Atlas, N Scale, Gunderson Cryogenic Reefer

The Gunderson-built Cryo‑Trans cryogenic reefers first appeared in 1986, developed from early CO₂‑based refrigeration research by inventor Ralph Hill. Cryo‑Trans partnered with Gunderson to produce these high‑cube reefers through the late 1980s and early 1990s, using liquid CO₂ tanks at the B‑end to keep loads deeply frozen. They were primarily used for frozen foods such as potatoes and processed products, serving major shippers across the Northwest and Midwest.

Only about 331 true cryogenic cars were ever built, though the broader Cryo‑Trans fleet—including later mechanical reefers—eventually grew to roughly 2,200 cars. The original CO₂‑cooled cars have since been retired as mechanical refrigeration became more efficient, but many rebuilt or later‑generation Cryo‑Trans mechanical reefers remain in active service today, still hauling temperature‑sensitive food products across North America.