Union Pacific Steel Cabooses
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This page was last updated on July 1, 2024.
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Steel Cupola Caboose Body Details
| CA-3 (1942) |
CA-4 (1944) |
CA-5 (1952) |
CA-6 (1955) |
CA-7 (1959) |
CA-8 (1964) |
CA-9 (1967) |
CA-10 (1975) |
|
| Riveted body (nine panels) and riveted underframe (welded underframe on CA-5, CA-6, and CA-7) | X | X | X | X | X | |||
| Welded body (eight panels) and welded underframe | X | X | X | |||||
| Small lavatory window centered vertically with other windows | X | X | X | X | ||||
| Small lavatory window aligned with bottom of other windows | X | X | X | X | ||||
| Right side end (conductor's) window closer to end corner | X | X | X | |||||
| Sash windows | X | X | X | X | X | X | X | |
| Rubber gasket windows (as delivered) | X | |||||||
| Rubber gasket windows, body end windows and cupola end windows (as later modified for pool service) | X | X | X | X | X | X |
Steel Cupola Caboose End Platform Details
| CA-3 (1942) |
CA-4 (1944) |
CA-5 (1952) |
CA-6 (1955) |
CA-7 (1959) |
CA-8 (1964) |
CA-9 (1967) |
CA-10 (1975) |
|
| End hand-railings and bracing, with end ladders for access to roof. Gate (CA-3s and CA-4s used chain) across opening in end hand-railings to allow access to roof ladder. (Removed beginning in 1980.) | X | X | X | X | X | |||
| Sparse amount of end hand-railings and bracing, with end ladders for access to roof. Gate across opening in end hand-railings to allow access to roof ladder. (Removed beginning in 1980.) | X | X | ||||||
| Minimal end hand-railings and bracing. No access to roof. | X | |||||||
| Ajax-brand hand brakes | X | X | 50 | |||||
| Equipco-brand hand brakes | X | X | ||||||
| National-brand hand brakes | 50 | |||||||
| Klasing Model 1150 hand brakes (Klasing and Equipco brands on CA-10s) | X | X | X | |||||
| Curved end platform step side panels | X | X | X | X | X | |||
| Vertical end platform step side panels | X | X | X | |||||
| Wooden end doors (changed to Met-L- Wood doors in 1959) | X | X | X | |||||
| "Met-L-Wood" end doors (metal sheathing over wooden core) | X | X | X | X | X | |||
| Wooden end platforms and steps (later replaced by Apex-brand metal steps) | X | X | 50 | |||||
| Apex-brand metal end platforms and steps (Apex and Gypsum brands on CA-7s) | 50 | X | X | X | X | |||
| Morton-brand metal platforms and steps | X |
Steel Cupola Caboose Truck Details
| CA-3 (1942) |
CA-4 (1944) |
CA-5 (1952) |
CA-6 (1955) |
CA-7 (1959) |
CA-8 (1964) |
CA-9 (1967) |
CA-10 (1975) |
|
| Wood beam trucks ("Q type") (until 1961) | X | X | ||||||
| General Steel Industries inside swing hanger trucks (used on all CA-6 in 1955; used on 49 CA-3 and CA-4 in 1956) | 49 | X | ||||||
| General Steel Industries outside swing hanger trucks (used on all CA-5 in 1952; used on 50 CA-3 and CA-4 in 1952; used on 97 CA-3 and CA-4 by 1958) | 147 | X | X | X | X | X | ||
| Plain bearing trucks (converted to roller bearings for pool service) | X | X | X | X | X | |||
| Roller bearing trucks (oil filled bearings) | X | X | ||||||
| Roller bearing trucks (second hand) | X | |||||||
| Truck centers at 21 feet, 7 inches | X | X | X | X | X | |||
| Truck centers at 23 feet, 2-1/2 inches (no change in body length trucks are closer to end steps) | X | X | X | |||||
| Belt-driven alternators (inside hung) | X | X | X | |||||
| Belt-driven Dayco or Dana alternators (outside hung, pool service) | X | X | X | X | ||||
Steel Cupola Caboose Roof Details
| CA-3 (1942) |
CA-4 (1944) |
CA-5 (1952) |
CA-6 (1955) |
CA-7 (1959) |
CA-8 (1964) |
CA-9 (1967) |
CA-10 (1975) |
|
| Murphy-brand "Solid, Steel" plain raised roof panels | X | X | ||||||
