Tyne & Wear Metro future type of electrification options

[D365]

Mod Note: This thread has been split from this discussion.

A pity they will stay on diesel for that bit!

Don't think Nexus would be happy to have the SETs on their electricity tariff!

No point in mucking about with line supply until they move along with their replacement rolling stock or have some idea of their specification.

 

[po8crg]

Don't think Nexus would be happy to have the SETs on their electricity tariff!

No point in mucking about with line supply until they move along with their replacement rolling stock or have some idea of their specification.

If there's budget for their replacement rolling stock to pay for a bit of extra flexibility, the long-term thinking should be tri-voltage (750V DC, 1500V DC, 25kV AC) stock. Until all the old stock has been replaced, everything would stay as 1500V, then shared track with NR could be converted to 25kV, while any new street-running (which has been suggested for Nexus) could be 750V (health & safety would be much happier with street-running 750V than 1500V). When 1500V equipment needs to be renewed, it could then be renewed to 750V - which is widely available for tram systems, so is almost certainly cheaper than replacement 1500V kit.

Then the generation-after rolling stock could be dual voltage 750V / 25kV stock, the same as any other tram-train stock, getting Nexus to a position where it is ordering standard stock rather than custom Nexus-only stock that will inevitably cost more.

I'm sure that SETs to Sunderland running on 25kV would make everyone much happier than hauling a diesel engine between London and Newcastle just to use it for the short run to Sunderland.

 

[Emblematic]

If there's budget for their replacement rolling stock to pay for a bit of extra flexibility, the long-term thinking should be tri-voltage (750V DC, 1500V DC, 25kV AC) stock. Until all the old stock has been replaced, everything would stay as 1500V, then shared track with NR could be converted to 25kV, while any new street-running (which has been suggested for Nexus) could be 750V (health & safety would be much happier with street-running 750V than 1500V). When 1500V equipment needs to be renewed, it could then be renewed to 750V - which is widely available for tram systems, so is almost certainly cheaper than replacement 1500V kit.

Then the generation-after rolling stock could be dual voltage 750V / 25kV stock, the same as any other tram-train stock, getting Nexus to a position where it is ordering standard stock rather than custom Nexus-only stock that will inevitably cost more.

I'm sure that SETs to Sunderland running on 25kV would make everyone much happier than hauling a diesel engine between London and Newcastle just to use it for the short run to Sunderland.

Nexus have recommended dual 25kV AC/ 1500V DC for the future tram rolling stock specification, and for their on-track infrastructure, renewal at 1500V is thought to be far cheaper than 750V, as the substation distribution is insufficient for 750V and the voltage switch would be massively expensive. A separate fleet for street running is being considered. I would have thought that one of the contact-free systems would be the best option for on-street operation myself. More details of what's proposed here.

 

[po8crg]

Nexus have recommended dual 25kV AC/ 1500V DC for the future tram rolling stock specification, and for their on-track infrastructure, renewal at 1500V is thought to be far cheaper than 750V, as the substation distribution is insufficient for 750V and the voltage switch would be massively expensive. A separate fleet for street running is being considered. I would have thought that one of the contact-free systems would be the best option for on-street operation myself. More details of what's proposed here.

Thanks for that.

 

[CLH]

Since the Metro 2030 document was published, Nexus have released a document about rolling stock replacement which makes no mention of street-running or trams at all. See here - http://www.skyscrapercity.com/showpost.php?p=124860588&postcount=4588

As a result of this, 25Kv/1500V is looking definite for the new stock (1500V needed due to the clearances in the tunnels. Separately, AFAIR all of the OHLE from Pelaw to South Hylton is entirely Network Rail and as part of the access arrangements, they pay for the electricity and Nexus pay them back through the track access fees.

 

[MidlandMainlie]

Nexus have recommended dual 25kV AC/ 1500V DC for the future tram rolling stock specification, and for their on-track infrastructure, renewal at 1500V is thought to be far cheaper than 750V, as the substation distribution is insufficient for 750V and the voltage switch would be massively expensive. A separate fleet for street running is being considered. I would have thought that one of the contact-free systems would be the best option for on-street operation myself. More details of what's proposed here.

Interesting document thanks for sharing.

