Union Pacific Wooden Cabooses

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This page was last updated on February 20, 2013.

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Pre-Harriman N.C.S. (Non-Common Standard) Class

(373 cars, built 1880-1905)

The Union Pacific Non-Common Standard (N.C.S.) class cabooses were built for and delivered to UP and its predecessor and subsidiary companies from 1880 to 1905, prior to the Harriman era and prior to Union Pacific's adoption of the Associated Lines Common Standard CA caboose design. Before the delivery of the first Common Standard CA-class cabooses in 1905-1907, there were at least two earlier standard designs. The earliest were built in the 1870s and were apparently rebuilt from retired coaches and chair cars. These cars appear in many early photographs with varying cupola designs, including the earliest eight-sided cupolas, but all seem to have six arch-top windows along their sides, with horizontal car siding.

Another early N.C.S. design was very similar to the later CA-1 design, but with a straight-sided narrow cupola and a rooftop running board along both sides of the cupola. By examination of photos, some cars may have had a running board on just one side of the cupola. Many appear to have had an unusual rooftop running board that angled from the car end to one side of the cupola, avoiding a center-mounted interior stove and smoke stack. These cars were all a standard 30 feet long and were equipped with wooden underframes and truss rods. The early examples were apparently built by UP itself in 1880-1882 and in 1888, and delivered from the commercial builders throughout the 1880s and the early 1890s. As the road recovered from bankruptcy in 1897, many cars of this same 30-foot length, four-window design were delivered from the car builders in 1898-1901.

Based on quantities shown in available records (including ICC valuation sheets, the 1926 equipment record book, and the 1941 equipment diagram sheets), UP and its subsidiaries owned at least 373 N.C.S. class cabooses. Almost certainly, the railroad operated many other cabooses that had been retired and disposed of before being included in these records. Only additional research will identify Union Pacific's total wooden caboose fleet.

Two-window N.C.S. Cabooses

Depending on local service conditions and local repair capabilities following the occasional wreck or fire damage, many of the original three-window N.C.S. cabooses were rebuilt using two side windows, at least on their right side. The missing (right side) third window seems to follow a pattern of always being the middle window, behind the stove. This may be a reflection of the fire danger of this location, and a possible fix that increased the metal sheathing on the interior wall behind the stove. All three known photos of two-window N.C.S. cabooses show only the right side, the same side as the relocated stove, which was originally located in the center of the car.

Short OSL N.C.S. cabooses

A design very similar to the standard UP N.C.S. cabooses were the shorter 24-foot cars were delivered to OSL in 1901 and 1903, with high road numbers of the OSL 600-series cars. These short OSL cabooses were almost identical to the standard design of the 1880s, but being shorter, they had two side windows, instead of the standard three side windows.

(A roster listing of OSL short N.C.S. cabooses)

Standard Cabooses

During the 1920s, UP had a tremendous variety of cabooses, all wooden. The first standard cabooses were the CA class. There were 331 CA-class cabooses built between 1907 and 1913. The later CA-1 class was built between 1914 and 1924, with 380 cabooses having been built. There were no cabooses built after 1924, until the first steel cabooses arrived in 1942.

During the 1920s, UP would have been running CA cabooses, CA-1 cabooses, and numerous examples of what the road called N.C.S., for Non Common Standard, which were wooden cabooses purchased or acquired before the first CA cabooses in 1907. These included regular cupola cabooses, converted passenger cars, and converted boxcars, but most were cupola cabooses of varying origin. Let photographs be your guide.

Basically, the difference between a CA and a CA-1 is that the CA cabooses had four windows and wooden underframes. The CA-1s had three windows and steel underframes. Slope-side cupolas are not a spotting feature of either the CA class or the CA-1 class, as both classes had slope-side cupolas. Of course, due to rebuilds after wrecks, there is also a great variety of actual body detail differences, such as CA-1s with four windows, and CAs with three windows. Once again, let photographs be your guide.

Class CA Wooden Cabooses

(373 cabooses, built 1905-1913)

Union Pacific's Common Standard CA-class cabooses first built in 1905-1907 were the system-wide standard design for cabooses until 1913, and were built using steel-strengthened wooden underframes.

