Location: Melbourne, Victoria, Australia
Not much to add, but I'm surprised no thread has been added here. Is it just a case of a union making the most of a new Labor Govt?
Union threats to strike a whinge or justified?
ScottAus
Station Master
Location: Melbourne, Victoria, Australia
kuldalai
Chief Commissioner
There have been numerous incidents where the solid state inverters under Siemens tarins have exploded and caught fire . As such this is a potential safety issue for both staff and passengers .
It appears that the Metro fix so far is to strap the cabinet smeg with extra strapping .
One wonders why the inverters are exploding and why Metro does not appear to be more pro active in finding a proper fix or replacement with inverters taht work .
So drivers appear to have legitimate cause for complaint, ditto with defective PA on some Comeng trains .
It appears that the Metro fix so far is to strap the cabinet smeg with extra strapping .
One wonders why the inverters are exploding and why Metro does not appear to be more pro active in finding a proper fix or replacement with inverters taht work .
So drivers appear to have legitimate cause for complaint, ditto with defective PA on some Comeng trains .
LancedDendrite
Chief Commissioner
Location: Gheringhap Loop Autonomous Zone
The Age report the other day seemed to indicate that they were running low on spare capacitors for the Static Inverters, so they're replacing them as they fail instead of doing it as preventative maintenance.
Bogong
Chief Commissioner
Location: Essendon Aerodrome circa 1980
While there will always be some concern with at least a few aspects of the thousands of things involved in running a large suburban railway system and it's rolling stock, it's interesting that the union picked a couple of them as the pretext for a possible strike, just weeks after the state election which was won be a political party they are affiliated with.
I suspect the original poster has it right, perhaps the union is just testing the new state government to see how far they can push the new premier and transport minister to see what they can get away with and if the state government is prepared to stand up against the union?
I suspect the original poster has it right, perhaps the union is just testing the new state government to see how far they can push the new premier and transport minister to see what they can get away with and if the state government is prepared to stand up against the union?
YM-Mundrabilla
Minister for Railways
Location: Mundrabilla but I'd rather be in Narvik
The Siemens trains have been around for 12 years.
What has changed so that the static inverters are (apparently suddenly) now a serious problem? Has Siemens/Metro maintenance managed to buy a job lot of el cheapos or has their maintenance regime changed whereby these things are being run beyond their use by date (assuming that they have one)?
There has to be more to this problem bearing in mind the four players, Metro, Siemens, the Government and the Union all of which have an axe of one sort or another to grind.
Reminds one of all the multitude of issues/spin surrounding the Siemens braking which, eventually, exonerated the drivers whom Connex/Metro had originally blamed for the problem.
Perhaps one of our good learned electrical people can put together a para or two on 'the life cycle of a static inverter'.
What has changed so that the static inverters are (apparently suddenly) now a serious problem? Has Siemens/Metro maintenance managed to buy a job lot of el cheapos or has their maintenance regime changed whereby these things are being run beyond their use by date (assuming that they have one)?
There has to be more to this problem bearing in mind the four players, Metro, Siemens, the Government and the Union all of which have an axe of one sort or another to grind.
Reminds one of all the multitude of issues/spin surrounding the Siemens braking which, eventually, exonerated the drivers whom Connex/Metro had originally blamed for the problem.
Perhaps one of our good learned electrical people can put together a para or two on 'the life cycle of a static inverter'.
JoppaJunction
Chief Train Controller
Location: Banned
https://www.railpage.com.au/news/s/rail-strike-fear-as-wage-talks-begin
Metro Trains image has improved.
Metro Trains image has improved.
YM-Mundrabilla
Minister for Railways
Location: Mundrabilla but I'd rather be in Narvik
https://www.railpage.com.au/news/s/rail-strike-fear-as-wage-talks-begin
Metro Trains image has improved.
Are you sure that she is a Metro mouth? They don't usually appear in public.
