i have never read anywhere about any frisco steamer, mainly referring to the mountains and northerns, about having roller bearings. i know the 1500's did not. also, i was surprised that the 4501 did not have a front end throttle when i sat in her cab back in the mid 80's and the age of steam museum. just curious......
Front-end throttles are multi-valved devices which were a part of the superheater header which were placed in the smokebox of a steam locomotive. The smaller individual valves were less prone to warpage and offered better control than did the single throttle valve that was located in the steam dome. They are best distinguished on a locomotive by the hatch which was located behind the stack and the external links and cranks from the throttle lever to the throttle. The rebuilt 182 class, the 4200 class, and the 4300 class locomotives used them. None of the Frisco locomotives carried roller bearings
Karl, it appears that as one opened the throttle, the valves would open in sequence as well as each individual valve opening increasing. I can see that it would provide very reliable control of steam flow.
At the risk of hijacking this thread away from the topic of roller bearings (which the consensus is that they did not exist on Frisco steam), this front-end throttle diagram fascinates me. Naturally, I wondered how each valve would be made to open in sequence, and a little logical thinking led me to imagine that if I were designing it, I'd make the cams on the rotating shaft each of slightly different size and shape, and this sequence would be a simple, predictable result. But I didn't even know how this thing works or just what the routing of the steam is, or to where exactly each chamber exhausts from here. Curious as to whether I could learn more on the internet, I looked up "American Multiple Throttle," and pretty soon I'm looking at a page of 2000 thumbnails of drawings pertaining to the Norfolk & Western railroad, including precision drawings of hundreds of parts to various steam locomotives. Further searching the page for occurrences of "multiple throttle," I found drawings of the very cams I had imagined: http://www.nwhs.org/archivesdb/detail.php?ID=49360 (See attached thumbnail, below) Other related drawings: Valve Lift Arrangement Rotating Cam Shaft Stuffing box details (seals the steam inside the valve around the rotating cam shaft that attaches to the throttle link) Utility valve details I know just enough about this kind of stuff to be amazed when looking at such drawings, such details of something so massive, powerful, and precise, and yet which has more in common with the hot water plumbing in my house than with most aspects of a diesel-electric locomotive. I don't mean to over-simplify. It's just that yes, the principles of steam locomotives are simple and logical. Anyone can figure them out -- in principle -- by thinking through the system very carefully. Where the 19th and early 20th century designers, draftsmen, engineers, machinists, and mechanics excelled and triumphed was in materials, metallurgy, and undoubtedly the trial-and-error testing to determine the failure point of their systems under heat and pressure. I shudder to think of how many head-end crews were the unwitting guinea pigs of such tests. Feedwater heaters, for example, were prone to early failure, and the likely result of a breakage in the crooks of those dry steam tubes inside the flues was a blast that sent a boiler full of steam roaring back through the firebox. Woe to whoever discovered that. But with each generation of newfound knowledge of these materials and their behaviors, it became easier to take an idea from a rough abstract to a mountain of precisely milled parts, giving credence to the idea that any man could do it, given a machine shop of savvy professionals who had developed a 6th sense about keeping steam inside the plumbing until it reached the smokebox and shot a round of exhaust skyward with each quarter-turn of the wheels of these giant behemoths that combined volcanic power with swiss-clockwork balance to move a train across the countryside safely, without incident. I'm not sure where it is, exactly, but somewhere in that previous paragraph has got to be a clue to why we still look upon these monuments to the mechanical age with such romance and awe. Multiple throttle, indeed! === Shooshie
But they don't live, breathe, spit, burp or, well, you know, like a steamer does! They simply don't have any soul or spirit like a steamer does.
Diesels sure are simpler critters! I'm reminded of the line in the Godfather "They're animals, they have no souls".
