1992 Tube Stock

[Sad Sprinter]

I noticed when the Central Line trains start up, there’s a high pitched hum that last a few seconds before giving way to a standard accelerating pitch as the train accelerates. Does anyone know what causes the initial high pitched hum?

 

[AM9]

Probably a chopper regulator to control the starting DC current, similar to that on the class 319s. Once the speed rises, the noise from the motor pinion drives and the magnetic fields that cause vibration of their ferrous parts, drowns the traction electronics sound.

 

[bramling]

Probably a chopper regulator to control the starting DC current, similar to that on the class 319s. Once the speed rises, the noise from the motor pinion drives and the magnetostriction causing vibraion of their steel parts drowns the traction electronics sound.

That’s what it is. There were a small handful of class 455s fitted with a similar system as an experiment, converted back to standard at refurbishment, these sounded very similar.

The 92 stock may not sound like that for long however - there are plans for retractioning.

 

[AM9]

That’s what it is. There were a small handful of class 455s fitted with a similar system as an experiment, converted back to standard at refurbishment, these sounded very similar.

The 92 stock may not sound like that for long however - there are plans for retractioning.

I'd heard that somewhere. Do you know what the DC kit will be replaced with, 3 phase ac?

 

[bramling]

I'd heard that somewhere. Do you know what the DC kit will be replaced with, 3 phase ac?

Off the top of my head, I seem to remember they had got as far as awarding the contract to Bombardier, although not much has been said since. One presumes this would be an updated version of what exists on the 2009 and S stocks.

Not sure if anything has changed, I’ll try and find some paperwork when I get a chance.

Lots of ongoing issues with these trains. As part of the same package there are plans to replace the train management system, and address issues such as poor condition of the bodyshells, other reliability issues, accessibility compliance and interior ambience.

 

[Sad Sprinter]

That’s a shame, I always find the sound of those trains very nostalgic. It was the sound of the future 20 years ago!

 

[Mikey C]

Off the top of my head, I seem to remember they had got as far as awarding the contract to Bombardier, although not much has been said since. One presumes this would be an updated version of what exists on the 2009 and S stocks.

Not sure if anything has changed, I’ll try and find some paperwork when I get a chance.

Lots of ongoing issues with these trains. As part of the same package there are plans to replace the train management system, and address issues such as poor condition of the bodyshells, other reliability issues, accessibility compliance and interior ambience.

So apart from the traction equipment, bodywork and interior they're fine

 

[bramling]

That’s a shame, I always find the sound of those trains very nostalgic. It was the sound of the future 20 years ago!

Ironically, when they work they’re actually not bad trains. Unfortunately their reliability is increasingly appalling. As you say, at one point they were the future, which unfortunately has been their big problem. Issues with traction motors and bogies showed up within a few years of introduction - the Chancery Lane derailment was roughly just a decade after their introduction.

 

[bramling]

So apart from the traction equipment, bodywork and interior they're fine

Add obsolescence of electronics to that list too!

I seem to remember the bogies have already been replaced a few years ago.

 

[Mikey C]

Add obsolescence of electronics to that list too!

I seem to remember the bogies have already been replaced a few years ago.

An amazing contrast to say the 1995 stock from only a few years later which has had only had a minor refurbishment with no major work planned (or needed)

 

[Journeyman]

As you say, at one point they were the future, which unfortunately has been their big problem.

Unfortunately, the earliest adoptions of fully electronic/digital traction equipment on other railways at the same time didn't go brilliantly well either, and resulted in some horrendous reliability problems. The 323s, the Networkers and early Electrostars were a nightmare, although all got better later.

The 92s started badly, only got fractionally better despite dozens of mods, and are starting to get a lot worse again.

Shame - in terms of performance, ambience and comfort, they're not bad, and I always enjoy a spin on them. When first introduced, they were a radical step forward, and I remember being blown away by the very, very different look and feel from anything that had gone before.

 

[bramling]

Unfortunately, the earliest adoptions of fully electronic/digital traction equipment on other railways at the same time didn't go brilliantly well either, and resulted in some horrendous reliability problems. The 323s, the Networkers and early Electrostars were a nightmare, although all got better later.

The 92s started badly, only got fractionally better despite dozens of mods, and are starting to get a lot worse again.

Shame - in terms of performance, ambience and comfort, they're not bad, and I always enjoy a spin on them. When first introduced, they were a radical step forward, and I remember being blown away by the very, very different look and feel from anything that had gone before.

