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Mechanical Refrigeration

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Mechanical Refrigerator Freight Cars

(The focus of this page is to establish a timeline of mechanical refrigeration on U. S. railroads, 1945 to 1959, using sources not previously readily available. Sources include a wide variety of internet searches, online newspapers, and current websites and abandoned websites and magazines at Archive.org.)

The earliest shipments of perishable goods on America's railroads were placed into boxcars that had been packed with ice, then covered with thick layers of straw or sawdust to provide insulation. These shipments were conducted over short distances and were only partially successful. It was not until the advent of ice bunker refrigerator cars—commonly known as reefers—that the transport of perishable items truly gained momentum. Inside these cars, the bunkers located at each end contained a combination of salt and pieces of ice broken from blocks of 300 pounds each, all of which served to keep the perishable cargo in the center portion of the car cool. While the car was in motion, the ice was replenished or topped off on several occasions.

The End Of Ice

Although the majority of ice operations ended in 1972, there were still ice operations as late as 1978 and 1979. But the large icing platforms and ice manufacturing infrastructure of earlier days were gone or at least retired. Each ice car, with shipments as single or pairs of cars, needed specialized handling and sources for manufactured ice, which drove the cost of ice-protected shipments higher.

The evolution of refrigerated rail transport was fundamentally altered by breakthroughs in mechanical refrigeration, which introduced refrigeration units powered by small gasoline and Diesel engines installed directly into railcar ends.

Before WWII, mechanical refrigeration in railroad cars saw unsuccessful experiments. After the war, proven small diesel engines and rising frozen food consumption spurred development. Santa Fe introduced the first mechanical reefer car (SFRD 12000) in December 1949, but it was not very successful and was later rebuilt to ice-cooling. Fruit Growers Express (FGE) built a fleet of 175 mechanical cars by January 1952, and other companies (including Pacific Fruit Express) sent engineers to learn from FGE, though Santa Fe did not participate and later used unique features. In March 1953, Santa Fe built 30 cars (Class Rr-54) with blue doors marked "MTC." Shortly before, PFE had built its first mechanical class (R-70-7, 25 cars), and soon after began a 100-car class (R-70-8), though delays pushed first completions to March 1954.

After World War II, car builders and railroads tried hard to meet shipper's needs by making incremental improvements in the basic ice car. Still, they seemed reluctant to give up the old ice-cooled cars, mainly because those cars were simple and dependable. Improvements like top-icing and Preco ventilation fans helped, but they were just Band-Aid fixes. Softer-riding trucks, better steels wheels, and better insulation seemed to make shippers happy, since rough rides could damage delicate fresh produce. Even the traditional hinged doors were replaced by sliding plug doors. Early plug doors were six feet wide, an improvement over four-foot wide double-hinged ones that had served so well for decades. By the 1970s the sliding plug doors had grown to 10 feet 6 inches.

But none of these changes could save the ice car. It could not handle frozen food well, which had become a major part of America’s diet after the war. Operating and maintaining both ice-car and mechanical-car repair facilities was too costly. Long after nearly all companies in the refrigeration industry of storing and shipping by truck had switched to mechanical cooling, railroads finally decided to retire their ice cars. Pacific Fruit Express bought its last ice car in 1957. By 1970, PFE was running 8,000 ice cars and 11,000 mechanical reefers. The goal was to retire all ice cars and ice stations by the end of 1972, though newer ice cars would remain for ventilated shipments. By late 1972, most ice stations were handling fewer than one car a day, and the plan was to close all of them by the fall of 1973.

Mechanical Refrigeration Tests

"After World War II, mechanical refrigeration took two distinct directions. The Thermo-King system comprised two separate packages, each consisting of a 28-h.p. Crosley water-cooled gasoline engine, a six-cylinder refrigeration compressor with associated controls, cooling coils and air circulating fans, all located at one end of the car. The Frigidaire System contained a 34 h. p. diesel engine with direct connected three phase 20-kw alternator and electrically driven refrigerator compressors, condensers, cooling units, fans and controls as separate units, suitably installed in one end of the car." ("The Post War Refrigerator Car, A Brief History: Pt. III," by Dave and Jennie Lambert, Railroad Model Craftsman, May 1994)

"Shortly after World War II the Santa Fe built an experimental car, fitted with mechanical refrigeration equipment and an elaborate set of test instruments. This car made several trips with commercial loads during which test observations were made. The car was also subjected to static tests. (Railway Age, April 18, 1955, Volume 138, Number 16)

January 19, 1948
"San Francisco, Jan. 19. (AP) - President Fred G. Gurley of the Santa Fe Railroad said today a controlled temperature freight car, substituting a mechanical unit for the ice used in conventional refrigerator cars, will be tested early next summer. He spoke at the opening session of the United Fresh Fruit and Vegetable Association’s 44th annual convention, attended by about 4000 delegates from all parts of the nation. The controlled temperature car was developed after Santa Fe in 1946 began studying means of handling perishable products that held promise of being superior to the present use of ice. It was finally concluded that a Diesel-driven compression refrigerator unit offered the best possibility. Such a machine has now been designed and is being built at La Crosse, Wisconsin. Even if the new car is successful, the conventional cars will continue to be used for a long time." (Long Beach Press-Telegram, January 19, 1948)

