South Wales 'Metro' updates

[gareth950]

I'm not familiar with modern trams (or vintage ones, come to that!)

How does the passenger environment compare with Pacers, 150's or 30 year old EMUs?

The ONE, and it is only one, good feature of the ATW Pacers and 150s is the chapman 2+2 seating. I'm guessing trams have longitudinal seating with lots of standing space, not ideal seating for what could be a journey of 50 mins (down from currently 1 hr 10 mins) to the heads of the valleys.

 

[Solaris]

The ONE, and it is only one, good feature of the ATW Pacers and 150s is the chapman 2+2 seating. I'm guessing trams have longitudinal seating with lots of standing space, not ideal seating for what could be a journey of 50 mins (down from currently 1 hr 10 mins) to the heads of the valleys.

. The passenger experience is a function of vehicle specification...

 

[Bletchleyite]

Indeed. Like modern EMUs the seating is usually on tracks and as such can be placed anywhere the purchaser wishes it to be placed.

The vehicle tends to be narrower (as there is a maximum width for road vehicles) which means no 3+2, though.

Really, there's not a lot of difference for the passenger between a modern low-floor tram and something like a Stadler GTW or FLIRT. Or indeed a high-floor tram and, err, something like a narrow version of a Pacer. The key differences are in strength of construction, weight and features allowing road operation e.g. skirting, bumpers etc.

FWIW I personally find modern trams have cack-handed seating layouts that are generally lacking in window alignment etc, but I don't see that this needs to be the case, it's just poor design.

 

[anthony263]

Heard locally that the idea of a passing loop at Llangynwydd on the Maesteg line has been dropped due to cost and the general plan now is to just upgrade the Lynfi lopp at Tondu so it can be used to cross services.

If a 2tph service is introduced between Maesteg and Cardiff using the lop at Tondu will be fun timetable wise.

However one idea to start off with is to have the extra service from Maesteg to be a Maesteg - Bridgend shuttle which would use platform 3 at Bridgend. Might not be a bade idea as that way the extra service would only require 1 dmu and perhaps the extra stopper service between Bridgend and Cardiff could come from Swansea that was Pencoed and Pontyclun get a regular daytime service to Swansea as well as Maesteg.

Sadly however also heared they are loop to take up the Tondu - Margam branch

 

[Dai Corner]

So we could have

(A) off the shelf trams, but these would be narrower and therefore lower seating capacity than the current stock and wouldn't be allowed past Queen Street. Cheap (relatively speaking). Possibility of street running if required.

(B) custom build trams built to railway loading gauge with similar capacity to current stock but still not allowed past Queen Street. More expensive. Possibility of street running.

(C) off the shelf EMUs. Able to go to Central and elsewhere on the main line. Cost?? Might be comparable with custom build trams?

 

[Bletchleyite]

So we could have

(A) off the shelf trams, but these would be narrower and therefore lower seating capacity than the current stock and wouldn't be allowed past Queen Street. Cheap (relatively speaking). Possibility of street running if required.

(B) custom build trams built to railway loading gauge with similar capacity to current stock but still not allowed past Queen Street. More expensive. Possibility of street running.

(C) off the shelf EMUs. Able to go to Central and elsewhere on the main line. Cost?? Might be comparable with custom build trams?

(D) used EMUs. Very cheap, as there will be a massive glut of them on the market as South East commuter operations replace theirs. Not posh (but can be refurbished, like the very high quality Class 321 rebuild) but possibly would allow the most capacity for the available funds.

(E) don't bother with the wires, and buy a fleet of Class 230s.

(F) similar, but new metro-style DMUs such as Stadler FLIRTs. Quite a number of US "sort-of-light-rail" commuter operations have gone this way.

(G) similar, but e-Pacers.

Surely lower capacity on trams would be less of a concern as a light rail style operation would substantially increase frequencies?

 

[Dai Corner]

(D) used EMUs. Very cheap, as there will be a massive glut of them on the market as South East commuter operations replace theirs. Not posh (but can be refurbished, like the very high quality Class 321 rebuild) but possibly would allow the most capacity for the available funds.