It’s ironic that in some ways the 92 stock traction system, at least, should have been okay - they had three prototypes, and went for a traction system which had already been surpassed, note how the 92 stock entered service roughly the same time as the first Networkers. In that sense they perhaps should have represented the ultimate pinnacle of DC traction. As you say, reality was rather different - and the fact that problems with the trains surfaced so early on shows it was design issues rather than wear and tear.

In fairness, is there a DC traction system in existence which is pushed quite so hard as the 92 stock? Initially 62mph running on ATO stop/start metro work with rapid acceleration and braking on a high-throughout signalling system on a torturous turn-of-the-century alignment with long end-to-end runs and an increased-since-inception off-peak availability requirement?

For those who enjoy the sound, perhaps the W&C units may escape the retractioning. Not sure if they are included in the improvement project scope, and even if they are that might change.

 

[rebmcr]

For those who enjoy the sound, perhaps the W&C units may escape the retractioning. Not sure if they are included in the improvement project scope, and even if they are that might change.

I would strongly suspect that the Central and W&C fleets share a spare parts inventory. Unless said inventory already has enough stock to last the rest of the 483's lifespan, it would make more sense to keep them compatible.

 

[bramling]

I would strongly suspect that the Central and W&C fleets share a spare parts inventory. Unless said inventory already has enough stock to last the rest of the 483's lifespan, it would make more sense to keep them compatible.

Unless the work can be done at Waterloo, which might be an ask as I’m not sure the depot would be able to cope with a road out of use on a medium term basis, there’s two issues with doing the W&C fleet. Firstly the cost of getting the units in and out, and secondly the impact on the service - either through removing a train at a time and running a reduced timetable, or closing the line for a period and doing the job in one hit. Quite a bit of pain for questionable gain - the W&C units aren’t so much of a problem, and presumably could be kept going with spares off the main fleet.

Not sure what the official plan is though, will try and find out.

 

[Journeyman]

I would strongly suspect that the Central and W&C fleets share a spare parts inventory. Unless said inventory already has enough stock to last the rest of the 483's lifespan, it would make more sense to keep them compatible.

There's actually now a number of very significant differences between the Central and W&C fleets. The Central trains have been upgraded for ATO and undergone a wide range of other mods, the W&C trains are much closer to original condition. At one point, there was a plan to refurbish 1972 Stock trains for the W&C, to allow the 1992 Stock on that line to boost the size of the Central fleet, but it was ruled out when it was realised that the trains were actually too different to make it feasible.

Unless the work can be done at Waterloo, which might be an ask as I’m not sure the depot would be able to cope with a road out of use on a medium term basis, there’s two issues with doing the W&C fleet. Firstly the cost of getting the units in and out, and secondly the impact on the service - either through removing a train at a time and running a reduced timetable, or closing the line for a period and doing the job in one hit. Quite a bit of pain for questionable gain - the W&C units aren’t so much of a problem, and presumably could be kept going with spares off the main fleet.

Not sure what the official plan is though, will try and find out.

Yeah, all the DC traction kit removed from the Central line trains will allow an enormous amount of spares for the W&C. I'm pretty sure the W&C is going to get the new Deep Tube Upgrade trains before the Central, so that all fits together quite logically.

 

[Journeyman]

In fairness, is there a DC traction system in existence which is pushed quite so hard as the 92 stock? Initially 62mph running on ATO stop/start metro work with rapid acceleration and braking on a high-throughout signalling system on a torturous turn-of-the-century alignment with long end-to-end runs and an increased-since-inception off-peak availability requirement?

Good point, I think much of LU presents very significant operating challenges, and it's a harsher environment than most people realise.

The amount of space available for equipment on a tube-sized train is tiny, and presents a lot of design constraints. Obviously, the 1938 Stock was the first successful attempt to fit everything under the floor, without a very large equipment compartment encroaching into the space available for passengers. The '38s had a long and successful career, and set the standards for all production fleets until the '92s broke the mould. However, the '38s were extremely problematic when they were new, and getting freshly-miniaturised motors, compressors and control gear working properly took a long time. Admittedly, this wasn't helped by war breaking out while they were being introduced, but besides that, the circumstances were similar - a radical departure from previous tried-and-tested principles, that caused quite a few problems while people got used to it. Sadly, the 92s haven't really improved much over the years.

I think the only really unsuccessful design of tube stock prior to the 92s was the 83s, but there were a lot of political and circumstantial factors involved in that, rather than technical ones.

 

[bramling]

Good point, I think much of LU presents very significant operating challenges, and it's a harsher environment than most people realise.

