 He experimented by moving dressed (cut) meat using a string of ten boxcars which ran with their doors removed, and made a few test shipments to New York City during the winter months over the Grand Trunk Railway (GTR).The method proved too limited to be practical.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.