area, I can see tram-trains running next year.
If Parkgate station is built, then provided any tracks are in the right place, this shouldn’t be a problem.
But the interesting idea could be to use Class 319 Flex trains on the route to Leeds via the Wakefield Line. The gaps in the electrification would be initially covered by the trains onboard diesel power.
As electrification is installed, they would eventually be able to do Rotherham Central to Leeds under electric power.
Whilst, Network Rail were electrifying the tram-train route, would it not be prudent to put up the wires to Meadowhall Interchange station or even Sheffield station?
The other way they could also electrify the short Swinton to Doncaster Line, which would allow electric trains from London to reach Rotherham Parkgate, Meadowhall and Sheffield stations.
I can certainly see something like the following services through Rotherham when Parkgate station is open.
- 1 tph Sheffield to Leeds calling at Parkgate and Central
- 1 tph Doncaster to Manchester and Manchester Airport calling at Parkgate and Sheffield
- 2 tph Doncaster to Sheffield calling at Parkgate and Central
Add in three tram-trains per hour between Sheffield Cathedral and Parkway via Central and the required frequencies are achieved.
It will be interesting to see what finally happens.
Could Third-Rail Tram-Trains Work The Epsom Downs Branch?
The Epsom Downs Branch is a single-track branch line from Sutton to Epsom Downs station.
Currently, it has a service to Victoria of around two trains per hour (tph), but it doesn’t seem to generate much business.
In 2015-16, Epsom Downs station had 112,000 passengers, whereas Sutton station had 7,111,000.
As the three stations on the branch are all single-platform stations with few facilities, can it be viable to run Class 377 and Class 455 trains on the branch?
When the London Tramlink arrives in Sutton, I wonder if the branch would be more suited to be running by trams.
But as the line is electrified with the standard 750 VDC third-rail system, is it one of those places, that could it be served by a third-rail tram-train, as I proposed in The Third-Rail Tram-Train?
I think the answer is in the affirmative.
Consider.
- The tram service could terminate at the proposed Streatham Common Interchange station.
- It takes less than ten minutes to go between Sutton and Epsom Downs
- In the Peak or when more capacity is needed, Class 377 trains could still run the service.
- The tram-trains could provide a step-free service.
Running the service with tram-trains, would give one big advantage; the ability to run a service to the Royal Marsden Hospital, which according to this document from the hospital is not the best, when it comes to public transport.
A single-track branch from the Epsom Downs Branch could start South of Belmont station and tram-trains running on batteries could serve both the Royal Marsden Hospital and the Institute of Cancer Research.
This Google Map shows Belmont station and the hospital.
Note.
- The rail line from Belmont station to Epsom Downs station running down the West side of the map.
- There are two prisons in the South East corner of the map.
- The road from Belmont to the Hospital may only be half a mile, but it is up a steep hill.
- Why is every train arriving at Belmont station, not met by a shuttle bus to the Royal Marsden Hospital?
- There is one train per hour through Belmont station in both directions.
A silent battery tram-train without any overhead wires, climbing up on the railway line and then turning East across Banstead Common calling at the prisons en route to the Hospital, might be acceptable to the Planning Authorities. It would surely be less intrusive than some of cars and vans, I saw rushing through the Downs.
I would think that the hospital needs a frequency of four trains per hour to Sutton, in addition to the current sewrvices between Sutton and Epsom Downs.
A charging station, like a Railbaar, at the end of the short branch might be needed, to make sure that the gradients were conquered.
These pictures show Belmont station and the walk to the Royal Marsden Hospital.
Knowing, what I now know of the Royal Masrsden Hospital, it wouldn’t be my choice of hospital.
I don’t think, I’vw seen a hospital with such terrible access by public transport!
