New locomotives for PN

 
  M636C Minister for Railways

Peter I think you sell the NRs short .
Earlier traction motor issues were actually pinion issues , not motors melting .

Aside from this I always though their adhesion issues were cause by their hardly hi tech bogie design .
I've told you of these times before .
Please explain how I got 1999 tonnes up Demondrille with one in admittedly good conditions , 1300 amps at 13 km/h down to about 8 over the top . Never missed a beat . Also got a bit more up Jerrawa with one in the dry .
One you wouldn't know about was the time we set sail out of Coot West one evening on PS6 . This one had part off a steel train attached out of Parks and weighed in at 4200 tonnes - a full load . As circumstances would have it the controller in Junee kept us going through Yass behind a wheatie , in the wet , that was leaking grain onto the rail heads .
Crawled up the Cullerin ranges as you'd imagine at 14-16 KM/H , never looked like slipping to a stand .
Unless things have changed full loads on the up south north of Junee were 1780 for Gs and 1840 for 81s , I think NRs were 2100 . I think you could easily substitute a pair of NRs on a wheatie that two 81s typically haul .
I think the best thing you could do was fit them with the later flexi curve bogies if suitable . I reckon that if you can get them to hold their feet you have a better chance of maintaining a speed at which the traction motors won't overheat .

Also , no spoke about it much but 81s didn't tend to survive too long tripping steel rakes out of Cringilla . Generally about a week or two and they would fry traction motors . They are good things but even the best can be beaten .
BDA
All I said was that the 81 and 82 classes were more suitable for slow and heavy trains..

The NRs are model Cv40-9i. The diesel engine will derate (the "v" for variable horsepower) down to 2650 HP.

Two 81s are theoretically allowed 39 NGPF/NGKF which are I think 82 tonnes fully loaded on the 1 in 66 ruling grades on the South, so 3198 tonnes. From memory these trains slow to around 19 km/h on the sharp curve just before the lower bridge, but increase speed until the curve at the turn to the final climb to the top bridge, where they slow again through the sharp curve.

Currently, PN allow up to 42 NGPF/NGKF on these trains. The 82s have slightly better motors and better controls, and two 82s or one 82 and one 81 make better time than two 81s.

On a sustained climb when a pair of NRs couldn't rely on maintainig a higher speed, they may well take longer on the climb  than two 81s if they had to fully derate to protect the motors.

Since the NRs aren't any more environmentally friendly than an 81 or 82, and spares might become a problem in future compared to the EMDs because of the larger number of similar units in the USA (particularly the traction motors), I'd expect the 81s to stick around. The V/line N class had their D43 motors replaced by D78s simply because D78s were available rebuilt ex the USA at a much lower cost. I have no idea if any other loco used the GE 793.....

While you could probably fit Flexicurve bogies, you couldn't use the existing traction motors which are not suitable for the "dogbone" suspension links used to allow the radial steering of the axles. You could re-use the armatures in a new casing, but that would be expensive and you end up with a locomotive that is no more capable.

The 81s have been hauling the grain for forty years or so, and unless their maintenance costs increase, they will keep doing so until replaced by AC locomotives, maybe 93 class when coal traffic declines.

Peter

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  BDA Chief Commissioner

Location: Sydney
Many people never quite got the "de-rate" thing with them , not really the correct term .
The consist monitor software was designed to allow you to "load limit" them to 1 or 6 or 7 or 8 throttle notch output .
Load Limit 1 was essentially off line . The power levels were 2850 3560 or 4020 horse power in LL 6/7/8 .
You could achieve the same thing with the throttle as long as you wanted all in the consist to do the same thing .

My finding was that running fewer of them in 8 where possible gave the best consumption overall .
For example it was typical to have 3 of them on say PS6 out of Goulburn , I used to get up to speed out towards Murrays Flats and put the two trailing units in LL1 . The extra 1000 horses meant that they could maintain higher traction motor loads at higher speeds compared to the lower powered 81 82 etc .

Anyway the ACs look to be the way of the future and any half decent one will make most or all DC traction units look pretty sick when it comes to heavy loads . This is old news , consider the GT46ACes and C44ACi vs 90 class .
The one area the GE based ones anyway could improve is higher speed trains . When the 92s ran to Melbourne the crews found they tend to run out of puff at about 90 km/h , I found same thing with 93s . I never got to run GT46ACes so I don't know if they go any better at speed . I did run SD70ACes in the wild west but they were limited to 80 .

