Union Pacific's Two-Tone Gray Steam Locomotives

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Two-Tone Gray

As a general statement, Union Pacific used its two-tone gray painting and lettering scheme for equipment assigned to non-Streamliner passenger trains from early 1946 through mid-1952. Union Pacific's two-tone paint scheme first came into use to match a similar paint scheme in use by The Pullman Company on its passenger cars since the late 1930s, including The Forty-Niner train, operated between 1937 and 1941.

(Read more about The Forty-Niner train)

Union Pacific began using the two tone gray scheme as a general makeover of its non-Streamliner First Class overnight trains in the post World War II era. At war's end, Pullman was reworking its cars due to poor condition of equipment with lack of maintenance during the war. Time was short for the refurbishment and one of the short cuts was the newer "two stripe" paint scheme. Art Riordan points out that some of these cars started showing up in the first months of 1946. Union Pacific chose to match the Pullman equipment, and to give its own trains a new general look. First of the UP fleet for this new look was the "San Francisco Overland" and the "Los Angeles Limited" -- the two premier non-Streamliner trains. Because of its history on the railroad, the "Overland" name was painted in the letterboards of cars assigned to the "SF Overland Limited," and later on to the "City of St. Louis" name was applied to cars assigned to that train. Through trains to the Northwest were also reworked. A general rule of thumb was that any overnight train was redone in the two-tone scheme, with the local and day trains remaining in green. (David Seidel, email dated January 11, 2008)

On June 2, 1946, Union Pacific initiated accelerated schedules for its transcontinental passenger trains. Ross Grenard wrote, "The railroad concentrated on using existing equipment to upgrade the Los Angeles Limited and Overland Limited; to commence operation of a City of St. Louis to link its namesake, Kansas City and Denver to Los Angeles, the Bay Area and the Northwest on an expedited schedule; and to operate a new train, the Transcon, to handle the UP's share of the new through Pullmans from New York to Los Angeles." He also wrote that "two-tone gray was formally introduced to the Overland Route by the 'American' and 'Imperial' series Pullmans in 1942. Having already proven near indispensable in coping with the monumental passenger loads of the war years, they would now serve as the nucleus of a new equipment pool involving three railroads (UP, SP and C&NW) and encompassing both the lightweight coaches, diners and head-end cars constructed in 1937 and 1941 for the Challengers and an armada of rebuilt, upgraded and roller-bearing-equipped heavyweights then rolling out of the car shops in two-tone gray. Eventually nearly all UP passenger equipment, from the humblest combine on a Nebraska branch line to the business cars, would be redone in the new scheme." (Ross Grenard, "Greyhounds of the Overland Trail," Railfan & Railroad, January 1988, Volume 7, Number 1, pages 48-53)

William Kratville wrote in The Mighty 800 (Kratville Publications, 1967) on page 85:

One of the more visible changes and certainly the most remembered of all was the two-tone paint scheme. In 1946 the road adopted a two-tone gray with light gray stripes color code for the 800s, 4-8-2s and some 4-6-2s and 4-6-6-4s. The scheme was designed to match the lightweight Pullman-Standard built 1941-42 cars for the Overland Limited, Los Angeles Limited and Portland Rose. Much Southern Pacific equipment was also painted in this scheme as was a similar pattern on Pullman pool cars and at times too, the 800s were pinch-hitting on the Streamliners.

The 809 received the first paint job and soon all 4-8-4s were painted. But before all received the new scheme, passenger department men suggested that yellow stripes be used instead as this would better match the new yellow Streamliner cars. At the end of the program only yellow stripes were being applied and in 1952, the scheme was dropped and succeeding shoppings went back to black with aluminum lettering.

Silver Gray Letters and Stripes (1946)

A limited number of steam locomotives were painted in 1946 with Silver Gray lettering and striping, but beginning in December 1946, Armour Yellow was used for the lettering and striping. Yellow continued to be used until mid-1949, when the lettering and striping on steam locomotives was changed back to Silver Gray.

