Union Pacific Steel Cabooses

Index For This Page

This page was last updated on February 2, 2021.

(Return to Union Pacific Caboose Index Page)


Along with its diverse fleet of steam and diesel locomotives, and its renowned fleet of Streamliner passenger trains, Union Pacific is also known for its unique fleet of steel cabooses. The design features of their high centered cupola make UP steel cabooses some of the most recognizable cabooses in North America.

Between 1942 and 1975, UP received 750 steel cupola cabooses, with another 100 compact body, bay window cabooses coming in 1979, which were the last new cabooses delivered to the railroad.

Steel Caboose Number Series

Following is a table showing the number series of UP's steel caboose fleet:

Car Number Date Built Builder Quantity Class Notes
UP 2700-2799 1955 UPRR 100 CA-6 To 25300-25399 in 1959-1962
UP 3700-3799 1942 Mt. Vernon 100 CA-3 To 25000-25099 in 1959-1960
UP 3800-3899 1944 Pullman 100 CA-4 To 25100-25199 in 1959-1960
UP 3900-3999 1952 UPRR 100 CA-5 To 25200-25299 in 1959-1960
UP 24500-24629     127 CA-13 Ex Rock Island (to UP in 1980)
UP 25000-25099 1942 Mt. Vernon 97 CA-3 From 3700-3799 (3 cars wrecked)
UP 25100-25199 1944 Pullman 99 CA-4 From 3800-3899 (1 car wrecked)
UP 25200-25299 1952 UPRR 100 CA-5 From 3900-3999
UP 25300-25399 1955 UPRR 100 CA-6 From 2700-2799
UP 25400-25499 1959 UPRR 100 CA-7  
UP 25500-25599 1964 International 100 CA-8  
UP 25600-25699 1967 International 100 CA-9  
UP 25700-25749 1975 International 50 CA-10  
UP 25800-25899 1979 International 100 CA-11 Compact Body

The First Steel Cabooses

During late 1939 and early 1940, with its newest wooden caboose being at least 15 years old, UP began working on the design of its first all-steel caboose. Research using available documents shows that UP had been investigating upgrading its caboose fleet as early as 1924, with the delivery of its last CA-1 wooden cabooses. The LA&SL high cupola of the 1918-1921 era was possibly the inspiration in 1937, when the railroad tried a high cupola design on one of its steel underframe standard CA-1 wooden cabooses, number 3270, changing the position of the cupola to the end of the car's roof at the same time. As the 1930s came to an end, the company began looking at updating its caboose fleet with steel cars. The trend towards steel cars was becoming an industry-wide consideration. Competitive pressure may have been a factor since competitors AT&SF and D&RGW were already operating steel cabooses. AT&SF began its steel caboose program in 1927, and D&RGW started its own steel caboose program in 1940.

Not wanting to just duplicate the basic design features of its earlier wooden cabooses, UP approached the operating unions for their input. A recently discovered pair of drawings shows that a new steel caboose design could have been a bit different from the CA-3 design that was actually built. Two drawings dated March 1941 show an all-steel caboose that was to be built by UP itself, in either the company's Omaha shop, or in its Grand Island shop. This other design was to be based on the steel underframe B-50-6 box cars from the very early Harriman era. Research has not yet shown exactly what UP's intention was with this "B-50-6" design compared to the final design that was built by Mount Vernon in 1942.

By 1936, Union Pacific had discovered that more than 50 percent of its boxcar fleet would need to be completely replaced and began a box car replacement program. Over the next five to six years, new steel box cars in the thousands began arriving, starting with the B-50-19 class in 1936. The new cars were actually assembled by the railroad's shops in Omaha, Grand Island, and Albina. New steel box cars allowed the previous wood box cars to be retired. Actually, it was the wood superstructures that was forcing the retirement of the early B-50-6 cars (built in 1909-1913) and the nearly identical B-50-11 and B-50-13 designs. During the late 1930s, UP found many uses for the refurbished steel underframes from these cars, and new steel cabooses using the B-50-6 underframe was to be another use.

