Class 93 Tri-mode Loco

[Peter Sarf]

If I were designing the battery charge management, I would plan for the battery to always have spare capacity to accept the kinetic energy of the train at its current speed. So for a 1000T train at 55mph (KE=80kWh), the batteries would be empty, hoping to recharge them fully with regenerative braking when coming to a stop.

And if we did have to dump energy into the friction brakes, the diesel would top up the batteries to full while waiting at the red signal, ready to boost the engine as soon as the signal went green.

Accelerating at full power with both 900kW engine and 400kW battery would leave the batteries about two-thirds full when you got back up to 55mph, but then you'd save diesel by using the batteries to maintain linespeed until they were empty again.

The system would only need to know the weight of the train and the speed. Obviously you could make if more sophisticated by for instance:

• adjusting for charging / discharge inefficiencies
• using geolocation data to anticipate hills and track speed limits
• linking into a Driver Advisory System.

Best to not lose sight of the point of batteries. That is to boost the engine power on acceleration and recoup most of the energy used for slowing down so that the next bit of acceleration is aided by the battery. The batteries are not for maintaining top speed - the engine should be capable of that except perhaps for maintaining line speed up a steep grade. In an ideal world the train would not be accelerating and braking so often but batteries help reduce the carbon footprint of changing speed and size/weight of engine required !.

How does the software work in a hybrid car ?.

 

[Nottingham59]

Minor point - that article describes the diesel engine as "a six-cylinder Caterpillar C32 turbocharged engine" - the C32 is actually a V12 (fairly compact at 2.3m x 1.5m x 1.6m, L-W-H)

It looks like Stadler has changed the spec from a Stage III to a Stage V engine since 2020

 

[BRX]

Shame they can't have 3rd rail shoes too - there's so much diesel haulage on routes where the majority (or even all) of it is either 3rd rail or overhead line.

 

[Spartacus]

Shame they can't have 3rd rail shoes too - there's so much diesel haulage on routes where the majority (or even all) of it is either 3rd rail or overhead line.

They'd probably spend half their time out of service being reshod due to the shoes getting knocked off by the ballast shoulder on non 3rd rail areas.

 

[Richard Scott]

They'd probably spend half their time out of service being reshod due to the shoes getting knocked off by the ballast shoulder on non 3rd rail areas.

You make them retractable like they are on 73s.

 

[Spartacus]

You make them retractable like they are on 73s.

All getting very speculative as they're not having them, but it all increases cost.

 

[Class15]

Yeah, I agree with the third rail idea. It’s really poor that so little freight from Dollands Moor is electric but if we were keen to use electrics on those we would’ve brought back the 92s.

Also, they would’ve been perfect for Southampton trains - third rail to Basingstoke, diesel to Birmingham or wherever it is and then overhead.

 

[zwk500]

Yeah, I agree with the third rail idea. It’s really poor that so little freight from Dollands Moor is electric but if we were keen to use electrics on those we would’ve brought back the 92s.

A big reason for the limited freight from Dollands Moor is that the classic network is only W8 max so can't even take swapbodies without needing well wagons. This means all freight needs to go on HS1 which eats up capacity.

Also, they would’ve been perfect for Southampton trains - third rail to Basingstoke, diesel to Birmingham or wherever it is and then overhead.

There's OLE from Reading to Didcot but at Birmingham only a limited amount of routes would be able to access OLE. If you're running diesel from Didcot through Tamworth and Toton to Leeds FLT carrying the electric kit is not really worth it.
Don't get me wrong, 93s are a great idea, but until rail electrification starts making serious inroads to regional lines then diesel will remain the primary power source for railfreight.

 

[Snow1964]

They'd probably spend half their time out of service being reshod due to the shoes getting knocked off by the ballast shoulder on non 3rd rail areas.

Seeing as third rail is mounted higher than running rails, and shoes can't drop below specific height (so they don't arc when passing over other rails on switches and crossings), and third rail location is inwards from end of sleepers.

Would need a hefty mound of a ballast shoulder over the ends of sleepers for shoes to come into contact. Aren't ballast shoulders outside the ends of sleepers, not on top of them.

