Unit taken out of service due to faulty PA

[ComUtoR]

What bothers me is that if it is such a critical safety system why do most TOCs not arrange for a proper PA check during a train prep. It really should be a 2 person check. 1 person making the PA and another making sure it is audible in every carriage. (Lots of train preps are done by just one person.)

Might wanna check your GSMR...

 

[Steve Harris]

with a few esoteric exceptions on UK mainline railway services in the 1980s, by which point PA was fitted to most trains

Now.. If you said 1990's I would have agreed. But in the 80's you still had MkI and MkII coaching stock which a hell of a lot didn't have working PA equipment.

 

[mmh]

yes, communication with the passengers is vital. But to take an unit out of service because it isn't working, surely that's over the top??

If it's vital, then clearly no, it isn't over the top, it's essential.

 

[800 Driver]

Day 1 stuff for a driver. No PA is a failure on DOO trains

 

[LOL The Irony]

I get that having a working PA system is "important" and would understand that a unit with a known fault probably shouldn't leave the depot, but is it so vital it justifies taking the unit out of service mid journey - particularly at a place it wasn't even due to stop? I'm struggling to think of a scenario when it would be a matter of life and death - and if they are so crucial why aren't they better designed / maintained in the first place?

I advise looking at the 1988 Gare de Lyon train crash to see the importance of a working PA system.

 

[221129]

Now.. If you said 1990's I would have agreed. But in the 80's you still had MkI and MkII coaching stock which a hell of a lot didn't have working PA equipment.

And how many of those were DOO?

 

[coxxy]

DOO always a failure.. and if I remember rightly if you have a failed hustle alarm at any door and failed PA then it's a failure.

 

[DynamicSpirit]

How about if you just get a faint buzzing noise and unintelligible garble? Should that class as a failure?

You mean, like, the way PA systems normally sounded until about 20-ish years ago?

 

[bobbyrail]

The title of this thread is mis-leading, the unit was NOT taken out of service it actually arrived at London Kings cross (KGX) 42 late and then went to depot as per the diagram for this unit. I presume the fault will have been logged at depot and the unit would not re-enter service until fixed.

 

[tom1649]

You mean, like, the way PA systems normally sounded until about 20-ish years ago?

Yes, exactly that, except it still happens sometimes in Northern-land, always on BR era stock it must be said.

 

[Bikeman78]

On the 0720 from Hitchin->KGX this morning - just south of Digswell we stopped on the fast line for about 10mins. There a few bing-bongs on the PA but no announcement. We then got moving but instead of continuing on the fast line pulled into platform 1 at WGC where we sat for a few minutes. There was then an announcement that the driver was investigating a problem with the PA system in the from two carriages (I was in the rear carriage so suspect the problem was more widespread than he thought). A bit later the doors were released, then a stopping service appeared on platform 2 so most people transferred to that. I don't know if the original service ever got going again.

Something similar happened a few months ago - a crowded 700 was de-trained at Stevenage (it was due to stop there) due to a faulty PA system. This resulted in the platform being dangerously overcrowded IMO.

I get that having a working PA system is "important" and would understand that a unit with a known fault probably shouldn't leave the depot, but is it so vital it justifies taking the unit out of service mid journey - particularly at a place it wasn't even due to stop? I'm struggling to think of a scenario when it would be a matter of life and death - and if they are so crucial why aren't they better designed / maintained in the first place?

I wonder if there was another fault as well? The train was booked non stop from Welwyn North where it departed on time. Stopping on the up fast for 10 minutes seems like a very strange thing to do. I wonder how the driver became aware of the PA fault; is there a fault light in the cab of a 365? Had the driver been aware of the fault prior to Welwyn North I'd expect them to speak with the signaller there if they wanted to be routed into a platform at WGC.

 

[Nagora]

Passengers not getting announcements tend to panic and then self evacuate.

At which point it becomes a problem for the cleaning staff...

More seriously: if the PA system is that vital it seems that there should be pairs of speakers connected to two parallel systems. It can't be that expensive to give a PA a redundant backup, surely?

 

[ComUtoR]

More seriously: if the PA system is that vital it seems that there should be pairs of speakers connected to two parallel systems. It can't be that expensive to give a PA a redundant backup, surely?

I had a conversation with fleet last week. I was reporting a fault and jokingly moaned a bit. The guy at fleet remarked that units have an incredible uptime. Considering how many times the PA is used; they don't break that often.

As to redundancy. How much do you build in. Do you back up the backup ? What happens when the backup fails ?

 

[Dougal2345]

You mean, like, the way PA systems normally sounded until about 20-ish years ago?

Not being funny but I'm amazed by how confident those in this thread seem to be that PA systems work effectively virtually 100% of the time.

It seems pretty commonplace to me to be vaguely aware that an announcement is being made, hearing a soft tinny bleating at the periphery of my hearing, but totally swamped by engine noise, noise through the windows, and passengers shouting to be heard over the engine noise and noise through the windows.

When the systems are tested at the depot as we're assured they are, do they simulate the background noise of being inside a packed 150 with the windows open doing 60 through a tunnel and ensure the PA can be heard over that?

 

[Andyh82]

How about if you just get a faint buzzing noise and unintelligible garble? Should that class as a failure?

If it did, I don’t think Northern would have run a service in the last 20 years. You can hardly ever hear what is being said in a pacer and many sprinters, the conductor would do better shouting down the aisle.

 

[45107]

At which point it becomes a problem for the cleaning staff...

More seriously: if the PA system is that vital it seems that there should be pairs of speakers connected to two parallel systems. It can't be that expensive to give a PA a redundant backup, surely?

Maybe you offer your services to the ROSCOs to solve this if it isn’t expensive.