This car building effort that began in 1936 proved that the company car shops were more than capable of constructing steel cars, and that they could be called on in late 1941 to construct new steel cabooses. A drawing of the new caboose design is identified as a CA-3, but the design shows a car with an arch roof and round upper corners on both the body roof and the cupola roof. Floor plans were presented to the operating unions, one dated March 1941 and another dated July 1941. Both floor plans showed a caboose that was 30 feet long, with a centered cupola that extended 3 feet, 9 inches above the roof itself (the cupola of the later CA-3 extended 4 feet, 1 inch above the roof). Additional documentation is missing, so we can only speculate as why this design was set aside in favor of the design delivered from commercial car builder Mount Vernon in 1942.

The resulting design built by Mount Vernon became Union Pacific's trademark, a steel car with a tall, centered cupola, and ample interior room for sleeping during extended crew layovers. Upon completion, the new design received favorable comments in the trade press about its combined economy of construction, and its functionality for train crews, especially the large windows that allowed ample light into the caboose interior. The design proved so successful that its basic features remained unchanged for over 30 years.

When the first steel cabooses began arriving on UP in 1942, there were still 767 wooden cabooses on UP and its three subsidiaries. These 767 wooden cabooses included 353 steel underframe CA-1 cabooses and 170 steel reinforced, wood underframe CA cabooses, along with 167 wooden underframe, Non-Common Standard cabooses and 77 transfer and drover cabooses.

UP's steel cabooses can be categorized into four basic groups, differing mostly in major car body components. The first, the two CA-3 and CA-4 classes, were cupola cabooses with riveted body panels, plain roofs and flat bar end ladder extensions and riveted underframes. The second group, made up of classes CA-5, CA-6, and CA-7, had similar riveted bodies, but had diagonal panel roofs and a safety cage at the top of the end ladder made up of round rod. They also had welded underframes. The third, made up of classes CA-8, CA-9, and CA-10, were also cupola cabooses, but with welded, body panels. The fourth, the CA-11s, were bay window cabooses with compact, bodies.

Other body details further separate the classes. The CA-3s and CA-4s had plain raised roof panels, furnished by Standard Railway Equipment Manufacturing under the "Solid Steel" brand name, also known as "Murphy" roof panels, possibly named after Standard's chief engineer. The CA-5s through CA-10s all had the stronger Standard Railway diagonal roof panels, known as brand-name "StanRay" panels. Both styles of roof panels were riveted along their connecting seams on all cabooses, up to and including the CA-9s. Not until the CA-10s were the roof panels welded at their seams. The CA-5 and CA-6 classes had a plain raised panel next to the rooftop toilet vent, and all classes had a plain raised panel for the stove smoke stack panel.

The location of the small lavatory window has always been another indicator of UP cupola cabooses, with the window being centered vertically with the other side windows on the CA-3 through CA-6. The later CA-7s through CA-10s had the position of their lavatory window lowered by six inches, aligning the window's lower edge with the lower edge of the other side windows.

With the delivery of the 100 welded body CA-8s, the wheelbase length of UP's cupola caboose changed. The previous cars, classes CA-3 through CA-7, all were built with their truck centers at 21 feet 7 inches. With the delivery of the CA-8s, and the subsequent CA-9s and CA-10s, the truck centers were lengthened 23 feet 2-1/2 inches, a difference of 19-1/2 inches, without any change in the actual body length.

Also changing with the new welded bodies was the number of panels used to construct the sides. The riveted CA-3 to CA-7 bodies had nine panels per side, whereas the welded CA-8 to CA-10 bodies had only eight panels per side. Additionally, the size and shape of the end platform steps was changed on the new welded body cars.

All of the steel cupola cabooses were delivered with rooftop running boards, except the CA-10s in 1975. Only the CA-3 class cars had a running board over the cupola, and it was soon removed by the railroad for safety reasons in 1943. It was replaced by a cast plaque reading, "Keep Off Cupola." The federal government's requirement for rooftop running boards was withdrawn in April 1966, stating also that all cars built after October 1966 must not be equipped with running boards, and that by the end of 1983, all cars built before 1966 must have their running boards removed. Research has yet to discover why the CA-9s were delivered in 1967 with running boards, one year after the federal ruling that banned them. Only the CA-10s were delivered without rooftop running boards. To comply with the 1983 date for removal of all running boards, Union Pacific began removing the feature in early 1980 (drawing 343-C-37512 is dated March 28, 1980), along with any and all ladder rungs and hand holds that allowed access to the roof.

