I’ve been watching the Bailey Yard cam a lot lately, and I noticed it’s not uncommon for the hump engines to reach down into the bowl tracks and pull a cut of cars back up over the hump, then push them over the hump again for reclassification. Does anyone have any idea what’s going on there? It seems terribly inefficient to hump cars twice in succession.
I can think of several possibilities.
Not enough bowl tracks - once space is available, the cars are sorted as actually needed.
Perhaps the cars need to be blocked in behind other cars. There’s a lot of pre-blocking going on these days.
There may be reasons why they have to be placed someplace in a train besides where they would have gone - ie, loads/empties distribution.
I’m sure there are other reasons.
Maybe the cars are smarter than we give them credit for and they just want to ride down the hump again… [swg]
I once had a medium size pile of dirt in my back garden for some project. Looking out my window one morning I saw a small squirrel skid down the pile on its back. I figured it was just clumsy and fell off the pile…except it immediate ran back up and slid down the pile on its back again. The squirrel did this several more times IIRC, so clearly it enjoyed it.
This has nothing to do with freight cars going down a hump…unless as tree68 suggests freight cars have the sentience of juvenile squirrels…
[:D]
I’m thinking that the second round is more specific.
There are not enough tracks in the bowl, at first, to have separate ones for, say, San Diego, LA and SF cars. So the cars (let’s say from a train that came in from the east) were all sent to the then-designated “California track.”
But later, when more tracks are free (because some tracks’ cuts have been pulled) they get down to blocking at city level, using a track for each city.
I have a little experience with hump yards.
Safety first…when a crew is in the other end of the yard and making couplings to pull the cars out for the train that’s due out of town later that day, they will have the track locked up. And if you have cars destined for that track, you have to put them on a rehump track, which then gets pulled and the cars properly classified.
Same thing for “holds”: A car could be “held” for various reasons, no waybill (actual or perceived) being chief among those. They give the cars a day for their information to catch up with them, and pull the track back.
Third reason is “OKs”. Somewhere down at the other end of the yard is the car repair track, accompanied by a job spotting and pulling the cars from time to time. It’s easier to gather the repaired cars and shove them back up into the hump classification tracks, where a hump job will pull them back and sort 'em out.
At one time we did the same thing for inspected grain box cars…when the track was released, it would get pulled and classified.
We didn’t do any of the more precise classification at the yard where I worked, but it could have been done easily enough. With a few extra rehumpings, you could, for example, make 16 classifications, all lined up in proper order, out of four classification tracks.
Quoting Carl “I have a little experience with hump yards.”
[(-D] Carl, don’t be so modest.
Fascinating. Thanks for the replies!
Hi Carl,
Yes, that pretty much covers it. I don’t know how many tracks there are in Bailey Yard, that’s one I’ve never been in, the biggest were the new (1997) BNSF Argentine Yard and CSX’s Selkirk Yard, but there were also some small yards with only 16 or so tracks so rehumping was common. However, I was a software engineer designing computer control systems, starting with hump yards in 1973 then after a few years going to Transit control systems then CTC before returning to hump yards in the early 1990’s. Most of my activities were with BN/BNSF, Southern/NS, CP and CSX yards as well as some “singles”, TRRA and BRC. Most of my work was Kansas City or east of there. Each yard had its own movement plans depending on both the capabilities of the facility and of course the (constantly changing) mix of traffic at that site. Usually both “RIP” and “Hold” tracks were dynamically assigned to specific tracks and at some sites, where outgoing trains might experience limited clearances, there would be a detector at the crest of the hump to detect various high/wide limits and if a car violated those limits for its planned route, it would be last minute rerouted to what was sometimes referred to as the “Overload” track, again dynamically assigned. Selkirk Yard was one of these. This was of course all done by the computer control system and of course eventually these cars would likely be rehumped.