Two-tone gray paint was used on most, if not all, of the steam locomotives assigned to passenger service, including the 4-6-2 Pacifics, the 4-8-2 Mountains and the 4-8-4 Northerns. Read more about the passenger-assigned steam locomotives is presented below, with the range of dates as taken from dated photographs. (Research has not yet identified internal company documents directing the use of two-tone gray for steam locomotives assigned to passenger service.)

UP 809, a 4-8-4 Northern, was apparently the first, in April 1946, matching early examples of passenger cars painted in the new two-tone gray scheme. Other locomotives followed quickly throughout 1946. These cars and locomotives painted during 1946 used silver gray as the lettering and striping color; the locomotives to match the striping color used on all other two-tone gray equipment.

When UP first applied the two-tone gray (TTG) scheme to steam locos in Spring 1946 they used silver gray for the lettering and stripes, to match the scheme used on the TTG passenger cars. There are several first-hand accounts that confirm this fact. And yes, we are still searching for written or photo documentation. By Fall 1946, the color of the lettering and striping on TTG steam locos had been changed to Armour Yellow, reportedly to better match the Streamliner trains they occasionally pulled. (Dick Harley, email dated March 12, 2008)

The following comes from the Wyoming State Tribune newspaper for May 28, 1946:

U. P. Engines Get New Paint Job -- A new paint job is being accomplished on the giant passenger locomotives used by the Union Pacific, railroad officials revealed here today. The already sleek appearance of the engines is further enhanced by a two-tone gray paint job. The huge boilers are being painted a dark gray, while the tender is a lighter gray with a dark strip on which "Union Pacific" is lettered in white [silver gray]. The new color scheme matches closely the color of the new [TTG] U. P. passenger cars. The canary yellow of the streamliners will remain the same. (Wyoming State Tribune, Cheyenne, Wyoming, May 28, 1946)

There are dated photos of about a dozen FEFs that were painted TTG before the December 1946 date of the official drawing. One photo is dated in March and others in June. Photo date accuracy is always a concern, but it makes much sense that the program was originally started to match the steam locos with the TTG passenger trains they often pulled. And hence, the original color of the lettering and striping was "silver gray." Certainly, the December drawing calls out the use of Armour Yellow, but what happened before that is hard to tell without color photos or copies of the shop records or directive letters. (Dick Harley, email dated May 24, 2007)

Yellow Letters and Stripes (1946)

There are photos of two-tone gray 800's taken in June 1946, some six months before the scheme was adopted for all steam locomotives. Initial emphasis in two-tone gray painting was to match the existing gray paint scheme of lightweight Pullman equipment used on the faster non-Streamliner West Coast trains. This included the same Silver Gray lettering and striping on both cars and locomotives. The first 800 out-shopped in two-tone gray with Silver Gray lettering and striping was in April 1946. A desire to reflect the Streamliners' Armour Yellow led to the later use of yellow lettering and striping on locomotives. Armour Yellow first appeared in August 1946. This latter scheme with Armour Yellow lettering and striping was the one formally adopted in December 1946 as a standard for all steam locomotives in passenger service. (Lou Schmitz, "Two-Tone Gray Footnote" in The Streamliner, Volume 4, Number 3, July 1988, page 23)

In mid-December 1946, the ten 4-6-6-4 Challengers assigned to passenger service in the Pacific Northwest were painted two-tone gray, but with yellow stripes in place of the earlier silver gray stripes.

Based on dated photographs, it appears that when the Pacifics or Mountains received their initial two-tone gray paint scheme, the dates suggest that they also received yellow lettering and striping. About 12 to 14 Northerns were painted during 1946, receiving silver gray lettering and stripes prior to the change to yellow lettering and striping.