But maybe there will be subsequent builds of class 93 derivative that is a 6axle go anywhere (RA4 or unrestricted RA5) that uses same standard components inside the body.

Would be useful for freight to Southampton if third rail capabilities added, or the proposed Reading-Basingstoke, Didcot-Oxford, Bristol-Warminster/Frome electrifications ever happen

 

[zwk500]

Would need a hefty mound of a ballast shoulder over the ends of sleepers for shoes to come into contact. Aren't ballast shoulders outside the ends of sleepers, not on top of them.

And yet, shoes of dual.voltage EMUs are/were regularly ripped off by ballast shoulders on the ECML and in France (the 373s), not to mention getting torn off in 3rd rail land by scrap rail and the like.

 

[Peter Sarf]

Seeing as third rail is mounted higher than running rails, and shoes can't drop below specific height (so they don't arc when passing over other rails on switches and crossings), and third rail location is inwards from end of sleepers.

Would need a hefty mound of a ballast shoulder over the ends of sleepers for shoes to come into contact. Aren't ballast shoulders outside the ends of sleepers, not on top of them.

But maybe there will be subsequent builds of class 93 derivative that is a 6axle go anywhere (RA4 or unrestricted RA5) that uses same standard components inside the body.

Would be useful for freight to Southampton if third rail capabilities added, or the proposed Reading-Basingstoke, Didcot-Oxford, Bristol-Warminster/Frome electrifications ever happen

And yet, shoes of dual.voltage EMUs are/were regularly ripped off by ballast shoulders on the ECML and in France (the 373s), not to mention getting torn off in 3rd rail land by scrap rail and the like.

Oh yes, in the early months I recall, the 700s were repeatedly falling victim to spare Ballast piled too high near the sleeper ends on the ECML etc.

I think Southampton to Basingstoke is not long enough to justify 3rd rail pickup and DC to AC conversion equipment. Perhaps 3rd rail capability would be more use/tempting when there are only a few diesel only routes/part-routes are left in the UK. But currently the diesel is too necessary so a big enough engine to not warrant an occasional alternative of 3rd rail. Heck its the lack of OHLE in the UK that's making 93s and other Bi-Modes a borderline case anyway !.

 

[Spartacus]

Seeing as third rail is mounted higher than running rails, and shoes can't drop below specific height (so they don't arc when passing over other rails on switches and crossings), and third rail location is inwards from end of sleepers.

Would need a hefty mound of a ballast shoulder over the ends of sleepers for shoes to come into contact. Aren't ballast shoulders outside the ends of sleepers, not on top of them.

But maybe there will be subsequent builds of class 93 derivative that is a 6axle go anywhere (RA4 or unrestricted RA5) that uses same standard components inside the body.

Would be useful for freight to Southampton if third rail capabilities added, or the proposed Reading-Basingstoke, Didcot-Oxford, Bristol-Warminster/Frome electrifications ever happen

Every time stock fitted with shoes goes onto new territory there's always an epidemic of lost shoes, I know full well as I was dealing with stock losing them on the MML.

Oh yes, in the early months, the 700s were repeatedly falling victim to spare Ballast piled too high near the sleeper ends.

I think Southampton to Basingstoke is not long enpugh to justify 3rd rail pickup and DC to AC conversion equipment. Perhaps more would be use/tempting when there are little diesel only routes/part-routes left in the UK. But currently the diesel is too necessary.

Here here.

 

[ac6000cw]

It looks like Stadler has changed the spec from a Stage III to a Stage V engine since 2020

According to the emissions standards info here (which might not be the whole story) - https://dieselnet.com/standards/eu/nonroad.php#rail - for locomotive use Stage V (from 2021) basically isn't any different to Stage III B (from 2012).

 

[Snow1964]

According to the emissions standards info here (which might not be the whole story) - https://dieselnet.com/standards/eu/nonroad.php#rail - for locomotive use Stage V (from 2021) basically isn't any different to Stage III B (from 2012).

The limits change only makes difference to small engines, upto 130Kw (174HP) as now included. Probably only relevant to auxiliary engines for cab pre-heating, and similar when main engine is shut down. Not even sure if any UK locos use these Webasco type heaters.