Class CA-3

Union Pacific's first 100 steel CA-3 class cabooses were delivered in May through July 1942, from Mount Vernon Car Manufacturing Co. of Mount Vernon, Illinois. They entered service as the UP 3700-3799 number series, numbered to follow the existing OWR&N 3600-series wooden cabooses. These first steel cabooses for UP were delivered with the better riding wood beam trucks, often referred to as "Q trucks".

UP's CA-3 steel cabooses were delivered beginning in May 1942. Jim Adams was employed by Mount Vernon Car Company at the time as a draftsman in the engineering department. He shares this story:

"At the time I was delivering the cabooses I was an employee of the car shop. However, due to war time employee shortages the UP didn't want to assign one of their employees to act a messenger on these shipments and asked the car company to find someone. I had ridden with Dad so many times when I was in grade and high school that I knew how to handle myself  on the railroad so I volunteered for the job. When a shipment was ready to be pulled out of the shop grounds, I would punch out, load up my stuff and get aboard before the shop engine set the shipment on either the L&N or the C&EI siding. My time from the time I checked out of the engineering department until I arrived back home was paid by the car shop with the car shop being reimbursed by the UP for my time and expenses. 'Doc' Bates, the car shop timekeeper checked it out and found that I was due straight time for the first 8 hours, time and a half after 8 hours and double time on the 7th day! So, not only did I get to live a rail fan's dream, I got well paid for doing it! I wrote an article about the cabooses for Model Craftsman and still have a print of the drawing I made for that.

"According to my records I left Mt. Vernon Car Shops at 3:30 PM, May 11, 1942 with 10 brand new cabooses to be delivered to the UP at North Platte, Nebraska. They were Nos. 3700 thru 3709. I was living in the 3709 which was at the rear of the string. At 1:15 AM the next morning an L&N freight picked up the string and we headed west. I delivered them to Mr. J. A. Nicholson, Chief Inspector of Equipment for the UP at North Platte at 10 AM May 14th. I made 7 more trips out there to deliver the 100 car order. Due to heavy war time traffic and weather conditions some of the trips were pretty tedious what with being stuck in hot train yards until they could find a train that wasn't already over tonnage. With war material moving company owned cabooses were not high priority traffic. The car manufacturing company wanted to divide the shipments among as many railroads as possible both from a patronage and an advertising standpoint. I conducted a lot of 'tours' of the new cars for officials from the 14 different RR's I traveled over. One final note; would you believe I got PAID for doing that??"

UP's CA-3s were the only class of UP cabooses to be equipped with running boards over the tops of their cupolas. These running boards were almost immediately found to be a significant safety hazard. Following a design change dated as September 1943, cupola-top running boards were soon removed. However, the hand railings that surrounded the edge of the cupolas on the CA-3s (and later CA-4s to CA-9s) were retained; the CA-3s to CA-7s with 12 mounting brackets around the cupola top outside edge, and the CA-8s, and CA-9s with just six mounting brackets for the railings.

It was common for UP equipment from locomotives to rolling stock to be purchased with borrowed funds in what was called an Equipment Trust. It was also common to have information about the Trust stenciled on the applicable equipment. In the 1940's it became the practice to mount a cast plaque on both sides of equipment owned by a trust. Such plaques were called Ownership Plates, and on CA-3 (and CA-4) cabooses they were mounted on the car side to the left of the reporting mark. The plates were removed when the funds were repaid to the trust.

After being delivered with wood beam trucks in 1942 and 1944, a combined total of 50 CA-3s and CA-4s were equipped in 1952 with new outside swing hanger trucks, the same as delivered on the new CA-5s. By 1958, an additional 97 cabooses in these same two classes were equipped with outside swing hanger trucks, making a total of 147 cabooses in these two classes to be so equipped. In 1955, 11 CA-3 and 39 CA-4 cabooses were equipped with the same inside swing hanger truck delivered on the CA-6 cabooses, also in 1955.

