A previous post regarding distributed power (DP) such as using several locomotives lashed together at both ends of a long coal drag raised a question in my mind. Are there any articles written on modeling operations over mountain passes where helper engines are required? Questions arise such as: Would there be engine service facilities at one end of the pass, in the middle or both ends? How would engine facitlites for steam or modern diesel differ?
Contibutors to the previous post on DP lash ups mentioned some of the major mountain passes in the Canadian Rockies such as Crowsnest Pass etc. I would think that modeling the Kicking Horse Pass with the town of Field, BC would be a source of much operational interest. Likewise the Rogers Pass. Also the major passes in the US Rockes might have variations on a theme.
It depended a lot on the terrain of the run. In the Sierra Nevada of California over Donner Pass, the eastbound line is almost a continual gradient of 2.2/2.4% for well over 80 miles from Roseville to Norden, and the rail line climbs over 7000 feet in elevation from the Sacramento Valley to Donner Summit in the Sierra without a break. Generally speaking, during the steam era, this was the stomping grounds of the big AC 4-8-8-2 cab-forwards, and depending on the train length, the Southern Pacific would use one AC as primary power, with one to two AC’s as helpers cut either midway into the train or several cars ahead of the caboose. If the train was particularly heavy, a stop in Colfax (at about 2500’ elevation and at the bottom of a very severe grade) would require the addition of a 2-8-0 ahead of the road locomotive for about 30 miles to Emigrant Gap, where the grade eased and the lead helper could be cut out on a baloon track. The mid and end train AC’s would continue on up to Norden, almost at Donner Pass, where they would be cut out and turned on a covered turntable (Norden was an important stop during the steam era and was completely covered by snowsheds) then run light back to Roseville. The train would then continue over Donner Pass toward Sparks, where the AC would often be cut off and a lighter loco assigned for the more level route through Nevada.
Conversely, at Truckee, CA, which was at the bottom of Donner Pass, westbound AC’s would be coupled onto the train for the 18 mile pull up the 1.8-2.0% grades of Donner Pass, and again, turned at Norden and run light back into the Truckee Yards. At Truckee, there was an additional balloon track for turning the locos to meet the next westbound run.
Passenger trains eastbound often had one of the big MT-series 4-8-2’s assigned as helpers for the AC’s, and in turn, they would be cut off at Norden and turned. Westbound passenger trains could generally make it
Just to add to that, transition era saw consists of ABBA F units in Black Widow scheme, often with ABA helpers cut in as well. And they were in no real position to replace the Cab Forwards, which were still kickin’ and in service when PAs had the City of Los Angeles (?) (doesn’t sound right) And the Donner Pass blizzard that stranded it.
Perhaps the best known “hill” on the UP is Sherman Hill, which for years of steam and into the transition period were the home of Big Boys, Challengers, 2-10-2’s and even some of the UP’s 2-12-2’s!! Almost everything going up had helpers. [:)]
City of San Francisco. Believe it or not, when it got stranded, my dad, who worked for the Forest Service out of Nevada City, was one of the rescuers who helped take supplies to the stranded train at Yuba Gap. The snow was AT THE LEAST between 10 and 14 feet deep up there at the time–the Sierra Nevada are famous for being one of the snowiest mountain ranges in the world, during the winter. I wanted to go with him, but he said I was too short (I was 12 and only 5’7" at the time) and if I fell into a snowbank, he didn’t want to rescue ME, also, LOL! But you’re right–if it hadn’t been for some of the cab-forwards driving the snowplows toward the stalled train, it could have been a MAJOR disaster! In fact, an avalanche wiped out one of the cab-forwards and a snowplow, killing the crew. That was quite the winter up there in the Sierra. Around this area, that winter is still talked about and the City of San Francisco is compared to the 1848 Donner Party–though thankfully with a much better outcome.
I don’t know whether or not this is true, but I have heard that one of the reasons that the Donner Pass line was the last to be dieselized by the SP was because the early EMD F-units actually couldn’t ‘breathe’ well in the mountains because of the very sudden and very sharp changes in elevation (7000 feet in a little over 80 miles). I can tell you that back then, a lot of those big 'fifties gas-guzzling automobiles bought in Sacramento and ran beautifully in the Valley would be gasping like all get-
The important part is not the enginehouse, it’s where the engine crews go to work, where they tie up, where they live, and whether they are governed by hours of service laws. Engines are a lot more tolerant of sitting outside in blizzards than human beings, and they have no hours of service before they “hog out.”
Usually the helper terminal was located at the base of the pass because the winter weather was the least severe at that location. In some instances in the early days crew dormitories and engine houses were also built at the summits of passes because it took so long to get a train to the summit that the crew needed to tie up, or because snowfighting capabilities were very rudimentary and crews could spend all day fighting drifts to get to the summit and descending the other side in darkness with weak oil headlamps was too dangerous. There are a few 20th Century examples of helper terminals at the top of a pass, including Soldier Summit, Utah, on the D&RGW, for about 10 years. This was done to balance crew mileage and avoid paying a train crew a full day’s pay for less than a full day’s mileage. It was a terrible idea and the terminal was removed back to Helper where it belonged.
Long mountain districts with steep grades on both sides that required helpers on each side often had a helper terminal on each side, e.g., Soldier Summit with a westbound
There are several valid reasons why the engine servicing facilities for a helper district are usually at the bottom of the hill, rather than at the summit:
Weather conditions are more likely to be unpleasant at the summit - Donner Pass is extreme, but there are plenty of grades where, the higher you go, the colder and windier it gets.
Why haul loco fuel, sand and water treatment chemicals up the hill if you don’t have to. If the loco is running downhill light, it won’t need much.
Water - it has to be pumped uphill, but runs downhill by itself.
That said, I’m modeling a prototype where the helper operated out of the subdivision yard near the summit - engine shed, coal, water, sand, the works. The downhill station where it waited to help upgrade freights only had servicing facilities for the 762mm gauge forest railway, not the JNR.
The introduction of diesel-electric locomotives and elimination of steam locomotives had a big impact on mountain pass operations.
There was less need for helpers because the railroads learned to put more locomotives on the train at the beginning so the train had enough power for the entire route.
There was less need for engine-service facilities because diesels needed less servicing.
Diesel helpers might stay with the train for both sides of the hill so that the helpers’ dynamic brakes could be used on the downhill ride, not just for the power to get to the top.
Trains didn’t have to make lengthy stops for water on the trip.
Trains didn’t have to stop at the top of the hill to adjust the retainers or do the same at bottom as well as so much time to cool-off the brakes.