 

[BRX]

A big reason for the limited freight from Dollands Moor is that the classic network is only W8 max so can't even take swapbodies without needing well wagons. This means all freight needs to go on HS1 which eats up capacity.

Not all tunnel freight goes via HS1 - several flows still go via the "classic route". The most obviously wasteful of these (in terms of diesel use) is the bottled water train that goes back and forth to Daventry pretty much every day. Of course this used to be 92 hauled, and the issue is insufficient incentive to use electric haulage rather than a lack of bi-mode locos as such.

(Presumably something with diesel & battery options on board would avoid some of the issues that seem to be associated with 92s in 3rd rail land, getting stranded in gaps, locations where there's a limit on power draw and so on?)

Aside form the tunnel though there's quite a lot of mostly aggregates freight that goes to and from various places in Kent - Grain, Angerstein Wharf, Mountfield, Allington, Tonbridge. These couldn't be handled by 92s but at least some of them could be handled by something that could use 3rd rail with some limited diesel capacity.

Many of these routes pass through densely populated parts of London so have significant implications for localised air pollution as well as climate related emissions. Isn't it a bit embarassing for the rail freight industry that with all the effort being put into reducing road vehicle air pollution in London we will probably end up with class 66s being the worst polluting vehicles around - especially when they are operating along routes that are electrified.

 

[Greybeard33]

If I were designing the battery charge management, I would plan for the battery to always have spare capacity to accept the kinetic energy of the train at its current speed. So for a 1000T train at 55mph (KE=80kWh), the batteries would be empty, hoping to recharge them fully with regenerative braking when coming to a stop.

And if we did have to dump energy into the friction brakes, the diesel would top up the batteries to full while waiting at the red signal, ready to boost the engine as soon as the signal went green.

Accelerating at full power with both 900kW engine and 400kW battery would leave the batteries about two-thirds full when you got back up to 55mph, but then you'd save diesel by using the batteries to maintain linespeed until they were empty again.

The system would only need to know the weight of the train and the speed. Obviously you could make if more sophisticated by for instance:

• adjusting for charging / discharge inefficiencies
• using geolocation data to anticipate hills and track speed limits
• linking into a Driver Advisory System.

But, when stopping a laden train, regenerative braking alone will often not provide sufficient deceleration - the wagons' friction brakes will be needed as well to stop in the required distance. Therefore it is not necessary to keep the batteries empty to have adequate regenerative braking capability.

Also, the strategy of keeping the batteries empty would only work if the route were completely level. In reality, most lines undulate, even in lowland areas. Another back of envelope calculation shows that a 1000T train will gain gravitational potential energy (m*g*h) of about 70kWh during a climb of just 25m in elevation. About 30% of this energy needs to come from the batteries in order to apply full power and maintain momentum. It would not be acceptable for the train to slow to a diesel-only crawl on each and every gradient.

I imagine the default management strategy will be to aim to keep the batteries partly charged as a compromise between the available duration of hill climbing boost versus available duration of regenerative braking. With geolocation data, or driver override, this could be modulated to increase charge before a climb and decrease charge before a descent/speed restriction.

Aside form the tunnel though there's quite a lot of mostly aggregates freight that goes to and from various places in Kent - Grain, Angerstein Wharf, Mountfield, Allington, Tonbridge. These couldn't be handled by 92s but at least some of them could be handled by something that could use 3rd rail with some limited diesel capacity.

Many of these routes pass through densely populated parts of London so have significant implications for localised air pollution as well as climate related emissions. Isn't it a bit embarassing for the rail freight industry that with all the effort being put into reducing road vehicle air pollution in London we will probably end up with class 66s being the worst polluting vehicles around - especially when they are operating along routes that are electrified.

But do the third rail substations have sufficient spare capacity to power heavy freight trains in addition to the normal passenger service? And even where they do, would the voltage drop remain within acceptable limits?

 

[BRX]

But do the third rail substations have sufficient spare capacity to power heavy freight trains in addition to the normal passenger service? And even where they do, would the voltage drop remain within acceptable limits?