 

[Emblematic]

Since the Metro 2030 document was published, Nexus have released a document about rolling stock replacement which makes no mention of street-running or trams at all. See here - http://www.skyscrapercity.com/showpost.php?p=124860588&postcount=4588

As a result of this, 25Kv/1500V is looking definite for the new stock (1500V needed due to the clearances in the tunnels. Separately, AFAIR all of the OHLE from Pelaw to South Hylton is entirely Network Rail and as part of the access arrangements, they pay for the electricity and Nexus pay them back through the track access fees.

That's good, looks like the strategy is being applied then. I wouldn't expect to see street running mentioned here, as the future extensions all seem to be aspirational, and waiting for development on the corridors or other triggers before they go beyond the basic plan outline/protection of line of route stage; stock replacement is unavoidable in the next decade though. It will be interesting to see whether the new stock arrives 25kV-ready or just as a capability for conversion (extra controls/ indicators, space for transformer, that sort of thing.)

 

[142094]

Separately, AFAIR all of the OHLE from Pelaw to South Hylton is entirely Network Rail and as part of the access arrangements, they pay for the electricity and Nexus pay them back through the track access fees.

Everything from the Pelaw Chords to South Hylton is owned and maintained by Network Rail. OHL is controlled on this section by York IECC.

 

[edwin_m]

As far as I'm aware previous ideas of through running from the Metro to the street ("Project Orpheus" circa 2000) have been dropped. Any new tramway "extensions" might be branded as Metro with through ticketing, but will be separate routes requiring passengers to change vehicles at the interchange. Therefore they can use different technologies.

Any new tram route would use a 750V supply like new trams everywhere except when there is a lower voltage for historic reasons, and unless they were tram-trains they would not be equipped any other voltage.

There is then no need to change the voltage of the existing Metro, except to allow 25kV operation of the Sunderland line so other electric trains can use it. There are enough 1500V operations around the world (for example most of the Netherlands and about half of France) that equipment of this voltage will continue to be available.

 

[SpacePhoenix]

How long are the trains on the Tyne & Wear Metro? If they's getting anywhere near half the length of a London Underground S stock train then what about a Movia based unit running on 25Kv AC?

 

[edwin_m]

Does the Movia range include options for the transformer that would be needed for 25kV? It's also a lot heavier than Metro stock - probably the more suitable replacement would be something from the tram-train family but with a high floor.

 

[sprinterguy]

How long are the trains on the Tyne & Wear Metro? If they's getting anywhere near half the length of a London Underground S stock train then what about a Movia based unit running on 25Kv AC?

The Metrocars are 27.8 metres long and they run in pairs, so a total of 55.6 metres for each train (Only just greater than a hypothetical three carriage S-stock train).

I believe that at least some of the stations through the core section (notably the underground ones beneath Newcastle city centre) were designed to handle maximum three unit formations, so a maximum train length of 83.8 metres (which would allow for a 5-car S-stock train). Elsewhere on the network however I think this would require an extensive programme of platform lengthening.

 

[Stats]

The Metrocars are 27.8 metres long and they run in pairs, so a total of 55.6 metres for each train (Only just greater than a hypothetical three carriage S-stock train).

Nearly. 27.4m long.

 

[142094]

I believe that at least some of the stations through the core section (notably the underground ones beneath Newcastle city centre) were designed to handle maximum three unit formations

That's correct - all underground stations in the city centre have headwalls and space for platform extensions apart from Haymarket platform 2, which is already long enough for 3 car trains due to the location of the lift to the concourse. Stations would need work done move the DOO monitors and mirrors.

A lot of the surface stations also can hold 3 car sets but there are a few which would need lengthening.

 

[nerd]

As far as I'm aware previous ideas of through running from the Metro to the street ("Project Orpheus" circa 2000) have been dropped. Any new tramway "extensions" might be branded as Metro with through ticketing, but will be separate routes requiring passengers to change vehicles at the interchange. Therefore they can use different technologies.

Any new tram route would use a 750V supply like new trams everywhere except when there is a lower voltage for historic reasons, and unless they were tram-trains they would not be equipped any other voltage.

There is then no need to change the voltage of the existing Metro, except to allow 25kV operation of the Sunderland line so other electric trains can use it. There are enough 1500V operations around the world (for example most of the Netherlands and about half of France) that equipment of this voltage will continue to be available.

