Detroit's William Davis patented a refrigerator car that employed metal racks to suspend the carcasses above a frozen mixture of ice and salt. He sold the design in 1868 to George Hammond, a Chicago meat-packer, who built a set of cars to transport his products to Boston. In 1878, meat packer Gustavus Swift hired engineer Andrew Chase to design a ventilated car, one that proved to be a practical solution to providing temperature-controlled carriage of dressed meats, and allowed Swift & Company to ship their products all over the United States, and even internationally. The refrigerator car radically altered the meat business. Swift's attempts to sell Chase's design to the major railroads were unanimously 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 Grand Trunk Railway (who 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 to Swift the first of these units, 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. Competing firms such as Armour and Company quickly followed suit. 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. Specialized applications Horse cars For many decades, racehorse owners regarded the railway as the quickest, cheapest, safest, and most efficient medium of equine transport. The horse express car allowed the animals (in some instances) to leave home the morning of a race, theoretically reducing stress and fatigue. As early as 1833 in England, specially-padded boxcars equipped with feeding and water apparatus were constructed specifically for transporting draft and sport horses. In the United States, however, horses generally traveled in conventional stock cars or ventilated boxcars. Early on, the need for improved methods for tethering horses in boxcars, while at the same time allowing a horse enough room to maintain its balance while in transit, was recognized. Racehorses, and those kept as breeding stock, were highly valued animals that required special handling.