"In 1948 the Fruit Growers Express Company, and its two associates; the Burlington Refrigerator Express Company and the Western Fruit Express Company, in whose cars most of the perishable rail traffic out of Florida moves, set up an experimental program in which 16 cars were equipped with nine different refrigerating systems. These included water ice, dry ice, the split ammonia system, the Thermo-King gasoline-driven cycling system, and the Frigidaire diesel-powered continuously operated system." (Railway Age, April 18, 1955, Volume 138, Number 16)

February 25, 1949
The first mechanical refrigerator car went into service on February 25, 1949 for the associated Fruit Growers Express, Western Fruit Express and Burlington Refrigerator Express. This was reported on the occasion of the most modern refrigerator car to enter service, WFEX 7900, a 50-foot mechanical refrigerator car, being displayed at Whitefish, Montana, as part of the town's special "Ship By Rail Day." (Kalispell Montana Daily Inter Lake, June 26, 1958) (Whitefish was an important division point on the Great Northern, and remains today as a crew change point on BNSF)

December 1949
"Santa Fe was first out of the box, with a single car, SFRD 12000. It had a Sheppard 3-cycle diesel engine, and entered service in December 1949. This car, rebuilt from a standard ice car of Class RR-46, was not too successful as a prototype. After three years, it was rebuilt back into a conventional ice-bunker reefer. But a great deal was learned from it, in a four-year testing program." (Tony Thompson, June 2022)

(The car used Trane refrigeration equipment and was painted aluminum with a black roof, underframe and hardware. No slogan was applied.. This car was renumbered 1200 in May 1950. At the end of the four-year testing program it was rebuilt back into a conventional ice-bunker reefer. When converted back to a conventional ice bunker reefer, it was painted standard Santa Fe colors and renumbered 10869.)

December 1950
At the annual convention of the National Association Practical Refrigerating Engineers, held in Los Angeles November 28 to December 1, 1950, J. F. Daly, manager of ice plants for the AT&SF presented the following comments.

This innovation in the late 1940s and early 1950s triggered an industry shift, as mechanical reefers began be seen as a solution to improve service and lower the cost of providing icing services for traditional ice-cooled cars.

(Read more about the history of Thermo King and its place in the mechanical refrigerator car designs)

The FGE tests of 1948 and later innovations continued to make for an improved picture. The first car equipped with a Frigidaire refrigeration system was delivered on January 26, 1950. Much development work followed, resulting in the ultimate triumph of the mechanical refrigerator car.

After The Tests (1951-1952)

November 21, 1951
"The Santa Fe Railway announced Wednesday that it will build 30 mechanical refrigerator cars in its shops. The cars will be built here [Wichita] because the Santa Fe normally makes its refrigerator cars in Wichita. Each car will be equipped with diesel powered refrigeration systems which will be provided by the Trane company of La Crosse, Wisconsin, Frigidaire division of General Motors corporation, Dayton, Ohio, and Carrier corporation of Syracuse, New York." "This development climaxes a test program inaugurated by Santa Fe in 1947, and may become one of the most important developments in railroading since the diesel-electric locomotive. What the Santa Fe is trying to do, one spokesman said, is get away from delay in re-icing cars. At one time the railroad tried to get power to cool refrigerator cars by running a belt off the axle. This was not practical, because when the car stopped there was no power to keep up refrigeration." (Wichita Evening-Eagle, November 21, 1951)

(These 30 cars were delivered in March 1953.)

January 1952
"Fruit Growers Express had been not only testing, but creating a sizable fleet of mechanical cars. Already in January 1952, they had 175 cars, with a variety of mechanical equipment. Several refrigerator car-owning companies, including PFE, assigned engineering people to be stationed at the FGE shops (with FGE permission, of course), to observe developments and learn. Santa Fe, however, did not participate, and in later years, often chose mechanical features that no other reefer company used." (Tony Thompson, June 2022)

January 1953
"With construction of Class R-70-7 barely underway, PFE began work on a follow-up 100-car class, Class R-70-8. They began car construction during 1953, but design modifications and slow delivery of refrigeration equipment pushed back completion of the first cars to March 1954. Though the class was entirely designed by PFE, it shared a number of mechanical approaches with the FGE cars." (Tony Thompson, June 2022)

March 1953
"In March 1953, the first SFRD mechanical reefer class, Class RR-54, began to be built, in the amount of 30 cars. These introduced the familiar blue door paint, with the initials MTC, for "mechanical temperature control." (Tony Thompson, June 2022)

Research suggests that the following were operators of mechanical refrigerator cars, all beginning in 1953:

• Fruit Growers Express (Eastern roads)
• Pacific Fruit Express (UP/SP)
• Santa Fe Refrigerator Despatch (AT&SF)
• Western Fruit Express (GN)
• Merchants Despatch (NYC) (beginning in 1956)

PFE's first mechanical cars were class R-70-7. In 1955, the earlier R-70-5 ice cars were rebuilt as mechanicals. Classes R-70-8, R-70-9 and R-70-10 followed on quickly. In 1957 PFE added 40' cars in the classes R-40-29, R-40-30 and R-50-6, all prior to 1960.

