The Anonymous Widower

Caerphilly Station

Caerphilly station is an important  one on the South Wales Metro.

The current service is a four trains per hour (tph) service to Cardiff Queen Street and Cardiff Central stations. Some trains travel through to Penarth station

In 2023, the service will be upgraded.

  • Two tph between Barry Island and Rhymney stations via Cardiff Central.
  • Two tph between Bridgend and Rhymney stations via Cardiff Central and Rhoose Airport
  • Two tph between Penarth and Caerphilly stations via Cardiff Central.

In 2023, the service will be three minutes quicker to and from Cardiff.

In addition, note the following about Caerphilly station.

  • The station is on the Rhymney Line, which will be worked by Tri-Mode Stadler Flirts.
  • The station lies just to the North of the Caerphilly Tunnel, which is not being electrified and trains are expected to transit using battery power.
  • The station has a bay platform.
  • The station appears to be a hub for buses.

This Google Map shows the station.

Note.

  1. The long bay platform on the North side of the station. It may be long enough to accommodate two of the Tri-Mode Stradler Flirts, which are 65/80 metres long. This means that the bay platform could be very valuable for service recovery.
  2. The station serves as a Park-and-Ride.
  3. Three structures cross the track, which from the left are the old station buildings, the station footbridge and a footbridge independent from the station.
  4. Looking at the track layout on the Eastern approach to the station, the cross-overs are within fifty metres of the platform end.

These pictures show the station.

These are my thoughts on various issues.

Electrification Under The Bridges And The Old Buildings

I think there would be serious issues with standards for electrification at this station.

The three structures will have to be handled in the way I described in How Can Discontinuous Electrification Be Handled?

The Old Station Building

The old station building is integral with a road bridge and would be a costly and very disruptive operation to replace.

So if the structure will safely last a hundred years or so and the wires can be squeezed underneath using discontinuous methods, everybody wins.

The Easternmost Footbridge

The Easternmost bridge at the far end of the platforms looks to be a fairly recent structure and is independent of the station, as it just gives pedestrians a route across the railway. It might even have been built, when the bay platform was built a few years ago.

The Station Footbridge

So that leaves the elderly footbridge, which probably dates from 1871, when the station was moved to its present position.

It is the main way that passengers cross the line and given that Caerphilly station has nearly a million passengers a year, it would be classed by disabled activists as a disgrace.

A few stations up the line, lifts were added to the footbridge at Ystrad Mynach station, in conjunction with other works. Wikipedia says this.

In 2014, the station underwent a £1.6 million refurbishment with new ticket machines, waiting areas and ticket office, with disabled toilet being installed in addition to major work carried out on the footbridge with lifts being installed to improve accessibility.

Surely some of the money saved on electrification could be spent on improving access?

Electrification Between The Structures

25 KVAC  wires have to be several metres away from any staff and passengers.

The Northbound Platform 3 is wide and if the overhead wire can be suspended high enough, I suspect that the latest regulations can be met.

The Southbound Platform 2 is narrower and the platform has a low roof, which might mean electrification is trickier.

But if as I suspect, battery power and gravity will be used to power the trains on the downhill track, then there could be a case for leaving the downhill track without wires.

That could save half the costs on some sections of the route.

Electrification Of The Crossover

On a railway with full electrification all crossovers must be electrified..

But on the Rhymney Line, all the trains will be Swiss all-purpose trains, that can work on all power sources, probably including cuckoo-clock motors.

So imagine a Tri-Mode Stadler Flirt arriving from Penarth, which will be turning back in the bay platform at Caerphilly.

  • It would use the electrification between the unelectrified Caerphilly Tunnel to just before the crossover to come up the hill and probably add some charge to the batteries, that have been depleted in the run through the mile-long tunnel.
  • \\\the train would probably rate at a signal just before the crossover, until told to proceed by the signalling system.
  • The pantograph will be dropped and the train switched to battery or diesel power.
  • When giving the green by the signal, the train would move into the bay platform.

All done efficiently and safely without any electrification, which would not be installed on the crossover or in the bay platform.

Train Failure In The Caerphilly Tunnel

There will have to be a plan for handling train failures in the tunnel. I suspect that as Switzerland has lots of railways in the mountains, some with extensive tunnels, that the Swiss have pretty good methods for dealing with failures.

One Train Rescues Another

Trains are generally designed, so that a second train can rescue a failed train of the same class or even a similar type. This makes good sense, as a train operator generally has several trains of the same type and their Thunderbird locomotive may be working miles away.

I’m sure that the Tri-Mode Stadler Flirts will have this capability.

