Western Railroad Discussion > Re-humping?

While reading the new NORTH AMERICAN RAILYARDS book by Rhodes, I noticed several pictures where the caption states yard power was pulling cars back to be "re-humped." I had originally thought it was because they didn't roll far enough to connect with the other cars on that track, but "trimming" with the yard switchers would cover that. What necessitates re-humping?
Just wondering...

The could have set aside the local cars and then rehump them for the various locals that operate out of that yard once the through destination cuts have been pulled. they could also need them in cuts that are set out somewhere enroute. they could also be cars that weren't on the train list and had unknown destinations. Bad orders for the RIP track. No doubt there are several other possible reasons.

Rob

Often there are tracks in the Classification Yard that are used as hold tracks for cars that may not have a certain destination or are not ready to be moved on to their final destination. Cars that are humped into these tracks are held, then the track is pulled and re-humped when cars in that track need to be moved out of the yard. One interesting example I read on Trainorders was a car that was being sent to a customer where there was a payment issue. The car was placed on the hold track until issue was resolved, then it was delivered to the customer.

All of the above is true. At CB&Q Daytons Bluff westbound (a flat yard) it was track 7 - the "Gut Track". Eastbound, it was track 17, "Shorts".

-John

The primary thing you need to know is that hump yards sort for far more destinations than they have bowl tracks for. The imbalance is such that many Hump Yards become directional based on time of day. They will sort westbounds trains for half a day, then eastbounds the second half of the day. When the cutoff for one destination is reached, further cars for that destination will be routed to a hold track to be re-humped for the next day's train to that particular direction. Meanwhile the the bowl track is reassigned to a new destination.

Ted Curphey
Ontario, OR

All of the above is true and could necessitate re-humping. However, here's another reason. On the Southern Pacific in the 70s and 80s at City of Industry's "econometric" hump yard, we employed what was referred to as "geometric" switching. Big name for a simple process! Initial humping of cars would "clump" destinations and switching zones (Anaheim, Buena Park, Norwalk, etc., as example). Once all inbound connections had been humped into these general destinations, then the "re-hump" process would begin. The re-hump process would sort the general destination cars into separate blocks of cars for the various switching zones (3100-4900 for the Buena Park Hauler and Anaheim Hauler if memory serves me correctly). When re-humping was complete, the various Haulers would put their trains together in zone order. In the end, the Hauler would depart City of Industry and make set-outs at switching zone destination storage tracks. As a result of this process, road switchers for the various zones would then have their cars "blocked" for each zone when they went to work. In essence, the process saved the road switchers serving 4 or 5 zones from having to switch all of the cars into the various zone areas. It was accomplished for them in the re-humping process! This process is undoubtedly repeated today in various classification hump yards across the nation. It's an efficient method of assembling multiple switching zone trains!

And, sometimes a track or two in a bowl will fill up and the computer will send cars for those tracks to others as overflow. They will need to be rehumped.

Geometric switching is but one way to make more blocks than one has tracks for. Where more blocks were made than there were tracks, re-humps were a way of life.

A more common cause of re-humps was where one block overflowed its assigned tracks and the cars for that block had to be sloughed off into another block or a track designated for re-humps.

By the way, the way SP implemented "geometric switching" is an abuse of the term, i.e., it wasn't really geometric switching. True geometric switching is where you first hump by block position in the outbound train, then pull everything out and re-hump by outbound train. If all outbound trains carry the same number of blocks each of about the same size, it works pretty slick.

Best regards,

Rob L.

WOW! Thanks to all who responded. I (along with some others) had no idea that classification tracks could have so many varied purposes, including what time of day it is and which railyard it is. There's certainly a ton more to classifying a freight car, than moving it from "A" to "B" in one trip over the hump. Thanks again.

As a yard master at a hump yard, in my case Allentown, PA, I can assure you rehumping is a way of life! Our bowl has 29 tracks but we have somewhere around 80-90 different class codes. Obviously there is no way they all can be kept "straight" where each one has it's own track.

We will build pullbacks for certain trains then when it comes time to set that train we will rehump them. Obviously this takes knowing what class codes are going to be running light or heavy.

For example one mix we build is usually for 12T, Allentown to Buffalo. It carries 5 blocks, usually the bulk of it is Penobscot traffic for the RN. Now if I see I have 25 RN cars I will likely start those straight. No sense in filling up the mix with them leaving no room for the rest. The rest become a mix. that mix may also acquire other odds and ends that just didn't have a hone at the time either.

So instead of using up 5 tracks in the. Bowl you can consolidate it to 1 or 2 until you are ready for the cars. Otherwise you may blow a track that'll hold 50 cars for 5 cars. Then that track will be "live" meaning you may have more cars for that particular class code during the day. So you can't hump other blocks up behind them until the first block is finished off.

Posted from Android

Why "Penobscot"? That's a river, a county, and an Indian tribe in Maine!

I did that a lot when I was a lot younger...

Zephyr Wrote:
-------------------------------------------------------
> All of the above is true and could necessitate
> re-humping. However, here's another reason. On
> the Southern Pacific in the 70s and 80s at City of
> Industry's "econometric" hump yard, we employed
> what was referred to as "geometric" switching.
> Big name for a simple process! Initial humping of
> cars would "clump" destinations and switching
> zones (Anaheim, Buena Park, Norwalk, etc., as
> example). Once all inbound connections had been
> humped into these general destinations, then the
> "re-hump" process would begin. The re-hump
> process would sort the general destination cars
> into separate blocks of cars for the various
> switching zones (3100-4900 for the Buena Park
> Hauler and Anaheim Hauler if memory serves me
> correctly). When re-humping was complete, the
> various Haulers would put their trains together in
> zone order. In the end, the Hauler would depart
> City of Industry and make set-outs at switching
> zone destination storage tracks. As a result of
> this process, road switchers for the various zones
> would then have their cars "blocked" for each zone
> when they went to work. In essence, the process
> saved the road switchers serving 4 or 5 zones from
> having to switch all of the cars into the various
> zone areas. It was accomplished for them in the
> re-humping process! This process is undoubtedly
> repeated today in various classification hump
> yards across the nation. It's an efficient method
> of assembling multiple switching zone trains!


Yup, and I remember doing it for you, young man.



V

SLCONDR