The CA-3s were painted in the standard freight car red paint scheme with white lettering. In early July 1947, CA-3 3763 was released from the East Los Angeles paint shop officially labeled as the first caboose to be painted in the new yellow paint scheme. Other cars had already been completed as much as four months earlier, in March 1947, making this official announcement more likely applicable to being the first yellow caboose painted by the railroad's East Los Angeles shops. The new paint scheme worn by 3763 included a thin black edge surrounding the red letters, a feature that would not be part of the standard caboose paint scheme until much later.

In early March 1955, the Western Pacific contacted the UP, SP and D&RGW about evaluating some of their caboose designs to find out what features they liked and didn't like so they could figure out some specific design features to incorporate in their own new steel cabooses that were already on-order from Morrison-International. These tests mostly revolved around trucks/ride quality and draft gear designs. All roads obliged. The UP provided CA-3 3712 for trials and the WP was impressed with the ride quality. Then a two-man team from the WP visited the Rio Grande and rode cabooses 01477 in Colorado then borrowed 01478 for a quick evaluation trip on the east end of the WP. Then the SP loaned them a C-30-6 bay window SP 1337, which was still pretty new at the time having been built in 1951. (Information from Mike Mucklin, email dated December 22, 2008)

Ninety-seven of the 100 CA-3s were renumbered to the 25000-25099 series in February 1959 to August 1960. The three missing CA-3 class cabooses had been retired from the active roster prior to the time of the renumbering to the 25000-series: UP 3710 (assigned UP 25010) was wrecked on 13 October 1946 at Pegram, Idaho, then was retired in November 1946; UP 3746 (assigned UP 25046) was wrecked on 21 November 1947 at Medicine Bow, Wyoming, and was retired in March 1948; UP 3757 (assigned UP 25057) was wrecked on 15 January 1959 at North Platte, Nebraska, and was retired in March 1959.

According to an October 1974 drawing, a total of nine CA-3s and CA-4s were upgraded for system-wide pool service. Two CA-3s were included -- UP 25012 and 25049. The upgrade included improved draft gear retention toilets, safety windows, interior and exterior electric lighting and refrigerators, oil-burning heaters (instead of coal), and radios, outside swing hanger roller bearing trucks with axle-driven alternators, and steel platforms and steps.

After retirement by UP, the road's CA-3s were donated, sold, and scrapped. In one of the more flamboyant examples of post-railroad service, UP CA-3 25004 was painted purple in June 1972 and used as a visitor information center near the campground of the Lagoon amusement park in Farmington, Utah. Later (in about 1978) it was moved about 20 miles south to private property in Midvale, Utah. The caboose was still there as late as November 1993, although badly burned and "tagged" with graffiti. As of 1995 it had either been scrapped, or moved to an unknown location.

During the 1970s, UP 25048 was one of at least two steel cabooses (CA-4 25142 was the other) modified for transfer service by blanking out the cupola windows. To designate the new service, a large green T was painted on the cupola sides.

UP 25053 was renumbered to 903226 in April 1975. It was retired in April 1983 and renumbered back to 25053, then donated to the State of Nebraska in January 1984 to replace a CA-6 burned during its conversion to a cabin. Along with nine CA-6s, UP 25053 is preserved at Two Rivers State Recreation Area in Venice, Nebraska.

The last CA-3 (25012) was removed from service in April 1988 after a wreck in Louisiana.

Complete roster of UP's CA-3 class steel cabooses.

Class CA-4

Essentially identical to the 100 CA-3s, the 100 CA-4s were delivered by Pullman-Standard Manufacturing Co. from its Michigan City, Indiana, plant in September through November 1944. Like the CA-3s before them, these cabooses were delivered at the rate of two per day, in freight car red (at that time known on UP as Synthetic Red), with white lettering. The cars carried the 3800-3899 number series, numbered following the 3700-3799 number group of the CA-3s. Like the CA-3s, these 100 CA-4 class cars were also delivered riding on wood beam trucks, and had cast ownership plates on their sides.

The CA-4s were repainted to the yellow paint scheme, following the June 1947 change in paint scheme colors. They were renumbered to UP 25100-25199 in January 1959 to June 1960. One car was not on the active roster to be renumbered to the 25000-series: UP 3849 was wrecked on July 9, 1947 at Black Buttes, Wyoming, and retired in October 1947, leaving the number slot for 25149 blank and unused.

