Coal ops question, Central West line

 
  james.au Chief Commissioner

Location: Sydney, NSW
I drove along the Central West line this weekend just past, Rocky to Emerald and was astounded by the volume of coal moving on the line.  There were trains waiting at Bluff and beyond to pass, that duplication will be well used!

I saw though that most trains have an engine in the middle.  Can someone explain to me why this is done?  I understand push/pull and figure its an extension of this, but not so much an engine in the middle idea.  Thanks.

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  Raichase Captain Rant!

Location: Sydney, NSW
I saw though that most trains have an engine in the middle.  Can someone explain to me why this is done?  I understand push/pull and figure its an extension of this, but not so much an engine in the middle idea.  Thanks.
jamesbushell.au
It's known as "distributed power", running with a locomotive in the middle of the train helps move the load on grades, without having all of the power at the front. This would likely result in less strain on the drawgear of the wagons, and improve train handling when the front of the train is on a downhill section whilst the rear is still climbing.
  james.au Chief Commissioner

Location: Sydney, NSW
So in theory, a consist with 4 locos would perform better by spacing the 4 locos throughout the consist instead of all at the head?
  Raichase Captain Rant!

Location: Sydney, NSW
So in theory, a consist with 4 locos would perform better by spacing the 4 locos throughout the consist instead of all at the head?
jamesbushell.au
I'm sure there are pros and cons to the distributed power arrangement. My understanding is that it works better for the locomotives to be spaced in such a way on the electric coal trains. NSW Hunter Valley coal trains typically have three locomotives up the front and up to 92 120t wagons trailing though, so who's to say which is "better" overall.

On two different visits to Sarina, I've seen the QLD coal trains run as loco/loco/wagons/loco/wagons change to the current loco/wagons/loco/wagons/loco/wagons arrangement. I imagine this has improved train handling for these heavy trains. The diesel trains I believe have one loco on the front, one in the middle and one on the rear.
  Sulla1 Chief Commissioner

Aurizon runs its 4100 class diesels mid train on the Newlands line too in 1+1+1 Distributed power arrangement. On the same line PN runs its 83 class in 2+1 DP combo with a single loco on the rear. This is what it looks like...



http://youtu.be/0zPvqVZpjP4
  The Vinelander Minister for Railways

Location: Ballan, Victoria on the Ballarat RFR Line
You should have been watching the Central line about a year ago before coal transport started to go off the boil which it clearly has over the past few months.

Mike.
  EMBaldwin Chief Commissioner

Location: Amongst the Cane Fields
Aurizon has a rule in Qld with tandem pair wagons of no triple valve being more than 62 wagons from a brake valve (loco)... or maxium of 62 wagons between brake valves.  When Newlands system first started using 106t tandem-pair wagons, consists were 2x4100-42 wagons-1x4100, 40 wagons.  PN initially started as 3x83s, 82 wagons, as they don't have the same restrictions on number of wagons between brake valves due to use of ECP.  

PN changed to 2x83s-82 wagons-1x83 to service Riverside & Goonyella mines (load in reverse).  When Aurizon started servicing these mines across GAP, consists changed to 1x4100-42 wagons-1x4100-40 wagons-1x4100.

Both PN & Aurizon have since increased trains to 84 wagons in length, with Aurizon also running a 122 wagon train, which runs as 2x4100-38 wagons-1x4100-42 wagons-1x4100-42 wagons.

PN on the Goonyella system changed to a loco-wagons-loco-wagons-loco-wagons setup to allow for block change-outs for servicing of wagons.  Train arrives in depot, 1 loco and 40 wagons taken off of front, and another loco and 40 wagons added to rear, train goes again.  Aurizon and BMA also run in this manner in the Goonshow also now.

The recent change by Aurizon in Blackwater system of FMB setup on 37/3800 trains is apparently to distribute the tractive effort more and reduce the occurence of broken draw gear...
  james.au Chief Commissioner

Location: Sydney, NSW
Thanks EM, very informative.  So essentially safety requirement set by the operators are governing these requirements?

Can I assume from your response that a train can power brakes ahead of and behind it?  Ie, in the first Aurizon example, a loco could power brakes on +62/-62, so in total 124 wagons?
  Exqr Locomotive Driver

Location: Gympie Q.
Thanks EM, very informative.  So essentially safety requirement set by the operators are governing these requirements?

Can I assume from your response that a train can power brakes ahead of and behind it?  Ie, in the first Aurizon example, a loco could power brakes on +62/-62, so in total 124 wagons?
jamesbushell.au
... not long after I came back from the Cent west yrs ago a story went the rounds about problems with braking on an eastbound coal train on the Drummond Range.
It had that on one train, the first 2 locos had climbed the summit and were in braking mode on the way down. Front two locos were in braking mode that is, but the second two were still pushing, resulting in them taking over the train, which ended up with 7000 tonnes of coal in the dirt.
I can't speak for the veracity of the story but it makes interesting reading.
  M636C Minister for Railways

... not long after I came back from the Cent west yrs ago a story went the rounds about problems with braking on an eastbound coal train on the Drummond Range.
It had that on one train, the first 2 locos had climbed the summit and were in braking mode on the way down. Front two locos were in braking mode that is, but the second two were still pushing, resulting in them taking over the train, which ended up with 7000 tonnes of coal in the dirt.
I can't speak for the veracity of the story but it makes interesting reading.
Exqr
I didn't know of any coal trains that crossed the Drummond Range....

