Scotrail fleet procurement competition - Class 156, 318 & 320 replacements

[NotATrainspott]

The North Clyde network could probably be made to work at 6x23m with a combination of SDO and platform (re)extensions. I think we'll end up with one basic design for the entire new fleet - something quite similar to the 380 or 385. Some would be kitted out with a regional interior and BEMU capability while the rest would be set up as Strathclyde electrics commuter trains. The Queen Street low level network now stretches all the way to Edinburgh so a slightly more regional layout than the 334s would suit. The 334s can live out the rest of their lives going via Central low level with its shorter 6x20m island platforms.

IIRC a problem with the 380s and 385s on Strathclyde electrics routes is that they struggle to cool the traction systems in low speed, stop-start conditions. I'm sure a new fleet (or subfleet) could be designed to make that not a problem without requiring everything to be changed.

 

[318259]

The North Clyde network could probably be made to work at 6x23m with a combination of SDO and platform (re)extensions. I think we'll end up with one basic design for the entire new fleet - something quite similar to the 380 or 385. Some would be kitted out with a regional interior and BEMU capability while the rest would be set up as Strathclyde electrics commuter trains. The Queen Street low level network now stretches all the way to Edinburgh so a slightly more regional layout than the 334s would suit. The 334s can live out the rest of their lives going via Central low level with its shorter 6x20m island platforms.

IIRC a problem with the 380s and 385s on Strathclyde electrics routes is that they struggle to cool the traction systems in low speed, stop-start conditions. I'm sure a new fleet (or subfleet) could be designed to make that not a problem without requiring everything to be changed.

The end cars of the 334s have 2+2 seating with armrests (but no tables). They’re quite comfortable, even on longer suburban journeys. I used to get them form Glasgow to Ayr quite a lot.

The middle cars have pretty nasty 3+2 seats with a very narrow aisle. They’re not so great, especially because it’s the designated disabled carriage. I’ve always deliberately avoided the central carriage on a 334.

You’re right about the traction overheating. This is mostly a problem on the Cathcart Circle. Newer units are only allowed to go around twice before being assigned to a different duty.

 

[Scotrail314209]

Was the electrification of the Maryhill line mentioned at all in the report? Surely any new EMU fleet order may need to cover the prospective electrification of that route. Are 385s suitable for it due to the fact it's got extremely short distances between stations.

 

[Wyrleybart]

Couldn't agree more.

Yes the Scottish 158s are some of the oldest, dating from 1990 so already 32 years old now so makes sense to replace all 156, 158, 318 and 320 together. By which time new trains enter service they'll all be 35+ years old with 318s closer to 40.

Whilst the Scottish 158s are mostly the oldest and GWR's are some of the youngest, and the EMR fleet in the middling, I believe the latter two fleets are about to be signed off for a big refurb and life extension. Wouldn't be surprised for similar to be authorised for the Scottish 158s, unless other unknown factors might play a part.

I still struggle to understand why Scotland cannot invest in significantly more hydro electric than it does. There must be scope to generate power for at least the WHL fairly locally - and that is only needed from Helensburgh.

 

[Snow1964]

So is a potential order covering 21 x 3car = 63 (318) + 34 x 3car = 102 (320) + 43 x 2car = 86 (156) and maybe 40 x 2 car = 80 (158)

About 250 vehicles, or possibly nearer 350 if includes the 158s and bit of growth. But not yet clear if 20m or 23m (or maybe some length in between to fit the platforms). Probably 3car and gangwayed as many will be used as 6car. Not yet clear if they could be a 6car single units (with some of the existing fleets eg 334 taking over single unit workings)

From other posts, requirements seem to include not overheating on slow closely spaced stations, with possibly about third of fleet fitted with batteries for few miles off the overhead (although if adding cost and complexity of batteries vs cost of few short electrification schemes is still to be determined). Suitable for inner suburban (metro style) routes, but can also cover journeys nearer hour - 1.5 hours on some lines

Delivery timescale seems to be 2025-2028

Hopefully that is fair summary

 

[Scotrail314209]

I think Scotrail should go for the Desiro City family for the suburban services. Fixed 6 car sets based on the 717, which do incredible in eating up peak time crowds down in London.

