Multiple working shenanigans

[skyhigh]

You do get some interesting anomalies, however, when units that aren't often coupled end up together. For instance, I remember once coupling a 170 (ex-Scotrail) with a 153 (ex-GWR), which resulted in continuous hustle alarms sounding on the 153.

Something tells me there was/is also an issue for 156s with a certain modification coupling to 158s. When the DKS is turned on in the 158 you get a constant buzzer as if there were 2 DKS on, but there isn't.

 

[norbitonflyer]

Also the 376 is classified as if it were an overhead AC train when in fact its third rail only. Was 476 not fitting with the other Electrostars?

Don't look for logic in TOPS classes. SWT and Gatwick Express were the only privatised TOCs that used the old Southern Region 4xx range, (including, more recently, the Island Line) although their Desiros and Junipers were just as capable of conversion to AC as the class 37x Electrostars on Southern and South Eastern - indeed, some of the Desiro order was diverted to London Midland and became 350s

Note the pantograph well on this close up of a class 444

Or this 458 (the dark square patch at the leading end of the third car)

 

[matchmaker]

ScotRail still do run 158+170 pairs (mostly on Inverness services).

They used to occasionally run 150/170 combinations.

 

[edwin_m]

More modern units do this via a computer interface, and for obvious reasons there will be issues when, for instance, Siemens software tries to talk to CAF software.

There's also a liability issue. Unless the multiple working interface is very well specified, there is a risk that supplier A and supplier B blame each other when their trains fail to multiple as they were intended to. Adding software and communication protocols just makes this worse, and there's also the risk that critical features are now implemented in different ways and will no longer work across the coupler. Things like passenger announcements and visual displays, emergency intercoms etc are now mandatory for safety or accessiblity reasons when in the past all the safety-critical items were hardwired and nobody would be that bothered if the others weren't working in half of the train.

 

[Yorkshire09876]

All the hassle could be avoided by setting a national standard communication protocol and pin-out of the connector box, which could include the standard traction controls, braking, PA system Wifi etc, and have spare lines for additional functions to be added to the standard later. Manufacturers could then implement this using their own electronics. This is basically the same concept as widely used in computing - e.g. USB standards, SATA, the various monitor connectors, etc.

As regards locos the USA has done this, and they all use the AAR multiple working system. That is also the most widely-used system here now too and Classes 59, 66, 67, 69, 70, 73/9 and 99 can all work in multiple with each other.

The complete lack of standardization seen in modern UK passenger stock isn't because it's technically impossible. It's the result of there being no national standards and manufacturers being free to make up their own. The obvious candidate for the coupler would be a Dellner at a specified height (many units do have this already, hence they can do emergency rescues), plus the electrical connection box being in a specified location and having a standard set of connections - that is very much not the case at the moment.

 

[edwin_m]

All the hassle could be avoided by setting a national standard communication protocol and pin-out of the connector box, which could include the standard traction controls, braking, PA system Wifi etc, and have spare lines for additional functions to be added to the standard later. Manufacturers could then implement this using their own electronics. This is basically the same concept as widely used in computing - e.g. USB standards, SATA, the various monitor connectors, etc.

As regards locos the USA has done this, and they all use the AAR multiple working system. That is also the most widely-used system here now too and Classes 59, 66, 67, 69, 70, 73/9 and 99 can all work in multiple with each other.

The complete lack of standardization seen in modern UK passenger stock isn't because it's technically impossible. It's the result of there being no national standards and manufacturers being free to make up their own. The obvious candidate for the coupler would be a Dellner at a specified height (many units do have this already, hence they can do emergency rescues), plus the electrical connection box being in a specified location and having a standard set of connections - that is very much not the case at the moment.

In fact the way to approach some of this might be to forget the electrical connections and use a short-range wifi or similar to jump between coupled units. But you still have the issue of complex systems like train management integrating seamlessly. Not only are the systems themselves different, but the trains they are monitoring/controlling may have different features and equipment that need to be managed over the link from a coupled unit. For this you're probably looking at something sub-optimal like the TMS on unit A providing a virtual terminal to the one on unit B.

 

[pokemonsuper9]

In fact the way to approach some of this might be to forget the electrical connections and use a short-range wifi or similar to jump between coupled units.

I think a physical connection is almost certainly better than using a (theoretically) jamable signal.

