

Passenger Car Glossary

Index For This Page

This page was last updated on August 6, 2015.

(Return To UP Passenger Cars Index Page)

(This is a work in progress; research continues.)

Car Types on Union Pacific






Company Service


Arch Roof Heavyweight

(not "Harriman")

Arch roof, all-steel heavyweight cars first delivered to UP and its subsidiaries in 1909 to 1931.

(List of Union Pacific arch-roof heavyweight cars, sorted by date built)

Jeff Cauthen describes the changes in the "Harriman" design:

Just refer to them as arch roofs. My research into Common Standard designs ordered by the Associated (Harriman) Lines indicates that these Common Standard cars were built from 1909 (not counting the first experimental cars of 1906/1907) to mid-1914. The last Common Standard cars ordered by the Associated Lines arrived in May 1914. The Associated Lines ceased to exist after that due to the Supreme Court finding. The SP and UP were then "unmergered". After that, SP and UP adopted their own Common Standards.

The Illinois Central received Common Standard cars up to mid-1911. Beginning in August 1911 the IC cars appeared to be Common Standard, but in-fact had Pullman standard built-up fishbelly underframes. Central of Georgia received cars similar to the IC cars as they were controlled by IC. IC ordered more arch roof cars in the 1920s from ACF, and they had many Common Standard features, but again with fishbelly underframes. The roofs were also different at the ends than were Common Standard cars.

Rock Island received a number of cars in 1911 that appear to follow Common Standards, but on close inspection do not. They had belt rails and Pullman standard built-up fishbelly center sills. They did appear to have arch roofs that mimic Common Standard designs. Rock Island dinners built in the mid-1920s had arch roofs, but they were much flater than Common Standard designs.

By the mid-1920s UP was buying cars with clerestory roofs, not arch roofs. SP continued buying arch roof cars until 1927/1928. When SP switched to clerestory roofs on diners, they were built with Common Standard underframes, no fishbelly underframes. Also, it should be pointed out that the Associated Lines were still buying large numbers of wood smoker-observations and diners up until 1910. These were Common Standard cars and logically should be referred to as "Harriman cars", but of course we don't because they didn't have arch roofs.

It is my contention that the term "Harriman" car should apply only to those cars ordered by the Associated Lines and built between 1906 and mid-1914. Any cars constructed after this date can fairly be referred to as arch roof cars or possibly "Harriman copies". Common Standard steel cars had cast steel bolsters, the double "I" beam centersill and needle beams. The cars lacked raised belt rails and had door and window designs not used by other railroads. Also, as far as I can determine, all steel cars ordered by the Associated Lines between 1909 and mid-1914 were built by Pullman. (posted to Passenger Car List, March 28, 2006)

(Read more about UP's use of Common Standard)

Bob Ayers adds:

One spotting feature I have been informed of is above the windows. On a Harriman car, the "lettering" strip between the top of the windows and the bottom edge of the roof continues full width across the top of the doors. On non-Harriman cars, this strip narrows across the top of the door. (posted to Passenger Car List, March 28, 2006)

Steve Bartlett adds:

On the Harriman cars (I won't say "all" the Harriman cars) the trap opened before the vestibule door. Since it was not possible to open the door first and stand on the unopened trap, there was no need for as tall a door. From a modeling standpoint, there is no trap "lip" showing at the bottom of the closed doors. (posted to Passenger Car List, March 29, 2006)

Clerestory Roof Heavyweight

A heavyweight car had riveted carbon steel body-frame construction. Since 1940, these have been known as standard heavyweight cars to distinguish them from the lightweight cars of welded alloy steel.

All-steel heavyweight cars were delivered to UP and its subsidiaries in 1920-1931, with clerestory roofs, some with external air conditioning ducts added later.

No heavyweight cars were built for UP after 1931, when UP received 10 chair cars numbered as UP 1260-1269.

(List of Union Pacific clerestory heavyweight cars, sorted by car number)


Lightweight (13'-6" tall) -- Cars delivered to UP in 1937-1964, with straight sides.

A lightweight car is either an aluminum car or a steel car with non-opening windows, and full-width arch roof, most being built after 1935.

