Product Features and Details
The conversion programmes for 3yg- and 4yg coaches allowed the German�Federal Railway to address the shortage of coaches caused by the war for�the first time from the mid-1950s. However, the construction programmes�were limited initially to developing urban rapid transit and express train�coaches. Following this, the German Federal Railway created capacity for�developing new commuter coaches (n-coaches).�
The constantly growing demand for increased traffic volume and the fact�that the 3yg had only been designed for a short service life, led to the�appearance of the first prototypes for the new n-coaches in 1958. Based�on the findings of the preceding new developments and prototypes, three�basic types emerged with five 1st class compartments in the centre of the�coach and two large 2nd class cabins (AB4nb), three large 2nd class cabins�(B4nb) and two large 2nd class cabins and baggage compartment with�space for the train conductor (BD4nf). Although prototypes had also been trialled�with side panels made from aluminium, standard steel and corrugated side�walls, metal panelling made from stainless steel (V2A) was eventually chosen�for mass production. Since the coach paintwork corrosion protection was not�required for this material, the n-coaches were abraded under the windows�using a peacock eye pattern. This abrading pattern and the silver surface of the�V2A quickly earned the n coach the distinctive nickname 'Silberlinge'.�
Except for a few models fitted with lightweight design Minden-Deutz bogies,�the n-coaches were fitted with block brakes (MD42), which were replaced with�disk brakes (MD43) in later series. In order to change passengers as quickly as�possible, the otherwise common end entrances were abandoned and positioned�approximately a third of the way along the coach as double entrances�with hinged-folding doors. The basic design of the n-coach proved so successful�that between 1960 and 1980 a total of about 5000 coaches were constructed by different coach manufacturers as well as at the Karlsruhe and Hannover�refurbishment facilities (Aw). At first, conditions in the extremely cramped�conductor's space in the BD4nf were less than ideal, and it was soon nicknamed�the 'rabbit hutch' by staff, leading to discontent and safety concerns.�As a result, Aw Karlsruhe rebuilt the conductor's cab, producing a�control car in 1972 with a fully-fledged conductor's cab without any�through access to the next coach. These changes meant that the Karlsruhe�version differed significantly from the previous 'rabbit hutch' with its�passageway between the coaches.�From the mid-1980s, the Federal Railways started to modernise coaches�that were in some cases already 20 years old. Following several design�studies, the positive features of the individual programmes were combined�at Aw Hannover in the new Hannover design. New features also consisted�of the mint green paintwork or new sliding windows with plastic frames. This�design, which was also installed by PFA Weiden or OFV Verona using alternative�interior colours, can still be found in modern n-coaches that have been�painted in the DB AG corporate colours.
Other conversions were performed on the control cars. The two designs that had�been introduced earlier were only suitable for either diesel or electric traction,�depending on the control panel installed. For this reason, a new conductor's cab�was designed at Aw Wittenberge, based on the DB standard driver's cab of the�BR 111, so that the control cabs could be deployed with greater freedom.�Numerous 'rabbit hutches' and also Karlsruhe versions were subsequently�converted to the Wittenberge model. In order to meet the demand for push-pull�trains, DB AG also included standard 2nd class coaches in the conversion programme.