 

[Sun Chariot]

Something tells me there was/is also an issue for 156s with a certain modification coupling to 158s. When the DKS is turned on in the 158 you get a constant buzzer as if there were 2 DKS on, but there isn't.

I recall (from another thread on this forum) that for a short period Regional Railways ran 2-car hybrids, with 156 DMS + 158 DMS. The inner gangways required an adaptor to make them operable. No mention was made re: couplings. I took a 35mm photo of one hybrid at Manchester Piccadilly.
In the early 1990s I saw a 156 2-car coupled to 158 2-car in normal revenue service.

== Doublepost prevention - post automatically merged: 15 Jul 2025 ==

14x and 15x lashups were a daily occurrence on the Calder Valley in the late 2010s

142 + 156 combinations were used on the Settle & Carlisle in the early 1990s. I have photos of two such sets, at Garsdale.

 

[AJDesiro]

Not sure 172s ever worked in service with either 170s or any of the sprinters but they would've been compatible.

172s regularly ran in multiple with the 170s on the Hereford services during the 170’s time with WMT, owing to delays in the delivery of 196s if I recall correctly. Shrewsbury didn’t sign the 172s so it made sense to plonk them on the Worcester-crewed Hereford runs when the 170s started moving over to EMR.

The image below shows such an example of a 172+170 combo at New St.

 

[pokemonsuper9]

Probably worth noting that as the 142s reached the end of their life with Northern, they had to be coupled to a 15x (usually a 150) so that there are carriages meeting the PRM requirements in the formation.

My phone and PC background is one such combination, with 142003 and an unknown 150.

 

[The exile]

Probably worth noting that as the 142s reached the end of their life with Northern, they had to be coupled to a 15x (usually a 150) so that there are carriages meeting the PRM requirements in the formation.

My phone and PC background is one such combination, with 142003 and an unknown 150.

Devon Metro as well. (143s rather than 142s)

 

[Geeves]

Not that it happened often in service but Northern Class 170s were modified to work with 142 and 144s, as others have said one wire in the head was setting off the fire bells/alarm on board. Nothing too complicated, they came frequently off the shed coupled to anything and everything

 

[Yorkshire09876]

I think a physical connection is almost certainly better than using a (theoretically) jamable signal.

Yes, wireless connections would probably be too risky for this sort of thing - various ways in which the signal can get disrupted.

 

[zwk500]

Yes, wireless connections would probably be too risky for this sort of thing - various ways in which the signal can get disrupted.

Don't American railroads use wireless and even satellite comms to control distributed power units?

 

[hexagon789]

Don't American railroads use wireless and even satellite comms to control distributed power units?

Yes and the control signal is not infrequently lost due to terrain and other issues, in which case depending on the set-up it will either attempt to reconnect itself or the crew can manually attempt a reconnect. The system is designed to do into a default mode if signal is lost, these days typically half (Notch 4) power, but a brake application would automatically cut traction power.

Not sure it's suitable for high density operations here, certainly not passenger trains.

 

[driver9000]

I recall (from another thread on this forum) that for a short period Regional Railways ran 2-car hybrids, with 156 DMS + 158 DMS. The inner gangways required an adaptor to make them operable. No mention was made re: couplings.

The inner couplers of 15x units were the mechanical portion of the BSI coupler with electrical and air connections being separate jumpers or pipes. Very easy to create the hybrids in those days and from memory if a 153 was required to be coupled to the inner end the obstacle deflector shield had to come off.

 

[pokemonsuper9]

I recall (from another thread on this forum) that for a short period Regional Railways ran 2-car hybrids, with 156 DMS + 158 DMS.

There have also been 150/2+153 2 car consists (I believe it was numbered 153999) in the past.

 

[Yorkshire09876]

Yes and the control signal is not infrequently lost due to terrain and other issues, in which case depending on the set-up it will either attempt to reconnect itself or the crew can manually attempt a reconnect. The system is designed to do into a default mode if signal is lost, these days typically half (Notch 4) power, but a brake application would automatically cut traction power.

Not sure it's suitable for high density operations here, certainly not passenger trains.

Happened to see this article today: https://www.theregister.com/2025/07/14/train_brakes_flaw/

Describes how flaws in the protocol potentially allow miscreants to interfere with the communications.

