The mountain grade between Altoona and Johnstown, Pa has challenged the mettle of engines, couplers, and train crews all the way back to PRR days…
Despite today’s high horsepower, high adhesion locomotive capability, the grade over the Alleghenies still creates quite a challenge for heavy trains.
Yesterday, a heavy Eastbound NS 10N climbs the West Slope grade toward Cassandra, Pa, 4 miles West of Cresson and 7 miles West of the Gallitzin Tunnels…
Despite having helpers on both the head end and the rear of this train, it is down to a crawl on the grade.
The one element you overlook in trains struggling upgrade.
In the 30’s & 40’s with steam power the trains were struggling upgrade with maybe 3500 tons.
In the 50’s with Gen 1 diesels they struggled up grade with maybe 5000 tons.
In the 60’s & 70’s with Gen 2 diesels they were hauling maybe 7500 tons.
In the 80’s & 90’s with the advent of Dash-8’s and other high HP DC engines the limits went to 10000 tons.
In the 2000’s with high horsepower AC’s we are looking at maybe 15000 tons.
Trains will ALWAYS struggle upgrade…the carriers will ALWAYS load them to maximum tonnage for the power over the grades, and use helpers where head end only power is either insufficient for the tonnage or where the drawbar pull would be excessive for the draft gear.
I understand what you are saying…max. load / min. power necessary to get the job done. This has always been “helper” territory. This perticular consist seemed to be pulling the grade just a bit slower than the many we’ve seen on or near this site…
I don’t answer the questions, I only ask them: He’s empty. Would he still be that slow under normal conditions? Could this be a bad motor and that is why he is pulling so hard? Do loads go the other direction, down the hill?
Only the first block of open top cars are empty. The balance of the cars are all closed so we have no knowledge of load/empty status. According to Charles Roberts the heavy tonnage has always been eastward on this line, which is the former PRR main line.
I figured about 15 feet per second, which is 10 MPH. The train is in the bottom of the frame for about 8 minutes which gives a car count of about 120 cars, no I did not count.
He has five units, all DC. NS does not figure AC power is cost effective for them. Since they are known for having sharp pencils I certainly will not argue.
The last power I paid close attention to was SD-40s. They had a minimum continuous speed of 9 MPH. These are rebuilds so may be a bit more HP, but my 10 MPH looks correct for the power, that is they are on or just above their MCS. I know that GN and NP both rated SD-40 & 45s at 1200 tons on 2.2% ascending grade at MCS. Rolling resistance on 1% is conveniently half that of 2.2%, so these units are probably rated at 2400 to 2500 tons each on 1% which is ruling grade above Johnstown PA. The train had 5 units so combined rating is 12,000 to 12,500 tons. At 120 cars that is 100 tons per car, which implies that there were a few empties in addtion to that block on the head end.
This all looks in the ball park to me. As Baltimore points out the name of the game is, and always has been, to load the power to capacity for the ruling grade. This is true of bulk trains like coal, oil, and stone, and as we see here for carload, or manifest, traffic. Intermodal trains will often be a bit to a lot overpowered to enable them to make a tighter schedule than demanded for carload and bulk traffic. Carload trains may be overpowered on flat terri
The SD40-2’s are almost gone from helper service on the mountain…NS has embarked on a program to rebuild its SD50 fleet into an SD40E classification…basically tearing them down to the frame and completely rebuilding them while derating them to 3,000 hoesepower…
The one thing most noticeable when hearing them in person is that they are not as loud as an SD40-2 even though they are running the same 3,000 HP prime movers…reason is that they retain the exhaust silencers of the SD50’s that they are rebuilt from…
As of this writing, there is only one SD40-2 set in helper service…the NS 3348 and 3372…The SD40E’s run from #6300 to 6326 with #6327 to be released into service anytime now…
The SD40-2’s previously assigned to helper duty are now serving other duties around the NS system…
This particular symbol…10N is one of the heaviest Eastbound manifests on the mountain…There are manifest trains of varying tonnage and many will climb this grade with less effort and more speed…
This particular train was one of the ‘slowest’ seen that day…
There is likely a valid reason for the difference in exhaust…The SD40E helpers are rebuilt from SD50’s…and were rebuilt to whatever EPA standards were required of the SD50’s when they were built in the 1980’s…
Back then, starting in 1980, the noise reduction requirement came into existence requiring exhaust silencers (mufflers) on locomotives…
It wasn’t until the late 90’s or early 2000’s that emission control regulations were mandated for locomoties…starting with Tier0, then later Tier 1, Tier 2, etc…with each tier requiring more stringent emission reduction as time went on…The GE Dash-9W’s in NS’ fleet date from the mid 1990’s to the mid 2000’s…These locomotives fall under the more stringent emission regulations compared to the older SD40/SD50 models, which may explain the difference in exhaust plumes…
ZUG: If this is actually going to be NS’s purchase policy is there a possibility that the loco makers got the price of AC and DC locos close enough that it now makes sense to buy only ACs? Will have to see what other RRs buy in the near future with some wait on CN since they are getting that bunch of second hands from BNSF?
If the makers only get AC orders how soon will it be that there is a shortage of DC specific parts?
A properly maintained, turbocharged EMD running in N8 for more than 5 minutes should have crystal clear exhaust. Any brown at all means the injectors aren’t up to snuff - and there’s a measurable drop off in fuel economy, enough justify taking the time to replace the injectors. I wonder if Juniata has gone back to reusing injector nozzles or NS isn’t doing injectors every 2 years like Conrail did.