"In 1953 Pacific Fruit Express built 25 mechanical refrigerator cars on a more or less experimental basis. This company has continued its participation in research work for the improvement of mechanical refrigeration." (Railway Age, April 18, 1955, Volume 138, Number 16)

New cars for Western Fruit Express in June, 1953, contained six inches of insulation in the floor, six inches of insulation in the sides and nine inches in the roof. This more efficient insulation lowered the operating costs of the refrigeration itself by lowering the amount of fuel necessary to maintain the needed lower temperatures. Although it was still significant, space within the car body itself used by the mechanical equipment and the additional space required for the additional insulation, was still less than the space used by the ice bunkers at each end. The first mechanical refrigerator cars had about 20 percent more revenue space than their ice-cooled counterparts, and they were lighter, too. A 50-foot mechanical refrigerator car equipped with a Frigidaire system, fully serviced, was 7-1/2 tons lighter than a 50-foot ice bunker car serviced with crushed ice and 30 percent salt. A similar comparison of 40-foot cars showed a 5-ton advantage for the mechanical car.

The following comes from Ice and Refrigeration magazine, October 1953.

As mentioned above, Trane would combine a Hercules (engine), an Onan (generator), and a Louis Allis (electric motor), along with its own refrigeration compressor to create a functional system. Onan supplied the generators, while Louis Allis supplied the electric motors.

An article in the July 30, 1954 issue of the Norfolk Virginian-Pilot newspaper detailed the railroad industry's transition from ice-cooled to mechanical refrigerator cars, driven by competition from trucks that haul over half of all frozen foods. Rail revenue from this traffic was $25 million, or 6 percent of all perishable hauling income. A key quality factor is that mechanical units can maintain subzero temperatures necessary for frozen foods, unlike ice cars limited to 15 degrees F.

1955
"When present car-building programs are completed, there will be over 1,100 mechanical refrigerator cars in frozen-food service, predominantly in citrus concentrate service." (Railway Age, April 18, 1955, Volume 138, Number 16) (Plus a five-page "Special Report" article about mechanical refrigeration.)

1957 Mechanical Refrigerator Cars

(compiled by Bob Chaparo)

Marking	Total	Percent
FGEX	878	36.4%	Fruit Growers Express
PFE	700	29 0%	Pacific Fruit Express
WFEX	250	10.4%	Western Fruit Express (managed by FGE)
SFRD	219	9.1%	Santa Fe Refrigerator Despatch
NPMX	150	6.2%	Merchants Despatch Transportation
BREX	90	3.7%	Burlington Refrigerator Express (managed by FGE)
NYMX	50	2.1%	Merchants Despatch Transportation
URTX	40	1.7%	Union Refrigerator Transit (GATC)
NWX	34	1.4%	North Western Refrigerator Line (NAC)
Total	2,411	100.0%

1959
"In recent testimony in the Western Pacific control case, rail shipments of fresh fruits and vegetables from California declined 19 percent between 1949 and 1959. Outbound truck shipments of fresh fruits and vegetables more than tripled over the period. The most striking growth occurred in the volume of shipments destined outside the 11 western states, and in 1959 47 percent of the total was destined for the Midwest. Testimony also showed outbound truck shipments totaling 96,004 carload equivalents in 1959." (Railway Age, October 23, 1961)

The Refrigerator Car Fleet (1966)

(1966 report summarized from nationwide syndicated Herald Tribune News Service)

At the start of 1966, Atchison, Topeka & Santa Fe Railway on January 1, 1966 owned 13,137 reefers, or about 30 per cent of the Class I railroad total.

Pacific Fruit Express Co., jointly owned by Union Pacific Railroad and Southern Pacific Co., was the largest single operator of equipment in the food trade. At the start of 1966 the company had 20,852 refrigerated freight cars of all types, 2,039 refrigerated trailers, 17 containers, and 998 flat cars for the piggyback movement of the trailers. The company bought 1,704 reefers, 1,000 trailers and 500 flat cars last year. Plans for 1966 called for the addition of 1,798 rail cars, 500 trailers, 250 flat cars and 33 insulated containers.

The Pacific Fruit Express operation in 1965 originated 228,642 carloads of foodstuffs, mostly fresh and frozen perishables from the Pacific Coast and the Southwest producing areas.

Covering much of the rest of the country are the combined fleets of Fruit Growers Express, owned by 18 railroads, Western Fruit Express, controlled by Great Northern Railway, and Burlington Refrigerator Express. The fleets of these companies were operated under single management and with interchange of cars between regions as seasonal demands required. The combined fleet consisted of 23,267 refrigerator cars and 2,571 trailers. The group had 2,571 rail cars and 437 trailers on order.

Atlantic Coast Line Railroad, a major owner of Fruit Growers Express, reported that Fruit Growers Express moved 56,271 refrigerator carloads and 12,290 piggyback trailer-loads of perishables out of Florida.

The cars frequently moved in large blocks or even in solid trainloads. With ice-bunker cars, because of the lingering moisture from melted ice, the cars frequently returned empty with return loads of other kinds of freight often difficult or impossible to obtain. Mechanical refrigeration leaves the cars in condition for dry shipments in return.

Modernization Needed (1980)

Development of mechanical refrigerator cars stalled in the late 1950s and throughout the 1960s. By the 1980s, shippers were becoming more vocal about the need for an up-to-date fleet of refrigerator cars. New designs and technologies were soon being developed.

John H. White reported that by 1981, the entire nationwide fleet of railroad-owned mechanical refrigerator cars had declined to just 1,400 cars, plus a few railroad-owned containers. Mass produced highway trailers and containers were cheap when compared to small volume production railroad refrigerator cars, with the cost of a new railroad mechanical refrigerator car being well over $100,000 each; money that the railroads wanted to spend elsewhere.

An early example was the development of the cryogenic refrigerator car, which used a concept known as CO2 "snow-on-lading." During testing, ten tons of this CO2 "snow" were applied to a load of frozen food, reaching a temperature of -85 degrees F. This success led to the formation of the American Frozen Food Cryogenic Association for Railcar Research (AFFCAR), and three prototype test cars being in service by late 1984. These reefers underwent rigorous testing with various types of cargo during transcontinental trips, with crews monitoring them every few hours. The trials were an unqualified success.

Cryo-Trans was the leader in the development of the cryogenic CO2 car, and of the newer larger cubic capacity cars, bringing new attention to refrigerator car technology. Between 1986 and 1996, a total of 616 cryogenic cars were either rebuilt from older mechanical cars, or delivered new. The newer Cryogenic cars were the first to be longer and wider, increasing the capacity of the new designs, making shippers and railroads aware of the advantages of the larger size. Unfortunately for the cryogenic cars, the price of CO2 began climbing to uneconomical levels. But the super-insulated larger cars had everyone's attention. (By the middle of the 2000-2010 decade, all of the Cryo-Trans CO2 cars had either been retired and rebuilt with trailer-type, front mounted refrigerator units.)

(Read more about Cryo-Trans and the cryogenic refrigerator cars of the late 1980s and throughout the 1990s)

Subsequent technological progress into the late 1990s had resulted in the creation of highly compact refrigeration systems designed for mounting on highway trailers and shipping containers. Because these modern units offered superior efficiency and cooling capacity compared to early diesel models, a significant number of older mechanical reefers were retrofitted with this "truck-style" hardware. Today, the cutting edge of this technology is represented by large Plate F (longer and wider) refrigerator cars with much higher cubic capacity. These modern "hi-cube" cars utilize end-mounted truck-type units and are primarily operated by major carriers like BNSF Railway and Union Pacific Railroad (ARMN), alongside various private owners and leasing firms that include Lineage (LINX) and J. R. Simplot (JRSX).

From the standpoint of the railroad companies, refrigerators cars presented two major issues. First, perishable goods like meat, produce, and frozen food are typically a light cargo compared to the typical loads carried in many standard boxcars. Second, the ice bunkers or mechanical refrigeration units occupied a significant amount of space. The need for space was further increased by the fact that a wooden or steel car requires significant insulation for effective refrigeration. Consequently, while a typical boxcar from the 1940s offered 3,800 cubic feet of capacity, a refrigerator car (with insulation) provided only 2,000 cubic feet. This helps explain why mechanical reefers were built to 57 feet in length, whereas the standard boxcar remained at 50 feet. Even with that extra length, the boxcar usually had 5,000 cubic feet of capacity, compared to the reefer's roughly 4,000 cubic feet.

The super-insulated larger cars also found favor with shippers needing protection only, with no need for refrigeration. All of the operators have added fleets of these insulated boxcars, to provide this protection-only service.

The Mechanical Operators (1950s)

AT&SF

The first group of revenue-service mechanical refrigerator cars for the AT&SF was a class of 30 cars, designated Class Rr-54, built in March 1953. These cars, numbered 1220–1249 (later renumbered to 3150–3179 in May 1953), were the railroad's first production-series mechanical reefers and introduced the blue-door "MTC" (Mechanical Temperature Control) markings.

The reporting mark for Santa Fe Refrigerator Despatch cars remained as SFRD until 1953 when new fourth letter suffixes were changed to be more descriptive: SFRC was used for Mechanical Refrigerator cars equipped with load dividers; SFRM was used for Mechanical Refrigerator cars equipped with meat rails, and SFRP was used for Mechanical Refrigerator cars without load dividers (these SFRP cars were relettered from SFRD cars in 1963).

"The Santa Fe and Fruit Growers Express were both pioneers in the development of the mechanical refrigerator car. The Santa Fe shops at West Wichita built one of the first operating mechanical cars in May 1949 from an old 1926 vintage Pullman built wood ice car. A Trane Mechanical Refrigeration unit was installed in this experimental car numbered No. 12000. [Railway Age, September 7, 1953, p. 93-96] The car was supplied passenger car trucks and carried steam lines for passenger train service. The testing of this car led to the building of 30 mechanical cars at the Santa Fe’s West Wichita shops in 1953. The cars carried roller-bearing trucks, and all future mechanical cars would be so equipped." (The Great Yellow Fleet, A History of American Railroad Refrigerator Cars, by John H. White, Golden West Books, 1986)

"The new fleet of mechanical cars were equipped with roller-bearing trucks, side wall racks, sliding doors, metal floor racks and strap anchors, and became the most modern means of transporting frozen and perishable products. By March of 1970 the Santa Fe had 3,614 mechanical and 5,124 ice refrigerator cars on its roster. The count of ice cars on the roster was down to 190 units by late 1972." (The Great Yellow Fleet, A History of American Railroad Refrigerator Cars, by John H. White, Golden West Books, 1986)

After Santa Fe got rid of the last of their refrigerators cars in the early 1980s, they soon found that shippers were still requesting refrigerators cars. So they leased some FGE cars to cover the demand.

(Read more about the mechanical refrigerator cars of the Santa Fe)

American Refrigerator Transit Co. (ART)

American Refrigerator Transit Co. (ART, various) was a leaser and lease fleet operator of refrigerator cars. It was formed in 1881 as a partnership between the Missouri Pacific and Wabash (and later the N&W) railroads to provide refrigerator cars and insulated box cars (and some covered hoppers as well) to the respective railroads.

American Refrigerator Transit was among America's operators of refrigerator cars, including over 9,000 ice-cooled cars. The company was founded by Jay Gould in 1881 to serve all his railroads of that day, including the Wabash, Missouri Kansas and Texas, and particularly Missouri Pacific and subsidiaries. After 1925, Denver & Rio Grande Western was added. Primary business in the early years was meat transportation, but this gradually shifted to perishables, particularly from Texas and Colorado.

ART was jointly owned by Missouri Pacific (71 percent) and Wabash (29 percent).

Change came in 1964 when Norfolk & Western took over Wabash. In 1969, D&RGW moved its perishable business from ART to Fruit Growers Express. In 1973, Norfolk & Western pulled out of ART, and with the acquisition of Missouri Pacific by Union Pacific in 1983, all remaining ART properties were taken over by Union Pacific. Today's ARMN is UP's version of the old ART company.

The 1959 ORER lists only 75 cars in the RMAX 100-499 series, and five cars in the ART 300-304 series; listed as RP Mechanical Refrigerator designation. The greatest numbers of ART refrigerator cars were ice-cooled cars, a total of 9,913, not counting these 80 RP mechanical cars.

The 1960 ORER lists 585 cars in the RMAX, RMDX and MART reporting marks; listed as RP Mechanical Refrigerator designation:

• RMAX 100-324 (125 cars)
• RMDX 325-464, 500-700 (376 cars)
• MART 67000-67999 (series; 13 cars)
• MART 68000-68999 (series; 11 cars)

(Later ORER issues not available at this time.)

A later undated list of the total ART Mechanical Fleet:

RMAX 100-174	75 cars	44' Refrigerator; mechanical	-----
RMAX 175-324	150 cars	45' Refrigerator; mechanical	PC&F; 6/1960
RMBX 9000-9009	10 cars	45' Refrigerator; mechanical	-----
RMDX 325-464	140 cars	45' Refrigerator; mechanical	-----
RMDX 500-599	100 cars	50' Refrigerator; mechanical	-----
RMDX 600-700	101 cars	50' Refrigerator; mechanical	PC&F; 1964
RMDX 701-775	75 cars	50' Refrigerator; mechanical	PC&F; 5/1965
RMDX 776-850	75 cars	50' Refrigerator; mechanical	PC&F; 3/1965
RMDX 851-1050	200 cars	50' Refrigerator; mechanical	PC&F; 1967-1968
Total	926 cars

(Read the Wikipedia article about American Refrigerator Transit)

ART Book:

American Refrigerator Transit Company, by Stuart T. Maher, G.J. Michels, Jr., and Gene Semon (Hardcover; ISBN 10: 193001337X ISBN 13: 9781930013377; Publisher: Signature Press, 2018)

Burlington Refrigerator Express (BRE)

Burlington Refrigerator Express (BREX)

During the period 1926 to 1976, the refrigerator cars of Burlington Refrigerator Express, although owned as a subsidiary of Chicago, Burlington & Quincy, were managed by Fruit Grower Express, a consortium of eastern railroads. The mechanical refrigerator cars of Western Fruit Express were built FGE in their shops in Virginia, Florida and Indiana.

Changes came after the 1970 merger of GN, NP, CB&Q and SP&S that created Burlington Northern.