On the topic of why the Frisco did not have any roller bearing equipped locomotives, I was once told a story that the reason was one of the members of the Frisco Board of Directors owned a brass bearing company in St. Louis and exerted his influence to get the Frisco to buy bearings from him. Not sure if this is correct but sounds plausible. John Chambers
Frisco seems to have been very conservative in their choice of steam technology, wheel arrangements and accessories, at least in the later years of steam. I mean, we are talking about a railroad that tended to shun Baker valve gear! While roller bearings on steamers have very decided advantages (low friction, very little wear, longer servicing intervals) they in fact also have some disadvantages over plain bearings. For instance, if a roller bearing fails, an exact replacement would need to be ordered from the manufacturer if it was not on hand. Remember, this was before the days of next day shipping. If a plain bearing fails, the bearing and journal can be repaired at the backshop so long as the raw materials are available. Brass and steel need to be stocked for the bushings and journals, but the basic stock can be machined into a wide variety of plain bearings without having to keep each individual type of roller bearing at each repair facility. Another thing to keep in mind is that if a roller bearing fails on a drive axle, the driver will have to be removed from the axle to replace the bearing. A plain bearing can be replaced without having to remove the driver from the axle, so long as there is enough metal left on the axle to remachine into a smooth journal. Finally, the premium roller bearings also come with a premium price. To a frugal, conservative company like Frisco - one that was in receivership multiple times over the years - first cost is always an issue. As an aside, UP's 844, a modern 4-8-4 that was built relatively late, also utilizes plain bearings. Many remember the storied 611 of N&W fame - a hot rod Northern if there ever was one! It is, of course, sitting on rollers, but N&W set out to build the ultimate steamer to compete head to head with diesels. If that was my goal, roller bearings would be a given. Shoot, I would probably even put a Giesel exhaust on it... Still, it is neat to dream of a "super 4500" Northern sitting pretty on full roller bearings! By the way, just to prove I'm not prejudiced one way or another, #103 is on the traditional plain bearings, while the modern #205 is on roller and ball bearings throughout (even on the valve gear). Since #205 is just entering service, you'll have to ask me in 10 years which I prefer... - James
UP 844 is all roller bearing throughout. There were quite a few times I wish the 1522 was all roller bearings. Everything but the driving boxes was eventually converted by us.
I don't know about the driver axle bearings on 844, but the rods are plain bushings. Take a look at: http://www.chasingsteel.com/blog/2010/4/7/union-pacifics-no-844-suffers-a-seized-bearing.html The fourth and fifth pictures clearly show a floating brass bushing being replaced. To be honest, I had assumed that the driver boxes were plain bearings, too, but I don't have any proof of that. I'll see if I can find anything definite, plain or roller. - James Edit - I can't find anything that states what type of bearings are on the drive axles of 844, but I did find a picture taken at Strasburg that has a driver wheelset from 844 in it. The housing certainly looks big enough for roller bearings: http://www.railpictures.net/viewphoto.php?id=314079&nseq=82 Not sure why I made the leap from plain bearings on the rods to plain bearings on the drive axles, I should know better - even Timken's 1111 demonstator only had rollers on the axles, not the rods. Can we get an embarrassed emoticon / smiley face?
Go sit in the corner for an hour and reflect on what you've done. N&W 611 has roller bearing rod bearings, 844 has brass, as does the 3985. Both are roller bearing axles throughout. 4449 Is plain bearing driving boxes, but they are converting the rest of her to roller bearings like we did the 1522.
i have the pentrex video somewhere when the 844 and the 4449 were running side by side leaving somewhere in california i believe, and the 4449 had to stop because of hot bearings. rollers bearings just have to be better i would think. i think of steamers everytime i buy a timken roller bearing. sometimes i get lucky and it does not say china. James brings up a good point about the driver roller bearings. im wondering how they are applied to the driver axels. does the wheel have to be pulled from the axel, or can they be installed like the outboard marines engines? mercury outboard roller bearings are not one piece bearings, they are "put together", cage and rollers are separate...
OK, I sat in a corner for an hour, reflecting on what I've done while reading "The Locomotive Up to Date" . That's one of the great things about this forum, I get to learn something new each time I log on! - James
i didnt know that. i remember when you had trouble with the pony wheels and roller bearings were then applied to them. so was the trailer truck and tender also converted? while im being nosey here, would it be possible to install rollers on the drivers? a roller bearing 1500 would be great....
We converted everything BUT the drivers to roller bearings. Doing the drivers would be prohibitive unfortunately because it would require heavy modification the the frame, new axles, driving boxes and of course bearings. Yes, it would have been really nice!
