Emergency Power on Trains

[ryan125hst]

After hearing about trains breaking down or being delayed and left without power recently, I wondered what there backup battery systems are like.

How long does the backup battery last? How long does it power the following?:
1) Air Conditioning/Heating
2) Ventilation fans
3) Main Lighting (Not just emergency lights)
4) Buffet/Kitchen equipment e.g. Ovens, fridges and tea/coffee machines.
5) Toilet equipment e.g. Hand dryer, water heater, and flush if it is a vacuum toilet.
6) Plug sockets for mobile phones and laptops.
7) Wi-Fi
8) Passenger Information Systems/Seat Reservation Systems.
9) Emergency Lighting.

How long is it before everything including the PA and door control circuits fail?

I know that not all trains have everything but I have asked this to get a general idea.

How does it vary from train to train e.g. HST and Mark 3 coach/ Mk4 coaches on a 225 to, say, a class 222, as they are newer? How do DMU's vary to a EMU's e.g. a class 377?

Is there a difference between these and older stock with less auxiliary equipment e.g. a class 156 or a class 313?

 

[Wolf_359]

A lot depends on the age & state of the batteries. Good batteries will last longer that bad batteries.

Batteries only power certain essential systems. The main units I deal with are Class 321 & Class 350 EMU's.

I know from experience that Class 321 batteries would maintain emergency lights & PA for about 20-30 minutes with a reasonable set, i have had them pack up after 5 minutes with a bad set. The biggest draw back with these units are that once the batteries have died completely you have a devil of a job getting the unit restarted when the power returns.

However Class 350's seem to be a lot better, I would imagine this is due to the advances made in batteries but they only maintain emergency lights & a few other systems. The main thing with 350's is that the computer automatically shuts down the unit at a certain point to ensure that there is enough power to restart the unit when power returns.

These are the main units I work with so I cannot tell you how other units behave.

 

[Fincra5]

Very hard to tell. In most cases the driver would shut almost everything he/she can off to save batteries. (Always found it odd they are needed to start up and EMU ) Lighting and coms systems are usually the last to go. Aircon being the first

 

[BestWestern]

158 units can vary wildly, in many cases they emergency lighting will die within a very short space of time. I've never known the door control circuits to run out of juice, although clearly it will eventually happen. With many diesel units each car can be fitted with a 'remote supply' switch, which allows power to be drawn from an adjacent car for internal and external lighting and suchlike, though this is designed more with engine failure in mind. I'm not sure what the score is with a electric unit when the power has gone off though, I'm imagine it's pretty dire if the batteries aren't up to much. I'd have thought 'accessory' systems such as Wi-fi and power sockets will cease as soon as the main power supply goes off, and I'd take a guess the same would happen with kitchen and buffet equipment, electronic reservation systems and so on. Emergency power is there for the basic essentials only, and is designed to keep these going for as long as possible. I'd be interested to know whether the PIS stays on, as this could potentially be a safety aid I suppose??

 

[driver9000]

How long does the backup battery last? How long does it power the following?:
1) Air Conditioning/Heating
2) Ventilation fans
3) Main Lighting (Not just emergency lights)
4) Buffet/Kitchen equipment e.g. Ovens, fridges and tea/coffee machines.
5) Toilet equipment e.g. Hand dryer, water heater, and flush if it is a vacuum toilet.
6) Plug sockets for mobile phones and laptops.
7) Wi-Fi
8) Passenger Information Systems/Seat Reservation Systems.
9) Emergency Lighting.

Is there a difference between these and older stock with less auxiliary equipment e.g. a class 156 or a class 313?

Battery life depends on the condition of the battery, some can last quite some time others won't. The idea of emergency power from the auxiliary battery is to provide bare minimum systems. It's very variable between the different types of train (even among the same types). The Driver has no control over which systems to keep and which to lose, that is dictated by the wiring or TMS programming. The TMS display switches off in my experience. There is a procedure during extended failures of some aircon stock where crew can be authorised to open a passenger door for ventilation as long as certain criteria are met and the train is carrying a suitable barrier. GNER had a fabric barrier that was placed across the door, I believe TPE have this too.

Aircon/heating will shut down
Ventilators will run
Main saloon lighting will go out leaving emergency level lights
Buffet equipment is almost certain to shut down (a big power drain)
Toilet hand dryers etc will shut down, the toilet should work
Plug sockets and Wifi will definitely shut down given the massive drain on the battery they would cause
PIS/seat reservation systems will most likely shut down (PA may still be available while the battery lasts)
Emergency lighting will be on.

The batteries don't last forever but running bare minimum lighting and ventilation they can at least provide something to keep the passenger comfortable...until assistance can be sent.

Older trains such as the 156 which have very little in the way of auxiliary equipment are left with emergency lighting, external lights, PA and radio.