Looks more like Luba Grigorovitch from the RTBU to me.
freightgate
Minister for Railways
Location: Albury, New South Wales
I don't think that is what he meant. 
railblogger
Chief Commissioner
Location: At the back of the train, quitely doing exactly what you'd expect.
If this really is about the safety of the workers, then their complaints are justified because if they aren't safe, neither is the traveling public.
YM-Mundrabilla
Minister for Railways
Location: Mundrabilla but I'd rather be in Narvik
Once again where is the independent (invisible?) Rail Safety Regulator who should surely be providing a professional and impartial determination on the problem at hand?
LancedDendrite
Chief Commissioner
Location: Gheringhap Loop Autonomous Zone
The Siemens trains have been around for 12 years.Alright, here goes. Static inverters are a type of power electronics equipment, in this case used to convert the 1500V direct current overhead into alternating current that can be used by the induction motors in the bogies. Like many other kinds of power electronics, they use capacitors for voltage regulation. Judging by the stated public facts of 'Siemens train static inverters are blowing up violently' and 'it was the capacitors wot done it', I would guess that the capacitors used in this instance are electrolytic capacitors.
What has changed so that the static inverters are (apparently suddenly) now a serious problem? Has Siemens/Metro maintenance managed to buy a job lot of el cheapos or has their maintenance regime changed whereby these things are being run beyond their use by date (assuming that they have one)?
...
Perhaps one of our good learned electrical people can put together a para or two on 'the life cycle of a static inverter'.
Normally when an electronic component dies it will go quietly, perhaps emitting a puff of the 'magic smoke' as it finishes its useful life. Electrolytic capacitors have a different failure mode - they blow up. This happens when the dielectric materials inside the capacitor break down, from too much voltage and too high a temperature. High temperature conditions (such as when you flog a Siemens or send it out on one too many 40+ deg C days) prematurely 'age' the capacitor and assist in dielectric breakdown. What happens during a breakdown, you ask? Why, the material vaporises. A capacitor is a small confined space, so rapid vaporisation + confined space = explosion. Here's an example: The Case of the Exploding Capacitor
Given that the Siemens EMUs were introduced onto the network in 2003, I'd guess that their static inverter capacitors are coming up to the end of their life - in consumer electronics, electrolytic caps have a lifetime ranging from 2 years to a decade or more, depending on how well they were built. Of course, flogging the units hard doesn't help. In any case, they should've started replacing the capacitors around about now, but they don't seem to have many spares, if any. One might say that the underlying problem could be Metro's approach to maintenance as a whole, but I'll give them the benefit of a doubt until there's a publicly released report on the matter.
Regarding rail worker safety vs passenger safety: the static inverters on the Siemens EMUs are mounted in the undercarriage. When they blow up, they blow outward - the direction that the static inverter box channels them (the doors appear to be channelled along with the rapidly expanding ex-capacitor gas, hence the heavy duty straps remedy). This isn't a huge hazard to passengers, but is to rail workers walking or standing alongside a Siemens as it passes by or as it stands still but energised.
YM-Mundrabilla
Minister for Railways
Location: Mundrabilla but I'd rather be in Narvik
Many thanks LD that is very helpful to us non electrical types.
As things stand it seems that Metro is simply trying to contain any explosions with 'Grunt Straps' (available from Bunnings?) as an interim measure. I hope that Steamrail do not use band-aids on boilers!
Are the Siemens trains unique to Victoria in this regard (1,500V DC) or would/should this problem be well known in other countries where this basic train runs?
The bit that I don't understand is why there are no apparent reports or investigations on any of the Rail Safety Regulator(s) sites (that I can see anyway).
As things stand it seems that Metro is simply trying to contain any explosions with 'Grunt Straps' (available from Bunnings?) as an interim measure. I hope that Steamrail do not use band-aids on boilers!