Don't know!

Those along the main route between the tunnel & Wembley/Willesden must do, as heavy 92 hauled freights have previously used this route.

If the maximum amount of power that can drawn elsewhere is limited, though, this is where I was wondering if batteries & diesel backup could make a difference. In the same way that the idea seems to be that the batteries can offer extra power to the diesel units when starting off, etc, could the same be done to assist when on 3rd rail sections with limited power. I've no idea how these things work.

 

[Nottingham59]

But, when stopping a laden train, regenerative braking alone will often not provide sufficient deceleration - the wagons' friction brakes will be needed as well to stop in the required distance. Therefore it is not necessary to keep the batteries empty to have adequate regenerative braking capability.

Also, the strategy of keeping the batteries empty would only work if the route were completely level. In reality, most lines undulate, even in lowland areas. Another back of envelope calculation shows that a 1000T train will gain gravitational potential energy (m*g*h) of about 70kWh during a climb of just 25m in elevation. About 30% of this energy needs to come from the batteries in order to apply full power and maintain momentum. It would not be acceptable for the train to slow to a diesel-only crawl on each and every gradient.

I imagine the default management strategy will be to aim to keep the batteries partly charged as a compromise between the available duration of hill climbing boost versus available duration of regenerative braking. With geolocation data, or driver override, this could be modulated to increase charge before a climb and decrease charge before a descent/speed restriction.

You're right of course, but it all depends.

How much kinetic energy can be captured by the battery depends on how fast the batteries can absorb power. We don't know that figure yet. Going the other way, the batteries can supply 400kW. If they can only absorb 400kW in braking, then it would take 1/5hour = 10-12 minutes to absorb 80kWh. So not fast enought to accommodate an unexpected red signal, but enough with DAS or driver knowledge for many braking requirements.

Agree that gradients also could be a problem off the wires, but then don't use a 93 for those flows.

But I expect many intermodal flows will not be like that. Ports like Felixstowe and Gateway have pretty flat lines between them and the wires, and lots of inland rail freight terminals are also on the level not far from electrified line (e.g. Daventry, Mossend etc.) And East Anglia and Lincolnshire are pretty flat. If the operating cost advantages of the 93 over the 66 are as good as they say, then I expect the 93s could be fully employed on intermodal work.

How many lines are there, where slow freights cause capacity problems? AIUI It's mostly the intensively used lines like WCML and MML, which are or soon will be electrified.

 

[Greybeard33]

You're right of course, but it all depends.

How much kinetic energy can be captured by the battery depends on how fast the batteries can absorb power. We don't know that figure yet. Going the other way, the batteries can supply 400kW. If they can only absorb 400kW in braking, then it would take 1/5hour = 10-12 minutes to absorb 80kWh. So not fast enought to accommodate an unexpected red signal, but enough with DAS or driver knowledge for many braking requirements.

Agree that gradients also could be a problem off the wires, but then don't use a 93 for those flows.

But I expect many intermodal flows will not be like that. Ports like Felixstowe and Gateway have pretty flat lines between them and the wires, and lots of inland rail freight terminals are also on the level not far from electrified line (e.g. Daventry, Mossend etc.) And East Anglia and Lincolnshire are pretty flat. If the operating cost advantages of the 93 over the 66 are as good as they say, then I expect the 93s could be fully employed on intermodal work.

How many lines are there, where slow freights cause capacity problems? AIUI It's mostly the intensively used lines like WCML and MML, which are or soon will be electrified.

The batteries are liquid cooled to enable discharge at 400kW, giving a discharge time of only about 10 minutes. I think it is highly unlikely that charging could be any quicker than that. A Tesla supercharger needs 15 minutes for a full charge.

I am sure there are many unelectrified/third rail lines where slow freights would become a capacity problem, if 2400kW 66s were replaced by 93s artificially restricted to only 900kW on gradients because of a perverse insistence on keeping the batteries empty for regenerative braking. The unelectrified intermodal routes to the Midlands and North from Felixstowe via Ely and Nuneaton, and from Southampton via Reading and Nuneaton, are far from flat throughout, but maybe 93s could replace 66s on some of these workings if they take full advantage of the battery boost capability to maintain speed on gradients. Even if restrictions on use of regenerative braking increase diesel fuel consumption and incur additional friction brake maintenance costs, there should still be a worthwhile saving in overall operating cost compared with a 66.