Quite so; it does not now seem llikely that there will be any requirement to run services direectly through from the original metro-type routes to street running routes; but there will definitely be a requirement to run through from metro-type routes to tram-train routes (into Sunderland and likely beyond). It is unclear whether, if street-running sections are to be built, they might also connect to 25kv tram-train routes, but this is not unlikely, as it would enable the street-running trams to access common stabling and repair facilities.

But if the metro-type routes continue to be electrified to 1500v DC while any street-running routes are electrified to 750v DC, and both need to be able to run into a 25kV tram-train route, then converting from the one DC power supply to the other would simply be a matter of switching a 1500v inverter for a 750v inverter. The power delivery into the AC motors of LRV itself will be the same. So for the purpose of ordering replacement Metro vehicles, the issue of whether the DC power is delivered by 1500v or 750v current will be irrelevant. The same LRVs would equally be able to run under all three OLE power systems; and so, only one new vehicle type needs be specified for the order - all dual voltage, but some equipped with one DC-AC inverter, and some with the other.

 

[edwin_m]

Quite so; it does not now seem llikely that there will be any requirement to run services direectly through from the original metro-type routes to street running routes; but there will definitely be a requirement to run through from metro-type routes to tram-train routes (into Sunderland and likely beyond). It is unclear whether, if street-running sections are to be built, they might also connect to 25kv tram-train routes, but this is not unlikely, as it would enable the street-running trams to access common stabling and repair facilities.

But if the metro-type routes continue to be electrified to 1500v DC while any street-running routes are electrified to 750v DC, and both need to be able to run into a 25kV tram-train route, then converting from the one DC power supply to the other would simply be a matter of switching a 1500v inverter for a 750v inverter. The power delivery into the AC motors of LRV itself will be the same. So for the purpose of ordering replacement Metro vehicles, the issue of whether the DC power is delivered by 1500v or 750v current will be irrelevant. The same LRVs would equally be able to run under all three OLE power systems; and so, only one new vehicle type needs be specified for the order - all dual voltage, but some equipped with one DC-AC inverter, and some with the other.

This is essentially a tradeoff between providing more complex vehicles and providing more depots, and the details depend on what services are planned. Providing 25kV capability on a tram will be very expensive - probably less extra cost for a Metro as these need most of the tram-train features anyway. Dual 1500V and 750V capability may just be changing the software in the traction convertor, however this depends on the convertor design and would probably limit the number of suppliers who could offer competitive prices.

 

[nerd]

This is essentially a tradeoff between providing more complex vehicles and providing more depots, and the details depend on what services are planned. Providing 25kV capability on a tram will be very expensive - probably less extra cost for a Metro as these need most of the tram-train features anyway. Dual 1500V and 750V capability may just be changing the software in the traction convertor, however this depends on the convertor design and would probably limit the number of suppliers who could offer competitive prices.

Looking at the market for LRVs at the moment; there are effectively three categories of off-the-peg products; light-metros (as per Copenhagen); tram -trains (as per Sheffield); and pure trams (as per Edinburgh). The light-metro products now all assume driverless operation; and lack the collision resistance to share lines with heavy rail. The pure trams are now all configured as multi-segment units with 100% low-floor layout; the tram-trains have longer segments, and a high-low or 100% high floor layout and ride better at speed. The Nexus 2030 strategy ruled out pure trams; and while it explores the implications of splitting the Metro in two to allow for driverless operation on the bulk of the system, this is a question-expecting-the-answer-no. So whether Nexus continues with its interest in street-running or not, it will be shopping for replacement Metro units from the shelf marked 'tram-train', not 'light-metro'.

As it happens, Bombardier have just been awarded a contract to supply very similar high floor units to Cologne and Dusseldorf - to replace the exact Stadtbahnwagen B counterparts to the 90 Metrocars. And at a unit price of 3m euros each, which corresponds to the sums thats Nexus have put into their planning documents. And there are still a lot of other Stadtbahnwagen B replacement orders to happen, which may well interest other suppliers. As you say, it remains to be seen whether alternative DC/AC inverters can be installed within that sum; and it is also yet unclear as to whether the Bombardier units can be configured for dual voltage (and how much that will cost). But there does seem to be a likelihood that the market will be able to meet Nexus's specifications, with a tram-style product that will be able in principle to run both on the street and over a grade-separated system.