Rescuing A Train Going Downhill

If a train should fail in the Caerphilly tunnel on the downhill track, a second train would probably couple up and shepherd the train slowly down the hill to the depot at Canton.

Rescuing A Train Going Uphill

If a train should fail in the Caerphilly tunnel on the downhill track, a second train would probably couple up and push the stricken train into the bay platform at Caerphilly station.

Conclusion

The more I look at the South Wales Metro, it has been designed in an holistic manner with routes, tracks, electrification, stations and trains all designed to work together.

 

 

 

June 10, 2018 Posted by | Travel | , , , , , | 1 Comment

KeolisAmey’s Plans For The Rhymney Line

This document on the KeolisAmey web site details their plans for the new Wales and Borders Franchise.

The Rhymney Line has the following characteristics.

  • It runs between Cardiff Queen Street and Rhymney stations.
  • Most of the line is double-track, with a short length of single-track from Tir-Phil station.
  • There is the Coryton branch line to Coryton station.
  • From Cardiff to Bargoed station, there are four trains per hour (tph)
  • North of Bargoed, an hourly service generally operates.
  • \from Cardiff to Coryton station, there are two tph.
  • Some services, run through Cardiff to Penarth or Barry Island stations.
  • Services take sixty-one minutes between Rhymney and Cardiff.
  • Services take eighteen minutes between Coryton and Cardiff.

What improvements will be made to the Rhymney Line?

New Trains

From 2019, cascaded Class 170 trains will run services on the line.

In 2023, these trains will replaced by new Tri-Mode Stadler Flirts.

Current plans, don’t envisage any of the Stadler Citylink Metro Vehicles working the line. But I don’t see any reason why they can’t, if say Transport for Wales wanted to run a service from Cardiff Bay to Coryton or any other station.

It could be that their batteries don’t have enough capacity for the Caerphilly Tunnel.

New Stations

The KeolisAmey document, states that a new station will be built at  Crwys Road.

I’ve also read somewhere that there may be a station on the Coryton Line to serve a major new hospital.

Improved Services

In 2023, the following services will be in place.

  • From Cardiff to Rhymney station, there will be four tph.
  • From Cardiff to Coryton station, there will be two tph.
  • Services will take forty-eight minutes between Rhymney and Cardiff.
  • Services will take twenty minutes between Coryton and Cardiff.

The Coryton service is slower because of the proposed new station.

Electrification

The line will be electrified using 25 KVAC.

  • There is a short tunnel at Bargoed station.
  • There is a mile-long tunnel at Caerphilly.
  • There were quite a few footbridges across the tracks.
  • The margins on either side of the track seem adequate on much of the route.

It looks to me, that electrification of the Rhymney Line cshuld be possible, provided the design is good.

The Tri-Mode Stadler Flirts will have batteries, which will have these purposes.

  • Provide traction power for the trains, where there is no electrification.
  • Capture the energy generated by the traction motors under braking.
  • Ensure that power is always available for the train’s control, driver and passenger systems.

On the Rhymney Line, battery power will also be used to provide traction power in the mile-long Caerphilly Tunnel.

I have been told that although the tunnel will not be electrified, there will be an overhead rail for the pantograph in the tunnel, which will not be electrified.

This means that the pantograph doesn’t have to be raised and lowered, as the train goes up and down the hill, as there is a continuous overhead rail and line for the pantograph to use all the way.

I believe that when the train is coming down the hill, that gravity and the onboard battery will give sufficient power to bring the train safely down the hill.

So is there any point in electrifying the downhill path?

  • The two terminals on the line; Rhymney and Coryton stations, are single platform stations on single-track lines, which will surely be electrified.
  • If necessary batteries could be topped up before on the single track sections, before joining the double-rack line to Cardiff.
  • There is very little if any freight or engineering trains on the line. But these will be diesel-hauled.
  • After the modernisation, all the passenger trains will be the new electric trains with batteries and/or diesel engines.
  • Diesel trains and locomotives could continue to work the lines as required.

I don’t think there is any operational reason for the downhill path to be electrified.

It would reduce costs in both construction and maintenance.

 

 

 

 

 

June 9, 2018 Posted by | Travel | , , , , , , | 1 Comment

How Can Discontinuous Electrification Be Handled?

On the proposed South Wales Metro, it is proposed to use discontinuous electrification to avoid rebuilding a lot of bridges and other structures.

This document on the KeolisAmey web site details their plans for the new Wales and Borders Franchise.

The document states this about the electrification.

