Collection of New York Central System Historical Society, Inc., No 7347-4

The CB&Q built 900 AAR 50-foot single door box cars at its Havelock, Nebraska shops. They were CB&Q Class XM-33 and were delivered in three groups. The first was 21000-21399, with the last one hundred cars receiving Allied Full Cushion trucks. The next group was 330 cars numbered 22000-22329 and then 170 more cars were delivered in 1944, numbers 22330-22499.