Steam locomotives assigned to passenger service received yellow stripes because they were used to power Streamliner trains, and the railroad figured the locomotives would match better with the Streamliner cars. The main backup steam power for the Streamliners were the two yellow and brown streamlined steam engines: 2906 and 7002 in 1936. These engines were used on "The 49er" when it came on in 1937 as the heavyweight service to San Francisco on non-Streamliner days. In 1942 these two engines lost their streamlining. By 1949 the railroad had enough diesels on hand to protect the Streamliners; then on those engines, the stripes became silver gray to match the two-tone passenger equipment. (David Seidel, email dated January 11, 2008)

On June 2, 1949, the drawing (992-CA-33179) was revised to show that the color of the striping and lettering was changed from Armour Yellow to Silver Gray. The stripe itself, both upper and lower, was 1-3/4 inches, with a black 1/4 inch edge above and below the stripe, making for a total stripe width of 2-1/4 inches.

Striping Gray Letters and Stripes (1949)

In November 1949, the paint name Silver Gray was changed to Striping Gray, though the color remained the same. It was close to Pantone color 401C and was even referred to as 'white' by some authors at the time. (Dick Harley, email dated March 23, 2016)

In mid-1952, Union Pacific began repainting its passenger-assigned steam locomotives back the standard all-black paint scheme, and all passenger cars began receiving the newly adopted standard paint scheme of Armour Yellow and Harbor Mist Gray.

Locomotive Classes With Two-Tone Gray

Northern 4-8-4

The Northerns -- UP's two-tone gray 4-8-4 Northerns, Class FEF (45 locomotives) (Apr 1946 through Oct 1952)

Pacific 4-6-2

The Pacifics -- UP's two-tone gray 4-6-2 Pacifics, Class P (14 locomotives) (May 1947 through Nov 1951)

Challenger 4-6-6-4

The Challengers -- UP's two-tone gray 4-6-6-4 Challengers, Class 4-6-6-4 (10 locomotives) (Dec 1946 through May 1949)

Mountain 4-8-2

The Mountains -- UP's two-tone gray 4-8-2 Mountains, Class MT (60 locomotives) (Jun 1947 through Oct 1954)

Shades Of Gray

There were three separate shades of gray used as part of the Two-Tone Gray paint scheme: Light Gary, Dark Gray, and Striping Gray used to separate the two other colors.

The two primary colors used by Union Pacific for its passenger Two-Tone Gray scheme were C.S. 22 - No. 183 Light Gray and C.S. 22 - No. 184 Dark Gray, both using the title "Exterior Passenger Car Enamel." The other well-known Union Pacific gray was Harbor Mist Gray (or Harbormist Grey), which was C.S. 22 - No. 182. Harbor Mist Gray is only very slightly lighter than Light Gray. Dick Harley wrote in an email dated June 6, 2006, that the two color drift cards need to be held next to each other to see the slight difference. He speculated about how the very-similar-but-different colors came to be used. Maybe Harbor Mist Gray came from EMD and Light Gray came from Pullman.

For the separating stripe, later known as Striping Gray, the original Pullman color was called Imitation Silver because it was a non-metallic paint that was supposed to replace silver foil, but was definitely not "silver-appearing". By the time UP started to use it, they first called it Silver Gray, but eye-witness accounts (including from Bill Kratville) often referred to it as "white". That's because it was a very pale gray color. By 1950, UP had changed the name of that color to CS-22 No.28 Striping Gray Enamel. Examination of an actual color drift card of that color, as well as the DuPont color chip, shows that the two colors were not "silver," or metallic in any way. (Dick Harley, email dated March 12, 2008)

Dick Harley wrote via an email dated August 19 and 24, 2005:

The color used after June 1949 for the lettering and stripes on UP two-tone gray steam locos was called "Silver Gray". The primary color definer here is gray - not silver. In spite of many models and model decals using a metallic color, the UP color was not metallic and not "silver".

UP Silver Gray and UP Striping Gray appeared to be the same color in 1949, with the assumption being that UP would not use two different appearing colors for both stripes and letters at the same time on two-tone gray locomotives. Accurate observations and the Pantone references were made from a properly preserved Color Drift Control card for C.S. 22 - No. 28 Striping Gray, produced in November 1949 by Bowles Printing Corporation. No comparison has yet been made with a reliable sample of Dupont 95-7581 Silver Gray.

