About the Author J. D. Santucci (a.k.a. "Tuch") began his railroading career in 1978 as a trainman on the Missouri Pacific. After a round of lay-offs in 1985, Tuch embarked on a railroad odyssey, working in many different situations for different roads. This column tries to explain some of the nuts and bolts of the job and also demonstrates what we have to deal with on a regular basis within and without the industry. Tuch currently works through freights out of Chicago for Canadian National/Illinois Central. ©1999, 2003-2007 JD Santucci. Logo ©2002 The Railroad Network. By J.D. Santucci

October 31, 2002
There used to be a trucking company out of St Louis that used a camel as their emblem along with that phrase as their slogan. While they have gone bust, the phrase lives on. And it comes in handy for today’s lesson, which will be dealing with hump yards and humping operations.

Before we get into today’s lesson, I would recommend you go http://madisonrails.railfan.net/avon2.html which is Roger P.Hensley’s "Rails of Madison County" web site. This link goes right to a diagram of CSX Transportation’s Avon Yard, just west of Indianapolis. This is the former Conrail facility CSX acquired in the 1999 when they split up Conrail with Norfolk Southern. You can click onto the diagram to get a larger version of it for reference. I am going to use my firsthand experience at the Indiana Harbor Belt’s Blue Island Yard and describe its workings, but the Avon Yard map will work very well for a visual aid as the nuts and bolts of most hump yards are very similar. You can look to it as I discuss some of the workings.

In my career, I have had the opportunity to work at two different hump yards, the Indiana Harbor Belt's Blue Island Yard and the Elgin, Joliet & Eastern's Kirk Yard. I have also had numerous occasions to operate trains into and out of rail yards equipped with humps such as Chicago & Northwestern's (now Union Pacific) Proviso Yard, the Belt's Clearing Yard and the Soo Line's Bensenville Yard. I have been able to observe humping operations in progress. I have also seen things go horribly wrong while observing or being part of a hump crew. We'll save the bad stuff for another day, but just talk about the workings of a hump this time.

Very simply put, a hump yard is just that, a yard built with a hump. The hump is a portion of the real estate that is built up with inclines approaching either side of it. The tracks approaching the hump are laid on this incline with the grade rising towards the crest of the hump itself. On one side of the hump are one or more tracks often referred to as the approach tracks or hump leads. These hump leads are what hump engines shoving cuts of cars to be humped use to reach the crest of the grade where the actual operation of humping commences. At some hump yards there might be just one or two approach tracks. At others such as the Belt Railway of Chicago’s Clearing Yard, there are multiple approaches which offer great flexibility.

On the opposite side of the crest is the bowl. On the Indiana Harbor Belt, the bowl was called "the garden." It is in the bowl where the cars are actually classified into their proper tracks. There are normally multiple leads that fan out from the crest of the hump. This makes for an uncomplicated operation, as each lead will have a cluster or group of several classification tracks on them. These groups may vary from five to up to ten tracks per cluster. Hump yards are laid out in this way to make optimum use of the space. Otherwise, there would be dozens of switches, one right after the other, fanning off a single lead track. The lead tracks normally begin fanning off the main lead immediately beyond a car retarder. At the IHB’s Blue Island Yard, this retarder was known as the "junction" retarder. We’ll get into retarders in just a bit.

Humping can be carried out in most of the bowl with maybe one group of classification tracks (or even just one track in that cluster) locked out. Cars can continue to be humped into all the other groups, and even into all the other tracks in one group while a trimmer engine is working on track within a group, or within multiple tracks of a group. If a pull down job is working the bottom end of the hump in one of the bowl tracks, operations can continue uninterrupted.

At the crest of the hump there is a tower. Within this tower normally resides the Hump Yardmaster, called the Humpmaster on some railroads. This master of the hump oversees the operations on the hump end of the yard. Also located in the tower there may be a Clerk to assist in performing the PICLing duties to place the cars in the proper tracks in the computer. You may recall PICL being the acronym for Perpetual Inventory and Car Location. The Conductor or Foreman of the hump assignment will also be located in the tower. He or she will operate the control panel. This panel allows them to operate the switches to direct the cars being humped into their proper classification tracks. In a totally automated system, the Conductor or Foreman may simply override computer-generated instructions.