 

[Scotrail84]

I know some of our 170's have cross feeding system that kicks in if you lose an engine. After around 90 minutes this system will start to run out of juice and then your brakes come on and you lose door interlock. If that happens then your cream crackered needing assistance from another unit.

 

[driver9000]

I know some of our 170's have cross feeding system that kicks in if you lose an engine. After around 90 minutes this system will start to run out of juice and then your brakes come on and you lose door interlock. If that happens then your cream crackered needing assistance from another unit.

The 175/180 has a cross feeding facility for when running with an engine shut down or isolated. When in cross feed the next vehicle supplies the shut down one with a supply to power all normal systems without affecting the rest of the train. The only time it will cause a big problem and potentially lead to a failure is if it is a driving car that won't take a feed and loses the control voltage, although it doesn't bring about an automatic brake application it allows you to drive normally until you stop and then brake continuity is lost.

Some of the older trains I drive have an automatic switching facility to take a feed from the battery with the highest voltage and a few have a Remote supply switch to enable a shut down vehicle to take a feed from its partner to provide lighting.

 

[Scotrail84]

The 175/180 has a cross feeding facility for when running with an engine shut down or isolated. When in cross feed the next vehicle supplies the shut down one with a supply to power all normal systems without affecting the rest of the train. The only time it will cause a big problem and potentially lead to a failure is if it is a driving car that won't take a feed and loses the control voltage, although it doesn't bring about an automatic brake application it allows you to drive normally until you stop and then brake continuity is lost.

Some of the older trains I drive have an automatic switching facility to take a feed from the battery with the highest voltage and a few have a Remote supply switch to enable a shut down vehicle to take a feed from its partner to provide lighting.

Im not a driver but i think have a small amount of knowledge (i hope). Its something to do with a generator supply fault which causes problems for our 170's. Our control usually tell us to isolate the engine in the affected coach and hope you make it to your destination.

 

[jon0844]

I would have expected the batteries would be regularly checked and replaced as they will eventually wear out - even if not used (perhaps even more so if not used).

Then again, the landlord of our office building obviously didn't do any maintenance as we had a power outage and nearly all the lights in the stairwell were off in under 5 minutes, and some were so dim that they were useless! They have now been replaced them with all new lights, and new batteries, but it's not much good doing that AFTER an emergency.

Sadly that's how things normally happen; being reactive not proactive. But if there are 40 page rule books on how a driver deals with an emergency, how can the industry show such contempt for issues like emergency power? Nobody should be admitting that the batteries on their train are useless, and the TOC should be asked why they can allow this to happen.

For any new trains (and I mean trains being built now or in the last few years - so that includes the 377s, 378s, 379s and 172s), why aren't there LED lights to use as emergency lighting? A decent brightness LED lamp will be around 1W. You should be able to pack in a few Lithium Polymer batteries per coach, or even per lamp, and keep the lights on for hours. Maybe even days!

Bombardier and others could even put solar panels on the roof. You wouldn't need many, but this could power/top-up the emergency lighting batteries and probably power a PA system too. The power consumption would be minimal, and separate to any systems trying to power 1.5KW hand dryers, air con, Wi-Fi etc.

 

[michael769]

That's probably because the mechanisms are often pneumatic with, I would imagine, only minimal power required for the control system and valves. But that means it's not just lack of juice that can cause issues.

The 156 I get home normally sits in Waverley for about an hour (IIRC) with the engine off before it is due to leave. It's not unusual to have the driver rev the engine up to recharge the air whilst waiting for dispatch, but last Friday when the guard came to open it up, he operated the door control only for nothing to happen. Cue a request for help to manhandle the doors open. Turns out the air tanks were so low on pressure it could not move the doors. It seems this is the norm for 156s in the depot first thing in the morning - turns out the handle on the outside of the door is not just there for passengers to grab onto!

Which leads me to a question do diesels have any protection (or separate battery) to ensure they do not get run down to the point where the starter motor will not operate?

 

[driver9000]

There is a low voltage protection on diesels - on some this is identified by flashing tail lamps. Engine starting is worked from the starting battery although as with cars and buses flat batteries can occur meaning the engine will need to be boost started. I've only ever had one non starter though.

 

[Erniescooper]

That's probably because the mechanisms are often pneumatic with, I would imagine, only minimal power required for the control system and valves. But that means it's not just lack of juice that can cause issues.

The 156 I get home normally sits in Waverley for about an hour (IIRC) with the engine off before it is due to leave. It's not unusual to have the driver rev the engine up to recharge the air whilst waiting for dispatch, but last Friday when the guard came to open it up, he operated the door control only for nothing to happen. Cue a request for help to manhandle the doors open. Turns out the air tanks were so low on pressure it could not move the doors. It seems this is the norm for 156s in the depot first thing in the morning - turns out the handle on the outside of the door is not just there for passengers to grab onto!

Which leads me to a question do diesels have any protection (or separate battery) to ensure they do not get run down to the point where the starter motor will not operate?