 

[Suraggu]

But I expect many intermodal flows will not be like that. Ports like Felixstowe and Gateway have pretty flat lines between them and the wires, and lots of inland rail freight terminals are also on the level not far from electrified line (e.g. Daventry, Mossend etc.) And East Anglia and Lincolnshire are pretty flat. If the operating cost advantages of the 93 over the 66 are as good as they say, then I expect the 93s could be fully employed on intermodal work.

Felixstowe has quiet a gradient coming out of the port.

 

[Roger B]

Felixstowe has quiet a gradient coming out of the port.

Which potentially could be offset by regen braking to stop accelerating down the gradient when entering the port. Though admittedly the energy needed to haul freights back up the incline will be much greater as they will generally be considerably heavier leaving than arriving (empty containers in, loaded containers out).

 

[Nottingham59]

93s artificially restricted to only 900kW on gradients because of a perverse insistence on keeping the batteries empty for regenerative braking.

If you know a hill is coming up, then obviously the driver would normally over-ride the charge management system to boost the battery, in advance of the point where they needed full power to maintain line speed.

Felixstowe has quiet a gradient coming out of the port.

I didn't know that. Thank you. All the more reason to electrify the Felixstowe branch.

 

[ac6000cw]

The Felixstowe branch has significant climbs (for freight trains) in both directions - Ipswich (East Suffolk Jnc) to Westerfield is about a 1% climb and Derby Road to Westerfield is a climb, as are both port branches. Suffolk isn't flat...

Based on comments by DRS (published in magazines) about the performance of 68's versus 66's on the northern WCML, when the chips are down e.g. when it's wet & windy or worse, four AC-drive axles doesn't quite equal 6 DC-drive ones...

 

[ABB125]

Based on comments by DRS (published in magazines) about the performance of 68's versus 66's on the northern WCML, when the chips are down e.g. when it's wet & windy or worse, four AC-drive axles doesn't quite equal 6 DC-drive ones...

However, over in the rest of Europe BoBo seems to be the axle arrangement of choice for pretty much every type of freight (apart from a couple of very heavy-haul flows).
I will accept that a lot of the trains are double-headed over more challenging terrain though! 8 axles is better than 6...

 

[Nottingham59]

Ipswich (East Suffolk Jnc) to Westerfield is about a 1% climb

A 93 on full power (1300kW) could lug a 1000T train up a 1% grade at 13m/s = 30mph. You can see why ROG say they can haul 1500T off the wires and 2500T on electric.

 

[Suraggu]

I didn't know that. Thank you. All the more reason to electrify the Felixstowe branch.

You're most welcome. I know the major FOCs push for the Felixstowe branch to be electrified and no doubt if ROG decide to enter the competitive Intermodal game (subject to winning or creating traffic) then no doubt they would push for that too.

It would be a waste of resources for example to double head a intermodal service out of Felixstowe but in theory a London Gateway departure dependent on railhead a single 93 *could* haul a fair load to Thames Haven Jct before the pan is raised.

Again until its been tested its just a theory.

 

[hwl]

According to the emissions standards info here (which might not be the whole story) - https://dieselnet.com/standards/eu/nonroad.php#rail - for locomotive use Stage V (from 2021) basically isn't any different to Stage III B (from 2012).

You need to read the whole directive and ignore simple tables that get copied from it. The locomotive category RLL now (and for the last few years) now only applies to new Russian gauge (1520mm) locomotives up until till mid 2025 operating in the EU/EEA on cross border services (e.g. sort section from Ukraine into Slovenia/Poland and the line into Kaliningrad) or isolated branches if internal etc (baltic states). Hence why there is no change from the previous levels as this is a sunset clause.

