Would the planned TPE units also be suitable for GWR?

[JonathanH]

From https://www.railforums.co.uk/thread...ranspennine-routes.307056/page-9#post-7941797

New trains to suit upgraded infrastructure; GWR doesn't have an equivalent to the TransPennine Route Upgrade.

Although GWR do have routes that a similar spec train in would be ideal for eg Cardiff-Portsmouth or Bristol-Oxford

I realise former would need 750v dc to. (but of course GWR also serves Weymouth and Gatwick too in third rail areas)

And it's entirely possible that GWR will get something like the TPE train, the question is good much more electrification will be needed to make that viable.

If it has a 90 mile range, then is that true?

Depends on the routes they'd be used on.

In broad terms, Patchway to Redbridge is just under 90 miles, so the proposed range doesn't seem out of the question.

Is there anywhere convenient on the way to build in a feeder station for a short stretch of recharging?

Presumably by 2035 there will have been an upgrade in battery technology.

 

[Zomboid]

broad terms, Patchway to Redbridge is just under 90 miles, so the proposed range doesn't seem out of the question.

Is there anywhere convenient on the way to build in a feeder station for a short stretch of recharging?

Presumably by 2035 there will have been an upgrade in battery technology

It's unlikely that these would be planned to be used at anything like that proportion of their notional range.

The obvious thing would to finish the GWML project so that they're on the wires to Bath, and then Salisbury would be a good place to put some more since it's likely that the SWML service will also use BEMUs, and that's a reasonably sensible distance from Basingstoke.

But that only accounts for the Cardiff to Portsmouth service, there are many others that would need something providing in other places. Another stretch near Yeovil could be used to help the SWML and Heart of Wessex lines.

I don't disagree that it's likely that batteries by 2035 will be better, but that's the bionic duckweed argument.

 

[Snow1964]

In broad terms, Patchway to Redbridge is just under 90 miles, so the proposed range doesn't seem out of the question.

Is there anywhere convenient on the way to build in a feeder station for a short stretch of recharging?

There is a massive National Grid switching station near Shaw (about mile west of Melksham), already has feeder cables to Thingley Junction (and a link to east of Chippenham). It could easily link to Trowbridge too along the Melksham line. The feeder was designed to cover the Swindon - Bath - Bristol route so has lots of potential capacity

There are virtually no overbridges along line from Bradford on Avon - Trowbridge - Westbury, so would be one of the easier sections to wire

 

[edwin_m]

There are virtually no overbridges along line from Bradford on Avon - Trowbridge - Westbury, so would be one of the easier sections to wire

You'd have to start it beyond the level crossing at the tunnel mouth just east of Bradford, as wiring that would pose some very interesting clearance problems.

Apart from the battery range, the specification of the train looks about right to replace the remaining class 150-165 across the network, and I'd expect GBR to be looking for a bulk order from one or two suppliers for something to a similar spec over what are now multiple TOCs. There may be scope within the basic design platform to increase the battery capacity or even fit a diesel engine.

 

[Zomboid]

There may be scope within the basic design platform to increase the battery capacity or even fit a diesel engine

The lack of diesel engines might be what facilitates the low floor/level boarding. How much more battery could be installed down there is obviously not public domain at this stage...

 

[edwin_m]

The lack of diesel engines might be what facilitates the low floor/level boarding. How much more battery could be installed down there is obviously not public domain at this stage...

Yes it could be, one possible reason for the solution Stadler have adopted for the FLIRTs. However, the batteries could be used to boost acceleration (and provide regenerative braking) so the diesel would only need enough power to sustain constant speed and top up the batteries. Thus, it probably wouldn't need an engine in each car like a DMU - perhaps the end car has high floor between the single door and the cab to make space for a diesel at each end?

 

[brad465]

I don't disagree that it's likely that batteries by 2035 will be better, but that's the bionic duckweed argument.

At least in this instance you could still build the train and just replace/upgrade the batteries in future.

If GWR were to ever order these they would need loads of discontinuous electrification; it's also reasonable to assume they'd be wanted for Cardiff-Exeter/Plymouth/Penzance. This would require wires at least at Bristol, Exeter and probably the Devon Banks as well, along with somewhere in Cornwall if they're to go that far. At least IETs would also take advantage of additional wires though.

 

[HSTEd]

I'd think Saltash-Plymouth Laira would be a better choice than the Devon banks, about 10 route kilometres gets you 20 ish minutes per direction of charging, even for trains not terminating at Plymouth.
It's only about 16 route kilometres (albeit including the annoyance of the bridge).

It could also share the power supply with chargers at the depot.

 

[hexagon789]

From https://www.railforums.co.uk/thread...ranspennine-routes.307056/page-9#post-7941797





In broad terms, Patchway to Redbridge is just under 90 miles, so the proposed range doesn't seem out of the question.

Is there anywhere convenient on the way to build in a feeder station for a short stretch of recharging?

Presumably by 2035 there will have been an upgrade in battery technology.