The amount of space available for equipment on a tube-sized train is tiny, and presents a lot of design constraints. Obviously, the 1938 Stock was the first successful attempt to fit everything under the floor, without a very large equipment compartment encroaching into the space available for passengers. The '38s had a long and successful career, and set the standards for all production fleets until the '92s broke the mould. However, the '38s were extremely problematic when they were new, and getting freshly-miniaturised motors, compressors and control gear working properly took a long time. Admittedly, this wasn't helped by war breaking out while they were being introduced, but besides that, the circumstances were similar - a radical departure from previous tried-and-tested principles, that caused quite a few problems while people got used to it. Sadly, the 92s haven't really improved much over the years.

I think the only really unsuccessful design of tube stock prior to the 92s was the 83s, but there were a lot of political and circumstantial factors involved in that, rather than technical ones.

Some good points here. As you say the 83 stock never really had the chance to flourish, it was always going to be messed up by the single-leaf door decision which arose from reduced passenger numbers during the 1980s, and then face the issue of the JLE which meant a mixed fleet was always going to be a problem. The 83 stock was never a wonderful design, however many of the build quality and design issues could no doubt have been overcome had there been a desire to do so, albeit possibly at considerable expense in the case of the single-leaf doors.

Had the East London Line been rebuilt into simply a LU New Cross / New Cross Gate to Highbury service then they would almost certainly have found their way onto that.

 

[philthetube]

Lots of ongoing issues with these trains. As part of the same package there are plans to replace the train management system, and address issues such as poor condition of the bodyshells, other reliability issues, accessibility compliance and interior ambience.

Ironically, when they work they’re actually not bad trains. Unfortunately their reliability is increasingly appalling. As you say, at one point they were the future, which unfortunately has been their big problem. Issues with traction motors and bogies showed up within a few years of introduction - the Chancery Lane derailment was roughly just a decade after their introduction.

Add obsolescence of electronics to that list too!

I seem to remember the bogies have already been replaced a few years ago.

Keep the doors then.

 

[Mikey C]

Keep the doors then.

The advert holders are fine too...

 

[bramling]

For those interested, I've found out a little more on the subject of 92 stock improvements.

This is a few months old so things might have changed slightly in the meantime, however the list of things in scope is as follows:
AC retractioning plus replacing some parts of the auxiliary systems (e.g. static converter)
Train management system ("data transmission system" on the 92 stock) replacement
Achieving accessibility compliance as far as possible
Repairs to flooring including corrosion
Repairing door pillar cracks
Replacement of car body ends
Change to LED lighting
Install saloon CCTV
Door overhaul
Increase regenerative braking voltage capability

The plan appears to include a more limited scope for the Waterloo & City units, primarily focusing on accessibility and ambience. The W&C units will not be retractioned according to these proposals.

 

[Nym]

So apart from the traction equipment, bodywork and interior they're fine

The bogies and gearboxes have already been replaced...

 

[Nym]

An amazing contrast to say the 1995 stock from only a few years later which has had only had a minor refurbishment with no major work planned (or needed)

1996TS is having quite a lot of issues with obsolescent electronics though, remember that 1995TS is actually a 1999 era train.

There's actually now a number of very significant differences between the Central and W&C fleets. The Central trains have been upgraded for ATO and undergone a wide range of other mods, the W&C trains are much closer to original condition. At one point, there was a plan to refurbish 1972 Stock trains for the W&C, to allow the 1992 Stock on that line to boost the size of the Central fleet, but it was ruled out when it was realised that the trains were actually too different to make it feasible.

Yeah, all the DC traction kit removed from the Central line trains will allow an enormous amount of spares for the W&C. I'm pretty sure the W&C is going to get the new Deep Tube Upgrade trains before the Central, so that all fits together quite logically.

W&C Technically had ATO fitted, but it was only used for CSDE, but was since removed and replaced with the much older Redifon CSDE around 5 years ago to generate spares for the CL Fleet.

Also, not to mention the numerous, very numerous issues that prevent 1972TS fitting on the W&C, key among which is that it would very likely rip it's inter-car jumpers off of the multipoints while bending the tray coupler and causing a main line burst the first time it tried to go round the curves. (FYI, they don't technically even fit in London Road Depot 1 road without crashing the bogie side frames into the outer longs / sole bar).

Oh, and you'd need to take up quite a lot of units and convert some motor cars into trailer cars (or fit autocouplers to trailers) and do some other pretty serious re-wiring to be able to make them fit on the lifting road.

Keep the doors then.

They're replacing them too.

 

[Mikey C]

1996TS is having quite a lot of issues with obsolescent electronics though, remember that 1995TS is actually a 1999 era train.

The first 1995TS arrived for testing at the end of 1996 so they're older than that. Technology moved very quickly in that period I guess