Stadler type power cars for surplus EMUs to created BDEMUs?

[adamedwards]

There is frequent discussion on this forum of for example the 379s or the 350s made surplus from their homes by more recent EMUs. The problem at the moment for rolling stock is not enough wires so surplus EMUs and not enough DMUs, with the 150s getting near to life end.

So a question for the engineers, how feasible is a Stadler type power pack car fitted with diesels and batteries to be inserted into the middle of say a 4 car 379 to create a 4.5 car long BDEMU? This of course risks another 769 or electric Voyager type mess, but is fitting all the new kit in a new "engine" which then simply provides the power to the existing modern traction motors, less of a challenge than adding rafts to existing coaches which are to much older designs? (I'm sure its much more complex than that.) I'm envisaging that the battery is there to boost initial acceleration and absorb power when electric breaking, so as to reduce diesel pollution. I would hope the pantograph can stay so as to be able to run hotel power in stations and to use what bits of electrification there are, but the primary aim is a old DMU replacement. There's probably some sound technical reason why this is not possible that I don't know about, in which case my apologies in advance for my ignorance.

I suspect that once bitten twice shy will mean funding for this would be hard to come by, but might it be technically feasible? The aim would then be to run these BDEMUs with the power pack cars until electrification makes them redundant, when ever that is at which point they go back to being EMUs.

This was in part prompted by seeing an old film of a train leaving Waterloo in 1986 and passing a 4TC pushed by a class 33.

 

[Energy]

So a question for the engineers, how feasible is a Stadler type power pack car fitted with diesels and batteries to be inserted into the middle of say a 4 car 379 to create a 4.5 car long BDEMU? This of course risks another 769 or electric Voyager type mess, but is fitting all the new kit in a new "engine" which then simply provides the power to the existing modern traction motors, less of a challenge than adding rafts to existing coaches which are to much older designs?

In the BR era possibly, now however what connections are between the cars is really up to the manufacturer. If the ROSCO knows then possibly but controls would still need to be retrofitted to cabs.

 

[Bald Rick]

It would be technically feasible, yes. All sorts of potential issues of course, as the 769s showed us. Train length in stations and sidings, driver training, depot issues (length and training), software in the traction system, etc etc.

Much more feasible is putting some batteries underneath. Much more straightforward, albeit not as much range. But still useful.

 

[Meerkat]

First I thought this was a great idea. Then I looked up the 755 on Wikipedia. The Stadler power packs are articulated into the train. Squeezing two bogies under there would be pretty tricky and might not be allowed??

 

[stuu]

If such a thing were considered, wouldn't it be better to just join it on the front and make it interchangeable? Rings a bell somewhere

 

[Jack Hay]

Good idea. Maybe use one you made earlier?

 

[61653 HTAFC]

First I thought this was a great idea. Then I looked up the 755 on Wikipedia. The Stadler power packs are articulated into the train. Squeezing two bogies under there would be pretty tricky and might not be allowed??

You wouldn't have to build them identical to the ones on the 755s though. Even if Stadler themselves were supplying them, their speciality is small orders of bespoke vehicles or sets for specific use-cases. They also now have the expertise acquired when they took over Vossloh's factory where the 68s and 88s were built.

Doesn't make it any more likely, but it certainly isn't a showstopper.

 

[Nottingham59]

How many EMUs are there just sitting around unused? I think we are getting very close to the point with current electrification projects that will mean EMUs could be used in place of bimodes or diesels.

For instance on the MML it's only 3 miles from Wigston to Leicester station. When that's done they could recast the EMR timetable to extend Connect services to Leicester - say 2tph to Corby plus 2tph to Leicester. And timetable the 810s to run non-stop to Leicester. It would solve the apparent problem of EMR not having ordered enough 810s.

And wiring to Stalybridge seems close. How many EMUs will be needed then?

 

[Brubulus]

It would be technically feasible, yes. All sorts of potential issues of course, as the 769s showed us. Train length in stations and sidings, driver training, depot issues (length and training), software in the traction system, etc etc.

Much more feasible is putting some batteries underneath. Much more straightforward, albeit not as much range. But still useful.

How big could the batteries be (per coach) if in an under carriage configuration on a new train? I understand that the 777 has a 320kw battery, but I'm not sure if that's per coach with batteries or per train. I also believe that the 777 only has batteries in it's driving coaches. Given the 777 can achieve 85 miles fully loaded (presumably without stopping or any reserves), a 2 coach unit could go a similar distance (possibly slightly less due to smaller batteries as their needs to be space for AC or DC equipment) but being able to stop and have a reserve. An 80 mi battery unit would allow Northern to replace their entire sprinter fleet with battery units with 195s working what still cannot be done with them.

 

[Bald Rick]

For instance on the MML it's only 3 miles from Wigston to Leicester station. When that's done they could recast the EMR timetable to extend Connect services to Leicester - say 2tph to Corby plus 2tph to Leicester. And timetable the 810s to run non-stop to Leicester. It would solve the apparent problem of EMR not having ordered enough 810s.

