Refrigerator car

History

Background: North America

After the end of the American Civil War, Chicago, Illinois emerged as a major railway center for the distribution of livestock raised on the Great Plains to Eastern markets. Transporting the animals to market from ranches in Texas required herds to be driven up to 1,200 miles (1,900 km) to railheads in Kansas City, Missouri or later to more westerly locations, such as Abilene, Kansas (1867, Kansas Pacific Railway) and Dodge City, Kansas (1872, Santa Fe Railroad), where they were loaded into specialized stock cars and transported live ("on-the-hoof") to regional processing centers. Driving cattle across the plains also caused tremendous weight loss, with some animals dying in transit.

Upon arrival at the local processing facility, livestock were slaughtered by wholesalers and delivered fresh to nearby butcher shops for retail sale, smoked, or packed for shipment in barrels of salt. Costly inefficiencies were inherent in transporting live animals by rail, particularly the fact that approximately 60% of the animal's mass is inedible. The death of animals weakened by the long drive further increased the per-unit shipping cost. Meat processors sought a method to ship dressed meats from their Chicago packing plants to eastern markets.

Early attempts at refrigerated transport

During the mid-19th century, attempts were made to ship agricultural products by rail. As early as 1842, the Western Railroad of Massachusetts was reported in the June 15 edition of the Boston Traveler to be experimenting with innovative freight car designs capable of carrying all types of perishable goods without spoilage. The first refrigerated boxcar entered service in June 1851, on the Northern Railroad (New York) (or NRNY, which later became part of the Rutland Railroad). This "icebox on wheels" was a limited success since it was only functional in cold weather. That same year, the Ogdensburg and Lake Champlain Railroad (O&LC) began shipping butter to Boston in purpose-built freight cars, using ice for cooling.

Meat

The first consignment of dressed beef left the Chicago stock yards in 1857 in ordinary boxcars retrofitted with bins filled with ice. Placing meat directly against ice resulted in discoloration and affected the taste, proving to be impractical. During the same period Gustavus Swift experimented by moving cut meat using a string of ten boxcars with their doors removed, and made a few test shipments to New York during the winter months over the Grand Trunk Railway (GTR). The method proved too limited to be practical.

Detroit's William Davis patented a refrigerator car that employed metal racks to suspend the carcasses above a frozen mixture of ice and salt. In 1868, he sold the design to George H. Hammond, a Detroit meat packer, who built a set of cars to transport his products to Boston using ice from the Great Lakes for cooling. The load had the tendency of swinging to one side when the car entered a curve at high speed, and use of the units was discontinued after several derailments. In 1878 Swift hired engineer Andrew Chase to design a ventilated car that was well insulated, and positioned the ice in a compartment at the top of the car, allowing the chilled air to flow naturally downward. The meat was packed tightly at the bottom of the car to keep the center of gravity low and to prevent the cargo from shifting. Chase's design proved to be a practical solution, providing temperature-controlled carriage of dressed meats. This allowed Swift and Company to ship their products across the United States and internationally.

Swift's attempts to sell Chase's design to major railroads were rebuffed, as the companies feared that they would jeopardize their considerable investments in stock cars, animal pens, and feedlots if refrigerated meat transport gained wide acceptance. In response, Swift financed the initial production run on his own, then — when the American roads refused his business — he contracted with the GTR (a railroad that derived little income from transporting live cattle) to haul the cars into Michigan and then eastward through Canada. In 1880 the Peninsular Car Company (subsequently purchased by ACF) delivered the first of these units to Swift, and the Swift Refrigerator Line (SRL) was created. Within a year, the Line's roster had risen to nearly 200 units, and Swift was transporting an average of 3,000 carcasses a week to Boston, Massachusetts. Competing firms such as Armour and Company quickly followed suit. By 1920, the SRL owned and operated 7,000 of the ice-cooled rail cars. The General American Transportation Corporation would assume ownership of the line in 1930.

Live cattle and dressed beef deliveries to New York (short tons):

The subject cars travelled on the Erie, Lackawanna, New York Central, and Pennsylvania railroads.

Source: Railway Review, January 29, 1887, p. 62.

19th Century American Refrigerator Cars:

Source: Poor's Manual of Railroads and ICC and U.S. Census reports.

