#60 ~ A Little More.... Tonnage Ratings on the C&S

[Mike Trent]

To follow up a bit on the #60 thread earlier this week, which was pretty interesting, and the header photo above. I thought I'd share a little comparative data on the relative tonnage rating of #60, a Class B-4-C engine, to other classes.

On the timetable reference attached, pay attention to the listings for Como to Boreas, which is 4%, the ruling grade, the one that matters most.

You will see that the B-4-F Class (74-76) is rated at 145 tons,  the B-4-E Class (71-73) at 120 tons, the B-3-C (4-10) and the B-4-D (63-70) Classes are both rated at 110 tons, and both the B-3-B (21-22) and the B-4-C (57-62) Classes are rated at 80 tons.

As an aside, you will note that the B-3-A class, (11-13), is rated at only 70 tons. I believe this is due to either a difference in the cylinders or some other reason after the engines were reboilered, or, it is simply a mistake, as at least #12 and #13 after reboilering appear to be exactly as #'s 21 and #22 and should have been classed as B-3-B. Prior to reboilering, these three engines were UPD&G Cooke Moguls, exactly as the DSP&P Moguls which were reboilered by the C&S starting in 1900 and became the B-3-C Class.  

Bear in mind that the tonnage rating for a loaded 30 ft freight car is 25 tons, so with that number you can easily figure how many loaded cars could be handled by each class of engine. As a relevant example, #60, with a tonnage rating of 80 tons was only able to handle three loaded cars on a 4% grade.  There are a lot of other calculations that figure into tonnage ratings, including actual weight of empty or lighter than actual capacity cars, and even a flange friction factor based on curvatures of a particular section of the railroad added to the grade. But for a purely simple (Tonnage for Dummies) rule of thumb, figure these numbers for the 4% ruling grade as how many loaded cars in your consist. Light weight (22000 lbs) is 11 tons on a boxcar. It was the responsibility of the Conductor to keep track of this stuff, and the total tonnage of the train determined how many helpers were needed. I've seen a photo posted here fairly recently of a six car train with a road engine and one helper working the grade up "N" Hill out of Breckenridge. That would be right, figuring that even a single Big Hog B-4-F Class was only rated at five loads and these were almost certainly loads of Concentrate from Climax.    

Now you can easily imagine how it came to be that #60 and her sister engines were used as switching engines. Another rule of thumb, with the exception of the B-3-C's, is that the lower the number and class number, the older and smaller the locomotive.

Unless you are standing next to #9 and you actually see how fat that boiler is, or if you can see scale models of a B-3-C next to some of the other classes of engines, you would be surprised that it has a tonnage rating equal to a B-4-D or a C-19.

Regarding the tonnage of the passenger train, the old as-built Cooke Moguls were able to handle a Baggage/Mail and single Coach with no problem, so the rating of each car was probably about 30 tons, I would guess. That works, too, for the photo in the header of #60 carrying what was probably an empty boxcar picking up records and other items along the line for the last run in 1937. As mentioned above, the tonnage for that empty car was only 11 tons. A second coach making a three car train behind #60 might have been tense, but the B-3-C's could handle it easily.

Some of this is probably old hat to some of you, not so much for others, perhaps. But now you have some extra work to do, and you might have to consult the tonnage listings on your freight rosters to help figure out how many more engines you'll have to add to your motive power roster to handle your requirements.

Bob Stull's fantastic layout in Denver featured a 4% ruling grade. One night back in about 1986, I took my three B-4-F engines and #537 (also rated at 21,000 lbs/145 tons) and 10 freight cars. I had two engines doubleheaded at the front, one in the middle, and one just ahead of the caboose, just as the C&S would have. They had about all they could handle, so I figured that my engines and my weighted freight cars came out to just about the right ratio. It was quite a sight, I must say.  

[Keith Hayes]

Mike:

It is sure easy to see why the C&S kept the big engines! Also of note is how few locomotives were available during the last decade of operation (about 16 locomotives, plus leased equipment by my count after ~1935). As you observed, after the wreck of 73 and 75, the situation truly was dire, with no spare equipment.

Upon reflection, I am surprised how long 30 lasted on the roster. 58 and 60 were the last of the B-4-Cs, others in the class having been scrapped in 1930 and before. The B-4-Ds did not last much longer: 65, 68, 69 and 70 survived while the remainder of the class were scrapped in the 20s.

Derrell Poole and I discussed at one time the odd choices manufacturers made for models. In most instances, choices appear to have been influenced by surviving examples: 9, 60, 71 and 74. (If one of the towns had taken up the offer, we would count 8 among the survivors.) This did not take into consideration the odd domes and other peculiarities of these locomotives which require modification when converting them to others in the series. For reason's I don't understand (but I really do), in Sn3, Overland chose to import 65, 69 and 70, I think, but not 73. Fortunately the B-3-Cs maintained a very similar appearance over time (9s more rounded domes aside): the re-boilering sure made them into powerful locomotives!

(Oh, and for those of you who want to print out that handy tonnage chart, Rick Steele was kind enough to post it in the files section!)

[Lee Gustafson]

Mike,

Did weather or season have any impact on tonnage capacity? Thanks.

lee gustafson

[Mike Trent]

Hi Lee,

Those calls would have been made by the operating department, or maybe the Road Foreman of Engines. Heavy snow, or drifting would have probably called for extra power if available, but those issues would have been determined on a case by case basis. This information is related to common day to day operations. I don't believe weather related issues are covered in the rule book, other than if it affected the Conductor's duties.

#74 has a field weld in the frame just forward of the right cylinder. The break was caused by bucking snow somewhere near French Gulch, as I recall. Mickey Hansen did the welding, a much younger version than my Dad's old friend when I was a kid. So absolutely, weather in the High Country could always be a factor.

It is pretty certain that the roster of available power would have had to have an engine or two that could be brought out in emergency service. One would think that an extra locomotive would have been kept at Leadville if possible. Como did have an "emergency" engine in reserve for the passenger train, under steam.  

[Jim Courtney]

To expand on Mikes information, this is a copy of the last page of the Monday, June 5, 1922 Employees Timetable, South Park Division, No.1 (Effective at 1:01 A.M. Mountain Time):



Reprinted by the Rocky Mountain Railroad Club, 1976


The information on the left is pretty much what Mike provided above. Though not in use for 12 years, tonnage ratings for the entire Gunnison Subdivision though Alpine Tunnel to Gunnison are included, excepting the B-4-Fs 74-76 (probably wouldn't have cleared the tunnel portals at Alpine anyway)

At the bottom are engine ratings on the Clear Creek Subdivision. Note that although the timetable lists 2 trains daily in each direction from Forks to Central City, there is no tonnage rating provided for Blackhawk to Central City on the switchbacks.

Note also the tonnage rating for standard gauge engines between Denver and Golden. But no information is provided for the Morrison branch.

Curiously, although the big Brooks engines were never used on the Clear Creek Subdivision (are we sure?), nonetheless, they have been rated on the Clear Creek grades, even around the Georgetown Loop to Silver Plume.

The top right of the page includes the tare weights for passenger cars and empty freight cars, both narrow gauge and standard gauge, all of them for the entire railroad.

Jim