Freight Australia/Pacific National XRB Diesel Units

 
  lowtensionearth Station Master

While it is true that a branch line locomotive like a 49 class could MU with an XRB and act as a cab for it such a combination could never be considered optimal. Without modifications the 49 class cannot make use of the dynamic brake of the XRB. The two locomotives have different balance speeds and could in some circumstances require a reduction in haulage capacity to protect the traction motors of the 49 class from damage.

There are also the issues of the suboptimal brake equipment of the 49 class and local and MU reliability issues related to its outdated electrical equipment interfacing with the microprocessor control of the XRB.

Such a combination would be highly unlikely bedfellows away from Eastern Australia and even then very much only a suboptimal last resort.

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  nswtrains Chief Commissioner

While it is true that a branch line locomotive like a 49 class could MU with an XRB and act as a cab for it such a combination could never be considered optimal. Without modifications the 49 class cannot make use of the dynamic brake of the XRB. The two locomotives have different balance speeds and could in some circumstances require a reduction in haulage capacity to protect the traction motors of the 49 class from damage.

There are also the issues of the suboptimal brake equipment of the 49 class and local and MU reliability issues related to its outdated electrical equipment interfacing with the microprocessor control of the XRB.

Such a combination would be highly unlikely bedfellows away from Eastern Australia and even then very much only a suboptimal last resort.
lowtensionearth
Going by those real time video cameras they have all over the USA, the remaining B units still seem to be used currently. I cant see why the XRB's cant be used to get some value out of them?
  YM-Mundrabilla Minister for Railways

Location: Mundrabilla but I'd rather be in Narvik
While it is true that a branch line locomotive like a 49 class could MU with an XRB and act as a cab for it such a combination could never be considered optimal. Without modifications the 49 class cannot make use of the dynamic brake of the XRB. The two locomotives have different balance speeds and could in some circumstances require a reduction in haulage capacity to protect the traction motors of the 49 class from damage.

There are also the issues of the suboptimal brake equipment of the 49 class and local and MU reliability issues related to its outdated electrical equipment interfacing with the microprocessor control of the XRB.

Such a combination would be highly unlikely bedfellows away from Eastern Australia and even then very much only a suboptimal last resort.
Going by those real time video cameras they have all over the USA, the remaining B units still seem to be used currently. I cant see why the XRB's cant be used to get some value out of them?
nswtrains
Not worth the effort.
Orphans, white elephants and lemons come to mind. Twisted Evil
  Greensleeves Chief Commissioner

Location: If it isn't obvious by now, it should be.
While it is true that a branch line locomotive like a 49 class could MU with an XRB and act as a cab for it such a combination could never be considered optimal. Without modifications the 49 class cannot make use of the dynamic brake of the XRB. The two locomotives have different balance speeds and could in some circumstances require a reduction in haulage capacity to protect the traction motors of the 49 class from damage.

There are also the issues of the suboptimal brake equipment of the 49 class and local and MU reliability issues related to its outdated electrical equipment interfacing with the microprocessor control of the XRB.

Such a combination would be highly unlikely bedfellows away from Eastern Australia and even then very much only a suboptimal last resort.
Going by those real time video cameras they have all over the USA, the remaining B units still seem to be used currently. I cant see why the XRB's cant be used to get some value out of them?
nswtrains

Compare the number of B units in use to the amount of cabbed units. The difference is massive and the B units seem to be rarely ever seen on long distance workings.

Either way, there's a fair difference in the work patterns between Australia and the US as well. If they were suitable for how railways are worked here, they'd be more widely adopted.
  GT46C-ACe Deputy Commissioner

Location: Gold Coast QLD
Only B units in the US are the GP60Bs running in the Pacific Northwest on a dedicated service (fairly certain it's a branch line) always running with GP60/GP60M leaders. BNSF even went to the trouble of recabbing several as a test program.

If they had cabs I'd wager the XRBs would never have been stored at any point in their lives....
  davesvline Chief Commissioner

Location: 1983-1998
Plenty of 3rd series X’s sitting idle to provide said cab.
  M636C Minister for Railways

Only B units in the US are the GP60Bs running in the Pacific Northwest on a dedicated service (fairly certain it's a branch line) always running with GP60/GP60M leaders. BNSF even went to the trouble of recabbing several as a test program.

If they had cabs I'd wager the XRBs would never have been stored at any point in their lives....
GT46C-ACe
The XRs had a problem, because the frame wasn't long enough to allow both a full size EMD radiator and a crew toilet. The XR radiator it the same as the A (and possibly N) class locomotives which are only 2250 HP into the generator compared to 3000 HP into the generator.

This hasn't stopped VL class working ore and concentrate trains in the Northern Territory.

But the XRB has the full size 3000 HP radiator, like a C or G class.

Since there was no room for a crew toilet, there was no cab.

You can't just fit a cab because the XRB had different dynamic brakes of higher capacity than the XR which occupy the space of the cab anyway.

If you fitted XR dynamic brakes and a cab, there would still be no toilet.
You could fit the smaller radiator, a toilet, a new cab and new dynamic brakes...

But even if you took the cab, dynamics and toilet from an X class, with new radiators, it would cost quite a bit.
PN probably don't want a 3000 HP unit that badly...

Maybe they could sell them to SSR who run a lot of trains with multiple locomotives.
I'm sure they could use locomotives without cabs.

Peter
  Graham4405 The Ghost of George Stephenson

Location: Dalby Qld
Maybe they could sell them to SSR who run a lot of trains with multiple locomotives.
I'm sure they could use locomotives without cabs.
M636C

I suspect if SSR needed/wanted them they might have made an offer by now.
  Jack Le Lievre Assistant Commissioner

Location: Moolap Station, Vic
The XRs had a problem, because the frame wasn't long enough to allow both a full size EMD radiator and a crew toilet. The XR radiator it the same as the A (and possibly N) class locomotives which are only 2250 HP into the generator compared to 3000 HP into the generator.