Available diagram sheets from the Common Standard era show that CA-class cabooses, delivered after June 1907 were equipped with steel end platform components. Although the end platforms themselves were not steel, the frame components under the platforms were. Cabooses built in 1907 and later, used steel frame components to strengthen the mostly wood underframe, eliminating the need for truss rods. These steel components were in the form of two longitudinal I beams at the end of each caboose, installed below the wood crossbearer beams adjacent to the car centerline, and extended toward the car center, beyond each truck bolster.

An existing diagram sheet, unidentified by railroad company name, shows a car designated as "Common Standard Caboose Car, Class CA, Specification, CS-59A, Eight Wheel, Narrow Cupola." A later wide cupola version was designated as CS-59B. The cupolas in both specifications are the slope-sided design. (A summary of the UP and SP Common Standard specification)

The design features of the UP CA-class caboose were originally from Southern Pacific's Common Standard era that dates from 1893. Common Standard was an SP concept that brought common design features (and therefore lower costs) to everything from railroad cars to railroad spikes to switch lanterns. The Common Standard name was from the SP era, and after Harriman took control of SP, the concept became known as the Associated Lines Common Standard, with the Associated Lines name being a Harriman-era addition. After the operating and mechanical departments of the two roads were combined in June 1904, following the 1901 control of SP by UP, Union Pacific adopted Common Standard for its own use and the combined system shared many groups of cars from the various car builders. The CA caboose was adopted as Common Standard in 1905, and the first official CA-class car for the UP-SP trunk line was completed as an SP caboose in SP's own Sacramento shops in 1906. The UP CA caboose general design drawing has a date of April 3, 1906.

The CA design was first ordered in quantity for UP, SP, and many of the other affiliated Harriman lines in 1907, but there are examples of the design being used in April and May 1905 for cabooses for Harriman-associated lines North Coast Railroad in Washington (15 cars), and for the San Pedro, Los Angeles & Salt Lake Railroad between Salt Lake City and Los Angeles (25 cars).

The first 50 CA-class cabooses for Union Pacific or its direct subsidiaries came from Pullman in 1907, under Pullman lot 5162, an order built for the Harriman Associated Lines. Included in the order were 10 cars for UP (UP 2280-2289), 25, cars for OSL (OSL 700-724, renumbered to OSL 3056-3075), and 15 cars for OR&N (OR&N 249-263, renumbered to OWR&N 3538-3552). The same Pullman lot included SP caboose number 550, Las Vegas & Tonapah number 50, and a group for SP's Mexican lines that included Cananea, Rio Yaquis & Pacific number 52.

As delivered, all 373 CA-class cabooses had sloped cupolas, as shown in the Common Standard CS-59 specification. (The total includes two replacement cabooses, built by Pullman in 1910 and 1911, numbered as OSL 700 and 715.) Over the years, due to wrecks and modifications, some CA-class cabooses received, straight-sided cupolas. Also, while all CA-class cabooses were built as four window cabooses, some were changed to three window cabooses by removal of the center window, located just behind the cupola.

Research found a photocopied portion of a drawing of just the cupola of a wood caboose that definitely shows the later CA-1 style slope-side full width cupola, with a rooftop lantern. Just visible (cut off by who ever made the copy) is a revision block that shows different revisions with three successive dates, 4-3-06, 11-26-18, and 12-8-20. Although this confirms the 1906 initial date, the fact that it is the later CA-1 sloped cupola is a big question mark (unless all of the original CA class cars also had the same sloped cupola identical to the later CA-1 cars).

Following is a table showing the original quantities of the CA-class cabooses:

1925 to 1960
Car Numbers
Date Built
Car Numbers
UP 2280-2299 20 May 1907-Jun 1912    
UP 2400-2524 125 Nov 1907-Oct 1913    
OSL 3055-3147(93 cars) 100 June 1907-Aug 1913 OSL 700-797 1
LA&SL 3309-3329(21 cars) 25 April 1905 SPLA&SL 230-254 2
LA&SL 3330-3339(10 cars) 21 Oct 1907-Feb 1910 SPLA&SL 4255-4275 3
OWR&N 3538-3579(42 cars) 43 Jul 1907-Jul 1910 OR&N 249-291 4
OWR&N 3580-3594 15 May 1905 O&W 1000-1014 5
OWR&N 3595-3618 24 Mar 1910-Sep 1913 OWR&N 307-330 6