Are the Siemens trains unique to Victoria in this regard (1,500V DC) or would/should this problem be well known in other countries where this basic train runs?
The bit that I don't understand is why there are no apparent reports or investigations on any of the Rail Safety Regulator(s) sites (that I can see anyway).
railblogger
Chief Commissioner
Location: At the back of the train, quitely doing exactly what you'd expect.
I believe so. Correct me if I'm wrong but I'm quite sure they draw 25kw AC power.
YM-Mundrabilla
Minister for Railways
Location: Mundrabilla but I'd rather be in Narvik
I believe so. Correct me if I'm wrong but I'm quite sure they draw 25kw AC power.I thought that they may be unique having been modified to cater for the 1,500V DC and possibly other Melbourne requirements.
TheBlacksmith
Chief Commissioner
Location: Ankh Morpork
I believe so. Correct me if I'm wrong but I'm quite sure they draw 25kw AC power.
Are you speaking after voltage conversion or before? Did you really mean 25kw (watts) or 25kV (volts).
They run from 1500 volts DC off the existing catenary.
I don't believe 'flogging' the trains will shorten the life span of the electrolytic capacitors, it is more likely that they were under-specified for the job. As has already been pointed out, high temperatures can affect their life span, electrolytic capacitors have a wet electrolyte and are usually vented through a safety vale to release gas, however if there is a flashover internally, then an explosion of the capacitor can occur.
LancedDendrite
Chief Commissioner
Location: Gheringhap Loop Autonomous Zone
I don't believe 'flogging' the trains will shorten the life span of the electrolytic capacitors, it is more likely that they were under-specified for the job. As has already been pointed out, high temperatures can affect their life span, electrolytic capacitors have a wet electrolyte and are usually vented through a safety vale to release gas, however if there is a flashover internally, then an explosion of the capacitor can occur.Flogging a train involves high usage cycles = high temperature periods within the static inverter box = damage to the capacitors. High temperature days don't help either, as you and I have noted.
Such is the folly of purchasing an 'off-the-shelf' EMU designed for use in European subways.
Oh, and YM-Mundrabilla, the EMU family in question is used in a few other places - mostly actual metros in Europe and Asia.
woodford
Chief Commissioner
As the two previous replies say, the problem is the design of these particular convertors.
Electronic converson of power is now a stable engineering design state even at VERY high power levels, such convertors being used up 500,000 volts and in the 100's of megawatt range.
When designing such things particularly in regard to electrolytic capacitors its my opinion one MUST be real conservative, if you run them close to max temps and ripple currents you are simply asking for trouble, specially if one is running such items during a Victorian summer. In power electronics failure's caused be running such things (Capacitors) close to the upper limits is and has been a _________________WELL________________ known problem for many years, there's no excuse these days!.
woodford
Electronic converson of power is now a stable engineering design state even at VERY high power levels, such convertors being used up 500,000 volts and in the 100's of megawatt range.
When designing such things particularly in regard to electrolytic capacitors its my opinion one MUST be real conservative, if you run them close to max temps and ripple currents you are simply asking for trouble, specially if one is running such items during a Victorian summer. In power electronics failure's caused be running such things (Capacitors) close to the upper limits is and has been a _________________WELL________________ known problem for many years, there's no excuse these days!.
woodford
YM-Mundrabilla
Minister for Railways
Location: Mundrabilla but I'd rather be in Narvik
Thanks all. Perhaps they were cheap on the day which would meet the specification admirably.
Madjikthise
Deputy Commissioner
Regarding rail worker safety vs passenger safety: the static inverters on the Siemens EMUs are mounted in the undercarriage. When they blow up, they blow outward - the direction that the static inverter box channels them (the doors appear to be channelled along with the rapidly expanding ex-capacitor gas, hence the heavy duty straps remedy). This isn't a huge hazard to passengers, but is to rail workers walking or standing alongside a Siemens as it passes by or as it stands still but energised.
