As I develop the operating schemes for Leadville, I am most interested in duplicating C&S practice. This includes understanding the locomotive tonnage ratings (and operating rules). Klinger has published C&S locomotive tonnage ratings, and I have used these to develop a table of C&S and D&RGW ratings. There the matter of an adjustment factor, which seems to discount the weight of a car going upgrade, which does not make sense.
In any case, tonnage ratings help explain a lot about the C&S locomotive roster. The large number of B-4-B class locomotives disappeared early on as they were worth about half the cars on a steep grade of a B-4-E (71-73). This helps explain the trade of so many B-4-Bs to Morse Brothers in exchange for the B-4-Fs. By the mid-20s, all the less powerful locos were gone, save perhaps #30, which held down the Como-Alma run to the end.
For comparison purposes, the C&S rated their locos on the 4% for more tons than the D&RG rated the C-21s (#'s 360-361). The three C-19s appear to compare with the B-3-Cs (#'s 4-10) for tonnage (about 3 cars on 4%), confirming that these were powerful locomotives as rebuilt.
Why is this important? A B-4-F is rated for 15 cars between Denver and Waterton, but may only be able to haul 5 of those cars beyond through Platte Canon, and only 4 cars to the top of Kenosha. In modeling terms, it is entirely appropriate to have a train with 4-5 cars in the mountains, or better yet, a double-header with 10 cars. My question is, who on the railroad determined the combination of the number of cars to be handled and the locomotive assignment?
There were all manner of things which affected tonnage rating. As you may know, on the C&S, one of the things which increased adhesion over D&RGW engines was the half flange on the blind drivers. Another thing which surprised me to learn was if the main connecting rod was attached at the third axle, as it lessened the angle.. It wss for that reason that on the D&RGW, the C-18's actually had greater adhesion than the C-19's.
After the 1936 wreck on Boreas, the C&S leased three C-19's to compensate for the loss of #75 and #73.. The engine crews hated the C-19's as they "wouldn't pull their tonnage". On paper, the tractive effort of a C-19 should have been the same as a B-4-E, but actually was only similar to the B-4-D's. Reasons for this were the main rod driving the #2 axle and the true blind drivers. The C&S added half flanges to them but couldn't fix the main rod problem, as the frames were never engineered like that.
Another huge factor was steam pressure, which is yet another reason why the B-4-F class was so strong.
It is interesting to note that the B-3-C class was rated same as the B-4-D class, which is why they were often used in helper service.
Mike, I noticed that the C-18s were given a higher rating than the C-19s. I believe the C-18s all came from the F&CC. I also found it of interest that the B-3-Cs were such good pullers: that is why 8 is on my wish list as a helper.
I had not given much thought to the main rod length. The 2-8-0s with the main rod connected to the second driver have a squatty look; the longer rod connecting to the third driver is more elegant. I am not sure how this impacts pulling power. You are right a longer rod is heavier, and a review of photos indicate that the longer rods appear to be shorter in height and are fluted to reduce weight--I don't see this (or at least it is not as evident) in photos of shorter rods.
Looking through RRobb, I see a couple 2-8-0s where the rod moved between the 2nd and 3rd driver, but not many. Notable was the loco that became Milwaukee Road 4, which had it switch both before and after the sale. Curious.
This does beg some questions. The wheelset connecting the main rod should have a larger counterweight: if the rod is switched, can the 2nd and 3rd axel wheelsets simply be exchanged? Someone mentioned the notion that the cylinder stroke and main rod proportion are related--isn't the stroke more related to the radius from the axel center to the center of the rod pin? The diameter would be the cylinder stroke, no?
Keith, as locomotives evolved through the 1880's and 90's, they became larger and heavier. Steam pressure increased. and builders began to experiment with outside frames on narrow gauge locomotives.
Longer rods to the third instead of second drivers were used because it was discovered that the reduced angle to the main axle caused more efficiency and strength. Anything that improved performance was desirable. There was much competition between various builders at the time for this growing industry.
Consider the locomotives that became the B-4-F Class. After the C&N placed their order with Brooks, and the first had been built with the trademark Brooks canted steam chest and slide valves, the second two were fitted with piston valves, so this caught the three engines during construction. The UPD&G ordered new 2-8-0's that became the B-4-E class, #71-#73. Those engines had their driving axles in the third position.
All of the older engines used on the South Park had the drivers in the second position and were less efficient and somewhat smaller. But they were essentially always how they were built over the course of their lives.
The length of the rods and the additional weight of them would not have exceeded the increased weight of the stronger frames that were used to support and drive larger locomotives.
As to the Moguls that were rebuilt, well that's a different story. It is laughable that the C&S continued to regard the rebuilt #12, #13, #21, and #22 as Cooke and Brooks engines. There was nothing left of the Brooks engines they once were. They were all rebuilt by the UP in 1894 and were virtually identical to each other afterward. Same sort of thing for the rebuilt Cooke Moguls rebuilt by the C&S, the B-3-C's. The huge boilers increased their tractive effort considerably. The boiler diameter of a B-3-C is almost as large as the B-4-F Class. When you get your #8, you'll be amazed how they compare in thickness to the B-4-F's. I am also working on acquiring a #8, by the way. I have #6, but #7 can't quite be expected to toe the line on regular passenger service any more.