They are walk through too, so extra space.

 

[D365]

I think Scotrail should go for the Desiro City family for the suburban services. Fixed 6 car sets based on the 717, which do incredible in eating up peak time crowds down in London.

They are walk through too, so extra space.

Equally, there’s the Bombardier/Alstom offering. Or - dare I say it - Hitachi.

 

[Peter0124]

The end cars of the 334s have 2+2 seating with armrests (but no tables). They’re quite comfortable, even on longer suburban journeys. I used to get them form Glasgow to Ayr quite a lot.

The middle cars have pretty nasty 3+2 seats with a very narrow aisle. They’re not so great, especially because it’s the designated disabled carriage. I’ve always deliberately avoided the central carriage on a 334.

You’re right about the traction overheating. This is mostly a problem on the Cathcart Circle. Newer units are only allowed to go around twice before being assigned to a different duty.

Isn't there a 380 diagram which does Newton via Queens Park practically the entire day? With the odd hour wait at Central for the next working.

I think Scotrail should go for the Desiro City family for the suburban services. Fixed 6 car sets based on the 717, which do incredible in eating up peak time crowds down in London.

They are walk through too, so extra space.

Coming from someone with sensory issues I'm not too keen on them using walkthrough stock because it means you'd probably be able to hear people outside your own coach (eg crying babies or loud people). I like the idea of using coach doors as it keeps it a bit quieter.

Maybe one or both of the end coaches can have doors, similar to the first class sections on Thameslink 700s, keeps it a bit quieter.

 

[Strathclyder]

I think Scotrail should go for the Desiro City family for the suburban services. Fixed 6 car sets based on the 717, which do incredible in eating up peak time crowds down in London.

They are walk through too, so extra space.

Yeah, this is what I was basing my prior suggestion on. Failing the Desiro City, the equivalent from either the Stadler or Bombardier/Alstom ranges in fixed 6-car rakes would more than suffice.

 

[newguy]

I really hope they don’t order any more 385 as they are so uncomfortable. No doubt from a business perspective that is what they will go for because it will be cheaper to operate a uniform fleet

 

[Davester50]

I really hope they don’t order any more 385 as they are so uncomfortable. No doubt from a business perspective that is what they will go for because it will be cheaper to operate a uniform fleet

In their current form, I agree. Nasty trains.
Really not looking forward to them possibly ending up on local trains to Arbroath. The 158s and occasional 170 are much more comfortable.

They are walk through too, so extra space.

Agree with this. I like the open-ness of the Thameslink trains.

 

[newguy]

In their current form, I agree. Nasty trains.
Really not looking forward to them possibly ending up on local trains to Arbroath. The 158s and occasional 170 are much more comfortable.



Agree with this. I like the open-ness of the Thameslink trains.

Thinking about it, two changes could probably solve most of my issue. Firstly change the seat to something more comfortably and move the cable conduit near the window side.

Would Talgo be able to order any suitable products? Given that they were talking about opening a factory in Scotland.

 

[Adrian1980uk]

I can definitely see the stadler flirt bimodes working well for ScotRail like they do in East Anglia, really nice design and highly rated down here

 

[Energy]

I can definitely see the stadler flirt bimodes working well for ScotRail like they do in East Anglia, really nice design and highly rated down here

Remember that the procurement is asking for battery, not bimode. While Stadler do offer battery units most other manufacturers do as well with adding batteries underneath the train being less problematic than adding an engine.

I think its between more class 385s and desiro cities, as I understand the existing class 380s are much closer to desiro cities than desiro uk.

 

[Blindtraveler]

Battery units seems to me to be adding operational complexity unnecessarily to the borders route. Would a battery unit cope without being charged doing a round trip over those gradients? The turnaround time at tweedbank is never very long, based on current schedules and whilst they can plan up and use the juice for the last mile into Waverley, charge whilst in the platform there and again run on the juice until a mile out of the station they would be heavily reliant on batteries and the services are are well used much of the time, especially if ScotRail make the wrong call in my view and reduce them to hourly on a permanent basis.