Fruit and fresh produce

In the 1870s, the lack of a practical means to refrigerate peaches limited the markets open to Samuel Rumph, a Georgia peach grower. In 1875, he invented a refrigerated railcar and crates that allowed him to grow peaches on a very large scale and ship them to distant markets. He was the first to achieve this. His innovations created Georgia's fame for peaches, a crop now eclipsed economically by blueberries.

Edwin Tobias Earl was born on a fruit ranch near Red Bluff, California on May 30, 1858. His father was Joseph Earl, his mother Adelia Chaffee, and his brother was Guy Chaffee Earl. He started his career in the shipping of fruits. By 1886, he was President of the Earl Fruit Company. In 1890, he invented the refrigerator car to transport fruits to the East Coast of the United States. He established the Continental Fruit Express and invested US$2,000,000 in refrigerator cars. In 1901, he sold his refrigerator cars to Armour and Company of Chicago and became a millionaire.

By the turn of the 20th century, manufactured ice became more common. The Pacific Fruit Express (PFE) - a joint venture between the Union Pacific and Southern Pacific railroads, with a fleet of 6,600 refrigerator cars built by the American Car and Foundry Company (ACF) - maintained seven natural harvesting facilities, and operated 18 artificial ice plants. Their largest plant (located in Roseville, California) produced 1,200 short tons (1,100 t) of ice daily, and Roseville's docks could accommodate up to 254 cars. At the industry's peak, 1,300,000 short tons (1,200,000 t) of ice was produced for refrigerator car use annually.

On the east coast of the United States, in 1920 the company Fruit Growers Express (FGE) was established and owned by a consortium of eastern railroads to serve the wholesale market for refrigerated produce delivered by railcar. In addition to operating and servicing refrigerated railcars, FGE became a major manufacturer of insulated boxcars and mechanical refrigerated cars.

Ice

The use of ice to refrigerate and preserve food dates back to prehistoric times. Through the ages, the seasonal harvesting of snow and ice was a regular practice of many cultures. China, Greece, and Rome stored ice and snow in caves, dugouts or ice houses lined with straw or other insulating materials. Rationing of the ice allowed the preservation of foods during hot periods, a practice that was successfully employed for centuries. For most of the 19th century, natural ice (harvested from ponds and lakes) was used to supply refrigerator cars. At high altitudes or northern latitudes, one foot tanks were often filled with water and allowed to freeze. Ice was typically cut into blocks during the winter and stored in insulated warehouses for later use, with sawdust and hay packed around the ice blocks to provide additional insulation. A late-19th century wood-bodied reefer required re-icing every 250 miles (400 km) to 400 miles (640 km).

Top icing is the practice of placing a 2-inch (51 mm) to 4-inch (100 mm) layer of crushed ice on top of agricultural products that have high respiration rates, need high relative humidity, and benefit from having the cooling agent sit directly atop the load (or within individual boxes). Cars with pre-cooled fresh produce were top iced just before shipment. Top icing added considerable dead weight to the load. Top-icing a 40-foot (12 m) reefer required in excess of 10,000 pounds (4,500 kg) of ice. It had been postulated that as the ice melts, the resulting chilled water would trickle down through the load to continue the cooling process. It was found, however, that top-icing only benefited the uppermost layers of the cargo, and that the water from the melting ice often passed through spaces between the cartons and pallets with little or no cooling effect. It was ultimately determined that top-icing is useful only in preventing an increase in temperature, and was eventually discontinued.

The typical service cycle for an ice-cooled produce reefer (generally handled as a part of a block of cars):

1. The cars were cleaned with hot water or steam.
2. Depending on the cargo, the cars might have undergone four hours of "pre-cooling" prior to loading, which entailed blowing in cold air through one ice hatch and allowing the warmer air to be expelled through the other hatches. The practice, dating back almost to the inception of the refrigerator car, saved ice and resulted in fresher cargo.
3. The cars' ice bunkers were filled, either manually from an icing dock, via mechanical loading equipment, or (in locations where demand for ice was sporadic) using specially designed field icing cars.
4. The cars were delivered to the shipper for loading, and the ice was topped-off.
5. Depending on the cargo and destination, the cars may have been fumigated.
6. The train would depart for the eastern markets.
7. The cars were reiced in transit approximately once a day.
8. Upon reaching their destination, the cars were unloaded.
9. If in demand, the cars would be returned to their point of origin empty. If not in demand, the cars would be cleaned and possibly used for a dry shipment.

