As of 1954, the PRR's "Makeup of Trains" consist books list show only PRR reefers used in the creation of passenger trains. With few exceptions, class R50b is prescribed. Videos and photos, however, show Railway Express Agency reefers in use as well, though to a lesser extent.
The following table was created from data contained in The Official Railway Equipment Register.
| Express Reefer Ownership in 1954 "The Official Railway Equipment Register," January 1954 |
||
| Owner | Reporting Marks | Quantity |
|---|---|---|
| Railway Express Agency | R E X | 1,678 |
| Northern Refrigerator Line, Inc. | N.R.C. | 567 |
| Pennsylvania Railroad | P R R | 526 |
| Canadian National Railways | C N | 327 |
| Canadian Pacific Railway | C P | 295 |
| New York Central System | N Y C | 271 |
| Delaware, Lackawanna & Western R.R. Co. | D L & W | 216 |
| Pacific Fruit Express Express | P.F.E. | 187 |
| Great Northern Ry. Co. | G N | 184 |
| Western Fruit Express | W.F.E.X., W.H.I.X. | 95 |
| National Car Company | N.X. (all insulated milk tanks) | 67 |
| Burlington Refrigerator Express Company (passenger) | B.R.E.X., B.H.I.X. | 22 |
| Seaboard Air Line Railroad Company | S A L | 18 |
| Northern Pacific | N P | 3 |