| Standard Railway ("StanRay") diagonal roof panels with riveted seams (welded seams on CA-10) | X | X | X | X | X | X | ||
| Apex-brand running boards (both Apex and Gypsum brand on CA-7s) | X | X | X | X | X | X | ||
| Transco-brand running boards | X | |||||||
| No running boards (as delivered) | X | |||||||
| No running boards (as removed after 1980) | X | X | X | X | X | X | X | |
| Flat steel hand-railings on top of roof ladder | X | X | ||||||
| Round steel hand-railings on top of roof ladder, with protective enclosure at top | X | X | X | X | X | |||
| No end ladders or hand-railings to roof | X | |||||||
| 51-inch cast iron smoke stack | X | X | ||||||
| 56-inch cast iron smoke stack | X | X | X | X | X | |||
| 72-inch cast iron smoke stack | X | |||||||
| Cupola roof handrail posts (all posts are looped around handrail) | X | X | X | X | ||||
| Cupola roof handrail posts (corner posts are looped around handrail; intermediate posts are welded) | X | |||||||
| Cupola roof handrail posts (fewer posts looped around handrail) | X | X | ||||||
| No cupola roof handrails | X |
Per UP drawing 343-C-37512, "Removal Of Safety Appliances on Roofs Of Cupola Cabooses," dated March 28, 1980, all roof top handrails, grab irons, and "running boards" were to be removed.
Battery Box
Steel cabooses that were equipped with elecric lighting, were also equipped with a battery box, and an axle-driven generator to charge the batteries. Electrical power was used fof several lights only, and the radio. In later years, electricity was used on cabooses assigned to pool service, which included a refrigerator and additional lights, and explains why axle-driven generators would have been part of the modifications for pool service.
As the cabooses sat on the caboose service track at each terminal, each caboose was usually connected to a charging station to charge the batteries. The batteries were also serviced or changed while on the service track. Close examination of UP 25007, displayed at Lodgepole, Nebraska, revealed the presence of conduit coming out the side, plus the open grating on the bottom of the underslung box, indicates that batteries were added to many non-pool cabooses, such as the CA-3s. Photograph research that not all steel cabooses had batteries. Photos of the CA-6s delivered in 1955, show that they were not delivered with batteries.
Caboose Trucks
Union Pacific's fleet of steel cupola cabooses rode on three differing designs of trucks: wood beam trucks, with coil springs and leaf springs; steel inside swing hanger trucks, riding solely on coil springs; and steel outside swing hanger trucks, which rode on a combination of both leaf springs and coil springs. Throughout the majority of their lives because of the more numerous outside swing hanger truck, with its stabilizing exterior torsion bar, UP's mainline pool cabooses became well known by the railroad's own crews, and the crews of connecting roads, for the smooth "Cadillac" ride provided by their outside swing hanger trucks.
Builder photos in Terry Metcalfe's Union Pacific Freight Cars, 1936-1951, show that new CA-3 and CA-4 steel cabooses were equipped with wood beam trucks, known as "Q type" trucks, which had leaf springs to cushion the ride.
According to railroad drawings dated February 1952, the General Steel Castings outside swing hanger truck was first used on 50 CA-3 and CA-4s. An update to the drawing seven months later shows that the same trucks were used on the 100 new CA-5s. This truck had a wheel base of 5 feet 6 inches, with 33-inch wheels. Beginning in 1956 and completed in 1958, an additional 97 CA-3s and CA-4s had had their original wood beam trucks replaced by the new outside swing hanger trucks, making a total of 147 cabooses in the CA-3 and CA-4 classes with outside swing hanger trucks.
