I had some comments made at the train club on cetain engines are pulling more than they could in the real world. I looked on Wikipedia but just no seeing the information. So maybe you can help me.
How many 40ft cars (full) could a F7A or a E6 pull?
How many passenger cars?
H10-44 could pull how many bocx cars? Maybe 10?
Or a F-M H24-66?
I have been pulling 15-20 40ft box cars and I am being told its too many. I can add pushers or a helper but just wanted your thoughts please.
Thanks
Don’t have a real answer for that, but you could approximate it. A hundred car freight was, and is, considered a long train. I would expect a 100 car freight to have an ABBA four unit consist up front, at least back in covered wagon days… If it takes four F units to pull 100 cars, then one F unit ought to be good for 25 cars.
Regarding the E6, those were dual engined units of perhaps 2000 hp, as compared to the F7 which was some thing less, probably 1500 hp. So, if 1500 hp is good for 25 cars, then 2000 hp oughta be good for 30 cars. In actual fact, the E units were passenger power and rarely pulled freight trains in the early days. Later, after passsenger service dried up, some of the E units were put out to freight work, but back in the day, an E unit meant a passenger train.
Switchers had less hp than road locomotives. 700 to 1000 hp usually. On the other hand, the switchers didn’t have to move the cuts of cars very fast. Walking pace in many cases. Last time I watched a hump yard in action, a cow-calf pair of SW-something-or-others was pushing humungous cuts of cars over the hump.
Your basic question is right up there with, “How long is a string?”
A diesel locomotive could start more train than it could take over the road at track speed. A single unit could handle a longer (several times longer!) train over the dead flat terrain of the West Texas plain than it could take up Donner, Cajon or Tehachapi. So, the answer to your question is very much railroad and service specific. On the flats, your normal train might be considered a lightweight. In the mountains, a train half as long might be an overload for the traction motors.
Then, too, all cars are not created equal. An empty box car can triple in weight when loaded - and a 24 foot ore jimmy loaded with Minnesota taconite is heavier than an 89 foot humongubox loaded with boxed ping-pong balls.
So, what does the profile of your club railroad look like? Depending on which route you take, can you avoid grades? If so, your trains are probably normal. If not, they may be too long. You might consider assigning a helper…
Chuck (Modeling Central Japan in September, 1964)
The basic answer to your question is “It depends”. It depends on the grade profile of the line in question, it depends on the weather (cold weather increases train resistance) and it depends on whether the train is a fast freight or a slow drag.
There was a picture in “Pacific News” about 40 years ago of a single F7 unit pulling a long freight in the San Joaquin Valley, albeit slowly. While an F7 unit has the starting tractive effort of a heavy Mikado, it doesn’t produce as much horsepower at speed (the Mike will produce approximately double the HP). Tractive effort determines how much you can pull and horsepower how fast.
Southern Pacific rated its F7 units in Tehachapi at about the same tonnage as a C-8/9/10 Consolidation even though the F7 would produce 33% more starting tractive effort. IIRC, the F7 was rated for about 40,000 lbs tractive effort continuously at around 12 MPH or so (the 1 hour rating was somewhat higher). This is roughly comparable to the 2-8-0, which could sustain its starting tractive effort up to roughly the same speed.
I don’t have my handy dandy SP references nearby, but IIRC, the F7’s were rated at about 550 tons/unit on Tehachapi. A nominal 50 ton capacity boxcar has a light weight of around 20 tons. Assuming it’s loaded to weight capacity, a loaded 50 ton boxcar would weigh 70 tons. With a 550 ton rating, a single F7 would be
Thanks guys,
Really the layout is a 8x12 and has two main lines. One has a 2-3% grade and the other is flat with an s curve.
I was assuming the 40 ft cars are loaded, I was pulling about 15-20 cars with one F7, and then the debate started. I was also pulling about 10 cars with a H10-44. So I thought I was ok on the 1500hp of an F7 with 15-20 loaded 40ft box cars. When on the grade my decapod does not have the traction tires installed so i used a F7 with no issues. I have the traction tires but need to install them. I just want to be sure what was proto typical and not vulgar on the reprsentation of the motive power. I understand what you are saying though on the layout and the grades. I was just trying to set up my trains to match their overall power when pulling freight. I have some E series engines and they just seem to look real good pulling freight. I knew when they first appeared they were passenger trains but I have a E6 Southern “Freight Scheme” engine and have the E8 southern passenger scheme engine. i do have a E6 passenger but looks different from the E6 freighter. Must be a later version when the passenger service dried up.
Thanks
As far as switchers pulling long loads at low speeds, I have an interchange near my house between a N&S yard, and a Steel plant facility. Google says the plant railroad has a mix of Alco Ss and EMD SWs, at least one going back to the late 40s. I have been caught at the crossing and counted as many as 105 empty gondolas in a string, probably pulled by an SW1200. But, like it was said in a previous post, very slow. I think the track has almost no grade.
On a different road, paralleling the yard, the N&S frequently runs a transfer several times a day, blocking that crossing with sometimes 50 or 60 auto racks, and I have counted as many as 80 hoppers. This run is usually handled by 1 or 2 SD-40-2s. Also, usually slow, since they are entering the leg of a wye.