 

[Pokelet]

172s regularly ran in multiple with the 170s on the Hereford services during the 170’s time with WMT, owing to delays in the delivery of 196s if I recall correctly. Shrewsbury didn’t sign the 172s so it made sense to plonk them on the Worcester-crewed Hereford runs when the 170s started moving over to EMR.

The image below shows such an example of a 172+170 combo at New St.
View attachment 184069

170+172 as you say was common. In LM days 170+'anything' was also quite possible. 170+153 on Herefords had 1 diagram at least running all day. 170/6+153 ran on a Snow Hill diagram with a Worcester crew. Travelled on a few 150+170 combos too.

 

[tfw756rider]

Here's my own understanding / knowledge / observations (from before I had read this thread, unless put in square brackets) of mixed-class compatibility / multiple working of BSI coupler-equipped Diesel Multiple Units:

First off, there are two different electrical wiring configurations used with the BSI coupler:

1) wired for (14x)/150/153/155/156/158/159/170/172

2) wired for 165/166/168

Subclass 172/1 was wired in configuration "2" when with Chiltern, but rewired to configuration "1" for transfer to West Midlands in 2021 or whenever it was.

Cases I know of mixed-class working having been used in passenger service:

"1" wiring:

("within Sprinter family", "within Pacer family" and "Sprinter-Pacer" combinations excluded, as these were common on the Northern, Great Western and Wales & Borders operations etc.)

ScotRail 158+170 (I believe they still do this, and I think they fitted the "170" Bombardier/BTROS passenger information system to the 158s for this reason)

West Midlands 153+170 (was done for years but ended around 2019 I believe)

West Midlands 153+172 (from what I understand, it wasn't done very often, the coupling was difficult and the mismatch of 2-speed hydraulic and 6-speed mechanical transmissions didn't work ideally)

[West Midlands 170+172 - I'm not actually sure whether or not I knew about this one - I wonder if it had the same issues as 153+172, even if to a lesser extent?]

South Western 159+170 (I seem to recall this was done between about 2001 and 2006)

"2" wiring:

Great Western 165+166

Chiltern 165+168 (video on request)

Chiltern 168+172 (pre-2021) - see "West Midlands 170+172" above (video on request)

Cases I know of mixed-class working having been used in Empty Coaching Stock moves or rescue situations

"1" wiring:

Transport for Wales 150+170 (February 2023 video on request)

Transport for Wales 170+170+153 (December 2019 video on request)

Transport for Wales 153+153+170 (August 2021 video on request)

Transport for Wales 153+153+153+153+170 (September 2022 video on request)

Northern 142 rescuing a TransPennine Express 170 (all I can remember was unfortunate circumstances, well a little more than that but will obviously leave it at that)

The legendary January 2018 video West Midlands Railways (sic) 153375 + 170 + 172 + 170 + 153354 9 Car Combo Passes Rowley Regis by Southernrailwaysfan (which I will embed!):

== Doublepost prevention - post automatically merged: 17 Jul 2025 ==

Who even thinks of running a Class 141 and a 170/4 together?

The 170/4s were built in batches of 1999-2001, 2003-2004 and later 2004-2005 (much of the overall 170 production span of 1998-2005), but the 141s had already been withdrawn in 1997-1998 (and even the earliest 1998-built 170/1s didn't enter service until 1999), so 141-170 wouldn't have been possible, let alone 141-170/4.

However, Northern does have both the two oldest 150s - 150001 and 150002 (which were built in 1984, the same year the 141s were built in), and some of the youngest 170/4s - also some of the youngest 170s overall (which were built later 2004-2005). Therefore, if 1984 150001/002 have ever worked in multiple with say 2005 170478, that's the way of getting that potential 21-year age difference.

 

[frankmoh]

The 170/4s were built in batches of 1999-2001, 2003-2004 and later 2004-2005 (much of the overall 170 production span of 1998-2005), but the 141s had already been withdrawn in 1997-1998 (and even the earliest 1998-built 170/1s didn't enter service until 1999), so 141-170 wouldn't have been possible, let alone 141-170/4.

However, Northern does have both the two oldest 150s - 150001 and 150002 (which were built in 1984, the same year the 141s were built in), and some of the youngest 170/4s - also some of the youngest 170s overall (which were built later 2004-2005). Therefore, if 1984 150001/002 have ever worked in multiple with say 2005 170478, that's the way of getting that potential 21-year age difference.