Refrigerator cars required effective insulation to protect their contents from temperature extremes. "Hairfelt" derived from compressed cattle hair, sandwiched into the floor and walls of the car, was inexpensive, yet flawed over its three- to four-year service life it would decay, rotting out the car's wooden partitions and tainting the cargo with a foul odor. The higher cost of other materials such as "Linofelt" (woven from flax fibers) or cork prevented their widespread adoption. Synthetic materials such as fiberglass and polystyrene foam, both introduced after World War II, offered the most cost-effective and practical solution.

The United States Office of Defense Transportation implemented mandatory pooling of class RS produce refrigerator cars from 1941 through 1948. World War II experience found the cars spending 60 percent of their time traveling loaded, 30 percent traveling empty, and 10 percent idle; and indicated the average 14 loads each car carried per year included 5 requiring bunker icing, 1 requiring heating, and 8 using ventilation or top icing.

Following experience with assorted car specifications, the United Fresh Fruit and Vegetable Association (UFF&VA) listed what they considered the best features of ice refrigerator cars in 1948:

• Steel cars (vs wood) for better insulation protection and greater rigidity resulting in reduced leakage around doors
• A minimum of 4 inches (10 cm) insulation thickness with all insulation protected from moisture
• Cushioned trucks and draft gear to minimize jarring and bruising of produce
• Standardized interior dimensions to allow improved loading methods with standardized containers
• Adjustable ice bunker bulkheads to allow greater floor space for shippers using top icing alone
• Vertically adjustable grates within the ice bunkers to allow half-stage icing to reduce icing charges where appropriate
• Forced air circulation within the car
• An additional lining to allow side wall flues circulating air around all cargo preventing contact with exterior car walls
• Perforated floor racks providing similar protection and air circulation under the cargo
• Provisions for pre-cooling the cars with a portable unit at the loading platforms.

Mechanical refrigeration

In the latter half of the 20th century, mechanical refrigeration began to replace ice-based systems. Soon after, mechanical refrigeration units replaced the armies of personnel required to re-ice the cars. The sliding plug door was introduced experimentally by P.F.E. (Pacific Fruit Express) in April 1947, when one of their R-40-10 series cars, #42626, was equipped with one. P.F.E.'s R-40-26 series reefers, designed in 1949 and built in 1951, were the first production series cars to be so equipped. In addition, the Santa Fe Railroad first used plug doors on their SFRD RR-47 series cars, which were also built in 1951. This type of door provided a larger six foot opening to facilitate car loading and unloading. These tight-fitting doors were better insulated and could maintain an even temperature inside the car. By the mid-1970s, the few remaining ice bunker cars were relegated to "top-ice" service, where crushed ice was applied atop the commodity.

Cryogenic refrigeration

The Topeka, Kansas shops of the Santa Fe Railway built five experimental refrigerator cars employing liquid nitrogen as the cooling agent in 1965. A mist induced by liquefied nitrogen was released throughout the car if the temperature rose above a pre-determined level. Each car carried 3,000 pounds (1,400 kg) of refrigerant and could maintain a temperature of minus 20 degrees Fahrenheit (−30 °C). During the 1990s, a few railcar manufacturers experimented with the use of liquid carbon dioxide (CO₂) as a cooling agent. The move was in response to rising fuel costs, and was an attempt to eliminate the standard mechanical refrigeration systems that required periodic maintenance. The CO₂ system can keep the cargo frozen solid as long as 14 to 16 days.

Several hundred "cryogenic" refrigerator cars were placed in service transporting frozen foodstuffs, though they failed to gain wide acceptance (due, in part, to the rising cost of liquid carbon dioxide).