 

[6Gman]

If it did, I don’t think Northern would have run a service in the last 20 years. You can hardly ever hear what is being said in a pacer and many sprinters, the conductor would do better shouting down the aisle.

This is certainly my experience.

 

[Dougal2345]

If it did, I don’t think Northern would have run a service in the last 20 years. You can hardly ever hear what is being said in a pacer and many sprinters, the conductor would do better shouting down the aisle.

The guard on a FGW service Cardiff to Portsmouth to-day (cl 150) was doing just that. I wondered what all the shouting was about, until she came into our section and repeated it all (a total toilet failure). If the PA was working, she obviously didn't think it was the best option.

 

[satisnek]

East Midlands trains obvious didn't care about having properly working PA systems given the state of them in many of the 222s. About half of the fleet seemed to have PA issues at any one time with the sounds being virtually inaudible in many coaches and dropping in and out in others.

I've heard this once or twice. I thought it was the guard doing a Norman Collier routine...

 

[Tio Terry]

Whilst GSM-R has been mentioned I would point out that CSR also had the ability to let signallers make PA announcements.

The requirement came from a need to instruct an emergency evacuation, for buildings - such as stations and offices - BS5839 applies. There is no British Standard for a similar system for trains so BS5839 was used for guidance only and the systems are not fully compliant with it.

I would also point out that it’s primary design requirement is for a controlled emergency evacuation, the fact that it is used for general announcements is a bonus. It’s not designed to cope with noise from passing trains or wind noise etc., because an evacuation not at a station would mean the train was stationary and all lines blocked with traction power off.

 

[guilbert]

I wonder if there was another fault as well? The train was booked non stop from Welwyn North where it departed on time. Stopping on the up fast for 10 minutes seems like a very strange thing to do. I wonder how the driver became aware of the PA fault; is there a fault light in the cab of a 365? Had the driver been aware of the fault prior to Welwyn North I'd expect them to speak with the signaller there if they wanted to be routed into a platform at WGC.

My *guess* is that there was some other delay after leaving Welwyn North (I think there were power problems over night), the driver went to make a PA to announce the reason for this, realised it wasn't working somehow then contacted the signaller to ask to be routed into a platform at WGC, but as I say that's just a guess. I was really asking generally when/whether a faulty PA requires a train to be taken out of service rather than trying to get to the bottom of exactly what happened on Friday.

 

[Nagora]

As to redundancy. How much do you build in. Do you back up the backup ? What happens when the backup fails ?

All pretty obvious stuff: you have one backup and once one of the two fails you book in maintenance but the unit doesn't have to be pulled out immediately. Ideally you do this for everything up to and including the driver. In reality you only do it where the cost/benefit pays off, but a backup PA system doesn't sound like it should be very expensive. DOO only makes it more worthwhile, of course.

The point made about how reliable these systems is is, of course, important and I don't have any idea what the mean time between failure is. My experience is that PA systems have improved but even on the still-quite-new class 800s I ride to work and back every weekday on, it's not that unusual to have mysterious pops and crackles which make the message hard to understand. Low volume is a fairly common problem too.

Definitely better than anything SWT could muster in the 90's when I lived in Brookwood, though. Sometimes the carriage would dissolve into laughter as some completely garbled set of pops and whistles gibbered at us for a minute or more. It was unusual to have a journey without at least one lost announcement.

 

[whoosh]

If driver does not operate the vigilance function of the DSD then the emergency brakes apply. After about another minute the GSM-R (and the previous CSR -Cab Secure Radio system did the same) sends an emergency alarm to the Signaller. The Signaller can then remotely use the PA system to summon any railway staff travelling on the train etc. or give instructions to the passengers. It is therefore essential the PA works on DOO trains.

 

[daveo]

It is interesting that working PA is now considered vital to safety, when for most of history the railway operated fine before it was invented. I know of course that there were many horrendous accidents in 'the old days' for various reasons but it is unlikely that lack of PA was an issue.

In the old days the train would have passed a signalbox every couple of hundred yards or so. Now it may be many miles from the signaller under whose control it is running.

 

[Tio Terry]

In the old days the train would have passed a signalbox every couple of hundred yards or so. Now it may be many miles from the signaller under whose control it is running.

I think every couple of hundred yards is a bit of an exaggeration, certainly measured in miles in my native Norfolk!

The issue is emergency evacuation of a train, especially one in a tunnel. Without a guard and with the possibility of the driver being incapacitated on a DOO train it was considered essential at the time DOO was being planned that there was a way to tell people on the train what was happening and what they should do.

I know little of the design of the on train PA system but know more about the design of the CSR system.

 

[Surreytraveller]

The issue is emergency evacuation of a train, especially one in a tunnel. Without a guard and with the possibility of the driver being incapacitated on a DOO train it was considered essential at the time DOO was being planned that there was a way to tell people on the train what was happening and what they should do.

If the driver is incapacitated, there's a pretty good chance the GSMR will be incapacitated too.

 

[Tio Terry]

If the driver is incapacitated, there's a pretty good chance the GSMR will be incapacitated too.

Not really, could have a medical problem. Not thinking about some form of train crash. He may have to be out of the cab for some reason.

 

[Bikeman78]

My *guess* is that there was some other delay after leaving Welwyn North (I think there were power problems over night), the driver went to make a PA to announce the reason for this, realised it wasn't working somehow then contacted the signaller to ask to be routed into a platform at WGC, but as I say that's just a guess. I was really asking generally when/whether a faulty PA requires a train to be taken out of service rather than trying to get to the bottom of exactly what happened on Friday.

Yes there was a problem further up the line at Potters Bar. Your train was at the back of a queue of trains when it stopped near Digswell.