This hasn't stopped VL class working ore and concentrate trains in the Northern Territory.

But the XRB has the full size 3000 HP radiator, like a C or G class.

Since there was no room for a crew toilet, there was no cab.

You can't just fit a cab because the XRB had different dynamic brakes of higher capacity than the XR which occupy the space of the cab anyway.

If you fitted XR dynamic brakes and a cab, there would still be no toilet.
You could fit the smaller radiator, a toilet, a new cab and new dynamic brakes...

But even if you took the cab, dynamics and toilet from an X class, with new radiators, it would cost quite a bit.
PN probably don't want a 3000 HP unit that badly...

Maybe they could sell them to SSR who run a lot of trains with multiple locomotives.
I'm sure they could use locomotives without cabs.

Peter
M636C
Peter,

Do you know why the XRs were not built longer than the 18.34m? Why not go out to 22m? Was it simply because the original six frames were 18.53m?

Jack
  YM-Mundrabilla Minister for Railways

Location: Mundrabilla but I'd rather be in Narvik
The XRs had a problem, because the frame wasn't long enough to allow both a full size EMD radiator and a crew toilet. The XR radiator it the same as the A (and possibly N) class locomotives which are only 2250 HP into the generator compared to 3000 HP into the generator.

This hasn't stopped VL class working ore and concentrate trains in the Northern Territory.

But the XRB has the full size 3000 HP radiator, like a C or G class.

Since there was no room for a crew toilet, there was no cab.

You can't just fit a cab because the XRB had different dynamic brakes of higher capacity than the XR which occupy the space of the cab anyway.

If you fitted XR dynamic brakes and a cab, there would still be no toilet.
You could fit the smaller radiator, a toilet, a new cab and new dynamic brakes...

But even if you took the cab, dynamics and toilet from an X class, with new radiators, it would cost quite a bit.
PN probably don't want a 3000 HP unit that badly...

Maybe they could sell them to SSR who run a lot of trains with multiple locomotives.
I'm sure they could use locomotives without cabs.

Peter
Peter,

Do you know why the XRs were not built longer than the 18.34m? Why not go out to 22m? Was it simply because the original six frames were 18.53m?

Jack
Jack Le Lievre
No point if the XRBs which started out on X class frames met the then perceived operational requirements.
History has, however, largely overtaken them.

For the XRBs to be of any use you need at least a three loco consist that usually stays together for relatively lengthy periods. The Leigh Creek coal train was one such working but I would be hard pressed to think of another outside block coal trains for which 4,000 hp locos are needed.

Perhaps the armchair experts will accept a challenge as to where and how an XRB/XRBs might profitably and sensibly be used given their significant shortcomings.

We can all then all discuss (shoot down Smile ) any suggestions. Rolling Eyes
  james.au Minister for Railways

Location: Sydney, NSW
Maybe they could sell them to SSR who run a lot of trains with multiple locomotives.
I'm sure they could use locomotives without cabs.

I suspect if SSR needed/wanted them they might have made an offer by now.
Graham4405
Maybe they have but then PN wouldnt want HP going to its key competitor for grain haulage contracts...
  Greensleeves Chief Commissioner

Location: If it isn't obvious by now, it should be.
Maybe they could sell them to SSR who run a lot of trains with multiple locomotives.
I'm sure they could use locomotives without cabs.

I suspect if SSR needed/wanted them they might have made an offer by now.
Maybe they have but then PN wouldnt want HP going to its key competitor for grain haulage contracts...
james.au

Depends on how much they're paying- they sold V544 to One Rail and the BGKF's and BGVF's were ex-PN too.
  james.au Minister for Railways

Location: Sydney, NSW
OWA doest seem to compete much with PN on routes where the V will be used though.  SSR is the main competitor though in the east coast grain network...
  M636C Minister for Railways

Peter,

Do you know why the XRs were not built longer than the 18.34m? Why not go out to 22m? Was it simply because the original six frames were 18.53m?

Jack

My understanding is that PN thought the XR conversions were a good idea.
Some of the X class frames needed some repair or strengthening, around the alternator mounting and the front of the engine.
This area has to resist the torque between the engine and alternator (or generator in the earlier X class)

On Alcos and GEs the alternator is bolted up to the engine and this problem doesn't occur.

Someone in PN thought it would be a good idea to design a new frame that would not need these repairs.
This was done and it was checked using modern stress analysis techniques.
All this cost money, but it gave them the three new XRs.

It would have been as easy to get a new C class frame designed but apparently nobody thought about that at the time.
The whole scheme was to use up bogies left over from scrapped B and S class, which weren't used on C class.
A longer frame could have been designed but that would mean extra weight, particularly if a bigger fuel tank was used.

For some reason, the frame design was able to be used by Avteq and SSR to build the VL and BRM classes.

These had bigger fuel tanks obtained by moving the air reservoirs to the nose.
But they still couldn't fit a bigger radiator if they kept the toilet at the end of the long hood.

The new frame only needed to be around one metre longer to fit the toilet.
But they couldn't fit the bigger dynamic brakes above the engine and also fit the muffler required for new units to meet NSW noise regulations. This would still be a problem with a C class frame.

One of the early designs for the WAGR L class had two X class dynamic brake units, one in front and one behind the engine.

But a longer frame would be heavier and they didn't want a loco that would be limited to main lines, like the C class when it was new.

The XRB is the result of painting the design into a corner by not thinking about further developments fter the XR.

Peter

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