Outside of the tower at ground level, the headman of the hump assignment will perform the physical duties of uncoupling the cars. There is normally paved or concrete walkways along side the hump lead for this employee to be able to walk right along side the cars safely. As the cars reach the crest of the hump, the head man, also referred to as the "pin puller" can pull up the uncoupling lever (also called the pin) the uncouple this car or cut of cars from the cut being shoved up the hump lead. In addition to just pulling the pins, the headman may also bleed off any air that causes the brakes to remain applied on that car. On occasion, a Car Inspector may not get it all bled off. Or, there may be a slight handbrake on the car that needs to be removed.

The bowl of the hump is shaped just like its name, a bowl. Although I’ve called it and heard it referred to as the bowel on more than one occasion. You do not want the tracks rolling all downhill all the way to the other end of the yard as this would result in rollouts at that end. Cars would roll right out of a track and this is bad, very bad. The yard levels and then begins a slight ascending grade at the far end. While not as steep as the hump, there is a bit of an incline.

The philosophy of the individual railroad their and willingness to spend or save money determine the next feature. At the bottom end of the hump there are a couple of quite different variations to yard. On some railroads like the Elgin, Joliet & Eastern, the BRC, the Illinois Central Gulf and others, Skatemen were employed. Skatemen would place skates on every track as a stop to hold cars from rolling out of the tracks. They also applied handbrakes to the cars at the far end of each track. They would be in communication with the hump tower who would instruct them of cars rolling down into this track or that.

Other railroads like the IHB chose not to use Skatemen. Instead, they used cars as skates. Whenever a pull down job at the bottom end of the yard reached in to pull cars out of a track and swing them towards a departure track, they would cut off the very rear car about five or so car lengths in the track and apply a handbrake to that car. This car now became the skate. IHB also used inert retarders as well at the bottom end of each track in the hump. Inert retarders were not controlled by anybody. They were set up to act as a braking device to slow cars rolling in that track. They were usually placed approximately ten or so car lengths from the end of the track. Some other railroads also used inert retarders in their hump yards and also in some flat switching yards where they were required to prevent roll outs owing to the geography of the land on which the yard was located.

Back to the hump end and a look at retarders. Retarders are built into the tracks and used to slow the free rolling cars to safe coupling speeds. The safe coupling speed is not to exceed 4 MPH. You may observe decals or stencils on the sides of some freight cars that say "NO MORE THAN 4." Retarders are pneumatically powered and may be controlled manually or automatically. The retarders use pressure against the flange of the wheels to slow the cars to a safe speed. Remember that as the cars now roll free down into the bowl, they are coming down a short, steep, descending grade and rapidly accelerating. If their speed is not reduced through the use of retarders, the cars will smash right into the next car into the track at a fairly high rate of speed and likely cause a derailment and damage to both the car and its lading. A nickname for retarders is "squeezers" as they squeeze against the flange of the wheels.

Retarders are placed just below the crest of the hump and on each group of classification tracks. The one just below the crest is referred to as the junction or master retarder. Those placed in each group would be a group retarder. These retarders are either manually or automatically operated. Those that are manually operated use an employee called a Retarder Operator or Car Retarder Operator (CRO). The CRO also has a control panel to operate the switches like the Conductor or Foreman in the hump tower. He can override either the automated system or even the Conductor’s commands if the situation should warrant. The IHB still uses a manual system with CRO’s at Blue Island. In my brief time at the EJ&E, they also used CRO’s and a manual system. They have since fully automated their hump.

On the IHB, their hump lists indicated cars as loads or empties using the letters ""L" or "E" respectively. If the car were particularly heavy, it would be designated with the letter "X", the heavier the car, the more X’s. Loads of grain, coal, potash and other mineral freight in 100 capacity or greater cars would be XXXL cars. This alerted the CRO to the fact he would need to apply more retarding effort against the rolling cars. He had to keep track of the cars in the track and did all his calculations manually and by a good, sharp eye.

Many railroads have fully automated their hump operations and use an automated retarder system. This is tied into the computer program. An in motion scale is placed on the hump approach lead to weigh each car as it passes over. This information is stored in the computer. The computer also keeps track of the total amount of cars humped into each classification track. This is information that can be manually changed by a Clerk or Hump Yardmaster as cars are pulled from a particular track of diverted to another track. Wind speed, ambient temperature, the speed of the free rolling car and each car’s weight are factored into the system’s determination of how much retarding force should be applied to a car to slow it to safe coupling speed.

There are hump control signals used in conjunction with the humping operation. Their aspects varied from railroad to railroad. On the IHB, you had green for 5 MPH operation, yellow over yellow for 3 MPH, yellow for 2.MPH operation and red of course for stop. The ICG used yellow over green instead of yellow over yellow. The EJ&E used simple red, yellow and green signals. In addition to the line side signals, the IHB also used the radio. They would call the colors over the radio saying "Double yellow" for normal humping speed, "Yellow" to slow things down or "Red board" to bring the cut to a stop.

