The Western Maryland received two different types of AAR type 'GB' straight side sill gondolas, both 50-ton, but with different inside lengths. They were not actually built to the AAR design (Bethlehem Steel), but were similar, so they can loosley be referred to as AAR derivatives. Another distinguishing feature was the use of the Duryea Cushion Underframe. All groups were constructed for the WM by Bethlehem's Johnstown, PA facility. The data for these cars is as follows:
| Series Begin | Series End | Class | Build Date | IL | Capy. | Lot Number |
| 50701 | 50800 | G2, G3 | 3-4/1937 | 52'6" | 1678 | DB 85001 |
| 52001 | 52362 | G8, G9 | 4/1945 | 48'6" | 1382 | DF 77 |