I only know about 175/180 and if the 24v battery drops below a certain voltage the fire bells ring which provides the crew with a good incentive to trip the auxilliaries, also there is a separate 24v battery boost which will run off the 110v battery if the 24v side is too low.

 

[Crossover]

I was on a Voyager from Piccadilly yesterday which had computer trouble.

When I boarded, the engines were (unusually) all shut down and that meant all the doors were inoperative (either open or closed depending on their state at the time)
Didn't think anything of the quietness walking up until I tried to open a door and nothing happened...then noticed the door interlock lights were all off which I thought was odd as well as the display screens. Once on board all the door control lights were off (so open doors couldn't be closed either)

The engines shuddered into life not long after (about 10 min to departure but still had all those not travelling running for the hills!) and then they announced they were having computer trouble and the doors would be locked but then rereleased prior to departure. The engines stopped again, with it went all the reading lights, reservation systems and aircon, that I noticed. Couldn't say about the PIS or sockets. While the engines were off the PA system was used so that was being given power still and most of the centre aisle fluorescents were on.

I have also been on a Pendolino which has undergone a full reboot (which I'm guessing involved dropping the panto) apparently due to a PA fault, so we had no announcement of it happening. On that occasion most (if not all actually) of the lights went, aircon did, reservation systems and mobile signal went from full to nigh on non existant, so evidently all the boosters went too. Not sure about the doors etc. I don;t think they used the PA while the power was off either.

It would make sense that on reserve power non essentials go off so you don't get WiFi, most lighting, mobile boosters etc

 

[hairyhandedfool]

I think the batteries on a 319 give power to the CSR, emergency lighting, PA, tail light and auxiliary compressor.

 

[ryan125hst]

I think the batteries on a 319 give power to the CSR, emergency lighting, PA, tail light and auxiliary compressor.

So does everything else (such as main lighting) go off straight away. What about the equipment for the toilet? Is this the same for all older trains such as the class 14x's, 15x's and 31x's?

What about modern trains with other systems such as air conditioning? Does everything go off straight away or is there a power down sequence?

I know that when I went to York on the train from Retford, there is is neutral section shortly after leaving. Everything went quiet in the Mark 4 coach, so I think the fans and air conditioning shut down. The main lights were still on though. I'm guessing the 240v sockets and buffet/kitchen equipment would be the same, probably powered by the battery for at least a few seconds, as it would be very inconvenient for them to go off at every neutral section!

 

[driver9000]

The toilets on 14x and 15x are traditional flush toilets although the water on the 14x is drawn up to the toilet bowl by air, as long as there is air (and water) then the flush will work. On 15x the toilet tank is in the roof and works by gravity so again as long as there is water the flush will work.

With the air conditioning and other systems they will shut down when they lose their supply without going through any normal run down period (there would be no power for one) leaving the basic systems left to run off the auxiliaries. In a total power loss situation you want the battery to last as long as it possibly can without any undue drain from it, killing the extras off straight away is the best way of achieving it. For passing through neutral sections the systems may have a grace period before cutting off the power to account for the time the train spends between the APC magnets, however I wouldn't want to commit 100% to that as I drive exclusively diesel traction and I'm sure someone who works with AC traction would know better.

 

[Fincra5]

So does everything else (such as main lighting) go off straight away. What about the equipment for the toilet? Is this the same for all older trains such as the class 14x's, 15x's and 31x's?

What about modern trains with other systems such as air conditioning? Does everything go off straight away or is there a power down sequence?

I know that when I went to York on the train from Retford, there is is neutral section shortly after leaving. Everything went quiet in the Mark 4 coach, so I think the fans and air conditioning shut down. The main lights were still on though. I'm guessing the 240v sockets and buffet/kitchen equipment would be the same, probably powered by the battery for at least a few seconds, as it would be very inconvenient for them to go off at every neutral section!

Its kind of a shut down sequence AFAIK. Leaving the emergency systems/ comms last to be on.

 

[hairyhandedfool]

So does everything else (such as main lighting) go off straight away. What about the equipment for the toilet? Is this the same for all older trains such as the class 14x's, 15x's and 31x's?....

There is a delay as neutral sections don't seem to affect the 319s (although the sections aren't that close to stations on the MML, so we are talking about a couple of seconds of no main power supply). There is no air conditioning on a 319, so I don't know how that is affected by such things.

I doubt diesel units have the auxiliary compressor (if they do it does something different to the 319s), I'm relatively sure the toilet is a traditional flush one, so doesn't require power. Classes 317-322 are likely to be the same as they are mostly the same design.

 

[ryan125hst]

Taking the Mark 4 coach as an example (as I live near the ECML and it has most of the things that I listed in the first post), what order does the electrical equipment shut down?

Is the order different in a neutral section different to what would happen when the ETS is turned off, to change the loco, for example?

 

[driver9000]

All non essential systems would be lost immediately to conserve the batteries.