Constructed in version 3 (Type 1929R and 1931R type) and 4-axis (type 1928R, 1933R type, Type 1949R) were designed for local trains with high crowding, and characterized by various ports on each side (up to ten in the case of some cars 4-axis) in order to promote the rapid ascent and descent of the passengers. Eleven cars were transformed into carriages semipilota (6 Type 5 Type 1928RT and 1929RT).
The centoporte were among the first coaches in Italian metal case, even if obtained from the processing of pre-existing wooden carriages with cash (Type 1906 and Type 1910 for the 4 axes and carriages belonging to the Adriatic Network for 3-axis). The seats are made of wood, offering 78 seats (in the case of the most popular series Bz 36,000). Heating was by steam or electricity.
The first cars had the coloring 'green car', changed from 1935 in the classic pattern "brown-Isabella" and further simplified to "brown" in 1963 and subsequently took on the coloring "slate gray" introduced in the mid-year sixty.
During the Second World War were transformed into various Centoporte carriages-hospital transport of the wounded (Type 1928RT). Some coaches barellate were subsequently used to direct trains of pilgrims to shrines in Europe, and were the only centoporte engaged in international service.
Currently 52 surviving copies available of historic trains.