(E) don't bother with the wires, and buy a fleet of Class 230s.

(F) similar, but new metro-style DMUs such as Stadler FLIRTs.

Surely lower capacity on trams would be less of a concern as a light rail style operation would substantially increase frequencies?

(G) whatever used DMUs nobody else wants!

 

[edwin_m]

Indeed. Like modern EMUs the seating is usually on tracks and as such can be placed anywhere the purchaser wishes it to be placed.

The vehicle tends to be narrower (as there is a maximum width for road vehicles) which means no 3+2, though.

Really, there's not a lot of difference for the passenger between a modern low-floor tram and something like a Stadler GTW or FLIRT. Or indeed a high-floor tram and, err, something like a narrow version of a Pacer. The key differences are in strength of construction, weight and features allowing road operation e.g. skirting, bumpers etc.

FWIW I personally find modern trams have cack-handed seating layouts that are generally lacking in window alignment etc, but I don't see that this needs to be the case, it's just poor design.

In a 100% low-floor tram the running gear needs to project up through the floor, so the seats have to be arranged to fit over the raised parts. Usually the area away from the bogies, which could have seats laid out more freely, is a reserved area for wheelchairs and pushchairs so doesn't have any seats at all.

Presumably any light rail vehicle for Cardiff would be a high-floor version, where the floor is flat so the seating can be arranged in a wide variety of ways. The original Metrolink vehicles had about 90 seats each in a vehicle 30m long, though the legroom was pretty poor.

 

[Bletchleyite]

(G) whatever used DMUs nobody else wants!

Yeah, just added e-Pacers to the list
--- old post above --- --- new post below ---

In a 100% low-floor tram the running gear needs to project up through the floor, so the seats have to be arranged to fit over the raised parts. Usually the area away from the bogies, which could have seats laid out more freely, is a reserved area for wheelchairs and pushchairs so doesn't have any seats at all.

Presumably any light rail vehicle for Cardiff would be a high-floor version, where the floor is flat so the seating can be arranged in a wide variety of ways. The original Metrolink vehicles had about 90 seats each in a vehicle 30m long, though the legroom was pretty poor.

Yes, I'd expect that it would be cheaper, Metrolink-style[1], to build high platforms on street sections (if any) than rebuild the existing railway platforms. That said, the layout of the new Metrolink cars is really quite inefficient of space and there are few simple forward-facing rows of seats. They are near enough standee vehicles unless you require a priority seat.

[1] I suspect Metrolink regret this now, given that they have on the new ex-railway extensions demolished and rebuilt all the platforms anyway.

 

[Dai Corner]

Something else that is puzzling me is why light rail allows higher frequencies than heavy rail on the same tracks.

Also, can a tram be as long as a train? If not, capacity of the service as whole might be lower.

 

[Bletchleyite]

Something else that is puzzling me is why light rail allows higher frequencies than heavy rail on the same tracks.

It doesn't per-se. London Underground is a heavy rail metro service with frequencies as high as a train every 30 seconds at peak times. Merseyrail's central sections operate about every 3-5 minutes.

It's just that it's cheaper to operate a higher frequency service - drivers are generally paid less, it's usually DOO (not to start that debate here, just a fact ) but where there are conductors they are often not paid very highly, and vehicles are cheaper. And it's just that style of service.

Also, can a tram be as long as a train? If not, capacity of the service as whole might be lower.

If it'll run on the street there is a limit, but it's fairly long - Metrolink can run double sets, and the Sheffield trams are quite long. I have a feeling the Edinburgh ones are longer still.

But I doubt you'll get 8-car-EMU-length trams - but then if a conventional EMU solution is chosen I'd expect it to be 4-car, not 8, given the relatively low demand. Even 4x20m is quite an upgrade from 2x16m!

 

[Dai Corner]

It doesn't per-se. London Underground is a heavy rail metro service with frequencies as high as a train every 30 seconds at peak times. Merseyrail's central sections operate about every 3-5 minutes.

It's just that it's cheaper to operate a higher frequency service - drivers are generally paid less, it's usually DOO (not to start that debate here, just a fact ) but where there are conductors they are often not paid very highly, and vehicles are cheaper. And it's just that style of service.



