Freight Car Friday – Freight Car Data

Time to check your answers to our freight car data quiz! How did you do?

weight data

1: CAPY, LD LMT, LT WT? What do they mean and how are they different?

1. CAPY stands for “Capacity.” This is the nominal amount of material the car can carry, measured to the nearest 100 pounds. This marking is no longer required as the actual maximum load weight is determined by the load limit as described below.

LD LMT stands for “Load Limit.” It is the maximum amount of weight that the car can safely hold to the nearest 100 pounds. This is determined by the journals and the structural strength of the car design. The number is calculated by subtracting the car’s light weight from the known standards for the car’s trucks and journals. (Hence adding the LD LMT and LT WT will usually give you a nice round number – but not equal the capacity.) Note that there is usually a difference between what the car is designed to carry (CAPY) and what it will actually carry. The load limit must always be greater than capacity or else, well you get the picture!

LT WT is the “Light Weight” of the car when empty. This information is important for two reasons. First, it helps determine the load limit for the car. Second, when the car is empty it helps operators asses the actual weight of the train and assign the right locomotives among other things.

weigh date

2: “CR-AB 10-83” must mean something…  3: What type of car is this?

2. “CR-AB 10-83” This is the location and date at which the car was last weighed to determine its actual light weight. “CR-AB” indicates that this car was weighed by Conrail at their Abrams Yard (near Philadelphia). Railroads typically use their reporting marks and a two-letter yard or shop code. “NEW” is often seen here and means that the weight has not yet been calibrated since the car was built.

Steel cars are generally supposed to be reweighed every 30 months (15 for wood) but in practice it is often much less frequent than that. Cars are typically reweighed when they are serviced. A car’s light weight will decrease over the years through wear and tear but may go back up during repairs. Since many loads are billed by weight, having an accurate measure of the car is important. If the car has lost weight over time then the railroad could be hauling some of the load for free as it reads the scales.

3. Conrail (CR) 878330 is a covered hopper. How do you know? “LO” is the AAR (Association of American Railroads) designation for covered hoppers. Every car type has a designation. Most are easier to recognize – for example “T” for tank car. Some common car types have multiple sub classes. For example, XM is a general service boxcar. XF is a boxcar suitable for food loading. XP is a boxcar for a specific or restricted loading. These designations apply to all railroads. Some roads also apply specific class data to the side of the car to help identify it as part of a particular group. For example this car was Conrail’s class was 860H (held over from the New York Central, the original owner of the car.)

Santa Fe map

4: EXW, H, IL – Why are all these dimensions important?

4. These fields give the dimensional data of the car, both inside and out. The markings themselves are easy to interpret (IH = Inside Height, etc.) Exterior dimensions are important so that operators will know the car can fit within the clearances of particular routes. Interior dimensions help when assigning cars to a customer for loading and can help at the loading dock as well. Other dimensions like the size of door openings are also often included on the car as well.

“BLT 3-37” has nothing to do with the size of the car but is when the car was built (March, 1937.) This information is important to the railroad as many things are tied to the build date of the car including inspection periods, lease / payment accounting and retirement.


5: What does “COTS” mean?

5. As a car is serviced and inspected, that information needs to be recorded. In addition to paperwork, the data is kept on the car itself. Today most of this information is placed in one location, a “Consolidated Lube Stencil” like the black box shown here. “COTS” stands for Cleaned Oiled Tested Stenciled and applies to the air brake components which must generally be tested every 90 days or less. Like the weight stencils, railroads will usually include their reporting marks and shop initials along with the date.

Plate C

6: What is “Plate C”? 7: “Do Not Hump?”

6. Plate C is a simplified code to measure the exterior dimensions of a freight car. A standard boxcar for example will fall into “Plate C” and can travel just about anywhere. An autorack would be Plate F and may be too tall or long to operate on some lines. If a route is rated for Plate E, then anything above can’t pass. It is much easier for a car inspector to see “Plate D” and make a decision than to check all of the car’s dimensions before clearing it.

7. “DO NOT HUMP” refers to the humps used to sort cars in large classification yards. This means the car must be “flat switched” and even in that process should be handled with extra care. The warning usually accompanies fragile, dangerous or oversized loads that could shift or be damaged by rough handling. Some cars, like depressed center flatcars, can not be humped even when empty since their low carbody could bottom-out on the sharp crest of the hump.

yellow dot

8: Why were these yellow dots important in 1978?

8. In 1978, a bad batch of 33″ wheels from the Southern Wheel Company was suspected in causing several derailments. To quickly identify and eliminate the problem, all cars with 70 ton or less capacity and 33″ wheels had to be inspected. If the cars had the recalled wheels they were given a marking like this with a white dot. Cleared cars were given the yellow dot. The mandate came in March of 1978 and all bad wheels were to be identified and replaced by December of that year. (And through December cars with a “white dot” could not be included in any train carrying hazardous materials.) New cars built during the period were also given the yellow dot at construction. There was no pressing reason to remove the yellow dots, so many stayed on freight cars for decades until they were repainted or retired.

7 responses

6 09 2013
anthony s greco

very interesting about do not hump now i know and why this is used on certain freight cars.
all the imformation given i find very intersting keep it coming.
thank you
tony greco

6 09 2013
Bob Shubert

I really like these information emails. I learn a lot and its nice to know what these markings mean
Keep up the great work

6 09 2013
S. Karpel

Great information. Now, if only Lionel would stop putting “Made by Lionel” and the part number on the sides of the freight cars.

6 09 2013

A lot of our collectors would probably revolt if we did that, but there is an easy way to take off the lettering if you are after a more prototypical scheme. Take a look at this article: The technique is easy to master – just take your time and don’t rush the process and you won’t damage the paint under the lettering.

6 09 2013
Roman Kenenitz

Great information. I knew one or two of them but I am glad to know more of them

6 09 2013
john vecchio Blt 11-51

Thanks I look forward to Fridays for many reasons and this is one of them. Say how about an article on the markings you see on some cars not the spray paint graffiti but the little figurers made with a grease pencil I see them over and over. A man with a cowboy hat a dog with a big tongue a man snoozing under a palm tree ect

24 09 2013
John J. Blair

In question 6, the word “Plate” actually refers to a series of clearance diagrams in the AAR Manual of Standards and Recommended Practices. (“Plate” as used here is actually a synonym for “Figure” as in Figure B,C,D…)
Cars with a specific Plate letter comply with the dimensions given in that Plate in the AAR-MSRP.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: