Donnerbüchse Iron coaches Iron coaches

| Class_to_1928 | Class_from_1928 | Seats | Quantity | Years_of_Manufacture | Remarks |
|---|---|---|---|---|---|
| Bi-21 | Bi-21 | 40 | 10 | 1921/23 | Trial coaches |
| BCi-21 | BCi-21 | 16/34 | 10 | 1921/23 | Trial coaches |
| BDi-21 | BCid-21 | 16/39 | 10 | 1923 | Trial coaches |
| Ci-21 | Ci-21 | 58 | 10 | 1923 | Trial coaches |
| Di-21b | Cid-21b | 66 | 50 | 1922 | Trial coaches |