If it'll run on the street there is a limit, but it's fairly long - Metrolink can run double sets, and the Sheffield trams are quite long. I have a feeling the Edinburgh ones are longer still.

But I doubt you'll get 8-car-EMU-length trams - but then if a conventional EMU solution is chosen I'd expect it to be 4-car, not 8, given the relatively low demand. Even 4x20m is quite an upgrade from 2x16m!

Yes, I hadn't thought about Underground and Merseyrail.

Reducing drivers' wages and making guards redundant if they didn't want / weren't suitable to retrain as drivers would be quite a challenge!

 

[Bletchleyite]

Reducing drivers' wages and making guards redundant if they didn't want / weren't suitable to retrain as drivers would be quite a challenge!

It would depend on the structure. If it was ATW running it, or otherwise was considered part of the railway, you basically couldn't as (a) TUPE would apply to any change of operator and (b) the unions wouldn't allow it.

However, Metrolink came into being by formally closing the railway and starting a completely new, different operation. That's not a transfer of undertaking, it's a new thing - if you want the job, apply for it. Within the railway no doubt some drivers/guards would be redeployed onto the mainline and others made redundant, but none would directly transfer to become tram drivers.

 

[J-2739]

You can get trams as long as 142s

I suppose a tram the length of a single 387 would be rather expensive, wouldn't it?

Also you can get high frequency railways using guards; the Yamanote line train is an example (admittedly not like ours though).

 

[gareth950]

It doesn't per-se. London Underground is a heavy rail metro service with frequencies as high as a train every 30 seconds at peak times. Merseyrail's central sections operate about every 3-5 minutes.

It's just that it's cheaper to operate a higher frequency service - drivers are generally paid less, it's usually DOO (not to start that debate here, just a fact ) but where there are conductors they are often not paid very highly, and vehicles are cheaper. And it's just that style of service.

If it'll run on the street there is a limit, but it's fairly long - Metrolink can run double sets, and the Sheffield trams are quite long. I have a feeling the Edinburgh ones are longer still.

But I doubt you'll get 8-car-EMU-length trams - but then if a conventional EMU solution is chosen I'd expect it to be 4-car, not 8, given the relatively low demand. Even 4x20m is quite an upgrade from 2x16m!

I'm not against light rail/trams at all, but tons of time and money has just been spent by NR upgrading the entire signalling system on the valleys network and around Cardiff over the last 3 years, culminating in January. What will all of that have been for if it's all going to be torn up in under 5 years? (up the valleys anyway)
There's the splitting of the current network at Queen St.

Increased frequencies could be achieved by double tracking up the heads of the valleys. Of course the pinch points are the Newport Rd bridge north of Queen St and the bridge Queen St - Central - there's no easy solutions there.

In terms of car lengths, the Rhymney - Penarth line is already equppied for 6 car running, there's just never been enough stock for it. I'm sure platform lengthening on other lines wouldn't be too difficult. 6 car EMUs or DMUs in the peak are needed to comfortably relieve overcrowding and provide enough seats for everyone.

 

[Solaris]

Something else that is puzzling me is why light rail allows higher frequencies than heavy rail on the same tracks.

Also, can a tram be as long as a train? If not, capacity of the service as whole might be lower.

Frequency is function of safety and signalling. HR standards and new CASR signalling will enable 16tph to pass through QS in each direction. LR which operates on "Line of Sight" and as LRVs can be stopped much more quickly, could probably operate at ~24tph through QS - all on the same track. In capital and revenue terms its also "easier" to add stations or extend a LR network.

 

[gareth950]

Frequency is function of safety and signalling. HR standards and new CASR signalling will enable 16tph to pass through QS in each direction. LR which operates on "Line of Sight" and as LRVs can be stopped much more quickly, could probably operate at ~24tph through QS - all on the same track. In capital and revenue terms its also "easier" to add stations or extend a LR network.

So on 'line of sight' signalling, how would it be decided who gets priority getting into Queen St and over the Newport Rd bridge if two trains, one from the Taff Valley and one from the Rhymney valley arrived at the junction at the same time? A train from the Taff valley can't see a train coming down from the Rhymney valley and vice versa.