My recollection was that the Drummond Range was west of Emerald and east of Alpha.

I've ridden an official inspection train across there and came back on the locomotives of a freight (two 1600s). We stopped at the refreshment room at Bogantungan, as the list and the song says, run by a private individual (the ganger's wife, I think).

There have been a couple of nasty derailments around Black Mountain on the Goonyella line (which is still part of the Central Division, I think...)

M636C
  Exqr Locomotive Driver

Location: Gympie Q.
I didn't know of any coal trains that crossed the Drummond Range....

My recollection was that the Drummond Range was west of Emerald and east of Alpha.

I've ridden an official inspection train across there and came back on the locomotives of a freight (two 1600s). We stopped at the refreshment room at Bogantungan, as the list and the song says, run by a private individual (the ganger's wife, I think).

There have been a couple of nasty derailments around Black Mountain on the Goonyella line (which is still part of the Central Division, I think...)

M636C
M636C
Yeah, perhaps you're right. It wasn't the location that was the main point in the story, it was the derailment itself and what caused it.
  RTT_Rules Oliver Bullied, CME

Location: Dubai UAE
... not long after I came back from the Cent west yrs ago a story went the rounds about problems with braking on an eastbound coal train on the Drummond Range.
It had that on one train, the first 2 locos had climbed the summit and were in braking mode on the way down. Front two locos were in braking mode that is, but the second two were still pushing, resulting in them taking over the train, which ended up with 7000 tonnes of coal in the dirt.
I can't speak for the veracity of the story but it makes interesting reading.
Exqr
Sounds very like an incident on the Black Mountain range, on road to Hay Point.
  RTT_Rules Oliver Bullied, CME

Location: Dubai UAE


The recent change by Aurizon in Blackwater system of FMB setup on 37/3800 trains is apparently to distribute the tractive effort more and reduce the occurence of broken draw gear...
EMBaldwin

How often does the draw gear get damaged?
  Sulla1 Chief Commissioner

As far as I recall the first Black Mountain derailment was caused by crew fatigue and the second was caused by a blocked brake line. DP locomotives may have exacerbated derailments in the past but I haven't heard of a DP set actually causing a derailment. I believe it's fairly common practice to keep mid or rear DP sets pushing over a grade after the lead locos have been powered off.
  Exqr Locomotive Driver

Location: Gympie Q.
As far as I recall the first Black Mountain derailment was caused by crew fatigue and the second was caused by a blocked brake line. DP locomotives may have exacerbated derailments in the past but I haven't heard of a DP set actually causing a derailment. I believe it's fairly common practice to keep mid or rear DP sets pushing over a grade after the lead locos have been powered off.
Sulla1
The "accepted" (by all of us) reason was that a problem occurred in the locotrol unit and the second consist did not shut off on command , resulting in those locos were still pushing until they hit the dirt. But to me, it is only rumour as I don't know.
  Sulla1 Chief Commissioner

I'm pretty sure the official reason was a blocked brake pipe (caused by a piece of coal) behind the mid train locos that left the rear half of the train with no way of reducing brake pipe pressure...an issue not detected until the train ran away on the grade, it was not the DP. Of note, if there had been a rear DP loco that could have released the air on the other side of the blockage then the derailment would have never happened.
  M636C Minister for Railways

How often does the draw gear get damaged?
RTT_Rules

On visits I've seen cars parked on sidings near Waitara with one or more couplers or drawbars missing. Broken knuckles are more common, and the knuckles are designed to fail before the coupler itself.

Many years ago I was riding a Hamersley Iron train (in the first vehicle, a converted box car set up for instrumented testing). I'd walked up to the loco to check our running, and had returned to the car as we drifted down to Seven Mile Yard from the North West Coastal Highway. My recollection is that we had a green signal. In the yard at the far end a loaded moved out on to the main to head for Dampier and our signal was reversed to red and we made an emergency stop.

The train stopped clear of the signal but very roughly. Since nothing was going to happen for a while I walked back to my test cars in positions 201 and 202. The train had broken in five places, the most impressive being a drawbar pulling out between the two cars, but mainly broken knuckles. We'd been recording drawbar forces, but our equipment was turned off. I'd had two kilometres of coaxial cable (then worth a dollar a metre) strung down the train, tied to each ore car with four cable ties. None of the cable ties were damaged but we never found any of the cable apart from a metre and a half at the instrumentation car.