It was a joking statement. (unless there were some secret Turbostars in Iran)

I assume it would be possible to do a 170-153-143 connection then? Would it work all electrically too?

See here, a 153 and 143 coupled together.

 

[tfw756rider]

Why does this combination of trains work together?

Even though 168s and 170s (and even more so 172s) came after British Rail (BR), the Turbostar family is derived from the Networker Turbos (165s and 166s) which were the last Diesel Multiple Units (DMUs) built in the late BR years.

The 165s and 166s were built with their BSI couplers electrically wired differently to those on the 14x Pacers and 15x Sprinters that came before them (I don't actually know why, but would love to know if anyone does know!) but the 168s used the same electrical wiring in their BSI couplers as the 165s and 166s, because any mixed-class multiple working the 168s would be doing would be with 165s.

"168-like" units would continue to be ordered, but for operations outside the Thames and Chiltern areas that the 165s/166s/168s had been ordered for - operations in areas where it would be useful for them to be able to work in multiple with 15x Sprinters. Thus, the couplers were differently electrically wired as appropriate, and the 170 was born.

The 168s and 170s not only carried over BSI couplers from the Sprinter/Networker-era ex-BR DMUs, but also the Voith two-stage hydraulic transmissions and BREL-derived bogies (which weren't changed until the 172s - to ZF 6-speed mechanical gearboxes and Bombardier lightweight bogies respectively).

However, the engine supplier was changed from British Rail's contract suppliers of Cummins and Perkins, to MTU for the Turbostars. I believe this was due to ADtranz (the initial owner of the Derby Litchurch Lane operations including 168/170), MTU (the manufacturer of the Turbostar engines) and of course Mercedes-Benz (whose lorry engine design was what the design of the MTU Turbostar engines was derived from) all being part of DaimlerChrysler at the time.

The final drive supplier also changed from Gmeinder for the 158s/165s/166s to ZF for the Turbostars - my only guess for that is that maybe Gmeinder couldn't provide the appropriate final drives to gear the units for 100mph, but ZF could?

Anyway, I understand that, along with the Turbostars having BSI couplers, not changing the amount of power and brake notches/steps from the Sprinter/Networker DMUs, as well as not running on a "TMS - Train Management System" (or at least not in the sense of a Windows/Linux-based one, despite Electrostars, 175s etc. running on such systems) were other factors that allowed the shenanigans to continue. This must surely mean that even 172s don't run on an Electrostar-like TMS - I think they really are just that "basic".

== Doublepost prevention - post automatically merged: 17 Jul 2025 ==

It was a joking statement. (unless there were some secret Turbostars in Iran)

== Doublepost prevention - post automatically merged: 17 Jul 2025 ==

I assume it would be possible to do a 170-153-143 connection then? Would it work all electrically too?

See here, a 153 and 143 coupled together.

I can't see why not, but it would have to be Empty Coaching Stock (or rescue) because of the 143 (Pacer and 170 passenger door controls don't play nicely with each other).

 

[Mat17]

Would it technically be possible to have a Pacer + Sprinter + Turbostar formation without any issues? If they put the Sprinter in the middle and the Pacer and the Turbostar on either end?

I was wondering the exact same thing.

Does anyone know whether 14x + 15x + 170 would work?

 

[tfw756rider]

I was wondering the exact same thing.

Does anyone know whether 14x + 15x + 170 would work?

It would work, but again, not in passenger service as the door controls would go crazy. You'd have to remove the Pacer.

== Doublepost prevention - post automatically merged: 17 Jul 2025 ==

I'm highly doubtful any 14x and 170s were operated in multiple. Certainly the Cebtral 156s had to be modified to work with the Central 170s. When the Anglia 156s arrived there were some compatibility issues with the 170s.

I could've sworn I watched some level crossing spotter's video once (I know, I know, but I met one recently and they were actually really nice) and that was an East Midlands Railway 170+156 combo.

I can't remember whether or not that was a passenger service, or whether or not they were still even passenger-service-"compatible" (as we know that some modern changes can break that.)

== Doublepost prevention - post automatically merged: 17 Jul 2025 ==

Class 14x cannot work with 170s. There's a sticker in the 170 cab warning against it.

Not in passenger service, no. The door controls have never played nicely with each other. They can still "work" for Empty Coaching Stock or rescue though.

