Whenever I see a model train switcher, it is performing switching or shortline duties; never on the busiest mainlines.
But twice in the last few weeks, I saw a CSX MP-18 switcher in lashup with Dash-8s and other big, modern motive power.
At first I thought they were merely moving the switcher to another place for switching duties or to scrap it; but a group of railfans at Alexandria station told me it is common to run them with mainline engines and that the engine was reworked.
CN and CP had SW1200RS’s specifically set up for road service as well as yard service. They are geared for 65mph. CN is a king of mix & match power, occasionally even running GP9rm’s with Dash 9’s and SD75I’s.
So this does happen. There were even a few shortlines which dieselized completely with nothing but MU equipped switchers.
I remember SP using their SW1500s on the mainlines. I would expect that they were at the head of locals and transfers as opposed to through freights, but they were out there.
Modern railroads work off track warrants. If a switcher needs to enter the main, they just radio central dispatch and ask for permission. It happens all the time here around Chicago.
I’ve got several photos of steam switchers on the main, too. Sometimes, as with the N&W, all they had was big steam and 0-8-0 switchers! For my favorite road, the NKP, mainline engines were so highly utilized that they regularly ran out of Berkshires or Mikes to handle transfer runs or turns, so went with the next best thing, which was the fleet of 0-8-0s. And several towns had assigned switch engines that could enter the mainlines in town, within yard limits.
Running a real railroad can get confusing, especially for us outsiders, but there are rules set up to handle virtually verything!
Well as I have mention many times before we modelers worry far more about “correct” locomotive use then the real railroads…You see to the railroad a locomotive is just a mechine used to haul freight.I have seen SD40-2s in yard service as well as Dash 8-40b.I seen SD50s, 60s and 70s in local service as well…
You partly answered the 2nd question I thought about last night. Since I’m modeling the 50s and 60s period, I was curious if the SW and MP class switchers were used in mainline service, or if the engine retooling of those switchers is a recent phenomenon.
I didn’t know that about the 0-8-0s on the N&W. Very interesting.
The MP15 did not come out until the '70’s. The SW1500 was announced in '64, and did not show up for a year or so… If you put 1965 as your cuttoff, you shouldn’t have any SW1500, except maybe EMD Demo units (if they existed).
The Montour (I believe); a Penn State coal hauler, dieselized with EMD SW units with dynamic brakes !!
In the '50’s and '60’s there was more focus on specific locomotives for specific jobs, left over from the steam era. But in a pinch, whatever was available was used.
Up through the SW-9, I don’t believe switchers were meant for heavy mainline service. Keep in mind gearing and type of trucks. Not all could be used on 60mph freights. As long as the switcher you are using has the proper trucks/gearing, no reason not to use it on the main. A lot of railroads used the SW1500 and MP15 in long distance local freights.