A battery would probably not be too difficult round the the circle, although would need charging fully when the unit return to Waverley requiring unit swaps every time a train came back in. With wires to kill monarch and wires from gretna onwards I don't see battery operation on the gsw being particularly problematic, maybe do some infill to girvan to allow the Stranraer services to be battery operated for that section only and run on wires for the rest of the trip to Ayr or Glasgow


All in all I think that a by mode like the stadler flirt would be far more suitable and if we ordered a great big number of them they're higher cost would come down especially if we took the brave and bold decision to replace all the 158 and 170 straight away. If someone somewhere thinks the 158 still has life in it then by all means refurbish them and cascade them to somewhere else where they are needed and leave us with a completely standardised on and off the wires fleet which could be very easily swapped around if need be and in the case of the job falling over on the Glasgow electrics network could self-rescue itself as far as the nearest platform where passengers could be thrown out and put on buses or knowing ScotRail told to fend for themselves

 

[NotATrainspott]

Battery units seems to me to be adding operational complexity unnecessarily to the borders route. Would a battery unit cope without being charged doing a round trip over those gradients? The turnaround time at tweedbank is never very long, based on current schedules and whilst they can plan up and use the juice for the last mile into Waverley, charge whilst in the platform there and again run on the juice until a mile out of the station they would be heavily reliant on batteries and the services are are well used much of the time, especially if ScotRail make the wrong call in my view and reduce them to hourly on a permanent basis.


A battery would probably not be too difficult round the the circle, although would need charging fully when the unit return to Waverley requiring unit swaps every time a train came back in. With wires to kill monarch and wires from gretna onwards I don't see battery operation on the gsw being particularly problematic, maybe do some infill to girvan to allow the Stranraer services to be battery operated for that section only and run on wires for the rest of the trip to Ayr or Glasgow


All in all I think that a by mode like the stadler flirt would be far more suitable and if we ordered a great big number of them they're higher cost would come down especially if we took the brave and bold decision to replace all the 158 and 170 straight away. If someone somewhere thinks the 158 still has life in it then by all means refurbish them and cascade them to somewhere else where they are needed and leave us with a completely standardised on and off the wires fleet which could be very easily swapped around if need be and in the case of the job falling over on the Glasgow electrics network could self-rescue itself as far as the nearest platform where passengers could be thrown out and put on buses or knowing ScotRail told to fend for themselves

BEMUs will only take over a route once there's enough wiring to support the service pattern. There are different scales of discontinuous electrification ranging from opportunistic charging up to extended neutral sections on otherwise completely wired routes. The Fife and Borders plan is for something in between, where there'll be meaningful sections of running under 25kV combined with meaningful sections on battery power.

The 25kV wiring will radiate from grid supply points, which I expect will be sized for complete electrification in future. 25kV AC can deliver essentially arbitrarily large amounts of power to a train. Modern traction packages have to convert it to DC before feeding it to the motor inverters, so rapid charging should be possible when 25kV AC is available.

Getting the power supply right becomes harder than normal electrification as loads become quite peaky. A BEMU will use more energy than an equivalent EMU (with regenerative braking active) to do the same journey because power is needed to move the mass of the batteries. Then, it will only be able to pull that energy in when it is under the wires. If electrification is only available half of the time, then the average power draw and supply requirements will be twice as high. This won't be as much of a problem if the timetable means there'll always be the same number of trains charging at any time. The more track that's electrified, the more trains can charge at the same time and the less power each one needs to draw, smoothing out supply requirements further.

DC electrification is only really necessary when the local grid can't support peak charging power and trickle-charged lineside batteries are needed instead. There's little point converting lineside battery DC to AC and back to on-train batttery DC again. While I see these documents pointing to hydrogen being the only solution for rural routes, I can't see economies of scale favouring hydrogen vs BEMU tech. If nothing else, hydrogen costs are still largely tied to fossil fuels so they are unlikely to reduce energy costs.