== Doublepost prevention - post automatically merged: 17 Jul 2025 ==

It is said that Network SouthEast specified a different coupler pinout for the 165s and 166s deliberately to ensure their fleet couldn't be pinched by Regional Railways, and Chiltern's later units had to adopt this too.

Ah yes, so we reckon that's why!

== Doublepost prevention - post automatically merged: 17 Jul 2025 ==

I understand an example of a 170 shunting a failed Pacer at Hull was given as proof of the basic coupling ability though.

Oh, I had remembered it as the other way round for some reason.

== Doublepost prevention - post automatically merged: 17 Jul 2025 ==

When the (ex-)Chiltern 172/1s moved to West Mids they had to be modified because they had a different electrical arrangement to the rest of the 172 fleet, in order for them to work with the 165s when they lived down south.

That was just the 172/1s changing their coupler wiring configuration from the [165/166/168] one to the [150/153/155/156/158/159/170/172/0/2/3] one though.

What @hexagon789 said about Pacers and 170s not playing nicely enough for passenger service was due to a "small" incompatibility within the [150/153/155/156/158/159/170] coupler wiring configuration that only occurred between Pacers and 170s (and made the door controls go crazy).

== Doublepost prevention - post automatically merged: 17 Jul 2025 ==

Wasn't there a Pacer which worked an early morning Preston to Barrow service coupled to a 158? I think it ran non-stop through Lancaster for some reason, and was known to produce an exciting ride in the 142...

I do remember that from the older thread. You (generally speaking) could do e.g. 142-158 or 153-172 in passenger service. Just 142-170 was too far of a stretch for passenger service.

== Doublepost prevention - post automatically merged: 17 Jul 2025 ==

When the Pacers were new and had SCG gearboxes if they worked with a Sprinter a switch had to be operated in the Sprinter cab; it was marked "hold gear". I don't know the ins and outs but I understand that it synchronised the gearboxes. The SCG boxes set off at low revs whereas the Voith units in Sprinters set off at high revs, and this switch somehow evened it out.
After the Pacers were fitted with Voith gearboxes it wasn't required, and I recall seeing where the switch had been in Sprinter cabs although the switches themselves had been removed.
IIRC up to class 156 were originally fitted with it; by the time 158s were built the Pacers had been fitted with new gearboxes so it wasn't necessary.
I never have found anyone who could tell me exactly how it worked; does anyone know?

I knew the Pacers originally had the (awful) SCG gearboxes (which is why they were replaced with the Voith hydraulic transmissions), but I never knew about that "hold gear" switch for Sprinters working in multiple with SCG box Pacers - thank you!

== Doublepost prevention - post automatically merged: 17 Jul 2025 ==

"Hold Gear" meant literally that - hold the current gear, it would prevent the gearbox on the Pacer (when fitted with the 4-speed SCG mechanical transmission) from changing up to the next gear at the preset speed. Normally it would be used when climbing a steep gradient at a speed where the mechanical transmission would be hunting between gears.

That makes sense, thanks

== Doublepost prevention - post automatically merged: 17 Jul 2025 ==

196s could do with that for the Lickey bank...

I think it's that "eco mode" they're stuck in on top of not having driver-overridable gear holds. Surely it would be possible to have some clever location-based system where the gearboxes temporarily went into a Lickey climbing mode, only during that situation.

 

[frankmoh]

I can't see why not, but it would have to be Empty Coaching Stock (or rescue) because of the 143 (Pacer and 170 passenger door controls don't play nicely with each other).

The very simple solution would have someone else (the guard?) sat in the Sprinter because I assume it can work with with the 170's and 143's doors.

 

[tfw756rider]

Also the 376 is classified as if it were an overhead AC train when in fact its third rail only. Was 476 not fitting with the other Electrostars?

I seem to recall it can be in the 3xx series due to having "enough" provision for conversion to dual-voltage operation to be able to be numbered in the 3xx series.

== Doublepost prevention - post automatically merged: 17 Jul 2025 ==

The very simple solution would have someone else (the guard?) sat in the Sprinter because I assume it can work with with the 170's and 143's doors.

I'm not sure if that would necessarily have the desired outcome though. I'll leave that to anyone who knows more.

 

[LowLevel]

Some worked better than others. I once in extremis ended up working a 156/9 that had come from Anglia with a 170 on the back from Lincoln to Nottingham. The 170 was locked out but every time we got above 7 or 9 mph, whatever speed the low speed relay de-energised, the door hustle alarms sounded constantly in the 156. It was horrendous!

