Last evening I kidded a club member who was running his his first steam locomotive, a new sound-equipped Proto 2000 0-6-0 , that a speed over 50 mph with twenty cars in tow was a bit unrealistic, suggesting that a max speed of 30mph in short bursts in the yard and not long freights on the mainline was more realistic, based on my very faded memories.
Being keen on emulating prototype practice he quickly adjusted the max speed CV to 30mph, although planning to install the furnished traction tire drivers to haul longer trains on the club flatlands.
Comments on the “speed” and tractive efforts/boxcar capabilities of both the prototype 0-6-0 and 0-8-0’s would be welcomed. My Proto 0-8-0 chuffs along at about 20mph max.
[:)]
What is the driver diameter on those locos? Driver diameter was the primary determining factor for absolute top speed, although switchers rarely if ever ran anything like their top theoretical speed. 20-30mph is a good absolute - 30 might even be too fast.
Those kind of switching locomotives (other types were used to, particularly 2-8-0s in later years) were powerful for their size. They had no deadweight on leading or trailing wheels taking traction away from the drivers. Their fire boxes were usually small since they weren’t designed to be under full load continuously, so they couldn’t go fast with a heavy load at full throttle even on the flat. They usually ran at a fast walking or jogging pace, and I think they would rarely run more than 20 mph, and that with few if any cars attached. Tractive effort of an 0-8-0 was probably between 30 and 40 percent more than an 0-6-0 everthing else equal, but that’s just a guess.
The USRA 0-6-0 and the USRA 0-8-0 according to Linn Wescott had 51 inch diameter drivers. While the rule of thumb was max mph equals wheel diameter in inches obviously the rule didn’t apply to these and like switchers.
[:)]
On occasion, the NYC’s 0-8-0 Albany station switcher would have to push a departing passenger train up the West Albany Hill. From what I have been told, the maximum speed could reach about 30mph just before the pusher cut off on the fly. Then it would drift back to the station while the fireman rebuilt his fire and tried to bring steam pressure back into the “ready to work” range. The distance wasn’t all that much, and there was a Hudson on the other end of the train doing at least as much work.
Once up to speed and over the hill, the Hudson could easily exceed 60mph - and frequently did. At 60mph, dynamic augment and poor counterbalancing would have reduced the 0-8-0 to scrap metal.
According to Alfred W.Bruce, ‘The Steam Locomotive In America’, the 0-6-0 could take a cut on the average of 4 cars or 160 tons (statistics taken in1930), while the 0-8-0 would take an average cut of 11 cars at 436 tons. Maximum recorded moves for both types: 0-6-0 15 cars for 600 tons, the 0-8-0 took a maximum of 35 cars for 1400 tons, managaing one cut of 60 cars.
Hope this helps.
Danny meandmrd@sbcglobal.net
Not all 0-6-0’s were created equal. The last of the breed, the USRA design, were rated at 39,100 lbs TE - very close to the tractive force typical of contemporary ten-wheelers. Earlier 0-6-0’s were nowhere near as powerful.
Likewise, the USRA 0-8-0 was at least as powerful as the best contemporary consolidations - probably in the vicinity of 50,000 lbs TE. Earlier 0-8-0’s with lower boiler pressure were much less powerful.
Did Alfred Bruce identify the specific locomotives he was analyzing, or did he simply put down minimum, maximum and average? There are a LOT of variables to consider when performing statistical analyses of mechanical devices, whether they be locomotives or aircraft. Granted that the study was published in 1930, but how old were the sample locos at the time? Comparing performance between a USRA design and something with slide valves is comparing apples and crabapples.
When dealing with statistics, always look for a second opinion. There’s sure to be one.
CNR’s early 0-8-0s were rated at between 27,000 and 33,000 lbs. TE, while the more modern ones were up around 50,000 lbs. The P-4-d class of the GTW (Lima, 1923) were rated at 55,000 lbs. TE and were equipped with 56" drivers and Elesco fwhs. I recall reading that they could pull just about any train that came into the yard, if the fireman was capable of shovelling fast enough.
As for the Proto2000 0-8-0: out of the box, they run nicely, but they don’t pull very much at all. The performance was acceptable, as long as no grades or curves were involved, but that kind of trackage is rare on my layout. I was going to get rid of mine, but I managed to add quite a bit of weight to it and, based on its improved capabilities, modified it to ressemble a CNR P-5-h.
Modifications include lengthening the frame to accomodate the CNR-style front-end handrails and headlight, a revised rear frame, lowered running boards, new built-up pilot and tender footboards, and all new piping. She’ll handle 6-8 cars on a 2% grade, which satisfies my operating requirements.