You got to know your crews and who was capable of what. You could push the speeds a bit with the better ones. In fact, some of them would tell you to "Pick it up a notch" and you could hump at 3.5 to 4 MPH. The 4 MPH mark was really pushing it a bit, but if you had a good pin puller, good button pusher and good CRO, you could do it and do it well and safely.

Some railroads have cab signal and even remote control systems as part of their hump engines. The Louisville & Nashville had such a system in place in the 1980’s at Osborn Yard in Louisville, KY. The Engineer could set the locomotive up for remote operation from the hump tower or operate it on signal indication with a cab signal from the engine. The EJ&E has a system that allows the Engineer to preset his humping speed. The speed is maintained automatically by the on board system until the Engineer either requests a change or stops the cut manually. There is also a cab signal system tied into the hump operations.

The variety of hump yards is as diverse as the philosophy of the railroads that own them. The first hump yard I was ever involved in was Fort Worth, TX in 1978. MoPac trained me at their Centennial Yard before I got turned loose and sent back to Chicago. I was able to witness, up close and personal, a state of the art fully automated hump system. When I joined the IHB some fifteen years later, I was able to be a part of probably some of the earliest technology in manual hump yard systems still in service. The Engineers at the IHB did invent the first pneumatic retarder installing it and many others to follow at their Gibson Yard in Hammond, IN. This facility is long since closed as a hump yard but the original retarder is preserved at the Smithsonian Institute in Washington, DC.

Some hump yards are huge. Conrail’s hump yard in Elkhart, IN (which is now part of Norfolk Southern) has some seventy-six classification tracks with all of them being fairly long. When the ICG had hump yards at Markham, there were two of them with the larger of the two being sixty-four tracks. The Milwaukee Road, which became Soo Line and is now Canadian Pacific Heavy Haul U.S., had a seventy-two-track hump yard in Bensenville, IL. In the mid 90’s they ripped out much of the hump to build an intermodal facility. They reduced the classification tracks to just twenty-seven, but soon learned this was inefficient. DUH! They have since put some of the previously removed tracks back in. Here is a real lesson in economics. Remember the statement I have made in the past about how this industry spends millions to prove something doesn’t work? The IHB’s Blue Island Yard is probably the smallest hump yard I have ever operated within. There are just forty-four tracks in the garden and none of them is particularly long.

Each track in the bowl of a hump yard has a specific blocking designation. Depending upon the situation, the blocking could be changed as required. For example, in my Trainmaster days at Blue, we used to block four different groups for CSX. They were Barr Yard, Grand Rapids, Willard and Nashville. We would make up a transfer job with these cars all pre-blocked. When the transfer job arrived at Barr, they might have to yard this train in two separate locations within the yard there. At times, we would make two separate deliveries with only two of the blocks, all dictated by the volume of cars and yard congestion. On some occasions, we would build a train of all Grand Rapids and CSX would send a crew and power over to pull the train right out of Blue, bypassing the congestion at Barr altogether.

We used four letter codes for blocks at Blue Island, so I’ll use them here. If CSX wanted the BARR and WILL blocks to come on one delivery, that was fine, well sort of. Say in the course of humping, the WILL track fills out. A quick scan shows there are no more BARR cars in the inbound tracks we will hump before pulling these two tracks out and swinging them over to a departure track in the north yard. It would be arranged to then put the WILL overflow cars on top of the cars in the BARR track. When these two tracks were pulled, the BARR track would be pulled first and doubled to the WILL track. With this method, the WILL cars at the west end of the BARR track would be coupled right to the WILL cars in the WILL track and everything falls into place.

In other cases, we would put unrelated cars into a track on top of cars in a particular classification track. Let us say we have a huge amount of Montreal (MORT) cars for CP Rail and the track designated for them is about to fill out. There is only small amount of cars in say, the Flat Rock (FLAT) track. A quick scan shows just a couple of FLAT cars in the inbound tracks waiting to be humped. We would then start putting the overflow MORT’s on top of the cars in the FLAT track. Those one or two FLAT cars would be sloughed off into what was designated as the SLUFF track. Sluff was the track for oddballs, overflows, no waybills, cars to be weighed and the like. The block of FLAT’s would be pulled for GTW train 466 leaving this track as a MONT track. The crew pulling the cars out would be given a cut number by the East Yardmaster telling them to leave that one behind, that one being the first MONT car.