Inspection of Pullman and UP records shows that the appearance of Pullman Imitation Silver, UP Silver Gray and UP C.S. 22 - No. 28 Striping Gray (all in the 1946 to 1951 time frame) are very, very likely the same.

There is much documentation that in 1950 the primary paint used for the UP TTG lettering and stripes on passenger cars was Dupont Dulux 88-34793, and that the UP name of that paint color changed in that year from Silver Gray to Striping Gray.

Whether the paint used on steam locos changed from Dulux 95-7581 (Silver Gray) to 83-34793 or 88-34793 (Striping Gray) is still an open question.


1946 -- Convert all FEF class to burn oil. FEF-3s already had smoke lifters.

February 14, 1946 -- Lightweight passenger cars painted two-tone gray; drawing 357-CB-25391

February 27, 1946 -- Lightweight passenger cars painted two-tone gray, assigned to Overland or City of St. Louis service; drawing 357-CB-24002

April 1946 -- Some FEFs painted TTG with Silver Gray lettering and striping, beginning with UP 809.

May 25, 1946 -- Standard passenger cars painted two-tone gray; drawing 357-CB-23995

July 3, 1946 -- Express boxcars painted two-tone gray; drawing 304-C-7163

June to October 1946 -- Decision to change lettering and striping to Armour Yellow - exact date unknown.

August 1946 -- UP 800-series steam locomotives began receiving two-tone gray, with yellow stripes (UP also received eight new E7 locomotives from EMD)

December 26, 1946 -- Steam locomotives painted two-tone gray ("All Locos in Passenger Service"); drawing 992-CA-33179 revised to specify yellow lettering and stripes

1947 -- Photos show that 4-6-2s, 4-8-2s, 4-8-4s and 4-6-6-4s were painted TTG. Most photos are Black & White.

June 2, 1949 -- Steam locomotives painted two-tone gray; drawing 992-CA-33179 changed back from yellow stripes to silver gray stripes

Early 1950 -- Color name of Silver Gray is changed to Striping Gray.

August 5, 1950 -- Heavyweight ("Standard Weight") Pullman passenger cars painted two-tone gray; drawing 357-CB-25344

1950-1952 -- FEF-2s begin receiving smoke lifters.

March 1952 -- Directive was issued to henceforth paint all passenger cars yellow and gray, and all steam locos black with Aluminum lettering.

Two-Tone Gray On SP

UP's two-tone gray matched SP's scheme very closely which was introduced in about 1948-1949, and both roads' two-tone gray scheme matched an earlier version used by Pullman, which itself matched a still-earlier version introduced by New York Central.

"The best I can tell, the Shasta Daylight arrived with lettering gray (silver gray) stripping and that was 1949. The Pullman paint number for silver gray is 600-4. Also, the black edging on the stripping was removed February 23, 1956 and the total stripe width was reduced from 2 1/4 inches to 2 inches. Of course, now the 2-inch stripe was all silver gray." (Jeff Cauthen, email dated June 2005)

More Information

UP Two-Tone Gray Painting Diagram -- An online example at Dick Harley's web site, showing how UP painted its two-tone-gray steam locomotives.

"Greyhounds of the Overland Trail" -- Excerpts from an article by Ross Grenard about UP's two-tone paint scheme used on its steam locomotives.

"The Overland in Union Pacific Overland" by David Schumacher, Prototype Modeler, Volume 4, Number 1, August 1980, page 24

"Two-Tone Gray" by Lou Schmitz, in UPHS The Streamliner, Volume 4 Number 1, January 1988. "Striping and lettering on these locomotives was originally Armor Yellow to match Streamliner equipment, since they often served as standby power for these trains. However, by 1949 sufficient new diesel power was on hand to take over many of these assignments and the striping and lettering was changed to Silver Gray to match the other non streamliner equipment."

"Two Tone Gray Footnote" by Lou Schmitz, The Streamliner, Volume 4, Number 3, page 23, July 1988