Cracks found in Comeng bogies

 
  Madjikthise Assistant Commissioner

The trains are old, they leak. The state of the track also plays a big part in air usage as the airbags are constantly getting replenished with the train bouncing all over the place.
Yes, the compressors are designed to run continuously.
No, they are not supposed to run continuously. e.g. When at a platform for more than a couple of minutes.
If so, it will be booked as a fault.

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  Braddo Deputy Commissioner

Location: Narre Warren
It may be booked as a fault but nothing is ever done about it. I hope that the brakes are automatically applied if there is no air pressure, we may see a huge disaster in the future if they are not.
  Madjikthise Assistant Commissioner

It may be booked as a fault but nothing is ever done about it. I hope that the brakes are automatically applied if there is no air pressure, we may see a huge disaster in the future if they are not.
Braddo

Classified as a "Maintenance Fault", which is the lowest priority. Loss of pressure below a certain amount will automatically apply the brakes. If it sits there long enough for even the remaining air in the brake cylinders to leak out then the park brake is applied with spring pressure.

Probably reasoned out thus:
"Is it a safety issue?"
"No."
"Meh, fix it later."
  YM-Mundrabilla Minister for Railways

Location: Mundrabilla but I'd rather be in Narvik
'Wot me worry'
'She'll be right'
  FullSeries Assistant Commissioner

Location: Sydney, NSW
The trains are old, they leak. The state of the track also plays a big part in air usage as the airbags are constantly getting replenished with the train bouncing all over the place.
Yes, the compressors are designed to run continuously.
No, they are not supposed to run continuously. e.g. When at a platform for more than a couple of minutes.
If so, it will be booked as a fault.
Madjikthise

Actually they aren't. 1500vDC Pumps create a fair bit of heat. Faulty compressors have been knows to seize or catch fire from running continuously. Some states have rules for continuously running compressors to have the Sync and Governors isolated.
  FullSeries Assistant Commissioner

Location: Sydney, NSW
Classified as a "Maintenance Fault", which is the lowest priority. Loss of pressure below a certain amount will automatically apply the brakes. If it sits there long enough for even the remaining air in the brake cylinders to leak out then the park brake is applied with spring pressure.

Probably reasoned out thus:
"Is it a safety issue?"
"No."
"Meh, fix it later."
Madjikthise

A loss of Brake Pipe pressure will result in the automatic brakes being applied. Guaranteed for 10 mins only with an acceptable leakage of 35kpa/min. Once Main Res pressure gets below 200/300kpa the spring park brakes will begin to apply as there is no longer sufficient pressure to keep them released.
  Madjikthise Assistant Commissioner

Actually they aren't. 1500vDC Pumps create a fair bit of heat. Faulty compressors have been knows to seize or catch fire from running continuously. Some states have rules for continuously running compressors to have the Sync and Governors isolated.
FullSeries

Literature for the Comeng says they are designed to run continuously so as far as we're concerned, they're designed to run continuously. If they catch fire then it's a poor decision to spec it that way.
  Madjikthise Assistant Commissioner

A loss of Brake Pipe pressure will result in the automatic brakes being applied. Guaranteed for 10 mins only with an acceptable leakage of 35kpa/min. Once Main Res pressure gets below 200/300kpa the spring park brakes will begin to apply as there is no longer sufficient pressure to keep them released.
FullSeries

Isn't that what I wrote?
  Braddo Deputy Commissioner

Location: Narre Warren
Literature for the Comeng says they are designed to run continuously so as far as we're concerned, they're designed to run continuously. If they catch fire then it's a poor decision to spec it that way.
Madjikthise

I wish they did catch fire, maybe they'd actually do something about it then (probably not though).
  GvhftrKijl Locomotive Driver

Location: ERD
The governor on the pump in question is shot in which case it pumps regardless of whether air is needed or not. Whilst this is, perhaps, unlikely, I assume that there is a safety valve in the system somewhere which would blow more or less continuously.

...

I assume that a driver can cut out a level of defective compressors enroute if necessary?

YM-Mundrabilla

1. Yes there is. If Main Reservoir pressure exceeds about 775kPa the safety valve kicks in.

3. If we can identify which compressor is running continuously then yes, we can isolate it, however this is limited to when we're changing ends, and only if time permits.
  ljayvee6 Locomotive Fireman

Location: Near the Apm Siding
There would seem to be an element of "You reap what you sow" here...

The second batch of Comeng cars were a substitute for the rebuilding of Harris cars in the "Grey Ghost" program, when it was realised that the cost of the rebuilding was too high.

To digress for a moment. Some years ago I was taking photos around Grand Junction Road at the north end of Islington Freight Centre in Adelaide. As in many places where level crossings have been replaced by overpasses, the fences had been (unofficially) removed to allow pedestrians to cross the old level crossing site. Anyway it allowed me to cross the line for photos without a long walk. When crossing the line I found a small rectangular metal plate, and of course picked it up. i don't have it handy (I'm interstate for the Holiday Season right now).

It was a bogie plate from a 3000 class, and read something like (from memory)

"State Transit Authority of South Australia"

"Bogie Number....."

"Built by the Public Transport Commission of Victoria at their Bendigo Workshops under licence to Linke Hoffmann Busch (date)"


So I assume that the Victorian bogies were built there too, presumably as a trade off for the work lost in not performing the Harris upgrades, and that lowered the contract price compared to buying new cars with Bradken cast bogies, while providing better braking for the cars destined for the hilly Eastern lines.

However, The Victorian Government can't complain about poor workmanship to anybody else in this case.

I assume that the new bogies they are talking to Alstom about are new frames of the same design, to be built under the same licence.

I understand the motor alternator sets used on disc brake Comeng cars was a unit already in stock for the Harris upgrade program.

M636C
M636C

Oh god..
I remember riding in a refurbished harris.
They smelled of expended gunpowder, and were very shaky.
Hated 'em.
  YM-Mundrabilla Minister for Railways

Location: Mundrabilla but I'd rather be in Narvik
Getting back to bogie cracks (as distinct from compressors and motor alternators):

I was a little surprised at the level of detail in the Age article so far as crack lengths and weld repairs etc were concerned. One could be forgiven for thinking that part may have been written by someone with some knowlege as distinct from the usual Metro and/or Mulder mouths.

Does anyone know where the cracks are actually occurring, please?

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