EMR have ordered enough 810s. Not sure how you’d timetable additional services on the MML though. Nor how you’d explain matters to the good folk of Kettering and Market Harboro.

How big could the batteries be (per coach) if in an under carriage configuration on a new train?

a 500kWh battery pack of Lithium ion (as per automotive applications) would be about 3 tonnes and occupy about 2 cubic m.

The same battery of Lithium titanate (more suited to rail applications) would be twice as heavy and more than twice as large.

Nevertheless, both would comfortably fit under an EMU coach.

A 500kWh battery would keep a 4 car EMU, on a typical regional cycle (say max 75mph, stopping every 3-5 miles), going for about an hour, perhaps 90mins with more frequent stops.

 

[Energy]

EMR have ordered enough 810s. Not sure how you’d timetable additional services on the MML though. Nor how you’d explain matters to the good folk of Kettering and Market Harboro.

iirc they needed 31 810s for the original services, 33 is running it tight.

 

[Irascible]

a 500kWh battery pack of Lithium ion (as per automotive applications) would be about 3 tonnes and occupy about 2 cubic m.

The same battery of Lithium titanate (more suited to rail applications) would be twice as heavy and more than twice as large.

Nevertheless, both would comfortably fit under an EMU coach.

A 500kWh battery would keep a 4 car EMU, on a typical regional cycle (say max 75mph, stopping every 3-5 miles), going for about an hour, perhaps 90mins with more frequent stops.

Is this just the battery, or are you including cooling and cabling? how does cooling scale on these, if you used two smaller packs ( mounted on different cars probably ) then you'd presumably need not quite half the cooling for each if you were just talking of cooling lumps of matter. Batteries, I don't know about.

Has anyone decided on how much spare charge is needed as a safety margin yet? ( although I guess that would be somewhat route specific )

Of coruse then you have the complications of putting in charging vs a fuel hose in an already known environment, but we must progress at some point.

 

[Bald Rick]

Is this just the battery, or are you including cooling and cabling?

Battery pack, which includes the temperature management, put not the cabling to the traction system (which is negligible in the scheme of things). For comparison, Tesla’s 100kWh battery pack (incl cooling) weighs around 600kg, and there is an economy of scale with the cooling system for bigger packs.

 

[Jack Hay]

How big could the batteries be (per coach) if in an under carriage configuration on a new train? I understand that the 777 has a 320kw battery, but I'm not sure if that's per coach with batteries or per train. I also believe that the 777 only has batteries in it's driving coaches. Given the 777 can achieve 85 miles fully loaded (presumably without stopping or any reserves), a 2 coach unit could go a similar distance (possibly slightly less due to smaller batteries as their needs to be space for AC or DC equipment) but being able to stop and have a reserve. An 80 mi battery unit would allow Northern to replace their entire sprinter fleet with battery units with 195s working what still cannot be done with them.

Don't take the 85 mile figure as a practical range because the 'reserves', as you mention, have to be large. The battery has to power the train's heating and lighting too, so range is much reduced in winter. Heating and lighting have to be kept on if the train is delayed on the journey so that must be allowed for. Moreover, the efficiency of the batteries is less at lower temperatures, just when you'd like it to be better! Thus, the safe operating range is a lot less than the range achieved on test. Another thought to keep in mind; Merseyrail's first test of the range of a battery 777 was a journey from Bidston to Wrexham. The train made it, but couldn't get back. That was a lot less than 85 miles.

 

[Brubulus]

Looking at some basic parameters for a battery unit:
15 min recharge time
3 coach size
15%-90% regular use cycle so 75% is regularly used
Let's say the battery is 800kw, with 600kw regularly used. Let's assess power usage is 3kw per vehicle mile, so 10kw total per mile. This gives us a total range of 60 miles, which seems to be on the conservative side given a 777 (effectively 3 cars) can do 35 miles on a 320kw total battery. If that was to be multiplied by 2.5, we would get a range of around 85-90 miles, showing a 3 car unit with an 800kw battery could do something between 60-90 miles in regular service. 60 miles is just about enough to do the Calder Valley, while 90 would allow almost total replacement of the Northern dissel fleet.
To achieve a 15 min charge time, a max charging power draw of 3.5mw sounds reasonable, given there are trains that draw significantly more when at max power. If it didn't cause significant extra cost, said max power draw could be raised to 5mw (same as a class 700 12 car or class 345). This would also allow more flexibility in charging such as reducing power when a departing EMU is nearby. A battery EMU ordered for Northern should have a max speed of 90 on battery and 100/110 on electrified sections, even though this could impact range. Battery trains will have the longest range on routes where the line speed is relatively low, so I feel that this hypothetical 800kw battery train could do Stockport-Chester, but possibly not the Hope Valley stopper, even though they are a similar distance.