The similarities between the CA-3s and the CA-4s again came up as these two classes received improved trucks. Like the earlier CA-3s delivered in 1942, the CA-4s were delivered in 1944 with wood beam trucks. An upgrade in trucks came in 1952 when a combined total of 50 CA-3s and CA-4s were equipped with new outside swing hanger trucks. In 1955, 39 CA-4 and 11 CA-3 cabooses were equipped with the same inside swing hanger truck delivered on the CA-6 cabooses. By 1958, an additional 97 cabooses in these two classes were equipped with outside swing hanger trucks, making a total of 147 cabooses in the two classes to be so equipped.

During the 1970s, UP 25142 was one of at least two steel cabooses (CA-3 25048 was the other) modified for transfer service by blanking out the cupola windows. To designate the new service, a large green T was painted on the cupola sides.

Seven CA-4s were upgraded for system wide pool service in 1975. These seven cabooses were UP 25112, 25125, 25133, 25176, 25181, 25190, and 25193. As with the two upgraded CA-3s, pool service included improvements such as the newest federally approved toilets, shatter-roof polycarbonate safety windows, electric lighting and refrigerators, oil heating, radios, outside swing hanger roller bearing trucks with axle-driven alternators, and steel platforms and steps.

Of the original 100 cars, 56 cars remained in service in late 1979. The last CA-4 (25121) was removed from service in January 1992.

A total of eleven CA-4 Union Pacific steel cabooses were sold to Pittsburgh and Lake Erie in November 1969. At least seven were sold to Montour Railroad, a wholly-owned subsidiary of P&LE. Several were later sold to other companies upon the shutdown of Montour Railroad in 1983. (Read more about the sale of these 11 UP cabooses.)

Complete roster of UP's CA-4 class steel cabooses.

Class CA-5

The 100 CA-5s were built in 1952 by Union Pacific in their own Omaha Shops, using welded steel underframes supplied by International Steel Co., and body components supplied by Youngstown Steel Door Co. The cars entered service in July and August 1952 as the first new yellow cabooses, with numbers UP 3900-3999, and were renumbered to UP 25200-25299 in January 1959 to June 1960. The first 50 cars, UP 3900-3949, were equipped with wooden platforms and steps, and the remainder, UP 3950-3999, were equipped with Apex steel tread platforms and steps. A tell-tale that makes a UP CA-5 caboose unique is the design of the running board end-brackets. Rather than the fabricated brackets used on all other UP cabooses, the CA-5s used a specially made triangular steel casting.

The CA-5s were the first new UP cabooses to receive outside swing hanger trucks, which were also used in 1952, on 50 of the road's CA-3 and CA-4 cabooses. They were also the first to use the wrap-around rooftop ladder safety railings.

In February 1972, a CA-6 (UP 25344) and a CA-5 (UP 25250) were sold to Utah Railway, numbered as Utah 62 and 63. These two cars remained in service on Utah Railway until the early 1990s.

Forty-four CA-5 class cars were upgraded for pool service in 1976-1977 by the addition of axle-driven generators, shatter-proof polycarbonate safety windows, retention toilet, roller bearings and other items.

By late 1979, there were still 87 CA-5 class steel cabooses cars remaining in service. The last CA-5 (UP 25261) was removed from service in February 1990.

Complete roster of UP's CA-5 class steel cabooses.

Class CA-6

Union Pacific themselves built the 100 CA-6 class cabooses in their own Omaha shops in August to November 1955. As with the previous CA-5s, the CA-6s were built using welded steel underframes from International Steel Co. and body components from Youngstown Steel Door Co. The cars were painted in the standard yellow paint and numbered as 2700-2799. Ninety-nine of the original 100 CA-6s were renumbered to 25300-25399 series, between February 1959 and July 1962. The single missing CA-6, UP 2721, was retired in February 1960 after being burned on December 16, 1959 at Laramie, Wyoming.

The CA-6 class was unique in several ways, even though the class shared the same General Design drawing (246-C-11229) as the CA-5 class. The cars had safety slogan frames on their sides when delivered, and were the first to get the changeable safety slogan boards. Also, they were the only class of steel cabooses built without a tool/battery box under the frame. Boxes were added later as needed or when the cars were electrified.