Discontinuous overhead line electrification to 25 KVAC with permanently earthed sections around restricted structures, saving 55 interventions e.g. rebuilding bridges/no need for wire in Caerphilly tunnel.

So how are these interventions avoided?

The Karlsruhe Solution

On the Karlsruhe Stadbahn, similar Citylink vehicles to those proposed for Cardiff need to work on both the main line 15 KVAC used in Germany and the 750 VDC used by Karlsruhe trams.

To isolate the two voltages, a ceramic rod is placed in the catenary. The vehicle’s pantograph just rides across the voltage boundary and the vehicle’s electrical system uses whatever voltage is present.

Bridges On The South Wales Metro

These pictures show some of the types of bridges on the Cardiff Valleys Lines.

They are a real assortment.

  • Some station footbridges from the Victorian era with nice castings and decoration, but no much-needed step-free access.
  • Some quality brick and stone arch bridges.
  • British Rail-era steel bridges, with no architectural merit
  • Some modern road bridges in steel and concrete.

I also saw sizeable pipelines over the railway, which would need to be raised.

The greatest number were simple steel bridges like the one at Caerphilly station, designed to get pedestrians and cyclists, who were not using the railway, from one side of the tracks to the other.

I suspect the simplest way would be to erect two standard gantries at a safe distance of a few metres either side of the structure.

Between the two gantries would be an conductor, like this one. that I photographed in the Berlin Hauphtbahnhof.

It would be earthed, so that it offered no danger to life. There could even be extra supports under the bridge.

At each end, it would be connected to the 25 KVAC using a ceramic rod or other insulating device.

The vehicle’s pantograph would then ride from one side of the bridge to the other on its own track without being lowered.

Anything electrified at 25 KVAC would be kept at a very safe distance from the bridge.

In the earthed section, when the vehicle would be receiving no power, the vehicle would automatically switch to battery power. There would be no driver action required, except to monitor it was all working as it should.

As on the South Wales Metro, it appears that all vehicles using the lines proposed to be electrified will have their own onboard batteries, there shouldn’t be any problem.

In some ways, this discontinuous operation is a bit like using your laptop connected to the mains. When say the cleaner pulls out the plug to put in the vacuum cleaner, your laptop switches automatically to the battery.

The Caerphilly Tunnel

The Caerphilly tunnel is over a mile long. This picture shows the tunnel entrance.

It would probably be possible to electrify using a rail in the roof, but why bother if the trains running through the tunnel could go from one end to the other on their own battery power?

Trains could lower the pantograph before entry and then raise it again, when under the electrification at the other end.

This could be performed automatically using a GPS-based system.

I have also had an e-mail, which said this.

As I understand Caerphilly will have a natural bar in it but be much closer to the train roof than would be allowed with a live one.

Now there’s an idea!

A composite or earthed metal rail would be fixed to the roof of the tunnel, so that the pantograph could run smoothly from one electrified section on one side of the tunnel to the electrification on the other side, using battery power all the way.

Cost Savings

In Novel Solution Cuts Cardiff Bridge Wiring Cost, I talked about another method applied in South Wales to avoid rebuilding a bridge.

At this bridge, traditional electrification methods were used, but the need to demolish the bridge was avoided by using advanced insulation and protection measures.

This was my final statement.

Network Rail reckon that the solution will save about £10 million on this bridge alone, as it avoids the need for an expensive rebuild of the bridge.

The savings on this bridge will be higher as it is a large bridge over several tracks, but even saving a million on each bridge in the South Wales Metro is £55 million, which will probably be enough to build much of the infrastructure to extend to The Flourish, which would appear to not need expensive viaducts or electrification.

Should Downhill Tracks Be Left Without Electrification?

I think this may be possible on the South Wales Metro, as vehicles coming down the hills could use gravity and small amounts of battery power.

Regenerative braking would also be continuously charging the batteries.

It would certainly be simpler, than having to constantly swap between overhead and battery power on the descent, where the electrification was discontinuous.

As the lines are going to have a more intensive service, there will be additions of a second track in places to allow trains to pass.

Any electrification that could be removed from the project would be beneficial in terms of building and operational costs.

Other Routes

This post has used the South Wales Metro as an example, but I don’t see any reason, why the discontinous method and that used on the Cardiff Bridge can’t be applied to other bridges and structures over the lines on other routes in the country.

I suspect, that if they’d been used on the Gospel Oak to Barking Line, electric trains would have been running months ago!

Conclusion

Look what you get with thinking, when you have a Bonfire of the Boxes!

 

June 7, 2018 Posted by | Travel | , , , , , , , | 3 Comments