 

[Stats]

We will know more about the plans for the Metro when the Transport North East publish their Transport Vision for consultation during the summer. What we do know already is that they have aspirations to extend the Metro into Northumberland and Co Durham, and that the Metro will form the basis of an integrated regional rail network.

It seems to me that if the idea of combining street running with the existing Metro system has been abandoned, with street running extensions being separate then there is little need for tram-train or LRVs. LRV were the correct solution in the 70s, but modern day commuter EMUs can offer much the same benefits as the existing Metro stock. In my view the NECA should be looking to gradually transform the Metro to a North East version of the London Overground concession.

The North East part of the new Northern franchise is to be run with it's own business unit, branding and marketing. I can see this in a future franchise being merged with the Metro concession, and unbeknown to me, the idea is discussed as a possibility in the Metro Strategy. It may be too soon given the new Northern franchise has yet to be awarded, but if NECA could persuade the DfT of this idea for the franchise after soon then NECA could tender for one big order to replace the entire NE rolling stock in both the NEBU (with sprinters providing a temporary stopgap) and Metro, albeit with different traction and internal specifications suitable for the different needs of the Metro system, local rail and longer distance regional rail.

 

[edwin_m]

We will know more about the plans for the Metro when the Transport North East publish their Transport Vision for consultation during the summer. What we do know already is that they have aspirations to extend the Metro into Northumberland and Co Durham, and that the Metro will form the basis of an integrated regional rail network.

It seems to me that if the idea of combining street running with the existing Metro system has been abandoned, with street running extensions being separate then there is little need for tram-train or LRVs. LRV were the correct solution in the 70s, but modern day commuter EMUs can offer much the same benefits as the existing Metro stock. In my view the NECA should be looking to gradually transform the Metro to a North East version of the London Overground concession.

The North East part of the new Northern franchise is to be run with it's own business unit, branding and marketing. I can see this in a future franchise being merged with the Metro concession, and unbeknown to me, the idea is discussed as a possibility in the Metro Strategy. It may be too soon given the new Northern franchise has yet to be awarded, but if NECA could persuade the DfT of this idea for the franchise after soon then NECA could tender for one big order to replace the entire NE rolling stock in both the NEBU (with sprinters providing a temporary stopgap) and Metro, albeit with different traction and internal specifications suitable for the different needs of the Metro system, local rail and longer distance regional rail.

Interesting thought. However over most of the Metro network the DC wire was run under existing bridges and hence there is only enough clearance for Metrocars whose roofs are lower than trains. This means if either the route was converted to 25kV or was to run standard-size electric stock under OLE of any voltage, extensive bridge raising or track lowering would be needed.

Exceptions to the above are, rather obviously, Pelaw-Sunderland but also Benton to Bank Foot via the back of Gosforth depot, which ran BR freight trains for a few years after conversion to Metro.

Another problem is that the Metro vehicle floors are level with the platforms, making in the first network in the UK where wheelchair and pushchair users could easily board and alight. Any replacement heavy rail stock would have higher floors, so all the platforms would need raising too.

 

[nerd]

We will know more about the plans for the Metro when the Transport North East publish their Transport Vision for consultation during the summer. What we do know already is that they have aspirations to extend the Metro into Northumberland and Co Durham, and that the Metro will form the basis of an integrated regional rail network.

It seems to me that if the idea of combining street running with the existing Metro system has been abandoned, with street running extensions being separate then there is little need for tram-train or LRVs. LRV were the correct solution in the 70s, but modern day commuter EMUs can offer much the same benefits as the existing Metro stock. In my view the NECA should be looking to gradually transform the Metro to a North East version of the London Overground concession.

The North East part of the new Northern franchise is to be run with it's own business unit, branding and marketing. I can see this in a future franchise being merged with the Metro concession, and unbeknown to me, the idea is discussed as a possibility in the Metro Strategy. It may be too soon given the new Northern franchise has yet to be awarded, but if NECA could persuade the DfT of this idea for the franchise after soon then NECA could tender for one big order to replace the entire NE rolling stock in both the NEBU (with sprinters providing a temporary stopgap) and Metro, albeit with different traction and internal specifications suitable for the different needs of the Metro system, local rail and longer distance regional rail.