It seems no matter what signalling you have that bridge will always cause a bottleneck unless it's widened.

Genuine question please! Like I said, I'm not against LR in principle.

 

[edwin_m]

So on 'line of sight' signalling, how would it be decided who gets priority getting into Queen St and over the Newport Rd bridge if two trains, one from the Taff Valley and one from the Rhymney valley arrived at the junction at the same time? A train from the Taff valley can't see a train coming down from the Rhymney valley and vice versa.

It seems no matter what signalling you have that bridge will always cause a bottleneck unless it's widened.

Genuine question please! Like I said, I'm not against LR in principle.

On traditional tramway signalling it would be the first vehicle to get to the relevant detection loop. However I don't see why it couldn't be monitored by a controller or an ARS-type system if it was considered more important to have things running in timetable order.

 

[anthony263]

If more frequent services are wanted on the valley lines perhaps the bridge over Newport road should be widened however there is a multi-storey car park one side which would need demolishing. Also new signalling between Queen Street and Central to allow more trains to run on that section such as ATO.

Might be expensive however there is a large amount of emu's going to be available in the future including the 379's & class 360's

 

[daikilo]

The claim that "LRVs can be stopped much more quickly" (I assume this means in a shorter distance from a given speed) is not necessarily correct. The ability to stop is essentially driven by the weight of the vehicle and the contact surface between wheel and rail. LRVs tend to have smaller diameter wheels hence theoretically less contact surface though there may be more of them, but the LRV may have a lower axle-load. Deceleration rate is generally driven more by comfort factors these days.

Also, there is no physical reason why a conventional train should not have magnetic track brakes as many trams do, but they are only used in an emergency due to the deceleration achieved.

 

[glbotu]

The claim that "LRVs can be stopped much more quickly" (I assume this means in a shorter distance from a given speed) is not necessarily correct. The ability to stop is essentially driven by the weight of the vehicle and the contact surface between wheel and rail. LRVs tend to have smaller diameter wheels hence theoretically less contact surface though there may be more of them, but the LRV may have a lower axle-load. Deceleration rate is generally driven more by comfort factors these days.

Also, there is no physical reason why a conventional train should not have magnetic track brakes as many trams do, but they are only used in an emergency due to the deceleration achieved.

The issue is heavy rail vehicles are, well, heavier, so require more force to stop and start them. The greater the force, the greater the force on the passengers. ie: you'd feel the deceleration much more in a heavier train (to the point of being catapulted down the train). I've been on both Tramlink and T&W Metrocars with emergency break applications and you already feel that force quite a bit. It would be much worse in a 200 tonne EMU. It's less "passenger comfort" more "passenger safety".

 

[snowball]

The issue is heavy rail vehicles are, well, heavier, so require more force to stop and start them. The greater the force, the greater the force on the passengers. ie: you'd feel the deceleration much more in a heavier train (to the point of being catapulted down the train). I've been on both Tramlink and T&W Metrocars with emergency break applications and you already feel that force quite a bit. It would be much worse in a 200 tonne EMU. It's less "passenger comfort" more "passenger safety".

Are you suggesting that the effect of deceleration on passengers depends not only on the magnitude of the deceleration but also on the mass of the vehicle? That doesn't seem in line with Newton's laws.

 

[Bletchleyite]

The claim that "LRVs can be stopped much more quickly" (I assume this means in a shorter distance from a given speed) is not necessarily correct. The ability to stop is essentially driven by the weight of the vehicle and the contact surface between wheel and rail.

Erm, you are forgetting[1] magnetic track brakes, which are not fitted to any heavy rail vehicles in the UK but are I believe fitted to all trams.

Even in DB-land where they are used, the type used are non-contact eddy current brakes, not tram-style contact track brakes.

[1] You mentioned them at the end, but they are very relevant to the fact that a UK LRV can stop more quickly than a UK heavy rail vehicle - indeed, they are the cause of that fact.

 

[snowball]

However they're only used in emergencies, aren't they?