(Read more about Burlington Refrigerator Express, as part of the later Burlington Northern)

Fruit Growers Express (FGE)

(Read more about Fruit Growers Express)

Merchants Despatch Transportation Co. (MDT)

MDT's story is one of repeated reinvention: from a Vanderbilt-controlled fast freight line, to a dominant refrigerated car operator and builder, to a post-war survivor facing industry decline, and finally to a lean service provider that outlasted its parent railroads. While its iconic white fleets are gone, the corporation itself survives today, proving that adaptability matters more than sheer size.

In the post World War II era, MDT deliberately turned away from mechanical refrigeration, viewing it as a declining business. Instead, it invested in auto rack cars and Flexivan containers, and ultimately transformed into a service provider that survives to this day — a unique case of adaptation in the face of technological change.

(Read more about Merchants Despatch Transportation Co.)

Pacific Fruit Express (PFE and UPFE)

Pacific Fruit Express was formed on December 7, 1906, as a joint UP/SP company to operate refrigerator cars. The company grew to become the largest railroad refrigerator car company in the nation.

Union Pacific (UP) and Southern Pacific (SP) officially split the assets of their joint Pacific Fruit Express (PFE) venture on April 1, 1978, dissolving the partnership and dividing the remaining refrigerated cars between the two railroads, with SP retaining the PFE name for its portion.

(Read more about PFE before 1978)

(Read more about UPFE after 1978)

Western Fruit Express (WFE)

Western Fruit Express (WFEX)

During the period 1923 to 1976, the refrigerator cars of Western Fruit Express, although owned as a subsidiary of Great Northern, were managed by Fruit Grower Express, a consortium of eastern railroads. The mechanical refrigerator cars of Western Fruit Express were built FGE in their shops in Virginia, Florida and Indiana.

Changes came after the 1970 merger of GN, NP, CB&Q and SP&S that created Burlington Northern.

(Read more about Western Fruit Express, as part of the later Burlington Northern)

Mechanical Refrigerator Cars in 1952-1954

The following five tables showing the mechanical refrigerator car fleet in 1952-1954.

("The Post War Refrigerator Car, A Brief History: Pt. III," by Dave and Jennie Lambert, Railroad Model Craftsman, May 1994.)

Table 10: Mechanical Refrigerator Cars as of October 1, 1952

Ownership	Description	Status
Fruit Growers Express	50 Frigidaire 50-ft.	On order
Western Fruit Express	10 Frigidaire 40-ft.	Under construction
Western Fruit Express	50 Frigidaire 50-ft.	On order
AT&SF Railway	10 Trane equipped	Under construction
AT&SF Railway	10 Carrier equipped	Under construction
AT&SF Railway	10 Frigidaire equipped	Under construction
Pacific Fruit Express	14 Frigidaire equipped	On order
Pacific Fruit Express	11 Trane equipped	On order
Canadian National	1 Frigidaire 40-ft.	Completed 7/1952
Mather Stock Car Co.	25 Thermo-King 40-ft.	1 Built; 24 on order
Total: 191

(The first run of the Morrell MRRX 2500 in May 1952 was covered in Ice and Refrigeration magazine, August 1952, with photos and a diagram of the car.)

Table 11: Mechanical Refrigeration Cars in service as of April 15, 1953

Ownership	Description	Marks
Fruit Growers Express	102 Frigidaire 50-ft.	FGEX 205,209-249,340-399
Fruit Growers Express	52 Frigidaire 40-ft.	FGEX 115,116,150-199
Fruit Growers Express	11 Thermo-King 40-ft.	FHIX
Western Fruit Express	10 Frigidaire 40-ft.	WFEX 890-899
Canadian National	1 Frigidaire 40-ft.	CN?
Canadian Pacific	1 Trane 40-ft.	CP 282400
Mather Stock Car for John Morrell & Co	5 Thermo-King 40-ft.	MRRX 2500-2504
Boston & Maine for Bellows Falls Creamery	11 Thermo-King 50-ft.	B&M 1700-1724
Total: 193

Table 12: Mechanical Refrigeration Cars on order as of April 15, 1953

Ownership	Description	Marks
Fruit Growers Express	152 Frigidaire 50-ft.	FGEX 207, 208-250-299, 1000-1099
Western Fruit Express	50 Frigidaire 50 ft.	WFEX 800-849
Burlington Refrigerated Express	30 Frigidaire 50-ft.	BREX 120-149
AT&SF Railway	30 Frigidaire 50-ft.	SFRD 3150-3179
Pacific Fruit Express	114 Frigidaire 50-ft. 11 Trane 50-ft.	PFE 300001-300125
Mather Stock Car for John Morrell & Co.	20 Thermo-King 40-ft.	MRRX 2505-2524
Total: 407