Although I never worked for US&S, some of my memoirs of my early history in hump yards is documented on a web site maintained for former US&S employees: http://has-been4.ddns.net:8080/wp2/index.php/?p=15045 .
And yes Carl, I too finally got it right in 2010, retiring early that year at age 62. As I like to say, retirement is the best job I’ve ever had!
73, J. Chris Hausle
Must say I agree with all of the previous replies. But they’re all a result of the first explanation: Not enough bowl tracks. On the other hand, has any classification yard – hump or flat – ever been built with too many tracks? I doubt it.
is this CNW carl s proviso CRO
I would agree that, to a point, the answer is no. After all, gases expand to fill all available space, and Parkinson’s Law states that work expands to fill the available time.
Odds are that someone will find a use for any available empty track, even it it’s to park an old caboose. Conceivably, one could run out of uses for the empty tracks, but I have my doubts, too.
Carl does indeed have a “little experience” with hump yards. I always appreciated your knowledge about the railroad operations and hospitality.
The operation of hump yards is an overlooked aspect of the railfan hobby. Perhaps it is my history in the LTL trucking industry, but the efficient staging of cars (or LTL freight) is a daily puzzle.
Recently I began collecting railroad freight schedules, primarily from the 60s/70s/80s which go into detail with the classifications of trains with the blocks assembled. Fascinating stuff. The railroads would print these schedules and typically publish these for operations and sales teams.
Carl, what is your opinion on teh Proviso hump yard decommissioning? Any idea of the number of cars being processed there today?
Also curious if the rails will use BRC Clearing for more of this type of classification.
Ed
Ed, the printable portion of my opinion on the hump closing is that they could make the numbers say anything they wanted to. They probably didn’t want to put the money into automation and upkeep, so they just shut it down.
I used to demonstrate on a daily basis why it made more sense to preserve Proviso as a manually-operated classification machine…our reaction time to specific situations was faster than that of any computer system they could come up with.
We probably did have enough classification tracks (at 69, later 66), but the problem was that they weren’t long enough. I suppose that’s the same thing…if we’d had more tracks we could have made more different classifications.
One other very basic question comes to mind about hump yards: how does the person at the crest of the hump know when to pull the pin as the cars come at them? Are they working off a list, or does someone inside the tower tell them when to pull the cut lever?
The ‘pin puller’ does work off a list that indicates where to make the cut. Humps have restrictions in how many cars can be moved through the retarders in a single cut; different humps have a different number of cars.
Hump engines endeavor to shove the entire track being humped over the hump at a constant speed of 1 MPH or so, with the cars gaining speed from gravity as they go over the crest with the retarders (Master & Group) calibrated to control the speed of the cars so they are getting to the coupling point in their destination tracks at under 4 MPH (recognized Safe Coupling Speed).
The following video, while not from the USA, is representative of humping operations everywhere.
Some yards have a readout display of the list, minimal information like car initial and number and where to make the cut. I’ve seen pictures of them in Trains’ articles and elsewhere, but can’t find one to link to.
Jeff
At our yard, the list was held by the conductor (as well as the three Car Retarder Operators), who instructed the pin-puller where to make the next cut, when to stop, etc. By the time I retired the pin-puller was an RCO, which actually made eveyone’s jobs easier (I’ll get a lot of flak for that, but it’s true).
From my perch in Tower A, I was–in addition to my regular duties of controlling the speed and pointing the cars in the right direction–checking the cars against the list. The number of times I found discrepancies was pretty high. I felt good when I could spot them in time to get the word to everyone. It seemed that the railroad had AEI readers but used them only as a backup to their own computer system. I’ll never forget the shove they gave us that started in the center and worked out both ways!
Actually, I’ve thought for some time that humping operations are the one place where Beltpak would work well.
For regular flat-switching to work efficiently you need people in three places.
Thanks to all for the info!
I always wondered how they make hump yards work in Europe, where they have those ridiculous screw couplers that (I thought) required someone to actually get between the cars to uncouple them.