With the 7th and 8th trains of 1937, the 13'-6" overall height (and corresponding floor height) was established for "lightweight" cars. Those cars had a variety of names and numbers over their life, but were pretty much freely intermixed with subsequent lightweight cars. Admittedly there were a lot of individual cars in the 7th through 10th trains that may warrant a separate group roster, but I believe the 1st through 6th train cars should be in a group by themselves. (Dick Harley)

ORER - Official Railway Equipment Register

Published from late 1800s; included passenger equipment until 1941.

"The Official Railway Equipment Register, often called the Register for short, or sometimes just the ORER, has the purpose of listing and describing all active North American freight cars. First published in 1885, its interval of publication has varied over the years, monthly early in this century and quarterly since 1937. Interestingly, the Register has gotten thicker over the years, even as the size of the freight car fleet has steadily shrunk. This reflects the increasingly specialized design of freight cars, and the increasing use of specialized equipment in cars, requiring many more separate listings. Where once a large group of freight cars owned by a particular railroad might well be essentially identical and could be described by a single entry in the Register, today many smaller groups of specially equipped cars rate separate entries." (Tony Thompson, The Official Railway Equipment Register, 2015 update to 1995 essay included in NMRA reprint of 1953 ORER)

ORPTE - Official Register of Passenger Train Equipment

Published from March 1943 to March 1971.

"In earlier days, passenger equipment was also included in the ORER but starting in 1943, a separate Official Register of Passenger Train Equipment was issued, familiar to passenger enthusiasts as the ORPTE." (Tony Thompson, The Official Railway Equipment Register, 2015 update to 1995 essay included in NMRA reprint of 1953 ORER

Pullman published its own list of cars. It was the size of the ORPTE and basically needed to be used as a companion to it. After the Pullman divestiture the Pullman list showed both the cars it owned and the cars leased back to it. Railroads didn't need to list their sleepers in the ORPTE although most did. Cars leased to Pullman had a footnote so indicating. (Don Thomas, email dated October 19, 2011)

Most railroad-owned cars in the ORPTE were shown as part of number sequences rather than as individual car numbers or names. The formats of the Pullman list and the ORPTE were very different. Pullman had a line entry for each car including specific details not given in the ORPTE, so it required far more pages than even the largest railroad needed in ORPTE with most entries covering entire classes of cars. Having a Pullman section in ORPTE would have been redundant and wasteful, without providing much useful information. (Don Thomas, email dated October 19, 2011)

Streamlined Heavyweight

All-steel heavyweight cars originally built with clerestory roofs, and later modified by UP to include tapered roof ends to match UP's streamlined trains. A Streamlined heavyweight is a steel car originally built as a heavyweight car, but modernized in the 1940s with Streamliner features, mainly to match the newer lightweight cars.

Tapered Streamlined Train

(1st to 4th trains) -- All-aluminum cars delivered to UP as part of the 1st through 4th Streamliner trainsets; all cars articulated.

Streamlined Train

(5th and 6th trains) -- All-aluminum cars delivered to UP as part of the 5th and 6th Streamliner trainsets; some cars articulated.


In the "Description" block for each car group, lengths are taken from the folio diagram books. Fractions less than 1/2 inch have been rounded down (60'-3/8" becomes 60'-0"), and fractions greater than (and including) 1/2 inch have been rounded up (60'-1/2" becomes 60'-1"). Where possible, measurements have been compared for accuracy and consistency with other available sources and listings, and in most cases lengths given are "length over buffers".

"Date To xxxx Series"

In the UP equipment record book, the railroad recorded dates as "Converted Or Changed From" for cars with a previous class, number and date. These dates are used in this roster as the renumber dates.

"Date Vacated" "Date Retired"

In the UP equipment record book, the railroad recorded dates as "Mo. Vacated" in one column, and "Remarks" in another column for further disposition such as a new number, or "W.O." for "Worn Out" (scrapped). These dates are used in this roster for either dates of further disposition (renumbered, sold, scrapped, etc.), or for final retirement.

"Date Renumbered" is used when a car remained in Union Pacific service, but with a different number, whether remodeled, rebuilt, or simply renumbered to clear a number series.

"Date Retired" is used only for dates of final retirement (sale or scrap).