The CA-5s were the first new UP cabooses delivered with outside swing hanger trucks. The railroad's engineering staff investigated several designs and found that the outside swing hanger truck provided a smoother ride comparable to the wood beam truck of the wooden caboose era, as delivered on the earlier CA-3s and CA-4s, but without the high maintenance costs of maintaining the wood design. The new outside swing hanger truck used a combination of coil springs and leaf springs similar to the earlier wood beam truck, but benefited from a cast steel frame and an added stabilizing torsion bar.
UP's CA-6 cabooses were built by the railroad in their own shops in August to November 1955, using a new truck design, also from General Steel Industries. This design was known by the manufacturer and the railroad as the inside swing hanger truck and used only coil springs to soften the ride for crew members. Like the earlier outside swing hanger truck, the inside swing hanger truck also had a wheel base of 5 feet 6 inches, with 33 inch wheels. The engineering drawing is dated October 1955 and shows that the new truck used a combination of inside swing hangers, coil springs, and an outside drop equalizer.
Most, if not all, of the CA-6s retained their original inside swing hanger trucks throughout their operating lives on UP. One example of a CA-6 that received the outside swing hanger truck was UP 25353, which was seen in September 1980 in Las Vegas with the solid bearing version of the outside swing hanger truck design. In 1956, 50 CA-3s and CA-4s received inside swing hanger trucks.
The CA-7s, CA-8s and CA-9s were all delivered with smooth riding outside swing hanger trucks. The CA-10s were delivered with Buckeye outside swing hanger trucks, similar to the earlier General Steel trucks, which were no longer available.
By 1979 when the compact body CA-11 cabooses were delivered, neither the Buckeye or the General Steel outside swing hanger trucks were available. Instead, UP chose standard 70-ton National Swing Motion freight car trucks with special spring packs and side bearings to improve the ride characteristics. But even with modifications, the new cabooses' trucks didn't ride as well as the previous swing hanger design and the CA-11 class soon became known as rough riding "tin boxes."
Marker Lights
The permanently mounted rear-facing electric marker on UP cupolas was supposed to be on all the time when the caboose was on a train. It would display red, unless the train was completely off the main in non-CTC territory, when the marker would display green.
At the time those electric markers were installed on the cupolas, a red reflector with a hinged cover was installed at each end under the running board. It was for use if the electric system failed.
In "Union Pacific Modeler, Vol. 2", on page 65, Terry Metcalfe stated, "Around 1970, most cabooses received marker lights mounted on the front and back of the cupola so that they would be visible over the taller freight cars of the era. Some cabooses, presumably those assigned to local service, never received the new style markers." Further investigation into a 1970-era rule book would help explain the operation of the built-in markers.
Roller Bearings
The CA-3 thru CA-7's all had 5"x 9" plain journal bearings when new, according to the diagrams. The CA-8 and CA-9 had 5 1/2"x 10" Timken roller bearing journals when new. The CA-10's also had 5 1/2"x 10" roller bearing journals, which are described as "U.P. second hand".
When the "pool" upgrades started in earnest in 1969 with the CA-8's, and then more in 1973 with the CA-9's, these cars already had roller bearing journals. When the program extended to the CA-7's in 1975, those cars were fitted with 5 1/2"x 10" roller bearing journals too, and all subsequent cars in "pool" service also used the outside swing hanger roller bearing trucks (CA-3 thru CA-10 that is).
Questions:
- When were roller bearing trucks required on cars in interchange service?
- Did the CA-7's simply get their journals/axles replaced, or did they get new trucks?
- Was any of this done before the 1975 upgrades?
- How extensive was the use of roller bearing journals (yellow lids) on the CA-6's? Were they used on other classes too?
- Did the yellow lids mean something else?
Roof Panels
(based on research by Dick Harley, email dated April 11, 2000)
The CA-3s and CA-4s had seven plain raised panels; one on the cupola roof and three on each end of the main roof. The CA-5 and CA-6 cabooses had five diagonal panels and two plain roof panels.
On the CA-5s and CA-6s, the plain (or flat) panels were on the main roof, closest to the cupola, but not immediately adjacent to the cupola itself. One of these flat panels had the smokestack through it.
The CA-7 through CA-10 cabooses had six diagonal panels and only one plain raised panel, which was the panel with the smokestack through it.