To make all this work though, you had to keep close watch on what cars you put where. Certain trains left from the south yard while others departed from the north yard. Based upon the layout of the yard and the leads on the bottom end of the hump in the East Yard, you did not want to put cars for a south side train into a track that was designated for a north side train. If you made this mistake, this would require a pull down job working the East Yard to have to cross over the entire East Yard to accomplish this feat. A move like this could and would really jam up the works.

When pulling a track out to swing over to the departure yard or over to the West Yard for further handling for industries, you were required to cut off a car in that track and tie a hand brake on it to leave it as a skate. If the last car were not suited as a good car to leave as a skate, such as an empty flatcar, you would just pull the entire track. The East Yardmaster would have a job grab a car from another track and use it as a skate, or have the job pulling the track kick a car out of that cut to place back in there. We were not supposed to hump into a clear track, although from time to time, we did do it. And yes, even when I was Trainmaster. Sometimes bad things happened when this was done. Perhaps another column will convey some stories someday.


Several times per day the SLUFF track would get rehumped. When this occurred, the normal procedure was to have a pull down job in the East Yard couple up this track (normally track 25 in the garden). They would then make a cut on the last car in the track, butt the knuckles on those two cars so they would not couple when the hump engine tied on from the west end. A handbrake would be applied on that one car separated from the rest, This car became the skate.

There was a method of absolute protection for crew working in the tracks in the garden when they were coupling them up and either pulling them to the east end for more room at the hump end or for clearing the track out. A member of the crew on the job going into the track would call the hump and request a block on that track. The hump would inform the Conductor at the control board and also the CRO. They would both line the levers on their control panels for the switch routing into that track to route away from it, then apply blocking devices on their boards to prevent the switch being operated. They both notified the hump this had been performed and the Hump Yardmaster would then instruct the crew that track was blocked. The crew could then enter the track and do their work safely and under absolute protection. No cars could be humped in there on top of them. When finished with the track, the crew would call and release it back to the hump. The Hump Yardmaster would then inform the Conductor and CRO to remove the blocks and they track was then open to hump into again.

If a hump engine had to go into the garden to do trimmer work, there was protection afforded here as well. When you went over the hill and against the track you needed to work, you would be instructed to either clear up in that track or told you had the lead. You might be given the entire garden depending upon the situation. Whenever you were coming back out of a track though, you had to have the trimmer signal. This was a signal up by the hump tower. If you had the yellow signal, you could proceed. If not, you stayed in the clear. If you were instructed to stay in a particular track because the other hump job was going to begin humping, the CRO would call you and inform you that you were protected. This meant he had blocked out the track and no cars could be humped on top of you.

Trimmer work occurred fairly regularly. Sometimes cars would get a little too much retarding action and then just die, usually right in the way. Other times the track was hung up with the bulk of the cars in it at the hump end and now hanging out on the lead. They needed to be shoved all the way into the clear. Still other times, one car may have caught up with the car that went ahead of it too quickly. It could not be lined into the proper track as it may have clipped the car ahead of it, so the CRO would override the Conductor’s instructions and send this car into a different track, so now it needed to be dug out and placed into the correct track.


So now, with all this information at hand, we’re going to hump a cut. The IHB used sets of SW1500 Switchers mated to slugs known as hump trailers. These were non-powered trailers equipped with traction motors. The motors on these units were fed power from the mother engine. In addition to the extra tractive effort, they also provided extra braking effort. The hump trailers were coupled to the long or needle nose end of the engine leaving cab end nice and clear. The 9219 was mated with HT 478, the 9220 was mated with the HT 479 and the 9221 was mated with the HT 477.

So here we are aboard the 9219 when the Hump Yardmaster calls. He instructs us to tie onto track 9 in the North, use the middle lead and make a forty-car cut. There are three hump leads at Blue, the south, middle and north. From the North Yard you can use either the north or middle leads. From the South Yard you can use the south or middle leads. This arrangement offers a great deal of flexibility. To make a forty car cut you don’t count the cars, but instead use a landmark. There is a pole down the lead that is used to gauge forty car lengths, not necessarily forty actual cars.