Thanks for the notice of the Transport Vision document Stats; I shall look out for it. I don't expect that it will get much into specific routes or electric power technology. But I agree it is highly likely to support an extension of Metro operation over Network Rail lines into Northumberland and Durham.

Which is consistent, I would suggest, with the Nexus proposal that the replacement vehicles to the current Metrocars should be configured as tram-trains with dual voltage 25kv/1500v OLE power. Nexus are reckoning that, within the lifetime of any replacement order, their use of the existing Sunderland route could be curtailed when it is electrified to 25kv standard by Network Rail; and that accordingly their vehicles will have to conform to dual-voltage tram-train standards to maintain access to the route. But any dual voltage vehicle able to run on a 25kv line to Sunderland, would also be able to run on counterpart lines in Northumberland and Durham. There would be no need for an expensive installation of 25kv power across the whole Metro network.

The issue of street-running is really a footnote to this. Any tram-train LRV that Nexus may purchase will have been designed with an integral 750v DC-AC inverter. To run over the existing Metro network, they would need to be capable of having a 1500v inverter installed instead - or to have both DC voltages switchable. But necessarily, whatever LRV model Nexus order with 1500v capability, would also be optionally available with 750v capability at no extra cost; should Nexus want a street-running tram.

 

[MarkyT]

Interesting discussion!

Perhaps it would be easier for the Sunderland line heavy services to be operated by a fairly small fleet of heavy rail emus with dual system capability on 1500v rather than a large fleet of dual system Metro vehicles at 25kV being required. That precludes the route being used by 25kV-only Intercity diversions or electric freight (unless some new dual voltage or hybrid locos are available) The performance and energy penalty of additional dc control gear on a few heavy rail emu making few stops should be trivial compared to every Metrocar having to carry a main transformer.

 

[nerd]

Interesting discussion!

Perhaps it would be easier for the Sunderland line heavy services to be operated by a fairly small fleet of heavy rail emus with dual system capability on 1500v rather than a large fleet of dual system Metro vehicles at 25kV being required. That precludes the route being used by 25kV-only Intercity diversions or electric freight (unless some new dual voltage or hybrid locos are available) The performance and energy penalty of additional dc control gear on a few heavy rail emu making few stops should be trivial compared to every Metrocar having to carry a main transformer.

Not sure what you are suggesting here MT.

Are you thinking that everyone would change over at Pelaw from heavy rail 25kv EMU, to light rail 1500v LRV? I think that is exactly the split network that Nexus considered and rejected.

Or are you suggesting that the main Metro network should be reconstructed to accommodate heavy rail 1500v EMUs running from Sunderland through to the airport? Edwin, I think, suggests this as impractical and retrograde.

 

[edwin_m]

Interesting discussion!

Perhaps it would be easier for the Sunderland line heavy services to be operated by a fairly small fleet of heavy rail emus with dual system capability on 1500v rather than a large fleet of dual system Metro vehicles at 25kV being required. That precludes the route being used by 25kV-only Intercity diversions or electric freight (unless some new dual voltage or hybrid locos are available) The performance and energy penalty of additional dc control gear on a few heavy rail emu making few stops should be trivial compared to every Metrocar having to carry a main transformer.

I'm sure local interests would prefer to have the Newcastle-Sunderland line available to the maximum number of rolling stock types rather than being worked by a micro-fleet and therefore even more of a network backwater than it is now. For example VTEC plan to run to Sunderland with bi-modes and in the longer term they or TPE or even Grand Central might want to use electrics.

 

[nerd]

I acknowledge that it offends against a principle of parsimony, for Nexus to equip all 100 of the LRVs it intends to order with dual-voltage 25kv/1500v capability, when the current system would only require around 25 LRVs (the ones running between Sunderland and the Airport) to use dual-voltage at any one time. And that only when Network Rail have converted the Sunderland-Pelaw line to 25kv OLE electrification.

