Prototype coaches

Prototype coaches
AB4üm-52/A4üm-52/61/Aüm 201
ABC4üm-52/AB4üm-52/61/ABüm 221/222
C4üm-52/B4üm-52/61/Büm 231

Prototype coaches

The first three prototype coaches were delivered in 1953. These coaches were one coach ABüm-52 and two coaches ABC4üm-52. These were followed in 1954 by 10 other coaches, two of type AB4üm-52 with side skirts, one coach ABC4üm-52 and seven coaches C4üm-52. The ABC4üm-52 got later skirts. The coaches were equiped with newly developed bogies of type Minden-Deutz (MD 33).

The prototype coaches were initially equiped with the old style corridors between the coaches. From 1961 all 16 prototype coaches were getting the new modern coach corridors as also used in the mass produced serie coaches.

In total there are 16 prototype coaches of the following types built.

AB4üm-52/A4üm-52/61/Aüm 201

This coach was together with two coaches ABC4üm-52 built as the first 3 prototype coaches in 1953. In 1954 there were 2 more coaches built which got side skirts.

In total there were three coaches AB4üm-52 built in 1953 and 1954. The coaches were changed to completely first class in 1956 (with the abandoning of the third class) and were indicated as A4üm-52. When in 1961 the old style corridors were replaced by modern ones, the indication changed to A4üm-52/61. Finally in 1966 the coaches got the indication Aüm 201 as a result of the new UIC reIndication.

ABC4üm-52/AB4üm-52/61/ABüm 221/222

The first 2 prototype coaches ABC4üm-52 were built together with one coach AB4üm-52 as the first three prototype coaches in 1953. The indication ABC4üm-52 was changed to ABüm 221 in 1966. In 1954 another coach of this type was built, this coach was indicated after 1966 as ABüm 222. In total there are 3 coaches of this type built.

The coach which was built in 1954 was built by Rathgeber with side skirts like the trainsets VT 08 and VT 12.

By means of a test, one coach of 1953 was delivered with a heating system which worked with air as energy carrier. These coaches had the old style corridor brigdes, in 1961 all 16 prototype coaches got the new modern corridors.

C4üm-52/B4üm-52/61/Büm 231

In 1954 10 coaches of this type were built as prototypes. By means of a test, five coaches were equiped with a heating system which worked with air as energy carrier.

In total there were 10 coaches of type C4üm-52 built in 1954. The coaches became completely second class in 1956 and were indicated as B4üm-52. When in 1961 the old style corridors were replaced by modern ones, the indication was changed to B4üm-52/61. In 1966 all coaches of this type got the indication Büm 231 as a result of the new UIC Indication scheme.