I'm guessing that the larger diameter wheel reduces the peak stress on the wheel and rail. I would also guess that the peak allowable stress is set by fatigue.
Somehwere in the very early 1970's, Trains had a news item about the UP experimenting with 125 ton coal cars and noticing a very significant increase in rail wear for a given gross tonnage compared to 100 ton cars.
125 ton trucks required on 315K cars already use 38" wheels.
Overmod An interesting alternative that came to a head around the end of the 20th Century was the achievement of 315K interchange cars that would not ruin railhead steel or wreck track geometry -- the perceived solution was three-axle freight trucks. These were actually designed up to the point of marketability, and remain potentially attractive for a number of uses that have not quite developed here yet -- if you can track down the current owner of the intellectual property and design drawings!
An interesting alternative that came to a head around the end of the 20th Century was the achievement of 315K interchange cars that would not ruin railhead steel or wreck track geometry -- the perceived solution was three-axle freight trucks. These were actually designed up to the point of marketability, and remain potentially attractive for a number of uses that have not quite developed here yet -- if you can track down the current owner of the intellectual property and design drawings!
I have heard going to 38" wheels will be the solution for 315K.
Interestingly, early-'70s three-piece trucks with appropriate detail design ran quite happily on the Super C, which reached up to the lower end of your speed range.
A great deal of careful work into high-speed 3-piece suspension, improving ride quality and damping, was done in the '50s by Chrysler (commercialized by Symington IIRC) and others.
A problem that occurs at high speed is 'lozenging', where play or lost motion develops in the longitudinal contact surfaces between the sideframes and bolster. This allows skew motion of the sideframes, tipping up on the bearing seats, and this is difficult to damp externally without expensive and exposed equipment. At one point, privision was made for x-bracing, pinned to brackets on the underside of the sideframes, to prevent this effect -- I have seen the sideframes on intermodal equipment but have never seen one with the actual bracket installed...
Likewise, there needs to be a guarantee if smooth rotation of the truck on the center bowl and side bearings, while effectively and progressively restoring truck-frame rotation when encountering track roughness at high speed.
There is much to be said for a good modern radially-steered truck, but it has to have the relative foolproof simplicity and ease of inspection and maintenance of improved three-piece trucks. That has not quite happened yet; I have heard conspiracy theories that AAR et al. will not approve a new truck for interchange until multiple companies manufacture it, and replacement components for it.
So far, any attempt to actually ship interchange freight at above 79mph in the modern era has failed to thrive. With the advent of PSR-style operation, the necessary superelevation and track maintenance for freight on 110mph track cannot be justified by increased profitability, either in rates that can be demanded or in increased equipment utilization. I have found this tendency deplorable since the early 1970s... but there it is.
Can current freight trucks operate at sustained speeds 90 to 110 mph? Or,would there need to be a different design? Could current designs bear sustained speeds of 80 to 90 mph?
Yep, though pronunciation is close...
I ran across an article on the Semi-Automatic Ground Environment, where "bogey" was used as a short hand for unidentified aircraft.
Isn't that other guy 'Bergie'?
I think OM's right... Most of the written accounts I've about the air war in Europe used "bogey" for unidentified aircraft.
Had a radom thought about confusing "Bogie" with "Burgie" (the latter as in beer, though could refer to another Erik from the forum's past).
Overmod BaltACD I recall Bogie's at 12 O'clock High But did he graduate or did he have to get a GED? Bomber crews would have called them 'bogeys'... if you could tell the spelling from the language on TV.
BaltACD I recall Bogie's at 12 O'clock High
But did he graduate or did he have to get a GED?
Bomber crews would have called them 'bogeys'... if you could tell the spelling from the language on TV.
I have yet to see the spelling in a pronounced word.
Never too old to have a happy childhood!