What about the public walking beside the track? (Where it's allowed, plenty of places around the network.) Or standing on an opposing platform? Or waiting at the level crossing, standing barely 2m away from the undercarriage as it goes past?
Are they immune from flying debris?
railblogger
Chief Commissioner
Location: At the back of the train, quitely doing exactly what you'd expect.
Are you speaking after voltage conversion or before? Did you really mean 25kw (watts) or 25kV (volts).I may have confused the two but thanks for the clarification.
They run from 1500 volts DC off the existing catenary.
Pressman
Spirit of the Vine
Location: Wherever the Tin Chook or Qantas takes me
Normally when an electronic component dies it will go quietly, perhaps emitting a puff of the 'magic smoke' as it finishes its useful life. Electrolytic capacitors have a different failure mode - they blow up. This happens when the dielectric materials inside the capacitor break down, from too much voltage and too high a temperature. High temperature conditions (such as when you flog a Siemens or send it out on one too many 40+ deg C days) prematurely 'age' the capacitor and assist in dielectric breakdown. What happens during a breakdown, you ask? Why, the material vaporises. A capacitor is a small confined space, so rapid vaporisation + confined space = explosion. Here's an example: The Case of the Exploding Capacitor
A capacitor is a device that stores electrical potential, it is usually a pair of very thin plates of metal on a roll, the dielectric is an insulating gel that separates the two plates. A break down on the dielectric allows the plates to "short circuit", this short circuit is a quite violent sudden electrical discharge, which often vaporises the dielectric and hence the capacitor "explodes"
The resultant explosion often causes serious damage to the other electronic components surrounding it.
Excessive ambient temperature will cause failure in many electronic components, not just capacitors, likewise excessive voltage will also cause failure. This also relates to the quality of components used in a circuit (A Circuit card made with cheaper components will not last as long as one made with better quality components)
I think railblogger asked a question about voltage .... well an exploding capacitor can destroy a circuit card be it a 12 volt system or a 5,000 volt system, the result is similar regardless of voltage (other than the higher voltage system being a lot more expensive)
DalyWaters
Chief Commissioner
I would have expected that the Siemens trains, at around 10 years old, would have had the capacitors replaced at least once.
I recall hearing of MTM buying a batch of capacitors from China, no doubt to save money.
If so, the solution is straightforward. Buy a batch of capacitors from Siemens that are capable of doing the job.
I recall hearing of MTM buying a batch of capacitors from China, no doubt to save money.
If so, the solution is straightforward. Buy a batch of capacitors from Siemens that are capable of doing the job.
DalyWaters
Chief Commissioner
I would have expected that Railpage people would have been able to recognise the difference between industrial action and a strike. Yet the heading on this thread takes the disappointing media view of "threatened strike".
At no stage was any strike threatened, proposed or spoken of, other than in the media spin of Metro.
The industrial action was to prepare Siemens and Comeng trains in a manner that was considered to be safe for drivers and the public. A strike would have meant not reporting for duty. This was not the case. Each driver was to report as usual and XTrapolis trains would be totally unaffected.
Very bad media reporting, showing a serious anti-union bias and looking very much like it may have been mischievously assisted by the person in the picture above who is no friend of most train drivers.
As for the Comeng trains, the old PA system (and the tail lights) were connected to a battery so that when an overhead power failure occured, the driver could put the tail lights on for safety and also could communicate to the pasengers. This communication is vital, especially as the power to the doors is not there so people need to be warned of whether other trains are running nearby, etc. Also, any evacuation procedure needs to be done via the PA.
The new digital radio system had a major flaw. The PA runs off this radio system (no doubt so that one day Metrol can speak directly to passengers) and has no battery back up. It was all brought to a head by a Comeng breakdown in the City Loop a few weeks ago where the driver was unable to guide passengers at all.
