Freight Car Friday – Moving Empty Cars

12 07 2013

Last week we talked about how railroads use waybills to move loaded freight cars. Moving loads is relatively simple – they go from producer to consumer. But how does the railroad know what to do with the cars once they are empty? That process can be a lot more complicated.

There are several factors which contribute to the movement of empty cars. Car ownership, routing, size, and suitability for loading all play a role among other things. The rules for movement of empties have also changed over the years as railroads learned, or were forced, to cooperate and adapt to changing economic needs.

Dedicated Service

chlorine tank

Some cars make many round-trips between the same locations. Tank cars and other equipment which must be carefully cleaned before being loaded with a different commodity often fall into this category. It’s one reason most are not owned by the railroads themselves.

The easiest empty car movements to understand and replicate on a layout are those that are in a dedicated service. These cars make repeat trips between a single origin and destination. It could be a single car or an entire unit train.

Modeling these operations is easy, but railroads tend to avoid such moves whenever possible. Freight cars only make money when they are carrying a load and this arrangement offers only 50% utility. Some of this loss can be offset if the cycle is hastened by little idle time in yards, as with a unit train.

General Freight

For cars not assigned to a specific shipper, the railroad generally has three options for a car once it has been emptied. The car can be loaded, returned to its owner (if it belongs to a different railroad) or stored until another load can be found.

Empty car

Like loaded cars, each empty car in a train has routing paperwork. In addition to car ownership and routing information, these cars also list what the car can carry.

Obviously the third option is least desirable but it is often a reality particularly for cars that carry seasonal products or during economic downturns. Of the other two, changes in rates and interchange rules nationally and between individual carriers have created a variety of arrangements over the years.

While the rules and rates can be quite complex, much of it comes down to striking a balance between car utilization and ownership. In addition to being paid when a car delivers a load, railroads also charge each other for the use of their cars – loaded or empty. This is to prevent railroads from hijacking equipment (using another line’s cars to carry loads on their own routes.)

Here’s an example: Let’s say you’re the yardmaster on the Santa Fe in Tucson. You have an empty B&O boxcar and two local industries which could use a car of that type. One has a load for Eugene, Oregon, another for Cincinnati, Ohio. Under most operating agreements, you could probably send the car to pick up the Ohio-bound load as that will get the car closer to, if not back onto, its “home road.”

load debris

Where will this car go next?

If there were no potential eastbound loads, your best bet would be to route it back to the B&O empty. Another yard along the way may grab it for a load.

Of course in a real yard with hundreds of cars and destinations, it is much more complicated than this. The operators must weigh the costs of holding the foreign car for a few extra days vs. the added revenue of the load vs. possible home-road cars which could be loaded instead at a better profit margin, etc.

All of these considerations can make switching cars on your layout a lot more challenging if you enjoy a good puzzle. Of course, we have the luxury of writing some of our own rules!

Next Load Any Road


Equipment pools help increase car utility and decrease paperwork.

Anybody who’s seen one of the familiar yellow Railbox cars recognizes this slogan. These, and other cars like them, operate as an equipment pool. These arrangements greatly simplify empty movements since the “home road” often has no desire to see the cars return and instead earns its money from the cars’ use on other lines – loaded or empty.

Starting in the early 1970s, as regulations and rates covering those “per diem” or daily charges were changed, these operating pools became much more common. The so-called “per diem boxcars” owned by many shortlines brought a lot of color to the rails in an era that saw many favorite lines become fallen flags. We’ll loo k into more of these equipment pools in an upcoming blog.

As you can tell by now, the movement of freight cars on the railroad is a lot more complicated than it first appears. While a complete look at these would fill a book, hopefully this blog has opened your eyes for some new ways to have fun on your own empire. Next week we’ll put the paperwork and operating rules aside and look at a basic set out and pick up from the train crews’ perspective.



5 responses

12 07 2013
Louis Bruette

Another great freight car Friday article! thank you Lionel!