  1. OSL 3055-3147 renumbered from OSL 700-797 in 1915-1917; OSL 700 and 715 were wrecked and replaced with new cars in 1910 and 1911.
  2. LA&SL 3309-3329 were renumbered from LA&SL 4230-4254 in 1921-1922; built as SPLA&SL 230-254.
  3. LA&SL 3330-3339 were renumbered from LA&SL 4255-4275 in 1921-1922.
  4. OWR&N 3538-3579 were renumbered from OR&N 249-291 in 1916-1920.
  5. OWR&N 3580-3594 were renumbered from O&W 1000-1014 in 1915-1919.
  6. OWR&N 3595-3618 were renumbered from OWR&N 307-330 in 1915-1921.

Union Pacific and its three subsidiary roads (OSL, LA&SL, and OWR&N) owned a total of 373 CA-class cabooses, built between 1905 and 1913. Of the 373-car total, 333 were furnished by commercial builders. The remaining 40 cars (30 cars built in 1907 and 10 cars built in 1908) were completed by UP in its own Omaha shops.

Of the commercial builders, Standard Car Co. furnished a total of 174 of the 373 CA-class cabooses: 15 in 1905; 10 in 1909; 50 in 1910; 29 in 1912; and 70 in, 1913. Pullman furnished another 89 of the CA-class cars: 64 in 1907; five in 1909; two in 1910; eight in 1912; and 10 in 1913. American Car & Foundry furnished 45 cars: three in 1910 and 42 cabooses in 1912. Barney & Smith furnished the first 25 cars in April 1905 for San Pedro, Los Angeles & Salt Lake.

Following is a table showing the years and builders of UP's fleet of CA-class cabooses:

Year Builder Qty Original Number Series
1905 Barney & Smith 25 SPLA&SL 230-254 (renumbered to LA&SL 3309-3329)
1905 Standard 15 North Coast 1000-1014 (renumbered to OWR&N 3580-3594)
1907 Pullman 25 OSL 700-724 (renumbered to OSL 3056-3075) (700, 715 wrecked)
1907 Pullman 15 OR&N 249-263 (renumbered to OWR&N 3538-3552)
1907 Pullman 10 UP 2280-2289
1907 Pullman 14 SPLA&SL 255-268 (renumbered to LA&SL 3330-3339)
1907 UPRR-Omaha 30 UP 2400-2429
1908 UPRR-Omaha 10 UP 2430-2439
1909 Pullman 5 SPLA&SL 4269-4271, 4273, 4274
1909 Standard 10 OR&N 264-273
1910 Pullman 2 SPLA&SL 4272, 4275
1910 Standard 5 OSL 715, 725-728
1910 Standard 20 OR&N 274-291, OWR&N 307, 308
1910 Standard 25 UP 2440-2464
1910 AC&F 3 UP 2466, 2469, 2470
1911 AC&F 20 OSL 700, 729-747
1911 AC&F 22 UP 2465, 2467, 2468, 2471-2489
1912 Pullman 6 OWR&N 309-314
1912 Pullman 2 UP 2290, 2291
1912 Standard 21 OSL 748-768
1912 Standard 8 UP 2292-2299
1913 Pullman 10 UP 2490-2499
1913 Standard 29 OSL 769-797
1913 Standard 16 OWR&N 315-330
1913 Standard 25 UP 2500-2524

Class CA-1 wooden cabooses

(380 cabooses, built 1914-1924)

The CA-1 caboose was first built in 1914, and was not a Common Standard design, coming after the UP-SP breakup in 1912. Rather, it closely matched the earlier UP design from 30 years before, a design equipped with an all-wooden underframe and a straight-sided, narrow cupola.

Almost all of Union Pacific's fleet of CA-1 class cabooses were built using three window wooden bodies, slope-sided, wide cupolas, and riveted steel underframes. Most of these steel underframes were furnished by Bettendorf Co. Some cars, especially LA&SL cars, were built, or later rebuilt, with high straight-sided cupolas. (Although classed as CA-1s, LA&SL also stepped away from the CA-1 design with a few steel underframe cabooses that matched the Common Standard CA, design.)