Most of the CA-6 class cars retained their original inside swing hanger trucks throughout their service lives. Many were converted from plain bearings on their axles to roller bearings. When the change in bearing types was made the journal box lids were painted yellow to designate roller bearings. None of the CA-6s received the 1969-1977 upgrade for pool service.

Ten UP CA-6 cabooses (UP 25310, 25319, 25327, 25342, 25345, 25353, 25376, 25381, 25388, 25399) were donated in mid January 1984 (along with CA-3 25053, numbered as 903226) to the Nebraska Game and Parks Commission. All were rebuilt for use as cabins in the Two Rivers State Recreation Area, near Venice, Nebraska, seven miles south of Valley, Nebraska. "Union Pacific Caboose Park" was dedicated on April 27, 1986 and the caboose cabins were available for use beginning on May 1, 1986. Each caboose sits atop a separate piece of track also donated by Union Pacific. As a side note, UP 25053 was obtained to replace UP 25353, which burned during its conversion to a cabin.

Eighty-seven CA-6 class cabooses remained on the active roster by late 1979, and the last CA-6 (UP 25336) was removed from service in May 1989.

Complete roster of UP's CA-6 class steel cabooses.

Class CA-7

The 100 CA-7 class cabooses were built in 1959 by Union Pacific in their own Omaha Shops, like the CA-5s and CA-6s before them, and were the last series of cabooses on UP with riveted body components. Their design included an extra row of rivets beside each window, with spacing twice that of the previous CA-3 to CA-6 series cars. As with the previous CA-5s and CA-6s, the new CA-7s also used welded steel underframes from International Steel Co. and body components from Youngstown Steel Door Co. Numbered as UP 25400-25499, they were the first new cabooses to receive five-digit numbers.

The CA-7 class was the first steel cupola class to have the air brake reservoir on the toilet/stove side of the car, instead of next to the tool/battery box on the opposite side of the car. The CA-8 and CA-9 classes followed this same placement of the air reservoir.

In 1975, UP upgraded 75 CA-7 cabooses for pool service, with axle-driven generators, shatter-proof polycarbonate safety, windows, retention toilet, roller bearings for the trucks, and other items. The other 25 cars were upgraded in 1976-1977. The CA-7s were the heaviest caboose class, at 58,000 pounds lightweight, after the upgrade to pool service.

All 100 CA-7s were still in service in late 1979. The last CA-7 (UP 25422) was removed from service in July 1991.

Complete roster of UP's CA-7 class steel cabooses.

Class CA-8, Class CA-9, Class CA-10

The last three classes of steel cabooses on UP, the CA-8s (100 cars delivered in 1964), CA-9s (100 cars delivered in 1967) and CA-10s (50 cars delivered in 1975), were all built by International Car Co., of Kenton, Ohio, and were nearly identical.

The wheelbase on the CA-8s through the CA-10s was longer than on the earlier cabooses. The earlier cars (CA-3 through CA-7) had truck centers of 21 feet 7 inches. The later cars (CA-8 through CA-10) had truck centers of 23 feet 2-1/2 inches, without any change in the actual body length. The CA-8 class, built in 1964, was the first class to be delivered with roller bearing trucks.

All 100 CA-8s were upgraded in 1969 to include all features required of cabooses in system wide pool service, such as radios, axle, generators, interior and exterior lighting, and water-hopper toilets. The 100 CA-9s, delivered in 1967, were upgraded for system wide pool service in 1973.

There were at least six cabooses assigned to dedicated service on unit coal trains for Kaiser Steel Co. between its coal mines at Sunnyside, Utah, and Somerset, Colorado, and its steel mill in Fontana, California. These six cabooses were assigned to this service in 1968, along with SD45 motive power and gondolas from each road. Included in the group of cabooses was a single CA-8 (UP 25529) and three CA-9s (UP 25656, 25669, 25680). All six cabooses had the same features as standard pool service cabooses, and each caboose also had a large green K painted on each end of its cupola.