But against this; the current arrangement for shared access to the Sunderalnd line is an ad-hoc bodge, which cannot be expected to be allowed to persist for much longer. Moreover, as Stats points out, there have been consistent urgings from various North East public bodies for Metro to be extended into Northumberland (on the Ashington/Blyth line) and Durham (further along the coast behond Seaham, or towards Durham itself). Providing dual-voltage capability across the whole system would not only reconfigure the Sunderland route within a 'standard' pattern of shared use; it could also be a model that is applied to extensions elsewhere. For instance, were Network Rail (or some other public authority) to invest in 25kv electrification of the Ashington/Blyth line, there would already be the functionality on the Tyneside Metro loop for tram-train services to be extended over the newly electrified route as well.

 

[swt_passenger]

I thought I'd quote part of the Nexus view on electrification from the document I linked to in the main infrastructure thread, regarding depot stuff.

Fleet operating voltage

4.2.11 Despite the firm rejection of 25kV on Nexus’ network, the potential for direct operation on the 25kV national network has considerable strategic attraction. Outside the Metro network, only the ECML is currently electrified in the North East region; nevertheless this is unlikely to remain the case forever, especially when considering the likely Year 2070 design life of a new Metro fleet. Indeed, Nexus was consulted by Network Rail in 2013 about extending electrification to mainline routes in the region, as part of a national consultation on this issue. Electrification of the existing regional rail network to say Ashington, Hexham or Teesside would also offer clear opportunities for Metro to expand regionally if a new fleet could operate at 25kV AC.

4.2.12 It should be noted that Nexus’ access agreement to the Network Rail tracks to Sunderland expires in 2032, and this timeframe is also one in which the existing Sunderland electrification infrastructure may need substantial renewal, some 30 years after installation. Furthermore, while no specific plans have come forward, this timeframe is seen as a key one during which NR may also consider electrification of the wider Durham Coast Line at the standard 25kV AC. In this scenario, NR will be very likely to consider the existing 1500V DC electrification to Sunderland (owned and operated by them) as being an ‘obstacle’ requiring conversion to 25kV AC, rather than renewal at 1500V DC.

4.2.13 There is an obvious option to take advantage of the capital cost-effectiveness of retaining 1500V DC on the Metro network, while also allowing operation at 25kV AC: dual-voltage trains, which can easily and automatically swap between voltages when moving from one network to another. This facility is commonly found on Continental trains and light rail vehicles, such as those in Karlsruhe. It is also planned on the new Sheffield tram-train and Merseyrail vehicles (albeit 750V/25kV rather than 1500V/25kV).

4.2.14 In effect, the high capital costs and inflexibility involved in converting or providing different voltages on the overhead power supply, are swapped for a more modest capital cost for the provision of dual-voltage equipment on the vehicles, and potentially slightly increased maintenance (revenue) costs due to more complex on-board equipment.

4.2.15 While it is possible that routine 25kV operation might not come into effect until a few years after a new fleet entered service, installing dual-voltage at the point of manufacture will be more cost- effective than a later retrofit, and offer full ‘future-proofing’. If capital cannot be sourced to actually install dual-voltage equipment in the first instance, the vehicle design should be optimised to permit a lower-cost upgrade to dual voltage at a later date.

Recommendations

4.2.16 It is recommended that:
Nexus retain 1500V DC operation for its own on-track network, and investigate the implications of either extending this to on-street operation or using 750V DC in a separate on-street fleet.
A dual-voltage 1500V DC / 25kV AC facility be considered as a key specification for a new fleet.
The energy-efficiency benefits of regenerative braking are substantial and should be considered in detail in the design of both new vehicles and renewed substations.

http://www.nexus.org.uk/sites/default/files/Metro Strategy Background document.pdf

There is a lot more info in the whole document, although I see it has been linked earlier anyway...

 

[zuriblue]

So it looks like this kind of thing is what will be used. Karlsruhe have done this for a while

http://www.railjournal.com/index.php/light-rail/karlsruhe-receives-first-vossloh-tram-train.html

These run at 750 VDC on on-street running then 15 kVAC 16.7Hz on the DB network.

 

[edwin_m]

So it looks like this kind of thing is what will be used. Karlsruhe have done this for a while

http://www.railjournal.com/index.php/light-rail/karlsruhe-receives-first-vossloh-tram-train.html

These run at 750 VDC on on-street running then 15 kVAC 16.7Hz on the DB network.

This has been in use since the mid-90s on earlier designs of Karlsruhe tram-train. Some of the French tram-trains do the same but with 25kV 50Hz and 750VDC.