Fair Work Australia mediated and gave MTM one week to fix the Siemens exploding capacitor problem. MTM have now come up with their solution. They are fitting fire retardant blankets in the static invertor cabinet. They found that they couldn't wrap the blanket around the capacitor so they are lining the cabinet walls with this blanket. There are some already running about, looking ridiculous. As for the Comeng PA, somehow MTM have declared it to be a software problem and they think that Siemens will do a software update in the next few weeks.
At no stage was any strike threatened, proposed or spoken of, other than in the media spin of Metro.
The industrial action was to prepare Siemens and Comeng trains in a manner that was considered to be safe for drivers and the public. A strike would have meant not reporting for duty. This was not the case. Each driver was to report as usual and XTrapolis trains would be totally unaffected.
Very bad media reporting, showing a serious anti-union bias and looking very much like it may have been mischievously assisted by the person in the picture above who is no friend of most train drivers.
As for the Comeng trains, the old PA system (and the tail lights) were connected to a battery so that when an overhead power failure occured, the driver could put the tail lights on for safety and also could communicate to the pasengers. This communication is vital, especially as the power to the doors is not there so people need to be warned of whether other trains are running nearby, etc. Also, any evacuation procedure needs to be done via the PA.
The new digital radio system had a major flaw. The PA runs off this radio system (no doubt so that one day Metrol can speak directly to passengers) and has no battery back up. It was all brought to a head by a Comeng breakdown in the City Loop a few weeks ago where the driver was unable to guide passengers at all.
Fair Work Australia mediated and gave MTM one week to fix the Siemens exploding capacitor problem. MTM have now come up with their solution. They are fitting fire retardant blankets in the static invertor cabinet. They found that they couldn't wrap the blanket around the capacitor so they are lining the cabinet walls with this blanket. There are some already running about, looking ridiculous. As for the Comeng PA, somehow MTM have declared it to be a software problem and they think that Siemens will do a software update in the next few weeks.
YM-Mundrabilla
Minister for Railways
Location: Mundrabilla but I'd rather be in Narvik
Thanks DW.
I cannot help but think that the media (apart from anyone else) is hankering for strike action by someone/anyone following the change of government to help sales in the holiday period. Apart from the poor bastards in Paris what has been of major news recently. Even the Essendon hooha has gone quiet. Industrial action should not be necessary on safety issues anyway.
I cannot understand how some of these recent radio mods that have interfered with the Comeng PA system have been approved and implemented and that it took the failure in the underground to bring these 'unintended consequences' to light. The Comeng PA is frequently bad enough (unintelligible for whatever reason) to start with. How does a driver test it anyway as he cannot be at both ends of the train at the same time to listen to himself.
I really wonder sometimes how familiar with reality on the everyday network some of the experts really are and perhaps we should all be grateful for the dose of reality that the drivers have provided in this instance as no one else seems to be either aware or care.
I cannot help but think that the media (apart from anyone else) is hankering for strike action by someone/anyone following the change of government to help sales in the holiday period. Apart from the poor bastards in Paris what has been of major news recently. Even the Essendon hooha has gone quiet. Industrial action should not be necessary on safety issues anyway.
I cannot understand how some of these recent radio mods that have interfered with the Comeng PA system have been approved and implemented and that it took the failure in the underground to bring these 'unintended consequences' to light. The Comeng PA is frequently bad enough (unintelligible for whatever reason) to start with. How does a driver test it anyway as he cannot be at both ends of the train at the same time to listen to himself.
I really wonder sometimes how familiar with reality on the everyday network some of the experts really are and perhaps we should all be grateful for the dose of reality that the drivers have provided in this instance as no one else seems to be either aware or care.
Lad_Porter
Chief Commissioner
Location: Yarra Glen
LD's explanation on Jan 09 is excellent, but one thing not clear is why the exploding capacitor problem is limited to the Siemens trains. The other train types presumably also have to convert the overhead DC to AC? Do they do this in a different way, or use a different type of capacitor?
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