The word "Combine" can and has been used for any combination of functions. An MBE [Mail Baggage Express] is literally a combine, but usually (and inaccurately) referred to as a "RPO" - inaccurate as that is usually but one aspect of the car's functions. Pullman used the term "Composite" when multiple accommodation functions were used. (Bob Webber, Passenger Car List, message no. 77236, dated December 8, 2011)

One of the earliest uses of the "Composite" term was for "Aladdin", a combination observation-sleeper built by Pullman in 1888 for service on the "Golden Gate Limited" between Chicago and San Francisco. The train entered service on December 5, 1888. Aladdin was also one of the nation's first observation cars. (Some Classic Trains, Arthur Dubin, 1964, page 170)

Mail & Express

The following comes from the January 2012 issue of Model Railroader magazine:

Head-end traffic helped cover some of the costs of America's passenger trains for many years. Contracts with the United States Postal Service covered the transportation of mail, while the Railway Express Agency (REA) provided a nationwide package delivery service.

Small-to-medium-sized railroads forwarded most of the mail in Railway Post Office (RPO) cars and packages moved in a baggage car on regular trains. Local postal employees met these trains to transfer mail on and off the "working" mail cars during the station stop, and the train would wait for them to finish.

The REA handled packages with an "express messenger" who rode the baggage car. He sorted and dispatched the packages at the appropriate stops. Like the postal crew, REA also met the trains with enough men to make the transfers during the allotted station stop. Since REA was a private enterprise, its men had to get their work done within the scheduled stop, as the train didn't wait.

Sealed through cars were used by both the post office and REA during busy times. These baggage or storage mail cars were loaded in one city, closed and locked (sealed), moved to a destination, and then switched out and spotted for unloading. The post office commonly used sealed through baggage cars to transport pre-sorted consumer magazines from publishers to distant cities for faster distribution.

Railroads that handled large amounts of head-end traffic often operated scheduled mail and express (M&E) trains. In the 1960s, the New York Central's mainline M&E train often had up to 35 cars pulled by four E units. These dedicated trains reduced the station times for the regular passenger trains. Hauling full carloads of mail and express between major cities was more efficient, as switching cars in or out of the train was faster than waiting for the hand transfers.

Operating at passenger speeds, these trains made great time between intermediate stops. However, it wasn't unusual for them to sit for a half-hour or more while the manual transfers of mail and express took place at smaller stops.

Some railroads and REA tried container systems and piggyback trailers to improve efficiency. However, any flatcars used in these systems had to be fitted with approved high-speed trucks and steam, air brake, and signal lines for use in passenger trains.

In any case, the RPO cars usually stayed on their home railroad's normal routes, while sealed through baggage and mail storage cars could travel almost anywhere. Running a through baggage car from another railroad wouldn't be unusual and could add an interesting bit of color to your railroad's M&E train. (Jim Hediger, senior editor, Model Railroader, January 2012)

On Union Pacific, Postal Storage cars (almost identical to baggage cars) served the purpose for these "sealed" cars assigned to Mail & Express service. During the 1930s and 1940s, several 3000-series baggage cars (arch-roof cars, sometimes known as Harriman cars) were modified with six-wheel trucks and assigned magazine and catalog service. Magazines and catalogs were much heavier that regular mail, and the six-wheel trucks allowed a heavier load.

Air Conditioning

(Read more about air conditioning on UP's passenger cars.)

Roadway Service

Roadway service was Union Pacific's term for equipment assigned to non-revenue service (snow plows and derricks), and maintenance of way (trackwork and bridges and buildings), along with other assignments under the overall name of "Company Service". The assignment was usually abbreviated in equipment records as "Rdwy." There is no indication in internal documents or records that Union Pacific used the phrase "Maintenance of Way," or MoW.

Prior to 1959, the road numbers of cars assigned to Roadway service were usually numbered with a leading zero. Examples include OWRR&N 0596-0598 for the three Roadway Boarding cars shown immediately below.

In 1959, Union Pacific adopted the use of the 900000-series numbers for cars assigned to non-revenue company service, and non-revenue roadway service. The existing road numbers with leading zeros were filled out to become 900000-series numbers; OWRR&N 0596-0598 became OWRR&N 900596-900598.

(Read more about Union Pacific Roadway cars.)