Note should be made here some of that UP's own diagram folio sheets have the roof panels shown incorrectly. The diagrams for the CA-3 through the CA-6 are correct, but the diagram for the CA-7 is wrong. The diagram for the CA-9 incorrectly shows the smokestack as being through a diagonal panel. The diagram for the CA-10 uses a CA-5 body. Please don't assume that the railroad's diagram folio sheets can be used as scale drawings, or even as accurate representations of how the cars actually looked.
System-wide Pool Service
Between 1969 and 1977, 353 steel cupola cabooses (of a total remaining fleet of 629 cars) were modified to operate system wide, in what was known as pool service, including interchange on run-through trains, with SP, C&NW, CB&Q (later BN), and CRI&P. Added to that total were all 50 CA-10s, which were delivered in 1975 fully equipped for system-wide pool service, capable of operating in any of UP's districts and on all run-through trains. The 100 CA-8s and 100 CA-9s were modified for pool service in 1969 and 1973 respectively, and 75 cars in the CA-7 class were modified in 1975. In addition to these CA-7, CA-8 and CA-9 classes, two CA-3s (25012 and 25049), along with seven CA-4s (25112, 25125, 25133, 25176, 26181, 26190, and 25193) were modified for pool service in 1975. During 1976 and 1977, 44 CA-5s and the remaining 25 CA-7s were modified for system-wide pool service. The most obvious indicator of pool service cabooses was the large red letter P on the side and ends of the cupola.
The modifications for pool service included a radio, oil stoves for heating, a complete water system, and roller bearing, outside swing hanger trucks. To replace the use of batteries, which could not support the added electrical load, axle-driven alternators were added for electric lighting, together electric refrigerators, electric end platform lights, and electric red-over-green electric marker lights on the cupola ends. Also included in the pool service modifications were Dupont Lexan polycarbonate safety glass windows in sides and ends (body end windows and cupola end windows mounted in a round cornered rubber gasket), and federally approved retention toilets, along with wind deflectors on cupola side windows (single deflector centered on CA-8s and CA-10s, two deflectors on CA-7s and CA-9s). A large 20-inch red Scotchlite letter P was used on the cupola sides and ends to designate pool service, along with a red Scotchlite stripe on the top drip edges and ends of the cupola.
The six cabooses assigned to the Kaiser unit coal trains received the same modifications as other CA-9 cabooses, along with radios that allowed service on both D&RGW and AT&SF. These Kaiser cabooses were designated by a green K on the cupola sides and ends.
Trust Plates
UP's CA-3s and CA-4s were each delivered with a 9-inch by 18-inch cast metal trust plate, also known as an ownership plate. These trust plates on the first steel cabooses were identical to trust plates used during the same period on UP's freight cars, and on their FEF 4-8-4, Challenger 4-6-6-4, and Big Boy 4-8-8-4 steam locomotives. According to UP equipment historian Dick Harley, these trust plates were only mounted on the cabooses between the time of their delivery and about 1947. Examination of photos reveals the following information:
- All photos of CA-3s and CA-4s with their original "red" paint scheme have ownership plates and wood beam Q trucks. (1942-1947)
- All photos of CA-3s and CA-4s with ownership plates and "yellow" paint scheme have wood beam Q trucks and no safety slogan boards. (1947-1955)
- No photos of CA-3s and CA-4s with safety slogan boards or General Steel trucks have ownership plates. (after the mid 1950s)
- No photos of Ca-3s and CA-4s taken after the early 1960s have an ownership plate.
The lettering of the trust plates reads as follows, with the letter X actually being any letter designating the actual equipment trust under which the equipment was purchased:
UNION PACIFIC
EQUIPMENT TRUST, SERIES X
THE PENNSYLVANIA COMPANY
FOR INSURANCE ON LIVES
AND GRANTING ANNUITIES, TRUSTEE, OWNER AND LESSOR
The trust series for the FEF-1s was Series E; for the Challengers the series was Series G. For the CA-3s, the series is likely Series C, and Series H for the CA-4s.
Research by Dick Harley indicates that all ownership plates had been removed from all equipment (cars and locomotives) by the mid 1950s.
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