BaltACDI recall Bogie's at 12 O'clock High
I recall Bogie's at 12 O'clock High
My mind was on golf ....
https://www.youtube.com/watch?v=MCvgMNnM3OA
Paul of Covington I completely missed your point! I watched the whole clip waiting for any mention of anything train-related, then it hit me. (I'm not much of a movie fan.)
That's OK, sometimes it takes me a while to get the point, or a joke. But you got it, that's what matters. Personally I'm not much of a current movie fan, the last one I saw was "1917." The rest of the stuff they put out now doesn't interest me at all, I'd rather watch the classics.
That's OK, sometimes it takes me a while to get the point, or a joke. But you got it, that's what matters.
SD60MAC9500I guess the old saying holds true in all facets of life. There's nothing new under the sun.
The P-Company was also learning a few things about articulated train-sets, too:
PRR_P70-2 by Edmund, on Flickr
Eliminating two vestibules on these paired P70s increased seating capacity, too.
I don't recall which stack of "stuff" I have the further information buried in. If I find it I'll update.
Obviously, someone in the PRR hierarchy didn't go along with the experiment.
The "Budd Truck" didn't seem to catch on, either.
PRR_Budd-truck_P70 by Edmund, on Flickr
They almost look like something designed by Buddy-L!
Paul of Covington (I'm not much of a movie fan.)
Humphrey Bogart, AKA Bogie (and Bacall) a long-standing nickname for the Hollywood star.
Regards, Ed
Flintlock76 I don't know, the first thing that comes to mind when I hear bogie is this: https://www.youtube.com/watch?v=rEWaqUVac3M
I don't know, the first thing that comes to mind when I hear bogie is this:
https://www.youtube.com/watch?v=rEWaqUVac3M
I completely missed your point! I watched the whole clip waiting for any mention of anything train-related, then it hit me. (I'm not much of a movie fan.)
_____________
"A stranger's just a friend you ain't met yet." --- Dave Gardner
bogie_engineer The odds are against the ATS truck being a marketing success given the RR's don't buy many cars and give no credit to the car owner for having a superior performing truck.
The odds are against the ATS truck being a marketing success given the RR's don't buy many cars and give no credit to the car owner for having a superior performing truck.
Reminds me of the reasoning for applying roller bearings first to freight cars that stayed on-line: the owning railroad got the benefits, rather than some OTHER railroad (when the car was off-line).
Will ANYONE buy these? I'm sure the designers and builders of these would like to get some monetary return, perhaps enough to break even.
Ed
The spring between the bolster and sideframe looks to me to just be a rubber spring with a shape to give it a lower stiffness when unloaded and a much higher stiffness when compressed an inch or so. The bolster slides against the car bottom on plastic pads where the side bearings would normally be which gives it high friction yaw damping for stability. It looks to have steering arms attached to the bearing adapters that connect in the center under centerbearing like the Harold List truck which was licensed to Dresser as the DR-1 then later to ASF as the AR-1 when they bought Dresser. It's not visible but I think each sideframe has member going transversely across to the opposite sideframe which creates the warp stiffness. The sideframes can pitch independently providing wheel load equalization like a 3-piece truck.
Putting the rubber spring directly under the bolster end with the sliding wearplate directly above it was taken from a patent I got while at ASF seen here:
https://pdfpiw.uspto.gov/.piw?Docid=05438934&homeurl=http%3A%2F%2Fpatft.uspto.gov%2Fnetacgi%2Fnph-Parser%3FSect1%3DPTO2%2526Sect2%3DHITOFF%2526p%3D1%2526u%3D%25252Fnetahtml%25252FPTO%25252Fsearch-bool.html%2526r%3D1%2526f%3DG%2526l%3D50%2526co1%3DAND%2526d%3DPTXT%2526s1%3D5,438,934.PN.%2526OS%3DPN%2F5,438,934%2526RS%3DPN%2F5,438,934&PageNum=&Rtype=&SectionNum=&idkey=NONE&Input=View+first+page
This removes the vertical bending load on the bolster allowing a very lightweight design.