Around the TOC - that is between about 1895 and 1910 - roughly - several of the "older engines" were NOT so essentially the same as built! I think I pointed this out to you before, Mike. And I think somewhere we posted a list of the engines that happened to be photographed with long mains to the 3rd. I know the last time you expressed doubt (based on what? Osmosis?) I gave you two examples published in Mac Poor's bible. Do you not have this volume?
Here are just a few of the engines I found in about 15 minutes - by no means complete.
No I don't have that book here, so yeah. Osmosis. Were any of these engines left with long rods? #61 was not, amd neither was #69, for sure. Can't blame them for trying to work whatever tricks they could. Even if they were experimental. What did they have to lose? Some of that stuff actually worked.
Deciphering recordkeeping of things from those days can be as confusing as anything else. Tends to make one grumpy. At least that my excuse, if I need one, which I don't. And neither do you. Just makes us more lovable.
Not trying to be grumpy - already am. And it ain't your fault, either. But this is the second time I've seen you toss this significant detail aside and it is hard to not draw conclusion it's because you have no real interest in the era these changes took place. Fine. Why are you compelled to even say anything if you don't really know?
We all make mistakes - the biggest being off-hand comments out of over confidence. Derrell is as guilty of this as anyone. When that happens I try to have enough character to acknowledge my mistake - head on. Ain't no cherry for me to be wrong!
The engines changed. And then they changed back. The second point does not nullify the first - especially to someone who studies - intensely - that era and wishes to know the facts.
You're giving too much creedence to what should be significant insignifica. I can show you drawings of three stacked UP 800's, 4000's with Wind Wings and oil burners, and all kinds of modifications. These were done, sometimes at the behest of Master Mechanics and sometimes at the behest of Research and Development.
What we tend to forget is that the C&S wasn't static. They experimented. They cut hatches into the top of Box Cars, they put drop ends on wooden gons and then reinforced those ends with truss rods (or tie rods if you prefer), on the broad gauge they used wooden and steel ingoldsby dump cars, they used plug doors in their early broad gauge box cars and later replaced these doors with sliders.
In other words, they did what they felt they needed to do to compete and to make due with what they had. Changing the main rods on the locomotives? Fine. Go look at the 60 and tell me where the eccentrics for the Stephenson links are. What? You found them on the two inside drivers? Fancy that...
Yes, we get grumpy, but the railroad is a constantly evolving place. You can model a Coal Car based on a photo that was taken on September 1. If that car went into the shop on September 2nd, then you'd have to rebuild your model if you wanted it to look like the car that emerged on September 4th.
Hell, man, you know that. You also know that the 2-6-0's were converted to oil long before the 70, and converted back to coal permanently after a couple of summer seasons.
So the short mains didn't work out, at least not on the C&S, but neither did the compound New York Air Pump on the 71. But you don't know if you don't try. Just be glad that we have the photos to look at and wonder about.
It just makes life interesting, it's nothing to get irritated about.
I guess I'd have to say that, on reflection, while the experimentation, if that's what it was, is interesting to ponder, the fact that they were changed back indicates to me that the comments I have made at least twice about the frames having had to have been actually engineered to withstand the stress of the driving axle in the third position has merit. That they were all reverted back to the way they were built in the first place is a strong indicator. I had previously read somewhere about failures of early D&RG experimentation with respect to third axle conversions of older locomotives. The problem was that the old frames were unable to withstand the stress, and that the drivers tended to "walk" as the frame twisted. The cost and trouble of replacing the frames was not worth the return. Can't site the source, but it seems to be consistant with this discussion. Easier to simply say osmosis.
That's my last word on this. I do, however, appreciate your having shared this interesting info. Sorry if I appeared to have blown it off. As you say, we all make mistakes.
Rick, Am chilled. Been to Helena to wrangle legislators. (Nothing chilling about that except for stupid bills to "Fundamentally Change the United States".)
I never forget that the Railroad was constantly changing. It is the foremost thought in my mind as I study. That they were wedged between an obsolete property and the need for more powerful locomotives; the long rods were but one example....
Mike, The photos appear to span several years. How many years does it take to figure out something doesn't work? We see just two narrow gauge engines with half a dozen sanding tubes - or what appears to be sanding tubes - out of the sand box. There is an experiment that apparently didn't work! We see them in 1902 or 3 and that's it! One year - maybe. But we see multiple engines over an extended period and 3 company names switching main rods; and then they were all changed back.... Hmmmm. I'm just not making the connection on how that dynamics means long rods didn't exist on locomotives built with short rod.
Let me be blunt. You were wrong. Now you are rationalizing to somehow not be wrong. That is what offends me. Not holding it against you. But I've had to eat my words plenty of times and will again. What makes anyone here above that? Your Name perhaps? If we are truly historians then we must be willing to sacrifice our names and our egos upon the alter of the Truth as best we know it.