So down we go to 9 in the North, couple on and begin pulling. As I close in on the forty-car mark, I begin to slow the cut using the engine brakes, as there is no air on this track. I get stopped and it settles. The headman tells me to take ‘em out. I pull the cut and him out and onto the middle lead. He lines the switch and has me shove them ahead to the hump approach. When we reach the hump tower, he stops me, goes and pulls the list for this cut out of the dumb waiter, looks it over and tells the hump we are ready. Either he or the Conductor informs me "Double yellow". I open the throttle, release the engine brakes after the load on the amp meter is established and begin to start shoving the cut over the crest. I get the cut up to about 3.5 MPH. Most of the better crews can easily make due with this with some even up to 4 MPH. Being that the IHB did not order or install any type of speed control with their engines, I have to use the throttle to maintain the steady 3.5. This is not difficult to do; you just have to pay attention. The cut is heavy most loaded cars. This means the engine is really working hard, the cab is vibrating and there is all kinds of racket as that prime mover is giving it all she’s got. .

He then calls and tells me "Single yellow, we have some weighers." This means reduce the speed as we have several cars in a row that need to be weighed. There is an in motion scale on track 25, but the cars need to be spaced apart enough to prevent one from getting onto the scale while the one ahead of it is still on it. Once that is finished it is back to double yellow. A moment later he is calling the CRO and telling him to "Squeeze them a bit." This means he has a cut of heavies that are now pulling away from him and he cannot get the pin as the slack is stretched out. The CRO will apply a little pressure to the junction retarder to cause them to slow enough to give him the slack while the rest of the cut is still being shoved against these cars. When he gets the pin he tells the CRO to "Let ‘em go." They take off and he then says "Red Board." I stop the cut and immediately center the reverser handle.

Once the cut is stopped, the slack begins to roll back in on me. It usually hits with a pretty good jolt and may even shove the engine back a bit. Centering the reverser prevents any possible damage to the traction motors and pinion gears. This would be akin to having your car in drive and then having somebody run into your front end and pushing you backwards. It can cause all sorts of damage to the transmission.

He may have stopped the cut because he found a car with some air on it or a hand brake. Perhaps it is not on the list (known as a stranger) or possibly it has a long, cushioned drawbar that has popped to one side after uncoupling. What happens in this case is there is pressure on the couplers and drawbars when the slack is bunched. When the cars uncouple and break apart, the pressure is suddenly released and a car equipped with a long drawbar may have it pop to one side. The headman will shove it back over into the correct position. Doing this prevents a possibility of this drawbar bypassing the one on the car already in the track next to it and possibly causing a derailment or damage to one or both of the cars.

I need to mention the IHB prohibited cuts of more than five cars from going over the hill at one time. This had a lot to do with the retarders being able to slow a large heavy cut to a safe coupling speed. Like so many other rules, this one got violated more than once. Most of the time it worked well. Other times, it didn't. Again, another story for another time. Perhaps I'll do a piece all about hump yard boo boos.

While this humping activity is going on, I observe a train entering the north hump lead at North Harvey. This is why we took the forty-car cut instead of the entire track. The inbound train can pull into the yard while we hump cars. I notice the other hump job coming out with a cut on the south lead. When we finish this cut, if there is no trimming work to do, we will head over to the south side and then the other job will cross over and begin his next shove.

When this cut is finished they tell us to head into the garden to shove a couple of tracks in the clear and then get a hold of track 25, couple it up and get ready to pull it out. We handle these chores and then wait for the other job to finish his shove.

There are times they will have you pull an entire track out and hump it all at once. Tracks 7, 8 and 9 in the North are the three longest tracks at Blue Island Yard. This can be a great deal of weight to shove up the hill to the crest of the hump. It also has you over the Western Avenue Road crossing for an extended period. When shoving a big cut like this, they sometimes pull you well past the switch to be able to make a run for it when you shove it east. Even with the run, as soon as the first car hits the hill, you feel it immediately. Usually, you are already giving it all you have and you are hoping you don’t stall. On occasion, you do and make another attempt by pulling the cut even further back. But still, there is a time or two when that little 1500 Horsepower switcher and its hump trailer just cannot make it and you stall. This means you shove some of the cut back off from where you pulled it out and handle a smaller cut.

Humps are very interesting to observe in action. However, at night they can be brutal on an Engineer. All that really slow running and moving while sitting in a locomotive that is almost constantly revving in run 8 for long periods can become hypnotic.

With two hump jobs working a shift, humping in excess of 600 cars per shift was routine. However, you need the room in the bowl to handle such a volume. On more than one occasion, we did over 640 cars. This is moving them over the hill. Once upon a time in my early railroad days, the IHB had three hump jobs per shift. Back in those days when told to shove it, they really did.

And so it goes.

Tuch