The first perishable shipments on America’s railroads were simply loaded into boxcars, packed with ice, and covered in thick layers of straw or sawdust for insulation. These were short hauls and not altogether successful. Perishable traffic did not take off until the introduction of ice bunker refrigerator cars, commonly known as reefers. In the bunkers at each end of the car, combinations of ice blocks up to 300 pounds each, chipped ice, and salt served to cool the perishable load in the center part of the cars. The ice was replenished or topped off multiple times while the car was in transit.
Advances in mechanical refrigeration led to small diesel engines powering mechanical refrigeration units built into the ends of the cars. In the 1950s, mechanical reefers began to rapidly replace ice reefers. Further advances lead the compact mechanical refrigeration units mounted on the ends of truck trailers and containers. Since these were much more efficient and powerful than the old diesel reefer units, many older mechanical reefers were refitted with these “truck” units. The latest development in reefer cars are the large hi-cube reefers with end mounted “truck” units operated by BNSF Railway and Union Pacific Railroad, as well as some leasing companies and private owners.
From the railroad companies perspectives, reefers had two main problems. One was perishables such as meat, produce, and frozen food tend to be a lightweight load when compared to many typical boxcar loads. On the other hand, the ice bunkers or mechanical reefer units took up considerable space. Adding to the demand for space was the fact that a wooden or steel box needs insulation to make the refrigeration work properly. As a result, a typical 1940s boxcar had a 3,800 cubic foot capacity, while a reefer had a 2,000 cubic foot capacity. That was one reason why mechanical reefer went to 57’, while the standard boxcar stayed at 50’. Even then, the boxcar typically had 5,000 cubic foot capacity while the reefer was about 4,000 cubic feet.
BNSF and its predecessors, Santa Fe (ATSF) and Burlington Northern (BN), had extensive involvement with reefers. ATSF had the largest railroad fleet of ice reefers, second only to Pacific Fruit Express. ATSF’s reefers hauled produce from California’s San Joaquin Valley, Southern California, and Arizona’s Salt River Valley (Phoenix area) to eastern markets. The orange crop was the most famous of this traffic, but the largest commodity was the annual potato harvest from the area around Bakersfield. BN and predecessors also handled considerable potato traffic from the Pacific Northwest as well as apples and other produce. From packing plants in Iowa and South Dakota came loads of meat and meat products over BN tracks. Santa Fe also handled some meat shipments from Kansas to eastern destinations.
Operating an outdated fleet of 1960s and 1970s built reefers that were reaching their age limits (and were technologically obsolete), BNSF turned to Trinity Railcar for a modern reefer. In 2001, Trinity built 810 reefers with a 7883 cubic foot capacity. Another group followed in 2003 with internal modifications that gave them a 7711 cubic foot capacity. Both groups of cars were 82’ long and 17’ tall. One of several commercial refrigerator unit types, along with a 300-gallon fuel tank, were mounted outside the car body on the A-end. Heavy insulation lined the inside of the car body. Another 250 of the 7711 cubic foot cars was built for JR Simplot with JRSX reporting marks.
These modern reefers handle the same types of loads their ice-bunker and mechanical predecessors hauled. The hotshot BNSF intermodal from the San Joaquin Valley to Chicago usually has a block of these reefers on the head-end, just as the earlier versions of the same trains had on the Santa Fe since the 1960s. Others handle frozen potato products from Montana, Idaho, Oregon, and Washington over the former Northern Pacific and Great Northern lines. The JRSX cars also handle frozen potatoes from the same areas, usually routed over Canadian Pacific. Although most of the fresh meat traffic has left the rails, BNSF is still using the Trinity reefers to haul meat to the Port of Los Angeles for export to Asia. In addition to these specific usages, the BNSF Trinity reefers can be found in almost any BNSF manifest train as well as on any of the major railroads in the United States.
