Eilzugwagen

Not until the end of the 1920s did the Deutsche Reichsbahn consider developing special wagons as eight-wheeled open coaches for the semi-fast train class.

Following the construction of trials coaches in 1928 and 1929, the full production of 150 Eilzugwagen began in 1930; 2nd and 2nd/3rd class variants being turned out.

The gangways were open and only secured with folding lattice gates (Scherengitter), so there was no protection from the elements.

In addition an extra half-compartment was added because the coach, at 20 m long, had more space than its predecessor.

To enable a better view the bottom edge of the windows was lowered and the panes enlarged.

However the coach body was now streamlined (by tapering the ends) and had panels or 'skirts' covering the sole bars.

For the first time in the Deutsche Reichsbahn, Eilzugwagen were given gangways protected by folding bellows (Faltenbalge).

Two prototypes with 2nd and 3rd class seating were delivered by LHW to the Reichsbahn at Breslau in 1939: the BC4üp-39 (later the AByse 631) built to a very light structural design.

However, due to the shortage of raw materials during the Second World War, only 125 composite (AB) coaches were ordered, of which by 1944 only 45 could be delivered: the BC4üp-42a (later Abyse 633).

The coaches so converted were eventually classed as Ayse, AByse and Bye with code numbers in the 600 series.

Almost all these semi-fast coaches were used until the 1970s in their designated role; only then did many end up on local passenger services.

Like the UIC express coaches they were of welded, all-steel construction and were equipped with the rubber corridor connectors commonly used today.

The following variants were procured: C4ymg-51 (later Bylb 421), BC4yg (later ABylb 411), CPwymg-51, a large number of which were fitted with driver's cabs for push-pull operations and designated as CPwygmf (later BDylbf 456).

In their early years, the driving cars had been used with six-wheeled Umbauwagen (rebuild coaches) on suburban services in conurbations like Hamburg.

The last yl coaches were retired from the DB in 1990, because they wanted to avoid having to fit them for central locking which would have been expensive.

Several coaches have ended up, however, via a third party in the DR and were employed in Berlin suburban services including Berlin-Lichtenberg to Nauen and Falkensee.