In 1969 a total of 15 CA-9 cabooses (UP 25685-25699) were equipped with stoves, refrigerators and bunks for U. S. Air Force personnel to escort Minuteman missiles between Hill Air Force Base, Utah, and the various Air Force bases in Montana, Wyoming, North Dakota, South Dakota, and Missouri where the operational missile silos were located, and to California where the missiles were test-flown. This assignment changed in 1977 when it became more cost effective and more secure to transport the missiles by air, aboard C-141s, a practice that continues today.

During May 1995, UP 25571 was the last CA-8 in service. Five CA-9s (UP 25660, 25666, 25668, 25674, and 25684) remained in service, and seven CA-10s (UP 25704, 25707, 25709, 25719, 25730, 25734, and 25748) remained in service. Also in May 1995, UP 25749, as UP's newest cupola caboose, had been retained as part of the heritage collection at Cheyenne, Wyoming.

Complete roster of UP's CA-8 class steel cabooses.

Complete roster of UP's CA-9 class steel cabooses.

Complete roster of UP's CA-10 class steel cabooses.

Class CA-11

By the mid 1970s, the increased use of excess height cars by America's railroads had made the cupola caboose obsolete. After the delivery of the 50 new CA-10s in 1975, Union Pacific found that still more cabooses were needed to modernize its fleet, and to provide a caboose design that would be suitable for service on all UP's own trains, and on run-through trains on other railroads. In August 1977, UP borrowed one of Missouri Pacific's newest cabooses, with its distinctive design of a compact body and bay windows.

Missouri Pacific's compact body design differed from UP's traditional designs by its lack of a cupola, using side mounted bay windows instead. The design also had a much shorter body. The borrowed caboose was used in the eastern Nebraska area, and its design features were found to be significant enough to pursue a totally new design for UP's next group of modern cabooses.

By mid 1978, the new design was finalized, with International Car Co. of Kenton, Ohio, once again being selected as the builder, having furnished the CA-10s in 1975. The final price was also an important consideration, at $60,000 each for the compact body cabooses, compared to the $72,000 per car paid for the earlier cupola-equipped CA-10s.

The new compact body design retained the interior space of a cupola caboose, but without the space below the cupola, which was used only for storage space (which generally went unused) and for access up to the cupola. By relocating this space as larger end platforms, crew safety was enhanced. The new compact body was also less expensive to build, and did away with the cupola, which had lost much of its usefulness due to excess-height cars.

The first of 100 new cabooses of the new CA-11 class, UP 25800, arrived on UP in early May 1979, being delivered by C&NW to UP at Summit, Nebraska. The deliveries continued during May to August 1979. By May 1995, after six years of caboose retirements, there were still 48 CA-11s in service.

Complete roster of UP's CA-11 class steel cabooses.

Class CA-12

Almost before the paint was dry on the new CA-11s, UP began work on specifications for its next 100 modern cabooses, to be known as class CA-12. The last CA-11 was delivered in August 1979 and engineering design work on the CA-12s began in October. The new design included many features developed during the final construction of the CA-11s, based largely on input from the operating unions, but the improvements could not be included due to added costs. CA-11 caboose 25842 (built in June 1979) was selected at random, and was rebuilt and released in February 1980 as the CA-12 prototype.

The design improvements for the new CA-12 included:

Just as the improvements and design features of the new CA-12s were being finalized, and before an order for 100 new cars could be placed, UP received 127 cabooses that had previously been leased to Rock Island, and the CA-12 order was canceled. Like the CA-11s before them, the new CA-12s were to be built by International Car Co. The return of the Rock Island cabooses, together with a growing recession, resulted in UP canceling the CA-12 order on April 10, 1980, just 10 days after the Rock Island shut down.

However, many of the design features that were to be included in the new CA-12s were not lost. A modification program was initiated for the CA-11s and over the next four to five years, many received the planned CA-12 improvements. As each was completed, it was stenciled as a "Modified CA-11." There was also a "Modified CA-11-A" class.

Class CA-13

During the time that Union Pacific and Rock Island (Chicago, Rock Island & Pacific, CRI&P) were planning their merger in 1964 to 1974, the two companies cooperated on many administrative and operational matters. UP purchased several groups of locomotives, cars, and cabooses which it then leased to Rock Island. Included were 85 locomotives, 2,710 freight cars, and 130 steel bay window cabooses. The cabooses, with CRI&P numbers 17082-17211, were built in 1967, 1968, 1970, and 1971 for Union Pacific and leased to Rock Island.