I would concur with others, that some extensions to the OLE are needed to be practical.

 

[TastyMaltesers]

In broad terms, Patchway to Redbridge is just under 90 miles, so the proposed range doesn't seem out of the question.

If you're thinking of putting them on Cardiff - Portsmouth, you'd need to add the equipment to pick up power from a 3rd rail.

 

[Snow1964]

If you're thinking of putting them on Cardiff - Portsmouth, you'd need to add the equipment to pick up power from a 3rd rail.

Which is not usually difficult with modern units as they have rectifiers to convert the transformed ac voltage into dc for the batteries, and variable frequency inverters to drive the motors.

The power electronics is usually also able to use the motors to convert it in reverse during regenerative braking, and on a BEMU to use regenerative braking to top up batteries too.

So it is likely it's more a case of adding pick up shoes and tweaking the software, rather than adding loads of extra equipment for third rail operation.

 

[Class 317]

Don't forget 90 miles is the quoted range Alstrom are guaranteeing in service. There is no need to assume a lower range as this will take into account battery degradation in various weather scenarios etc.

Looking ahead to a GBR future these could be deployed in various lengths from 3 cars upwards on multiple routes within the GWR network but not necessarily all at once. As part of a GBR wife order, multiple routes over different current operating areas could be sequenced as part of a rolling stock and electrification cascade plan to maximise the benefits of any investment. Back in the day NSE used to try to ensure new trains on one route lead to better trains on a number of other routes spreading the benefits widely.

Within the GWR network the Thames Valley and North Downs line would be a likely first area.

In terms of Cardiff to Exeter and Cardiff to Portsmouth and OHLE island at Salisbury and Exeter plus Bristol Temple Meads to Parkway / Pathway etc would likely suffice. If this was done adding a Yeovil ISland on both routes would allow Weymouth to Bristol plus Waterloo to Exeter services as well.

All would be suitable for using these trains.

 

[Starmill]

More DC demand between Redbridge Jn and Portsmouth Harbour may bring some areas there not far from their upper limit of power supply of course.

 

[Zomboid]

More DC demand between Redbridge Jn and Portsmouth Harbour may bring some areas there not far from their upper limit of power supply of course.

And it'll be significant because it'll need to supply the energy for Readbridge to Portsmouth and back to Patchway (assuming no further electrification, though hopefully there would be some). A much higher load than just a straight DC train.

 

[Snow1964]

More DC demand between Redbridge Jn and Portsmouth Harbour may bring some areas there not far from their upper limit of power supply of course.

Redbridge substation is located at the junction of Romsey line, and could probably cope as Romsey line (and start of Fawley line) was never added.

And it'll be significant because it'll need to supply the energy for Readbridge to Portsmouth and back to Patchway (assuming no further electrification, though hopefully there would be some). A much higher load than just a straight DC train.

The real problem is the 1990s Solent lines (the routes via Netley, Botley and Fareham) they weren't generous with the power rating of the substations (there were already substations at Eastleigh, Portcreek and Northam near the junctions). Northam originally supplied the triangular junction and line to Canute Road (docks), but one side of triangle and line towards docks was de-electrified. Although Northam depot was added.

Although a limited 10-12 car diversion service is permitted, I suspect a couple of substations in the area will need strengthening if regular 5-6 car BEMU operations start, both operating and charging together. It might be ok if charging only happens during coasting and braking (but normally these non-power times allow substations to cool a bit).

At least in this instance you could still build the train and just replace/upgrade the batteries in future.

The Alstom press release says first trains will start build in 2028. Transpennine seem to say enter service late 2034. So unless there is going to be 4-5 years of testing, it sort of suggests that another operator could get the build slots around 2031-32.

It is not first time, order has switched, the original 25 Angel units that becomes 450s were swapped when SWT took over 17 of the 25 units

 

[JohnRegular]

It might be ok if charging only happens during coasting and braking (but normally these non-power times allow substations to cool a bit).

Is there a need for the trains to take any extra power for charging whilst on the move? Considering that the batteries would still be topped up by regen braking and during the turnarounds at the third rail termini.

 

[Zomboid]

Is there a need for the trains to take any extra power for charging whilst on the move? Considering that the batteries would still be topped up by regen braking and during the turnarounds at the third rail termini.

That depends on the route. Just to make up some numbers, if it take 1MWh to cross the gap between electrification, and the train spends 1 hour on that electrified area, it will need to draw an average of 1MW constantly in addition to the energy needed to move around on the electric infrastructure.

If it's sitting at the terminus for 20 minutes and doesn't charge elsewhere then that's 3MW plus the hotel load, which is 4000A at 750V. That'll warm up the cables and rails...

Regen won't be zero, but it's not going to be a game changer; In those numbers I've ignored the losses that are associated with batteries, and the gains from regen, so let's call it a wash...