The odds are against the ATS truck being a marketing success given the RR's don't buy many cars and give no credit to the car owner for having a superior performing truck. So any cost extra above a standard M-976 truck has to be balanced against any weight savings for greater capacity or wheel life improvement the car owner sees.
Dave
Here's a photograph of one of these trucks:
It's over two years old. I haven't found any info on them being tested under a railroad car, yet.
Nor do I find a company website, containing further information (like truck weight).
Looking at the photo, I'm wondering what the brake beam assembly (in yellow) pivots on. It appears in the photo that it's not even attached to anything.
Here's a drawing of the truck:
No brake beams are present. I also see what looks like a rubber air spring bag. Or whatever it's called. Is that acceptable on a freight truck?
SD70Dude I wonder if the radial steering part of the ATS design owes anything to Mr. Goding's work?
I wonder if the radial steering part of the ATS design owes anything to Mr. Goding's work?
No, this appears to simply have rubber shear pads at the bearing adapters allowing some axle motion to steer itself, with steering arms coupling the axles. This is really the same as an AAR M-976 truck re the shear pads with steering arms based on List design. The big advantage of the ATS design is the high warp stiffness compared to a 3-piece truck which limits parallelogramming of the truck.
Corrected re steering arms.
I read and watched enough 'Thomas the Tank Engine' in my younger years to be familiar with the British names for things.
Greetings from Alberta
-an Articulate Malcontent
At EMD, truck and bogie are used interchangeably. One recent group manager insisted calling it the "Bogie Group". Didn't manner to me, understood either way.
tdmidgetPretty sure they knew that they are called trucks. Bogey as in railroad use is British. Bogey as in the wheels on a tank refer to two wheels, not four.
I've heard bogies used here, too. Mostly with the old triple crown stuff, but it's not a complete foreign word on American RRs.
It's been fun. But it isn't much fun anymore. Signing off for now.
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.t fun any
tdmidget Pretty sure they knew that they are called trucks. Bogey as in railroad use is British. Bogey as in the wheels on a tank refer to two wheels, not four.
Pretty sure they knew that they are called trucks. Bogey as in railroad use is British. Bogey as in the wheels on a tank refer to two wheels, not four.
How do you know I'm not British?.. All of us who speak English understand words are and can be interchangeable ..
By the way make sure you email Amsted Rail and tell them the same thing... They are trucks not bogies.....
Yes electronic monitoring of the axle bearings is in order for the ATS truck. For as much as the AAR touts the rail industry and its benefits. Somewhat surprising to hear them holding back progress on connectors, advanced trucks, and suspension systems...
Agree about the brake shoe advantage of the inboard bearing truck but there's disadvantages too. One is roll stiffness and damping of the suspension - with the springing inboard of the wheels there is much lower roll stiffness for a given vertical stiffness. This can be made up with supplemental roll stiffness devices but that's an added complication. Another is wayside hot bearing detectors, to my knowledge they are all aimed at the bearing outboard of the rails. The AAR standard S-3007, in section D, defines at target area for the detector outside the wheel so any inboard design could not comply as currently written and would require an investment by the RR's to add inboard detectors. I am guessing all inboard bearing passenger car trucks have onboard bearing temperature detection systems to get around this, and I suppose with all the work done to add monitoring systems to freight cars that could be done here.
I'll add a rant about what I observed during my 3 years working on freight car truck design at ASF-Keystone. When a company develops a proprietary design for a new truck or component, the AAR stalls their approval of that device for interchange until a competing design is available to be able to pit suppliers against each other to get leverage and the lowest price. The biggest I saw was the articulated connector ASF developed for stack cars - it was such a great innovation the RR's didn't wait for AAR approval and handled it by inter-line agreement rather than wait for AAR to write a standard and grant approval for interchange. Same with yaw dampers. You can be sure AAR would not approve an new inboard bearing freight car truck for years, maybe decades.
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