(Read more about the proposed UP-CRI&P merger)

The 130 caboose cars were delivered to Rock Island in Rock Island's red paint scheme. The first 25 cars (CRI&P 17082-17106) were solid red. The remaining 105 cars (CRI&P 17107-17211) were delivered in red also, but with yellow ends. The last 30 cars (CRI&P 17181-17211) had Rock Island spelled out in speed lettering. The first 120 were equipped with roller bearing trucks, and the last 10 cars came with Rockwell high speed trucks, which they retained throughout their lives on UP.

Beginning in 1976, at least 19 cars received Rock Island's new light blue and white paint scheme, or a variation that was all-white. The lettering on these repainted cars varied also, some having "Route Rock", and others having "The Rock" spelled out in black letters.

Three of the original 130 cabooses were retired by Rock Island, leaving 127 cabooses to be returned to UP.

With the shut down of Rock Island, on April 1, 1980, the road returned the leased equipment to Union Pacific. The growing recession, together with the arrival of the former Rock Island cabooses, which UP classed as CA-13s, are the factors that lead UP to cancel its already-placed order for new CA-12 cabooses.

With their arrival back on UP property, UP began rebuilding the former Rock Island cabooses for service on its own lines, including federally approved retention toilets, which replaced the original dry hopper toilets. As the cabooses were released from the rebuild program, which also included removal of the running boards, they were classed as UP CA-13 cabooses (in four sub-classes: CA-13-1; CA-13-2; CA-13-3; and CA-13-4) and numbered in the UP 24500-24629 series.

A Union Pacific folio diagram sheet for the CA-13 class, dated December 1981, shows that UP had been able to complete 36 former Rock Island cabooses in its upgrade program, numbering them in the 24500-24599 number series. These cabooses received UP's full yellow and gray paint scheme, including a small P (denoting pool service) at the top of each side's bay window. UP 24552 (ex-CRI&P 17134) was the first, completed in May 1980.

The remaining 35 cars were completed throughout 1980 and 1981. UP 24567 was assigned to the steam program at Cheyenne, Wyoming. In 2013, UP 24567 was donated to Railway & Locomotive Historical Society, Southern California Chapter, and moved to Los Angeles County Fairplex in Pomona, California, at the same time that UP 4-8-8-4 steam locomotive no. 4014 was removed. The actual move took place in January 2014.

Some of the newer CA-13s (Class CA-13-4) in the 24600-24629 number series are known to have been upgraded to pool service, as evidenced by the word "Pool" on their bay windows, but none are known to have received full yellow and gray paint. The ten newest cabooses in the CA-13 class, UP 24620-24629 were equipped with unique Rockwell express trucks, which they retained in their service on UP.

In mid 1980 UP leased 52 random numbered ex CRI&P cabooses to C&NW. All were returned by December 1981.

Two ex CRI&P cabooses were rebuilt as test and laboratory cars, and numbered as UP 400 and 401 in November 1987 (the formal reporting marks are UPP, for Union Pacific Passenger). UPP 400 was the former UP 24531 (ex CRI&P 17113), and UPP 401 was the former UP 24540 (ex CRI&P 17122).

By May 1995, there were still 10 of the original 127 ex-Rock Island cabooses in service on UP.

Complete roster of UP's CA-13 class steel cabooses.

CRI&P Blue and White, or All-White cabooses

Based on information furnished by Steve Suhs, February 13, 2002

Road Number
Road Number
with White Ends
All-White Slogan
17063 - X   Route Rock
17070 -   X Route Rock
17081 - X   Route Rock
17121 24539 X   Route Rock
17154 24572 X   Route Rock
17159 24577 X   Route Rock
17170 24588   X Route Rock
17177 24595 X   The Little Rock
17184 24602   X Route Rock
17185 24603 X   Route Rock
17203 24621 X   The Rock
17209 24627 X   Route Rock
17210 24628 X   The Rock
17211 24629 X   The Rock