 

[tfw756rider]

Anyone know if the GWR 165s and 166s were modified to multiple with 158s etc when they transferred to the Bristol area?

I don't think they were, no, so they can only do separate pairings like a [165-166] train and a [158-158] train.

== Doublepost prevention - post automatically merged: 17 Jul 2025 ==

Some worked better than others. I once in extremis ended up working a 156/9 that had come from Anglia with a 170 on the back from Lincoln to Nottingham. The 170 was locked out but every time we got above 7 or 9 mph, whatever speed the low speed relay de-energised, the door hustle alarms sounded constantly in the 156. It was horrendous!

Yeah, unfortunately some of the modern changes to the units have broken the compatibility they once had.

In the September 2022 7-car Cardiff Central-Canton Empty Coaching Stock video (which I can embed on request), the hustle alarms of the rearmost of the 4 153s on the front of the 3-car 170 were beeping.

== Doublepost prevention - post automatically merged: 17 Jul 2025 ==

I wonder where it all went wrong then for the Electrostars.

I think in the Train Management System (TMS), and one factor may be that they couldn't make their mind up with what operating system (OS) to use.

As I understand it, the older ones use Windows NT 3.51 and the newer ones use a Linux-based OS (and there may be some Windows CE/Embedded chronologically in-between).

And then on top of each of those different operating systems, the TMS software running on them will have enough differences to cause the incompatibilities between the classes (don't quote me on any of this).

== Doublepost prevention - post automatically merged: 17 Jul 2025 ==

Something tells me there was/is also an issue for 156s with a certain modification coupling to 158s. When the DKS is turned on in the 158 you get a constant buzzer as if there were 2 DKS on, but there isn't.

What's the DKS?

== Doublepost prevention - post automatically merged: 17 Jul 2025 ==

Probably worth noting that as the 142s reached the end of their life with Northern, they had to be coupled to a 15x (usually a 150) so that there are carriages meeting the PRM requirements in the formation.

My phone and PC background is one such combination, with 142003 and an unknown 150.

So did the Transport for Wales (TfW) 143s at the very end in 2021 as part of their second dispensation, by which point they were effectively valleys lines-only.

The first TfW 143 dispensation though, in 2020, which also covered the 142s (as they were still in the fleet in 2020) did allow "running alone" (despite the one that Northern were given at that time not allowing that) and you'd still get the odd 143 running mainline on its own, on a Cardiff-Fishguard in 2020!

== Doublepost prevention - post automatically merged: 17 Jul 2025 ==

Not that it happened often in service but Northern Class 170s were modified to work with 142 and 144s, as others have said one wire in the head was setting off the fire bells/alarm on board. Nothing too complicated, they came frequently off the shed coupled to anything and everything

Wow, there were any Northern Pacer+170 passenger services at all though? I'm surprised they were modified honestly (even if a simple mod), considering Northern didn't have both Pacers and 170s for more than what, a couple of years?

For some reason, I thought it was door control-related, but maybe I've been misremembering.

 

[edwin_m]

I think in the Train Management System (TMS), and one factor may be that they couldn't make their mind up with what operating system (OS) to use.

The OS shouldn't make any difference. Software packages communicate with each other with specific protocols which govern what format the messages are sent and what they all mean, as well as things like voltages and connectors on cables. Software running under different operating systems is equally capable of producing and understanding these messages. However, each TMS supplier will develop their own protocols so they can talk to their own system (hopefully!) but not to any others.

In principle supplier B's system could generate and understand messages in previous supplier A's format and talk to that system. But that would need A to make the specification of their protocol available to a competitor and thereby lose the commercial advantage of being the only people able to deliver something that works with the previous fleet. They wouldn't do unless contractually required to at the time of delivering the first fleet, or paid handsomely to do so later. In the second procurement B the contract would have to require B to support communication with A's system. Again this is possible in principle but the price will increase to cover the extra software development and testing. And as I mentioned above if the two don't talk when tested then B will say A's specification excluded something important, and A would say B hadn't implemented it correctly.

 

[Rob F]

Yes, wireless connections would probably be too risky for this sort of thing - various ways in which the signal can get disrupted.

Not good news for ETCS, then?