Many people associate corridor railway coaches with earlier decades than this website covers, but they were in fact in service with British Rail up until the mid-1980s.
Even if you've never travelled in one, you will have seen such carriages in old films or news clips. They were partitioned into six separate compartments, each one seating 6 people, with a sliding door opening out onto a narrow corridor than ran the length of the carriage. The compartments had window-blinds that could be drawn down for extra privacy. In earlier decades, scenic pictures were on the compartment walls below the luggage-racks, although by the late '70s these had mostly become replaced with adverts or public info. notices.
Compartment coaches offered greater comfort, ensured better peace & quiet, and were also extremely warm in the Winter. However, by the late '70s rising crime-rates meant that they could easily become deathtraps for people travelling alone, particularly women, and were also a gift to fare-dodgers (mind you, they had ALWAYS been this!). They probably also failed to comply with the ever-rising health & safety requirements. British Rail also became aware that the modern style of central-aisle carriage could accommodate more passengers, and increase ticket sales.
These classic railway coaches were thus phased out when the last of the locomotive-hauled inter-city trains were replaced by 125s, in late 1986. However, they remain in use on preserved steam railways, and also in Continental Europe. Tickets, please....