So the things to look at currently would be the latest C44s with updated bogies and the C44AC Evos when they appear .
  BDA Chief Commissioner

Location: Sydney
Update .
More recently I got to run CF44s and QLs and if anything they seem to be a better all rounder than 93s , though admittedly its been some years since I've had a 93 .
I'd have thought the Flexi Curve bogies would make a noticeable difference but the ride characteristics are similar .
Off the top of my head QLs are rated at the same 1750T on the 1:40s , I haven't had full section loads with either but I'm told they are down to around 17 ks with with 3 on around 51-5200 tonnes .

The Gevo C44AC will be an interesting beast . You'd expect them to have the latest power electronics but its hard to say if they can do much better than say a QL - which is currently the latest C44ACi evolution here .
  BDA Chief Commissioner

Location: Sydney
For those curious about the Evolution V12 / 7FDL16 difference some may find this old RP thread interesting .

https://www.railpage.com.au:80/f-p1616418.htm

Some more info on the ES44AC's intercooling would be good .
Possibly the best the 7FDL will ever get is the AC4400 C6Ms currently heading to WA . These look like they have somethig similar to an AC6000's radiator cab , obviously the extra capacity would have a lot to do with water/air charge cooling because as we know CW44-9's don't have engine jacket cooling issues in the wild west .
  simstrain Chief Commissioner

Could these AC44evo loco's get a slight height increase in the middle to clear that extra height in the Gevo motor. I know the NR's are 12mm shorter in height then an 81 class and so maybe this extra few millimetres would help. I know the 86 class is 4,400mm which is a decent amount higher.
  M636C Minister for Railways

Could these AC44evo loco's get a slight height increase in the middle to clear that extra height in the Gevo motor. I know the NR's are 12mm shorter in height then an 81 class and so maybe this extra few millimetres would help. I know the 86 class is 4,400mm which is a decent amount higher.
simstrain
I can only repeat my comments of ten and a half years ago (linked above) that the difference in engine height is negligible as far as clearances are concerned. However, since then GE has built GEVO-engined locomotives for South Africa, India and Pakistan, all of which have air to air intercoolers that will fit loading gauges smaller than that on ARTC lines in Australia.

The lower surface of the muffler may be different to clear the GEVO engine. None of those units listed immediately above had mufflers like those required in NSW. But it should all fit under the same hood dimensions as the current C44ACi units.

However, the air to air intercoolers will provide an easy recognition feature.

Peter
  Sulla1 Chief Commissioner

Wabtec's current product line of mid-sized ES models...

https://www.wabteccorp.com/locomotive/medium-weight-locomotives
  fzr560 Chief Train Controller

Wabtec's current product line of mid-sized ES models...

https://www.wabteccorp.com/locomotive/medium-weight-locomotives
Sulla1
"Dynamic breaking...."???? Did they run that past Mr Westinghouse?
  KRviator Moderator

Location: Up the front
Wabtec's current product line of mid-sized ES models...

https://www.wabteccorp.com/locomotive/medium-weight-locomotives
"Dynamic breaking...."???? Did they run that past Mr Westinghouse?
fzr560
Well, too much Dynamic will break stuff. The TOC Manual prohibits you from using DB exclusively if you have more than 2000T behind an empty wagon lest you spit it out the side.Shocked

Then again, it is the Americans...Color/Colour, Meter/Metre, Ton/Tonne....
  M636C Minister for Railways

Wabtec's current product line of mid-sized ES models...

https://www.wabteccorp.com/locomotive/medium-weight-locomotives
"Dynamic breaking...."???? Did they run that past Mr Westinghouse?
Well, too much Dynamic will break stuff. The TOC Manual prohibits you from using DB exclusively if you have more than 2000T behind an empty wagon lest you spit it out the side.Shocked

Then again, it is the Americans...Color/Colour, Meter/Metre, Ton/Tonne....
KRviator
And since this is from the GE side of the shop, wouldn't it be Mr Edison to approve....
Westinghouse and Edison were serious competitors for most of their lives (which was some time ago now...)

Peter
  simstrain Chief Commissioner

Could these AC44evo loco's get a slight height increase in the middle to clear that extra height in the Gevo motor. I know the NR's are 12mm shorter in height then an 81 class and so maybe this extra few millimetres would help. I know the 86 class is 4,400mm which is a decent amount higher.
I can only repeat my comments of ten and a half years ago (linked above) that the difference in engine height is negligible as far as clearances are concerned. However, since then GE has built GEVO-engined locomotives for South Africa, India and Pakistan, all of which have air to air intercoolers that will fit loading gauges smaller than that on ARTC lines in Australia.

The lower surface of the muffler may be different to clear the GEVO engine. None of those units listed immediately above had mufflers like those required in NSW. But it should all fit under the same hood dimensions as the current C44ACi units.

However, the air to air intercoolers will provide an easy recognition feature.

Peter
M636C
Most if not all of those links are broken. I tried opening them and got "page not found".

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