Road vehicle fast charging is DC because there's little point feeding in AC and lugging around the rectifier circuitry that is otherwise useless when driving. Few cars support higher than 7kW single, 11kW three-phase AC now but almost all support well in excess of 50kW DC. The Renault Zoe has been the only outlier, supporting 22kW three-phase and optionally even 43kW by re-using the motor windings. Back when it was released they thought 22/43kW fast charging stations had a chance (being cheaper to install with no need for a rectifier) but that speed is neither fast enough to get you back on the motorway quickly nor worthwhile for home/office charging needs.

 

[Blindtraveler]

Very informative post. Hope the Scottish government see it as I'm left, maybe wrongly with the impression that they assume units can do huge distances just on batteries. Clearly not the case and they perhaps need to think more seriously about whether they want the expense of installing and maintaining 25kv vz sections for for running and charging or whether they prefer a bi-mode solution which would use an awful lot less diesel than throwing sprinters and 170s around on these routes

 

[NotATrainspott]

Very informative post. Hope the Scottish government see it as I'm left, maybe wrongly with the impression that they assume units can do huge distances just on batteries. Clearly not the case and they perhaps need to think more seriously about whether they want the expense of installing and maintaining 25kv vz sections for for running and charging or whether they prefer a bi-mode solution which would use an awful lot less diesel than throwing sprinters and 170s around on these routes

I presume the government and transport bodies have come up with these plans after discussions with industry. Hitachi's website says:

Hitachi’s UK regional battery train can reach top speeds of near of 144-162 km/h, without compromising on seats, carriages or passenger experience.
Travelling up to 90km just on batteries and recharging whilst in motion under the wires, it will offer seamless journeys on non-electrified suburban or branch routes, particularly around key towns and cities.
Our battery train technology is a perfect solution to help with the shift to a net-zero carbon economy, whilst supporting cost efficient and sustainable new train delivery options for non-electrified routes.
With a design focused on whole-life costing, the battery technology is based on our existing Class 385 commuter fleet currently in operation in the UK in Scotland.

Hitachi designed their AT200 for the EGIP order - their "generic" product image renders had it in Queen Street station. I'd be very surprised if Hitachi doesn't win the BEMU contract. Economies of scale favour Hitachi as there can be major commonality with the 385s, e.g. the Fife/Borders BEMU fleet being centred at Hitachi's Craigentinny and Millerhill depots.

It's worth remembering here that the plan is complete decarbonisation of the rail network. Diesel engines aren't a decarbonisation solution even in bi-mode form. They may be acceptable but only in a form that allows them to be removed or swapped out with hydrogen or battery modules as they become available. So, any designs optimised for diesel engines rather than batteries might struggle.

 

[hwl]

A few thoughts:
1) the rate of electrification and the routes being electrified or partially electrified initially concerned limits the number of DMUs that can be replaced in the short term hence 156 replacement is the limit in the short term, not point in getting delusional about 158 replacement any time soon.
2) Even complete 156 replacement will be a challenge in the short term as it will need several discontinuous electrification schemes and sub schemes completed to release the 170s and 158s currently used with multi-stage cascades and changes to 158/170 usage on existing routes where DMUs are retained.
3) Structurally the 158 and 170 should be good till at least 40 years
4) What is proposed is entirely realistic for the first stage on rolling stock replacement.
5) 23m for new fleet is the way to go with some cascades of existing EMUs especially as it provides more space for batteries than 20m.

Very informative post. Hope the Scottish government see it as I'm left, maybe wrongly with the impression that they assume units can do huge distances just on batteries. Clearly not the case and they perhaps need to think more seriously about whether they want the expense of installing and maintaining 25kv vz sections for for running and charging or whether they prefer a bi-mode solution which would use an awful lot less diesel than throwing sprinters and 170s around on these routes

The problem with BEMU range on battery isn't now the theoretical range (which is large) but often the recharging time which effectively needs to be under the wires and mostly while moving else you require long lay overs or very high charging rates and much more expensive batteries. Transport Scotland et al. north of the border understands this well, DfT less so as DFT always want to try BEMUs on locations with short lay overs...