Experimentation

Aluminum and stainless steel

Several experimental cars were built when wartime production restrictions were relaxed in 1946:

• Illinois Central Railroad number 51000 was built in the McComb, Mississippi shops with an aluminum superstructure to reduce weight with steel where required for strength and provided the standard dimensions, cushioned draft gear, easy-riding trucks, minimum 4 inches (10 cm) of insulation, adjustable ice bunker bulkheads and half-stage icing racks with forced air circulation through side wall flues and floor racks recommended by UFF&VA.
• Santa Fe Refrigerator Despatch number 13000 was built of stainless steel by the Consolidated Steel Corporation of Wilmington, California with convertible ice bunkers, side ventilation ducts, and axle-driven circulation fans. It was thought that stainless steel would better resist the corrosive deterioration resulting from salting the ice. The one-of-a-kind unit entered service as #13000, but was subsequently redesignated as #1300, and later given #4150 in 1955. The car spent most of its life in express service. Cost was cited as the reason no additional units were ordered. The car was dismantled at Clovis, New Mexico in February 1964.
• Pacific Fruit Express rebuilt two steel-sided ventilator refrigerator cars in their Los Angeles shops with aluminum car bodies to test durability of lightweight alloys versus that of steel. It was hoped that weight savings (the units weighed almost 10,000 lb (4,536 kg) less than a like-sized all-steel car) and better corrosion resistance would offset the higher initial cost. Alcoa provided the body for number 44739, and Reynolds Aluminum Company provided number 45698. The cars (outfitted with state-of-the-art fiberglass insulation and axle-driven fans for internal air circulation) traveled throughout the Southern Pacific and Union Pacific systems, where they were displayed to promote PFE's post-World War II modernization. Though both units remained in service over 15 years (#45698 was destroyed in a wreck in May 1962, while #44739 was scrapped in 1966), no additional aluminum reefers were constructed.
• Fruit Growers Express number 38374 was equipped with an experimental aluminum body in the Indiana Harbor, Indiana shops.

"Depression Baby"

During the 1930s, the North American Car Company produced a one-of-a-kind, four-wheeled ice bunker reefer intended to serve the needs of specialized shippers who did not generate sufficient product to fill a full-sized refrigerator car. NADX #10000 was a 22-foot (6.71 m)-long, all-steel car that resembled the forty-and-eights used in Europe during World War I. The prototype weighed 13.5 short tons (12.2 t; 12.1 long tons) and was outfitted with a 1,500 lb (680 kg) ice bunker at each end. The car was leased to Hormel and saw service between Chicago, Illinois and the southern United States. The concept failed to gain acceptance with eastern railroads and no additional units were built.

Dry ice

The Santa Fe Refrigerator Despatch (SFRD) briefly experimented with dry ice as a cooling agent in 1931. The compound was readily available and seemed like an ideal replacement for frozen water. Dry ice melts at −109 °F or −78.33 °C (versus 32 °F or 0 °C for conventional ice) and was twice as effective thermodynamically. Overall weight was reduced as the need for brine and water was eliminated. While the higher cost of dry ice was certainly a drawback, logistical issues in loading long lines of cars efficiently prevented it from gaining acceptance over conventional ice. Worst of all, it was found that dry ice can adversely affect the color and flavor of certain foods if placed too closely to them.

Hopper cars

In 1969, the Northern Pacific Railroad ordered a number of modified covered hopper cars from American Car and Foundry for transporting perishable food in bulk. The 55-foot (16.76 m)-long cars were blanketed with a layer of insulation, equipped with roof hatches for loading, and had centerflow openings along the bottom for fast discharge. A mechanical refrigeration unit was installed at each end of the car, where sheet metal ducting forced cool air into the cargo compartments.

The units, rated at 100 short tons (91 t; 89 long tons) capacity (more than twice that of the largest conventional refrigerator car of the day) were economical to load and unload, as no secondary packaging was required. Apples, carrots, onions, and potatoes were transported in this manner with moderate success. Oranges, on the other hand, tended to burst under their own weight, even after wooden baffles were installed to better distribute the load. The Santa Fe Railway leased 100 of the hoppers from ACF, and in April 1972 purchased 100 new units, known as "Conditionaire" cars.

The cars' irregular, orange-colored outer surface (though darker than the standard AT&SF yellow-orange used on reefers) tended to collect dirt easily, and proved difficult to clean. Santa Fe eventually relegated the cars to more typical, non-refrigerated applications.

Preservation

Examples of many styles of refrigerator and ice cars can be found at railroad museums around the world.

The Western Pacific Railroad Museum at Portola, California features a very complete roster of 20th century cars, including wood bodied ice cars, steel bodied ice cars, one of the earliest mechanical refrigerator cars, later mechanical refrigerator cars and a cryogenic reefer, as well as several "insulated" boxcars also used for food transport.