Mark, here are some facts. The following are the tractive efforts of typical Southern Pacific steam locomotives:
S-12 (0-6-0) 31,020 lbs.
Se-1 (0-8-0) 31,290 lbs.
Se-2 (0-8-0) 40,990 lbs.
Se-4 (0-8-0) 52,990 lbs.
M-4 (2-6-0) 28,710 lbs.
C-9 (2-8-0) 43,305 lbs. saturated, 45,470 lbs. superheated
Mk-5 (2-8-2) 51,080 lbs.
F-4 (2-10-2) 75,150 lbs. (booster added 9600 lbs.)
…A Southern Pacific Mogul (2-6-0) was observed pulling 80 or 90 cars in the level Central Valley of California at full throttle at a crawl (pg. 39 of Tom Dill’s book “Southern Pacific’s San Joaquin Valley Line”).
Let’s draw some observations:
SP’s 0-8-0s were equal to or up to 65% more powerful, depending on class, than SP’s typical 0-6-0.
The typical SP 0-6-0 (not a terribly large machine) had about 70 percent of the tractive effort of a typical SP 2-8-0.
The typical SP 0-6-0 had more tractive effort than the typical SP 2-6-0 that was capable of pulling at least 80 cars on the level.
My conclusion is that the S-12 0-6-0 could pull 80 or more cars on the level for a short distance; the distance restricted by the locomotive’s ability to create steam due to a small firebox.
Interesting, if irrelevant. But since you raise the subject, did the book specify whether the cars were loads or m/t’s? Did the book specify the class of 2-6-0? I’ll bet it was an M-6 or M-9, not the M-4 you have quoted the TE for. For that matter, how reliable is the original claim? “80 or 90 cars” is not a very specific number. How many was it?
Your “conclusion” is no more than surmise and speculation, based on some selective use of figures and hearsay. 80 or more cars equates to a minimum of 3200 tons, assuming 40 tons per car - I’d be surprised if an S-12 could start that load, let alone move it any distance. What I was hoping was that you would post some actual evidence to support your claims. In the absence of that, I’ll stick with Alfred Bruce. [:)]
Mark, you make a couple of valid points. (By the way, the train had been observed by an SP trainman, and SP’s Moguls were sometimes called "Valley Mallets, so I believe the observation of a Mogul pulling 80 or 90 cars on level track to be valid. Geez, talk about taking “drag freight” to the extreme.)
I’m curious. Did Alfred Bruce say how many cars a Mogul could pull?
Perhaps those Mogul “Valley Mallets” were the SP’s Class M21’s, 213,230 lbs weight, 45,710 lbs T.E.? Not a very small locomotive.
It would be useful to know what the dispatchers’ rules of thumb were at the time (1920’s/1930’s), relating locomotive’s rated tractive effort (ability to start a train moving) to trailing tonnage, schedule speed, rail conditions, ruling grades, 40 ft box cars, friction bearings etc. etc.
My information didn’t indicate what M (Mogul) class was being referred to in pulling those 80/90-car trains. Assuming it was M-21s with almost 50% (45,710 vs. 31,020 lbs.) more tractive effort over an S-12, that would indicate an S-12 0-6-0 could pull over 50 cars for a brief period.(and the USRA 0-6-0 was more powerful than the S-12 according to the info provided by others.) We’re probably talking empty cars here, and definitely on level track. The “other” Mark’s citation of 4 to 15 cars being pulled by 0-6-0s was probably typical of their workload. Nevertheless, my point was, that in a pinch, the typical 0-6-0 could pull much more for a short distance. All the train tonnage rating info I have relative to particular ruling grades concern locomotives larger than the Ms.
Anybody out there got more info?
Mark.
Unless the lead drivers of an 0-6-0 or 0-8-0 were fitted with lateral motion devices, they couldn’t run much over 20 MPH without making enemies in the M/W department. The lack of a leading truck would cause nosing problems at higher speeds. Even with lateral motion devices, switchers would still be restricted to about 35 MPH.
Eh? Lateral motion devices were intended to shorten the effective fixed wheelbase of large locomotives like 4-8-4s, not substitute for leading trucks on switchers. Nor would they inhibit nosing - quite the opposite. Can you cite any examples of US 0-6-0s or 0-8-0s so fitted? Cheers, Mark.
D&H rebuilt several 2-8-0’s into 0-8-0’s and fitted them with lateral motion devices for optional road service. Such service would probably be a local freight or road switch job.
Bizarre. But then, the D&H did any number of things that were odd. I can’t understand what benefit they hoped to obtain by having lateral motion devices on a short wheelbase, low speed locomotive. But thanks for responding, CSSHEGEWISCH. You’re the first person I can recall who actually gave more detail wehn asked. Cheers, mate! Mark.