== Doublepost prevention - post automatically merged: Sunday at 21:12 ==

https://assets.publishing.service.gov.uk/media/5a79b82e40f0b63d72fc7f58/tts-redacted.pdf

A 130m Electric IEP Unit on a journey from Kings Cross to Newcastle under the
conditions defined in Annex B shall consume no more than 4600kWh;

So 1MWh is perhaps a bit high for Redbridge to Patchway, but it's the right order of magnitude.

 

[43096]

It is not first time, order has switched, the original 25 Angel units that becomes 450s were swapped when SWT took over 17 of the 25 units

Which 17 units were they?

 

[Zomboid]

So 10 minutes on a spreadsheet and a few probably reasonable assumptions... That IEP specification works out to 18.7 kWh/mile. For Cardiff - Portsmouth line speed is much lower, so consumption will be quite a lot less - let's call it a nice round 10kWh/ mile.

Patchway to Redbridge is 90 miles according to this thread, so 900kWh needs to be stored whilst the train is between Redbridge - Portsmouth - Redbridge.

Additionally the trains must complete that journey, which I make (using Google Earth distance measurement) as being about 28 miles each way, so 280kWh x 2 = 560kWh.

Therefore the DC system must deliver 1460kWh to the train to fuel it for Redbridge - Portsmouth - Redbridge - Patchway. They spend just over 2 hours in the area, so the equivalent of a constant 700kW, 450kW of which is charging the battery. Higher if the inbound is delayed and needs to turn round in a hurry.

It's about 2.5 times the draw of a straight electric or diesel bi-mode where the 900kWh charging can be negated. The existing trains are diesel, so no load on the electrification system.

If it were static terminus charging only, the trains are scheduled to stop at Portsmouth Harbour for about 30 minutes, so a constant charge rate of 1.8MW would be needed, though the peak would be higher, and that would sit on top of all the existing traction load.

So the point? The train battery might be ok to handle the Patchway to Redbridge and return, but there's a lot of load to add to the DC system if no further electrification is added on the route, which may or may not be straightforward to accommodate. And relying solely on static charging at Portsmouth would not be a sensible plan.

 

[The exile]

So the point? The train battery might be ok to handle the Patchway to Redbridge and return, but there's a lot of load to add to the DC system if no further electrification is added on the route, which may or may not be straightforward to accommodate. And relying solely on static charging at Portsmouth would not be a sensible plan.

The battery needs to be able to cope with the distance plus (maybe) supplying hotel power for a couple of hours on a winter night while a blockage is cleared and still be able to get to its destination. Ideally, it should be able to cope with at least one opportunity for recharging not being available (or indeed only running Bristol - Romsey all day because of engineering work - which would be interesting!)

 

[Zomboid]

The battery needs to be able to cope with the distance plus (maybe) supplying hotel power for a couple of hours on a winter night while a blockage is cleared and still be able to get to its destination. Ideally, it should be able to cope with at least one opportunity for recharging not being available (or indeed only running Bristol - Romsey all day because of engineering work - which would be interesting!)

Indeed. It's why I'd personally advocate for finishing the GWML electrification through Bath, and also for electrifying Southampton - Salisbury - Basingstoke - Reading to allow the freight to divert from the SWML and be electrically hauled (eventually! It could at least get to Acton without anything else wiring), and to allow pretty much everything through Salisbury to go over to Battery or straight electric operation.

 

[JohnRegular]

Indeed. It's why I'd personally advocate for finishing the GWML electrification through Bath, and also for electrifying Southampton - Salisbury - Basingstoke - Reading to allow the freight to divert from the SWML and be electrically hauled (eventually! It could at least get to Acton without anything else wiring), and to allow pretty much everything through Salisbury to go over to Battery or straight electric operation.

Westbury is another logical place an to put up OLE 'island' - indeed it would be foolish not to, given the number of trains which stable in the nearby sidings or start/terminate there.

 

[Snow1964]

Which 17 units were they?

Angel originally ordered 25 units, 3 were completed as dual voltage and were tested in Germany and UK, 17 units were transferred to SWT order (they weren't additional within the big initial order), the other 3 were moved to build after SWR units. But then it got complicated, because of fleet size changes, dropping the 32 x 5car suburban 450s, adding more standard 4car. Some of the already ordered ac equipment ended up on the 360s, and parts in production got swapped between build batches. I think the other 6 of the original 25 speculative Angel order ended up as part of 350/1 fleet.

Westbury is another logical place an to put up OLE 'island' - indeed it would be foolish not to, given the number of trains which stable in the nearby sidings or start/terminate there.

There are not many original Wilts Somerset and Weymouth Railway overbridges remaining in the area (due to complete rebuild in 1899 when line from Stert (Patney) was being built. Would probably make sense to wire Trowbridge to Warminster (there is big climb from Westbury to Warminster). Wiring Westbury-Frome would help BEMUs. Ideally would extend third rail few hundred yards from Dorchester junction to Dorchester West too, so change to battery can happen at Dorchester West.

But would need dual voltage version, (although with BEMUs having inverters to use dc batteries, fairly easy add on)