 

[HSTEd]

It should also be noted that if a default to friction brakes is required - a lighter vehicle is less likely to suffer from various brake overload effects (like 'brake fade' or the discs simply melting down) due to the disks likely forming a larger fraction of the vehicle's mass. This effect tends to reduce the heat duty requirement on each kilogramme of disk material.

 

[Bletchleyite]

However they're only used in emergencies, aren't they?

Yes, but that's the time when it matters how quickly you stop (and dictates why trams can drive on sight and can mix with road traffic). At other times, you plan to stop based on the capabilities of your vehicle.

 

[snowball]

Yes, but that's the time when it matters how quickly you stop (and dictates why trams can drive on sight and can mix with road traffic). At other times, you plan to stop based on the capabilities of your vehicle.

Depends on the context of the discussion. If the original claim that trams can stop more quickly than trains was made in relaton to routine braking distances, then anything used only in emergencies is irrelevant.

 

[edwin_m]

The ability to stop is essentially driven by the weight of the vehicle and the contact surface between wheel and rail.

No and no.

The decelerating force is the weight of the vehicle (the normal reaction) multipled by the coefficient of friction. Since it's steel on steel for both trains and trams, the coefficient of friction is the same unless the brakes are doing something clever to increase it.

But since the deceleration depends on the decelerating force divided by the weight, the weight cancels out. The deceleration of the train or tram, as a percentage of gravity, is the same as the achieved coefficient of friction.

The service deceleration of a tram (electric or friction braking of the wheels but no magnetic track brake) is about 13%g, which is not much more than the emergency deceleration of 12%g that modern EMUs achieve also relying on wheel-rail friction. However the service brake of the EMU will probably be set to 9%g, and defensive driving policies discourage use even of full service brake so as to keep something in reserve for unexpected circumstances.

On the other hand the tram has a track brake that roughly doubles its maximum deceleration in a hazard situation, and with that amount of stopping power in reserve the higher rates of service braking are more likely to be used routinely. Tram brakes work electrically rather than by air, and are designed for use in traffic, so apply and release more quickly than train brakes. On a slippery rail the sanders are probably more effective too.

 

[Lurpi]

So, as some of you have noticed, it appears that the Welsh Government have been briefing that Network Rail is preparing to hand over control of the 'core' Valley lines to them in order to enable them to carry out their Metro plans. (That answers my question about governance, although I still have no idea how the WG is going to pay for infrastructure works on the scale it's suggesting, but anyway):

According to November's Modern Railways, the core Valley lines comprise everything but the Vale of Glamorgan, Penarth, Maesteg and Ebbw Vale lines, which remain in NR's hands.

This is interesting because, when Valley Lines electrification was first announced in 2012, all four of those 'non-core' lines were included.

So will the £150 million promised by the Westminster government towards Valley lines wiring be shared between the core and non-core lines? And if not, will the non-core lines be wired at all?

I realise I should be asking NR but thought it was worth posing even just rhetorically.

 

[Envoy]

So, as some of you have noticed, it appears that the Welsh Government have been briefing that Network Rail is preparing to hand over control of the 'core' Valley lines to them in order to enable them to carry out their Metro plans. (That answers my question about governance, although I still have no idea how the WG is going to pay for infrastructure works on the scale it's suggesting, but anyway):

According to November's Modern Railways, the core Valley lines comprise everything but the Vale of Glamorgan, Penarth, Maesteg and Ebbw Vale lines, which remain in NR's hands.

This is interesting because, when Valley Lines electrification was first announced in 2012, all four of those 'non-core' lines were included.

So will the £150 million promised by the Westminster government towards Valley lines wiring be shared between the core and non-core lines? And if not, will the non-core lines be wired at all?

I realise I should be asking NR but thought it was worth posing even just rhetorically.

So, it looks like an end to through trains between the valleys north of Cardiff and the coast (Penarth/ Barry / Rhoose - Cardiff Airport). How daft is that with everybody having to change in Cardiff? Oh well, at least they will have a through tram or whatever between Rhymney & the Senedd in the Bay.

Still, you can’t blame the Welsh Government for not wanting Network Rail schemes as they have failed to deliver on time and budget the Great Western Mainline.