Following is a table of CA-1 cabooses on UP and its subsidiary and affiliated lines:

Car Numbers
Date, Built
UP 2525-2699 175 Jan 1918-Mar 1924    
OSL 3148-3162 15 Nov 1914 OSL 798-812 1
OSL 3163-3192 30 Jun 1923-Dec 1924    
UP 3200-3224 25 Apr 1924-Jun 1924 UP 2700-2724 2
UP 3225-3274 50 Sep 1924-Nov 1924    
LA&SL 3340-3363 24 Mar 1916-May 1921 LA&SL 4276-4299 3
LA&SL 3373-3420 48 Dec 1921-Sep 1924    
OWR&N 3619-3631 13 Jun 1923-Dec 1924    


  1. OSL 3148-3162 were renumbered from OSL 798-812 in 1915.
  2. UP 3200-3224 were renumbered from UP 2700-2724 in 1924.
  3. LA&SL 3340-3363 were renumbered from LA&SL 4276-4299 in 1921-1922.

For cabooses delivered after 1913, and with the availability of steel underframe components, UP returned to a modernized version of its earlier design used in the 1880-1901 time frame. The two designs shared the same body configuration of 30 feet long and three side widows. The earlier design had a narrow straight-sided cupola, and the later CA-1 design had the wide slope-sided cupola from the Common Standard CA design. The earlier 1880 design and the later CA-1 both had cupolas set more toward the car center, and three side windows set in an almost identical window configuration.

The 380 cabooses in the CA-1 class were built by five commercial builders, and by two of the railroad's own shops (OWR&N's Albina shops in Portland, Oregon, and LA&SL's East Los Angeles shops). The first 15 CA-1s were built by Standard Car Co. for Oregon Short Line in 1914. No CA-1s were completed during 1915, meaning that more CA-1s didn't arrive until 1916, when Pullman delivered five CA-1s and Mount Vernon delivered six, all to LA&SL (which was independent of full UP control until April, 1921). Mount Vernon Car Co., also delivered two UP-design CA-1 cabooses to Utah Railway in 1917, through the Union Pacific Equipment Association.

Union Pacific itself received its first CA-1s in 1918. These early cars included 50 from American Car & Foundry and 25 from Mount Vernon. Pacific Car & Foundry delivered 45 CA-1 cabooses to UP in 1920. During 1923, the shops of Mount Vernon delivered a total of 50 CA-1s, including 30 for UP, ten for OSL, and five each for both OWR&N and LA&SL.

The last 168 CA-1s to be built came in 1924 from OWR&N's Albina shops in Portland, Oregon. This final group included 100 cabooses for UP, 20 cabooses for OSL, 40 for, LA&SL, and eight for OWR&N. These totals show that the Albina shops, built most of the CA-1s (168 cabooses), and Mount Vernon furnished the largest number from the commercial builders (81 cabooses). Union Pacific did not receive any additional new cabooses for another 18 years, until the delivery of the first all-steel cars in 1942.

Although classed by UP on their diagram sheets as CA-1 cabooses, the 16 cabooses built by LA&SL in its own East Los Angeles shops in 1918 to 1921 were built using the previous four-window design of the earlier CA-class cabooses, but with a high cupola that was itself unique to LA&SL. The post-1922 road numbers for these cars were LA&SL 3351-3355 (built in 1918), 3356-3359 (built in 1920), 3360-3363 (built in 1921) and 3373-3375 (also built in 1921). These 16 cars, although members of the early CA-class by their appearance, were classed as CA-1 cars because they were built using all-steel underframes, UP's criteria for a then-modern caboose design.

Following is a table showing the years and builders of UP's fleet of CA-1 cabooses:

Year Builder Qty Number Series
1914 Standard 15 OSL 3148-3162 (built as OSL 798-812)
1916 Pullman 5 LA&SL 3340-3344 (built as LA&SL 4276-4280)
1916 Mt. Vernon 6 LA&SL 3345-3350 (built as LA&SL 4281-4286)
1918 AC&F 50 UP 2550-2599
1918 Mt. Vernon 25 UP 2525-2549
1918 LA&SL 5 LA&SL 3351-3355 (built as LA&SL 4287-4291) (CA-class bodies)
1920 PC&F 45 UP 2600-2644
1920 LA&SL 8 LA&SL 3356-3363 (built as LA&SL 4292-4299) (CA-class bodies)
1921 LA&SL 3 LA&SL 3373-3375 (CA-class bodies)
1923 Mt. Vernon 30 UP 2645-2674
1923 Mt. Vernon 10 OSL 3163-3172
1923 Mt. Vernon 5 LA&SL 3376-3380
1923 Mt. Vernon 5 OWR&N 3619-3623
1924 OW&RN 25 UP 2675-2699
1924 OWR&N 20 OSL 3173-3192
1924 OWR&N 75 UP 3200-3274 (UP 3200-3224 built as UP 2700-2724)
1924 OWR&N 40 LA&SL 3381-3420
1924 OWR&N 8 OWR&N 3624-3631

A list dating from August to October 1951 shows 111 CA-1s assigned to the Eastern District, comprised of the Nebraska and Wyoming Divisions, and the Kansas Division. Of the original fleet of 250 UP-assigned CA-1s, by late 1951, 39 had been retired due to wreck damage, leaving an active fleet of 211 cabooses, 100 of these were apparently assigned to the OSL, LA&SL, and OWR&N subsidiaries. On the subsidiary roads, also by late 1951, Oregon Short Line's fleet of 45 CA-1s had been reduced by three cabooses, leaving them with 42; LA&SL had lost 10 of its 72 cabooses; and OWR&N had retired three of its 13 CA-1s.

Comparing the CA and the CA-1 designs

While the two designs of UP standard cabooses are very similar, there are several important differences. The CA cabooses were built between 1905 and 1913. The CA-1 cabooses were built between 1914 and 1924. One feature that is shared by both designs is the Harriman-era slope-sided cupola.

Using the railroad's own general design drawing for each class as the source, the following table shows a comparison between the two designs.

Feature CA Class
(UP drawing 246-C-901)
CA-1 Class
(UP drawing 246-C-2313)
Length over roof ends 33 feet, 10-3/4 inches 34 feet, 10-3/4 inches
Body length 30 feet, 1-1/2 inches 30 feet, 1-1/2 inches
End platform length 21 inches 27 inches
Height top of rail to top of roof 11 feet, 8-1/2 inches 11 feet, 9-3/4 inches
Height top of rail to roof eaves 11 feet, 7/8 inch 11 feet, 2-1/8 inches
Height top of rail to top of roof 11 feet, 8-1/2 inches 11 feet, 9-3/4 inches
Body height (bottom edge to top of roof) 8 feet, 5-1/8 inches 8 feet, 3-1/8 inches
Body width 9 feet, 7-1/2 inches 9 feet, 7-1/2 inches
Cupola location 29-1/4 inches forward of car center (note 1) 2 inches forward of car center (note 1)
Cupola length 6 feet, 1-1/2 inches 6 feet, 1-1/2 inches
Rooftop stovepipe location 8-1/4 inches to the rear of car center 22 inches left of car centerline (note 1) 2 feet 11-3/4 inches to the rear of car center 22 inches right of car centerline (note 1)
Side windows 4 windows (3 to the rear of the cupola 1 forward of the cupola) 3 windows (2 to the rear of the cupola 1 forward of the cupola)
End windows (none) 2 windows (1 on each side)
Underframe Composite wood and steel, including two 14-3/4 inch by 5 inch wood center beams, with 8, inch by 4 inch wood intermediate sills, and steel reinforcements that, included two 10 feet, 5-1/2 inches long, 6 inch I beams at ends of each car, below wood crossbearers, 16-3/16 inches outside of car centerline. Steel, (18 inch center I beam, with 8 inch I beam crossbearers)
Platform, sill Wood, (7-3/4 inches by 7-3/4 inches) Steel, (8 inch channel beam)


1. On UP wooden cupola cabooses, the cupola end is the front end or the A end. The rear end, or the B end was the end away from the cupola since the brake cylinder pointed away from the cupola. Looking at the number of side windows, the rear was the three-window end on the CA and the two-window end on the CA-1.

2. The general design drawings show dimensions (30 feet length and 9 feet 6 inches width) without sheathing. For simplicity of overall dimensions, the above dimensions for body length and width assume 3/4 inch sheathing thickness.