Also you want to try to optimise battery usage to maximise battery life span e.g. slower charging and avoiding frequent deep cycling where possible, which is again best done with long periods of charging under the wires.

*** The minimum sensible distance of route wired for sensible BEMU operation is probably 35-40% depending on service pattern, gradients and layover times. ***

The plan for Borders is electrify southern end where a power supply is available far sooner than the northern end near Edinburgh which enables sufficient battery charging under the wires on the southern end and in Edinburgh. With the gap be electrified later which then enable the BEMU to be replace with and EMU and the BEMU to be cascaded else where to another recently electrified route.

The break even point for electrification vs other e.g. battery or hydrogen is through to be 2tph at 3car before local detail are considered (charging, unit diagrams (and spare units)).

Bi-mode are not a realistic decarbonisation option they are carbon reduction option for the short and medium term cases where there is (already) huge mileage under the wires with diesel units, which isn't the case with Scotrail.

 

[hooverboy]

A few thoughts:
1) the rate of electrification and the routes being electrified or partially electrified initially concerned limits the number of DMUs that can be replaced in the short term hence 156 replacement is the limit in the short term, not point in getting delusional about 158 replacement any time soon.
2) Even complete 156 replacement will be a challenge in the short term as it will need several discontinuous electrification schemes and sub schemes completed to release the 170s and 158s currently used with multi-stage cascades and changes to 158/170 usage on existing routes where DMUs are retained.
3) Structurally the 158 and 170 should be good till at least 40 years
4) What is proposed is entirely realistic for the first stage on rolling stock replacement.
5) 23m for new fleet is the way to go with some cascades of existing EMUs especially as it provides more space for batteries than 20m.


The problem with BEMU range on battery isn't now the theoretical range (which is large) but often the recharging time which effectively needs to be under the wires and mostly while moving else you require long lay overs or very high charging rates and much more expensive batteries. Transport Scotland et al. north of the border understands this well, DfT less so as DFT always want to try BEMUs on locations with short lay overs...

Also you want to try to optimise battery usage to maximise battery life span e.g. slower charging and avoiding frequent deep cycling where possible, which is again best done with long periods of charging under the wires.

The plan for Borders is electrify southern end where a power supply is available far sooner than the northern end near Edinburgh which enables sufficient battery charging under the wires on the southern end and in Edinburgh. With the gap be electrified later which then enable the BEMU to be replace with and EMU and the BEMU to be cascaded else where to another recently electrified route.

The break even point for electrification vs other e.g. battery or hydrogen is through to be 2tph at 3car before local detail are considered (charging, unit diagrams (and spare units)).

Bi-mode are not a realistic decarbonisation option they are carbon reduction option for the short and medium term cases where there is (already) huge mileage under the wires with diesel units, which isn't the case with Scotrail.

Don't forget that the range of these batteries drops rapidly with lower temperatures.Anyone who owns or hires a hybrid,plugin or ev can tell you it is effectively only about 2/3 the range,once the ambient temperature is below -10C, which it most certainly will be for a good deal of scotland in the midst of winter.

BEMU may not be the panacea that it's being made out to be.

 

[AlistairCowell]

There's a recent report from Transport Scotland about electricity and hydrogen demand forecasts, it also sets out "rail scenarios" and timelines for electrification and withdrawal/cascading of diesel trains.

The plan is to transfer 158's to SW scotland by 2027.

https://www.transport.gov.scot/media/51571/updated-zero-emission-energy-for-transport-forecasts-national-demand-forecasts-for-electricity-and-hydrogen.pdf

Also, Class 158s are reported to take over the Class 156s on WHL services in 2026.
According to that report, Class 156 units will be withdrawn in 2027, and Class 158s and 170s by 2035.

The question is when will Class 318 and 320 EMUs be replaced with new build emus?
I'm guessing that this will happen in the next five years or so.

 

[Snow1964]

Also, Class 158s are reported to take over the Class 156s on WHL services in 2026.
According to that report, Class 156 units will be withdrawn in 2027, and Class 158s and 170s by 2035.

The question is when will Class 318 and 320 EMUs be replaced with new build emus?
I'm guessing that this will happen in the next five years or so.