For 1435mm gauge locomotives diesel engines now have to comply with the RLR ("Railcar") levels which is a noticeable change and why lots of engine designs are no longer available and Stadler have gone for engines for 93 and 99 that are already re-engineered for Euro V NRMM for non rail so will meet RLR category requirements effectively automatically or US Tier 4 rail (locomotive) which will again effectively automatically meets the Euro V RLR requirements.

Don't know!

Those along the main route between the tunnel & Wembley/Willesden must do, as heavy 92 hauled freights have previously used this route.

If the maximum amount of power that can drawn elsewhere is limited, though, this is where I was wondering if batteries & diesel backup could make a difference. In the same way that the idea seems to be that the batteries can offer extra power to the diesel units when starting off, etc, could the same be done to assist when on 3rd rail sections with limited power. I've no idea how these things work.

Yes - off peak when freights run!
Power supplies are underwhelming in many area and other sources (battery /diesel) making up the difference would help.

 

[XAM2175]

Based on comments by DRS (published in magazines) about the performance of 68's versus 66's on the northern WCML, when the chips are down e.g. when it's wet & windy or worse, four AC-drive axles doesn't quite equal 6 DC-drive ones...

However, over in the rest of Europe BoBo seems to be the axle arrangement of choice for pretty much every type of freight (apart from a couple of very heavy-haul flows).
I will accept that a lot of the trains are double-headed over more challenging terrain though! 8 axles is better than 6...

Stadler claim that better WSP will make up most of the difference, and they've apparently demonstrated this to DRS' satisfaction at Velim. It's not a new tune - Siemens said the same thing when they convinced DB to buy the Bo′Bo′ ES64F (Br 152) and ES64F4 (Br 189), although they did end up doing a small run of Co′Co′ units for DSB (Litra EG) when 400 kN tractive effort was needed for the Great Belt Tunnel.

 

[ac6000cw]

You need to read the whole directive and ignore simple tables that get copied from it. The locomotive category RLL now (and for the last few years) now only applies to new Russian gauge (1520mm) locomotives up until till mid 2025 operating in the EU/EEA on cross border services (e.g. sort section from Ukraine into Slovenia/Poland and the line into Kaliningrad) or isolated branches if internal etc (baltic states). Hence why there is no change from the previous levels as this is a sunset clause.

For 1435mm gauge locomotives diesel engines now have to comply with the RLR ("Railcar") levels which is a noticeable change and why lots of engine designs are no longer available and Stadler have gone for engines for 93 and 99 that are already re-engineered for Euro V NRMM for non rail so will meet RLR category requirements effectively automatically or US Tier 4 rail (locomotive) which will again effectively automatically meets the Euro V RLR requirements.

Thanks for the info - I suspected there was rather more to the regulations than what was in the 'simple tables'.

 

[supervc-10]

The batteries are liquid cooled to enable discharge at 400kW, giving a discharge time of only about 10 minutes. I think it is highly unlikely that charging could be any quicker than that. A Tesla supercharger needs 15 minutes for a full charge.

A Tesla supercharger definitely needs a lot more than 15 minutes for a full charge. The quoted times are normally 10-80% charging, and I think the fastest charging cars out there (the Hyundai/Kia e-GMP cars, like the Ioniq 5 and EV6) take about 20 mins on the right charger to hit that - the fastest Hyundai quote for the Ioniq 6 is 18 mins, but that will be in very optimised conditions. Teslas aren't on the 800V architecture of the Korean cars, and the higher the voltage, the easier it is to pump in large amounts of power.

As you can see here, the charging speed (Y-axis) drops as the battery becomes more charged (X-axis). It's also dependent on things such as the temperature of the battery itself. Someone mentioned that the battery will be actively cooled- you can hear this happening with electric cars charging at high-power DC chargers at motorway services - the fans are all on buzzing away as the system is actively cooling the battery. If you don't do this, you end up with cars like the early Nissan Leafs which can now barely do 40 miles, or later Nissan Leafs which can only fast-charge once a day or so or the battery gets too warm and the speed is capped to avoid damage.

I think using the battery to sink in regen will be used as much as possible, but the friction brakes will definitely be doing a fair bit of work, especially when the battery is at higher states of charge. Unfortunately this is just a factor with the vast majority of battery chemistries, and I believe all of the high density ones.