What I'm trying to say is that there can be very high forces on couplers from train action, either on the road or when starting and stopping, although ECP brakes can help a lot with the stopping  since the delay in application is avoided. Going through a dip at speed where couplers go from compression to tension very quickly can be a problem, as well as the going over a hump as discussed above.
  EMBaldwin Chief Commissioner

Location: Amongst the Cane Fields
I'm pretty sure the official reason was a blocked brake pipe (caused by a piece of coal) behind the mid train locos that left the rear half of the train with no way of reducing brake pipe pressure...an issue not detected until the train ran away on the grade, it was not the DP. Of note, if there had been a rear DP loco that could have released the air on the other side of the blockage then the derailment would have never happened.
Sulla1
This derailment was caused by an errant O-ring in the brake gear of the ELRC wagon, causing the ELRC to pump the brakes off while the lead loco was trying to apply the brakes - resulting in only approx the first quarter of the train actually applying brakes.

Had nothing to do with the "accepted" reason as stated by Exqr
  Johnmc Moderator

Location: Cloncurry, Queensland
This derailment was caused by an errant O-ring in the brake gear of the ELRC wagon, causing the ELRC to pump the brakes off while the lead loco was trying to apply the brakes - resulting in only approx the first quarter of the train actually applying brakes.

Had nothing to do with the "accepted" reason as stated by Exqr
EMBaldwin
Confirmed - as part of my driver training, I saw a video where one of the operations managers showed the actual part of the ELRC which had the problem o-ring.

... which was the last time that QR bought o-rings from a NASA surplus sale Razz
  RTT_Rules Oliver Bullied, CME

Location: Dubai UAE


... which was the last time that QR bought o-rings from a NASA surplus sale Razz
Johnmc
And there it is!Smile

As soon as the word "O-ring" was mentioned in reference to a crash, I knew it was coming, thanks John!
  M636C Minister for Railways

This derailment was caused by an errant O-ring in the brake gear of the ELRC wagon, causing the ELRC to pump the brakes off while the lead loco was trying to apply the brakes - resulting in only approx the first quarter of the train actually applying brakes.

Had nothing to do with the "accepted" reason as stated by Exqr
EMBaldwin

Just a thought here...

As far as I know the ELRC contained just the electronic equipment of a Locotrol receiver and the remotely controlled brake valve. The trailing locomotives operated as if the ELRC was a lead locomotive. So the ELRC caused the trailing locomotives of the remote consist to pump air instead of applying the brakes, as the ELRC itself wouldn't have a compressor...

If the crew in the leading unit had been aware of the extent and cause of the problem they might have been able to apply dynamic brakes on the trailing units even if the Westinghouse was inoperable but presumably the problem was actually discovered much later during technical investigation.

M636C
  EMBaldwin Chief Commissioner

Location: Amongst the Cane Fields

If the crew in the leading unit had been aware of the extent and cause of the problem they might have been able to apply dynamic brakes on the trailing units even if the Westinghouse was inoperable but presumably the problem was actually discovered much later during technical investigation.

M636C
M636C
From my understanding of Black Mountain... train would have already been in dynamic braking.  Also, DB alone is not enough to control a train down the range.
  M636C Minister for Railways

From my understanding of Black Mountain... train would have already been in dynamic braking.  Also, DB alone is not enough to control a train down the range.
EMBaldwin

The report (the link posted above) says:

The accident investigation determined that an extended loss of Locotrol radio signal at the top of the range and the failure of the back-up safety mechanism in the train brake system caused the derailment.

It sounds as though the remote units did not enter dynamic braking, and may have still been powering down the grade. That combined with the failure of the Westinghouse brakes would have made the derailment inevitable.

ECP braking with direct control of remote units would have avoided the loss of radio control, and would have avoided the use of an air brake valve, defective or otherwise.

M636C
  coachdriver Chief Train Controller

Location: Rocky
A few points.

Locotrol2, as with all DP systems operated in QLD, had an automatic override.  If radio contact with the command loco is lost for more than 2 minutes, the remote feed valve drops out and the remote locos idle down regardless of whether they are in power or brake.  If communication is lost for less than two minutes but a BP flow is sensed at the ELRC, the ELRC will make two quick attempts to re-establish communication.  If this doesn't happen, the feed valve will drop out immediately and the locos will be idled down.  For BM2, the system lost radio contact and the remote locos did idle down but, due to the O ring, the feed valve did not drop out and continued to charge the brake pipe.

Contrary to statements above, it is the ELRC that applies and releases both automatic and independent brakes.  The locos operate as trailing in MU and do not in any way 'pump air" any where near the brake pipe.  Part of the L2 setup process is designed to identify if any of the remote locos are not set to trail.

No, the ELRC does not have a compressor, but the loco compressors are synchronised as per MU operation and controlled by the ELRC.

After the investigation, changes were made toe software to prevent a repeat performance.  These changes are continued into L-EB and EPIC

It is possible run down the wire DP without ECP.

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