The 318s ideally would be replaced 2025-6, the 320s nearer 2029-30, but will have to be a compromise date if aiming to buy one replacement fleet

 

[Peter0124]

The 318s ideally would be replaced 2025-6, the 320s nearer 2029-30, but will have to be a compromise date if aiming to buy one replacement fleet

Imo the 318s are better so would prefer if the years were swapped

 

[D365]

The 318s ideally would be replaced 2025-6, the 320s nearer 2029-30, but will have to be a compromise date if aiming to buy one replacement fleet

What makes you say that? It's impossible to determine accurate dates unless you are involved with assessing the mechanical condition of said rolling stock.

 

[snowball]

Some information on the plan for Fife electrification has been posted in relevant threads in the infrastructure forum in the last couple of days. Work starts this month on wiring from Haymarket to Dalmeny (the south end of the Forth bridge). This will be followed by sections in Fife. There will be a feeder station at Thornton with wired sections radiating from it in four directions: eastward on the reopened line to Levenmouth, southward to a point between Kirkcaldy and Kinghorn, westward to Lochgelly and northward to Ladybank.

The Borders line is at an earlier stage of planning but I believe there will be a feeder station at the south end and wiring will proceed northwards from there. Battery trains can start using it once it's long enough to charge them up for the journey to Portobello Junction.

 

[Speed43125]

Don't forget that the range of these batteries drops rapidly with lower temperatures.Anyone who owns or hires a hybrid,plugin or ev can tell you it is effectively only about 2/3 the range,once the ambient temperature is below -10C, which it most certainly will be for a good deal of scotland in the midst of winter.

BEMU may not be the panacea that it's being made out to be.

-10C is perhaps an exaggeration for the central belt. I'm sure there will be consideration for battery performance in adverse conditions on both sides of the eventual procurement though.

 

[chiltern trev]

A suggestion - that when the procurement reaches the contract stage, it also has a futures option to but more of the same for further of the same units.

Are the class 156 likely to be for fur further use elsewhere for a few years, e.g. cascade to Northern?

 

[snowball]

A suggestion - that when the procurement reaches the contract stage, it also has a futures option to but more of the same for further of the same units.

Presumably a second tranche of battery trains would have some differences to make them more suitable for longer distances than the first tranche, for services between the central belt, Aberdeen and Inverness, now run by HSTs.

Also most or all battery trains would need to allow for removal of the batteries when electrification of their routes is completed.

 

[JumpinTrainz]

A fleet rejig hasn’t taken place in over ten years but I think it may be time to reevaluate which fleet Scotrail have and where the units would be best suited.

Any modern stock (ie Class 334>) is un-suitable for ex-Class 314 work. The overheating is an obvious issue and once the 318s and 320s go there will be no other suitable units unless they have a mix of Class 380s and 385s being constantly swapped out. What they need is a more suburban style unit like the AT100 exclusively for these shorter workings. This will free up more 380s and 385s.

The Class 334s are still fairly modern units and there are 40 of them so it makes it more tricky to re-appoint them. The only solution would be to fully replace the 318s/320s with new units and have them run alongside the 334s on Argyle and North Clyde Line services. The A-B line could see new stock also (preferably with tables) and have the 334s predominantly used between Balloch-Airdrie/Springburn. I wish the 334s were adapted to 2x2 seating rather than the horrendous 3x3 or 3x2.

It would be ideal if the 334s could be cascaded elsewhere even replacing the 156s until they retire. It means the North Clyde and Argyle line services would have a more uniform fleet and would only ever need replaced in one big order but that would be impossible.

 

[Scotrail314209]

It would be ideal if the 334s could be cascaded elsewhere even replacing the 156s until they retire. It means the North Clyde and Argyle line services would have a more uniform fleet and would only ever need replaced in one big order but that would be impossible.

334s onto Gourock and Wemyss Bay may be a good shout. They worked fine on that route before. If you transfer all of them over there, you could possibly run most if not all services as 6 car. Would also mean you can move the 380s for strengthening elsewhere. Maybe put them on the Lanark services to free up some 385s too.