12 07 2013
Fred Patton

Very interesting about the routing of freight cars back to their owners, and whether or not to load them. Never thought about that. Thanks! These are great articles – keep ’em coming!

12 07 2013
mike kaludjer

Dear Lionel Writer:
To whom do you write this Freight Car Friday newsletter?
I refer to the casual way in which you make references such as “the home road.” Are you conversing with people already in the know about railbox, because I read that first paragraph in a fog of questions?
I did learn a slogan and that the cars are from a pool (meaning that they’re owned by someone.) That’s when the fog rolled in.
If there is a company named railbox, then how does a shortline, or regular railroad, OWN (given the ‘returned’ idea) a railbox car OR be its base? How does an empty freight car earn money, especially when it’s not returned to home base where ever that is? I wouldn’t pay a “per diem” when it’s empty just because it’s NOT AT MY HOME BASE.
As I read further, your “hopefully” made me aware that you write for a toy train maker and that a superficial look at railbox is all that’s needed.
I send this package of questions and suggestion, despite my realization, in the hopes that there could be a sentence to simplify the equipment pool mystery.
For me, if a door to an idea exists, then I’ll want to open it. Yet, if no door is made available, then I cannot be confounded.

15 07 2013


Railbox is owned by TTX Corporation (Trailer Train.) They aren’t a railroad themselves as they don’t own any track, only rail cars (and lots of them.) Their Railbox cars operate very much like the intermodal equipment (flatcars, doublestack well cars, etc.) and autorack flatcars that form the core of the TTX business. These cars essentially roam the rails of North America and can be loaded and shipped by any railroad that needs them.

When the customer calls the railroad for a shipment, they normally won’t specify whose car is used. The rate they are quoted is based on the load, mileage, and weight. If the railroad can supply one of their own cars, they generally will. If none are available or convenient, then another company’s car may be used instead. In this case, that company will need to be reimbursed for the use of the car. This cuts into the originating railroad’s profits, but it still may be preferable to delaying and losing the shipment. Also, maintaining enough cars to protect every possible shipment would also be prohibitively expensive as the cars sat in yards waiting work.

The reason for per diem rates is to motivate railroads to return empty cars to their owners or in the case of a leasing car like a Railbox for example, to pass it along to another road that can use it as quickly as possible. A railroad will pay a per-diem charge on every car on it doesn’t own that is on its property every day. Individually the rate is cheap, but you can see how quickly that could add up. Some of these charges are passed along to the customers in billing for the load as well as in charges for the number of days they have a car on their siding for loading/unloading. Again, this encourages the customers to only order the cars they need and process them quickly.

Many of these charges originated after the railroads gridlocked during WWI. Poor cooperation between roads led to empty cars clogging yards while customers sat waiting for cars to ship critical supplies. Other roads were known to essentially confiscate new freight cars from other companies for their own use rather than not buy their own equipment by simply not returning the better cars and using them for their own online shipments.

The more in depth you get with the billing side of railroading, the more complicated in becomes. For example, if a shipment travels on more than one railroad then both are paid for a portion of the trip. The railroad that delivers the car is responsible for collecting payment from the customer and distributing the revenue back to the other carriers based on mileage as well as car owner fees.

All of this can be interesting, but is usually of little relevance for model railroaders – the main audience for this blog. It is the actual movement of the cars themselves which modelers may duplicate, so this overview was intended simply to provide some background on that. I hope this has answered some of your questions, and I’m sure it has raised a few more. Feel free to write back and keep an eye on the blog for future articles like this which may also shed some more light on the subject.

17 07 2013
Ernest Roberts

From the 26-foot wood framed truss rod cars of the 1860s, freight car production has evolved into today’s modern art of steel articulated well cars and 86-foot autoracks. In between, were several distinct eras of freight car production. During the 1890s, railroads began equipping their cars with safety couplers and air brakes. By the early 1920s, they started replacing truss rod cars with steel framed cars. By the 1930s, most freight cars were built entirely of steel.

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