Every day, the Dakota & Iowa Railroad runs trainloads of big, pink rocks down the BNSF about a half mile out my office window. In the morning, they head south with a loaded train. In the afternoon, the same train comes by empty going north. Power is usually 3 to 5 of their older Geeps and SD-45s. On their entire 80+ mile daily journey, there is only one real hill, at Sioux Falls, about 7 miles north of my office.
The track appears to be flat as a pancake for a couple miles in each direction. As the loaded trains run south, the engines make a steady rumble. On the trip north, on the same strip of track, the engines really growl, as if they were pulling hard up a big hill, but the cars are empty!
Any thoughts on what would cause the growl? Could empty cars being hauled up an imperceptible grade require that much more effort than hauling loaded cars down that same grade? Prevailing wind? UFO’s?
Perhaps the locomotives are in reverse (my car growls when I go faster than about 30 when in reverse).
UFO’s? Possibly, but the one’s I’ve seen and been on board had no growling noise, except for my stomach which gets real empty on those interplanetary voyages (I can’t even imagine how hungry I’d get on a interstellar journey!) Maybe the locomotives are hungry after hauling all that tonnage.
Are all of the units on-line during the return (empty) trip? It might be that without much in the way of tonnage, these locomotives are running in just the lower notches, and (at least with the older units) I’ve frequently heard a growly-type of noise from the traction motors when I ran trains with similar conditions.
While not any kind of an “Expert” on this, I would suspect a “Gear-Ratio” problem.(?)
Growing up, and graduating from high school in the late 1960s, I saw numerous trains crossing the Ohio river from Cincinnati to Northern Kentucky pulled by C & O AS 6-616s, GP-7s & GP-9s, SD-18s B & O AS 6-616s, L & N RS-3s along with others. (Pennsy, NYC, etc.) They"Growled" as if they were pulling hard, and it was on semi flat ground. No turbo charger whine or, etc.
Would understand better if I saw the C & O trains pulling out of Cincy going up Cheviot Hill on that grade; but most of what I saw was on semi level grade.
I’m sorry Morris, I didn’t see you say anything about grinding the gears, etc.
It sounds like if you want to put it in that perspective; it would be like a vehicle with a standard shift pulling in “Low” gear when they should have shifted to “High”.
The backbone of their road fleet is four SD40-2’s – numbers 3025, 3026, 3029 & 3030. Other than having fresher paint and more recent wash jobs than most engines, they are standard EMD’s.
When I was riding trains - there were a lot of place where the only way to tell one was on a grade was to watch the locomotive load meter. Visually everything was billiard table flat - the load meter would tell a different tale.
Also remember, the economics of railroading require matching power to the tonnage being handled. While a loaded train movement may require 5 units over a territory because of the tonnage. The empty movement over the same territory may require only 1 or 2 of those units be on line account of the lesser tonnage of the empties. The intent in both cases is to get maximum tonnage moved with minimum fuel used.
I remember the term “growler” to be generic to diesels, especially when starting or when pulling up hill and especially, too, in lower notches with or without automatic transitioning. Some locomotives were geared to have better traction at low speeds (usually freight locomotives or when in pusher service) and thus produced a low, growling sound often. But I think an electric locomotive could also be a “growler” when starting or working hard…even MU’s can have a low, growling cry when pulling hard up a hill or when starting with a long train.
Lacking a profile chart of the line, a visit to Acme Mapper may be just the ticket for you. One of the options for viewing is topo maps. A check of relative elevations in the area to which you refer may show a definitive grade.
Is that your facility off Cliff Ave in northern Harrisburg? If so, then according to Google the elevation of the siding leading into it is 1439’. Roughly a half mile north of you the track is 1443’ and a half mile south it is 1433’.
Yep- that’s us. You’d never tell by looking at the track, or driving on Cliff ave which parallels a track a half mile west, that there was any grade at all. Is there a way to use Goggle maps to pinpoint the elevation a spot?
Murph - Using Acme and the topo maps, I found that from the 476th Ave crossing south of Harrisburg, to the East 57th Street crossing at Sioux Falls is an average upgrade of .35%. The elevation 476th is 1390 feet (bench mark) and at E57th it’s 1500’ (another bench mark).
It’s not a steep grade, for sure, but it’s enough to make the units work. Such minor grades can be deceiving to the eye. I’ve found that now that I’m an engineer, they’ve become a lot more obvious.
If anyone wants to do the math for a “closer” look, here’s what I pulled off the map:
Distance from Harrisburg miles, feet, elevation: (southbound)
Murph - Using Acme and the topo maps, I found that from the 476th Ave crossing south of Harrisburg, to the East 57th Street crossing at Sioux Falls is an average upgrade of .35%. The elevation 476th is 1390 feet (bench mark) and at E57th it’s 1500’ (another bench mark).
It’s not a steep grade, for sure, but it’s enough to make the units work. Such minor grades can be deceiving to the eye. I’ve found that now that I’m an engineer, they’ve become a lot more obvious.
If anyone wants to do the math for a “closer” look, here’s what I pulled off the map:
Distance from Harrisburg miles, feet, elevation: (southbound)