Table 13: Mechanical refrigeration cars in service as of April 15, 1954

Ownership	Description	Marks
Fruit Growers Express	254 Frigidaire 50-ft.	FGEX 205, 207, 208-299, 340-399, 1000-1099
Fruit Growers Express	52 Frigidaire 40-ft.	FGEX 115, 116 150-199
Fruit Growers Express	1 Thermo-King 40-ft.	FHIX 41127
Western Fruit Express	100 Frigidaire 50 ft.	WFEX 800-849, 8000-8049
Western Fruit Express	10 Frigidaire 40-ft.	WFEX 890-899
Burlington Refrigerated Express	30 Frigidaire 50-ft.	BREX 120-149
AT&SF Railway	30 Frigidaire 50-ft.	SFRD 3150-3179
Pacific Fruit Express	114 Frigidaire 50-ft.	PFE 300001-300125
Pacific Fruit Express	11 Trane 50-ft.	PFE 300001-300125
Canadian National	1 Frigidaire 40-ft.	CN?
Canadian Pacific	1 Trane 40-ft.	CP 282400
Mather Stock Car for John Morrell & Co.	25 Thermo-King 40-ft.	MRRX 2500-2524
Boston & Maine for Bellows Falls Creamery	11 Thermo-King 50-ft.	B&M 1700-1724
North Western Refrigerator Line	1 Dole Cold Plate 40-ft.	NWX 100-199
Total: 641
Note: In some cases, not all reporting marks set aside in a series were used.

Table 14: Mechanical refrigeration cars on order as of April 15, 1954

Ownership	Description	Marks
Fruit Growers Express	100 Frigidaire 50-ft.	FGEX 1100,1199
Fruit Growers Express	10 Thermo-King 40-ft.	FHIX (?) ?
Western Fruit Express	50 Frigidaire 50 ft.	WFEX 8050-8099
Merchants Despatch Transportation Co. for Northern Pacific Railway	50 Frigidaire 50-ft.	NPMX 100-149
Pacific Fruit Express	162 Frigidaire 50-ft.*	PFE 300126-300337
Pacific Fruit Express	50 Carrier 50-ft.	PFE 300126-300337
General American Transportation Co. for Swift & Co.	1 Frigidaire 40-ft.	SRLX 900-925
General American Transportation Co. for Swift & Co.	1 Thermo-King 40-ft.	SRLX 926-999
Total: 424
*Includes twelve cars to be converted from overhead bunker configuration, PFE 300126-300137.
Note: In some cases, not all reporting marks set aside in a series were used.

(Various issues of Food Engineering magazine in 1952-1953 reported that the John Morrell cars were built and owned by Mather Stock Car under their MRRX reporting mark. The John Morrell company contracted with Thermo King Railway Corp. to maintain the gasoline-fueled refrigeration units at Sioux Falls, Iowa. Mather became part of North American Car Company in 1955, and the MRRX 2500-2524 remained as part of North American fleet, marked specifically as meat refrigerator cars.)

Mechanical Refrigeration Technology

Mechanical refrigeration of the late 1940s and early 1950s required two basic components of the refrigeration unit: a refrigeration compressor, and an engine fueled by diesel or gasoline to drive the compressor. Some were direct-drive between the engine and the compressor. Others were electro-mechanical, with the engine driving a generator to create the electricity which in-turn was used to drive an electric mother that drove the compressor. Each rail car also had a fuel tank for the engine. The engine was connected directly to the compressor, and the two were usually mounted to a common platform, or a skid to allow easy maintenance, removal and replacement. These common platforms were at time called generator sets, or gensets.

From the time of early adoption in the late 1940s and early 1950s, through to the last car built in 1971-1972, the basic technology did not change. There were regular upgrades and rebuilding programs to modernize the fleets with better engines and better refrigeration compressors, but the concept did not change.

Then in the early 1990s, there was a move to adopt the well-established designs used in the trucking industry, which mounted a smaller and more efficient refrigeration unit (engine and compressor) to the front wall of highway trailers. The operators of large mechanical railroad refrigerator cars began limited rebuild programs to remove the older inefficient refrigerator units from the 1950s-1970s, and replace them with the modern trailer-style front-mount designs.

(Read more about the technology of mechanical refrigeration)

The New Operators (1990s)

BNSF

BNFE is the reporting mark used by BN (and later BNSF) for its refrigerator cars.

(Read more about the mechanical refrigerator cars of BN, BNSF, and the cars that use the BNFE reporting mark)

ARMN (UP)

The ARMN refrigerator car fleet is a relatively new designation on Union Pacific after 2000. The ARMN reporting mark is a historical reporting mark from Missouri Pacific before its merger with UP in 1983. Union Pacific resurrected the ARMN reporting mark for use on its rebuilt refrigerator cars, upgraded from the older inefficient diesel-electric generator refrigeration units, to the modern truck-type front-mount refrigeration units. This rebuild program was active from 1989 to 1999, at which time UP began planning its purchase of modern Plate F super-insulated cars to match those being delivered to BNSF and a few shippers. UP was playing catch-up as its new cars were being delivered beginning in 2003, using the reactivated ARMN reporting mark.

(Read more about ARMN)

March 7, 2008
"Since 2003, Union Pacific has purchased 1,500 64-foot cars and completed an extensive upgrade of more than 3,500 of its 50-foot cars. Union Pacific handles more than 48,000 shipments of refrigerated and frozen products each year and is the country's largest owner of refrigerated rail cars with more than 5,000 refrigerated cars in the current fleet. The new reefers can carry more than 50 percent more product than their predecessors. A 64-foot rail car carries as much as four over-the-road trailers. The refrigeration units used in both new and refurbished cars are state-of-the-art and energy efficient. They use the latest technology, such as global positioning satellite (GPS) monitoring, not only to track rail cars' trip progress but also to check temperature, fresh-air exchange and diagnostics. Fresh-air exchange is an important feature for commodities such as onions that require fresh-air circulation. Temperature variance with the new units is as little as plus/minus two degrees." (Union Pacific press release dated March 7, 2008)

J. R. Simplot (JRSX)

Simplot was one of the first shippers to adopt the cryogenic normal Plate C cars and the later Plate F longer and wider modern refrigerator cars.

(Read more about the J. R. Simplot cryogenic cars)

When the cryogenic concept became too expensive, Simplot was also among the first to have Plate F cars with trailer-style front-mounted refrigeration units.

JRSX 7000-7249 (250 cars), built in July-November 2020 by Trinity, are R660 RP refrigerator cars with 7711 cu. ft. and 72-foot-3-inch IL, and are very similar (if not identical) to the Greenbrier-Gunderson mechanical refrigeration cars built for CRYX and LINX.

AAR Car Data

(Read more about AAR Plate Clearances -- (Plate C, Plate F, etc.)

(Read more about AAR Mechanical Designation codes (RB, RP, XLI, XPI, etc.) and Equipment Type codes (A616, R660, etc.) -- Codes for insulated boxcars and refrigerators cars.

Refrigerator Cars in 2012

From Surface Transportation Board 2012 Reports for BNSF and UP:

	BNSF	UP	Total
Mechanical Refrigerator Cars (RP)	994	4,908	5,902
Insulated Boxcars (RB or XP)	2,117	1,793	3,910
Total	3,111	6,701	9,812

Neither BNSF nor UP had any cryogenic cars. And by 2012, most of the cryogenic cars of Cryo-Trans and other operators had been retired. Cryogenic refrigerator cars appeared to be all but extinct, for whatever reason. Even the Cryo-Trans roster was comprised almost exclusively of mechanical cars (some converted from cryogenic cars).

UP has at least 1700 of the newer hi-cube mechanical reefers (which carry nearly twice as much in volume as the old ones): Series 110000-111499, and the recently-purchased 170000-170224.

"Insulated boxcar" is a generic term, since any boxcar without a refrigeration unit gets lumped into the same description. In fact, some are formally classed as an RP refrigerator car without a refrigeration unit.

There are Trinity Leasing (TILX) mechanical refrigerator cars that began life as BNSF and UPFE cars.

By 2013, there had been and continued to be a shortage of refrigerator cars. ARMN 110000-series and 90000 series were hard to get in peak season. The only reliable supply was the ARMN 70000 series cars, which were old retrofitted PFE cars.

Rail-Served Cold Storage Today

A comprehensive report in September 2024 of the Real Estate Investment Trusts (REIT) that had entered the cold storage business sector, found that cold storage was an essential business, with high barriers to entry and strong growth potential.

The report focused on the two main public players (Lineage and Americold), with the following brief points.

• Lineage Logistics: The report highlighted Lineage as a dominant force and a primary driver in the sector:
• The report noted Lineage's 2024 IPO as the largest of the year and the largest REIT IPO in history, raising approximately $5 billion.
• In 2024 Lineage held a 30 percent market share in North America, making it the largest operator.

The report found that Lineage was more focused on "last mile" facilities (close to population centers) compared to its competitors. Because of this strategically located real estate, Lineage had a higher value than its competitor, Americold.

• Lineage had been successful at the consolidation of a fragmented market, having acquired several of the top 10 companies that existed in 2019.
• While MHW Group and Cryo-Trans were not mentioned by name in the report, they were intrinsically linked to results based on their acquisition as part of the overall consolidation by Lineage.
• Lineage Logistics acquired MHW Group (and its subsidiary Cryo-Trans, the largest owner of refrigerated rail cars in North America) in early 2021.

The report emphasized the importance of transportation and rail links in the cold chain. It specifically mentioned a strategic partnership between Americold and CPKC Rail to move frozen products between Mexico and the US, with CPKC Rail being Canadian Pacific Kansas City Rail, a Class I railroad formed on April 14, 2023, by the merger of two historic companies: Canadian Pacific (CP) and Kansas City Southern (KCS).

Lineage's ownership of Cryo-Trans was found to be the real-world result of the overall consolidation taking place in the cold storage industry. By owning the rail assets (Cryo-Trans) formerly under MHW Group, Lineage fulfills the report's description of a "sophisticated operator" providing transportation and associated services to create a seamless, end-to-end cold chain.

(Link to the report)

 

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