Compartment coach

A compartment coach is a railway passenger coach (US: passenger car) divided into separate areas or compartments, with no means of moving between compartments. A compartment train with a corridor is a corridor coach. 
English origins.
Originally compartment coaches were passenger coaches with several separate compartments in the same coach body, each compartment having its own doors on the side of the coach to enable passengers to board and alight. The compartment coach was developed at the very beginning of the railway era in England simply by placing a post coach body on a railway undercarriage. Compartment coaches were used across almost the whole of Europe and were built right up to the 1930s. On the European continent they were sometimes referred to as "English coaches" or coaches built to the "English system".
American corridor coach.
The compartment coach should not be confused with the classic express train coach of the first part of the twentieth century; the corridor coach which also has separate compartments and is still known as a compartment coach in other languages (e.g. German: "Abteilwagen"). A corridor coach has covered gangways, side entrances and partitioned compartments with a corridor down one side. (This should not be confused with the first class sleeper accommodation, the "compartment.")
Early compartment coaches.
The first compartment coaches in the 19th century comprised several cabins on one undercarriage, similar to the post coaches. Compartment coaches with doors for each compartment, without any connexion between compartments, were built up to the end of the 20th century. The disadvantages of this design were that passengers could not use the toilet or visit the dining car and that train staff had to climb along the outside of the coach on running boards in order to check tickets. Countless four-, six- and eight-wheeled vehicles of this type were used in Germany and especially by the Prussian state railways.
Development in Prussia.
Until about 1880, four-wheeled compartment coaches were typical. After the end of the wave of nationalisations the Prussian state railways, around 1895, acquired the quieter-running six-wheelers. For this, so-called norms were established for four-, six- and, later, eight-wheeled classes of coach. For the six-wheelers, both fixed axle and sliding axle designs were envisaged. Those coaches designed specifically for suburban traffic (Berlin, Hamburg) had no toilets. On the other coaches, a gangway was specified in order to keep the number of toilets to a minimum for economic reasons. Numerous coaches had therefore to be converted. After the end of the 19th century, fourth class compartment coaches were also procured.
Four- and six-wheeled compartment coaches were initially used in all train categories on main lines. With the advent of the "D-Zug" express coaches in 1892, compartment coaches were deployed in passenger trains on main lines and in built-up areas. Here it became abundantly clear that, in addition a faster turn round of passengers, access to station platforms on main lines could only be permitted if passengers had valid tickets and trains could not be boarded until shortly before their departure. So ticket checking by the guard became a function of station staff. By contrast, open coaches were common on branch lines, because there were often no platform barriers on branch line stations and so tickets had to be checked in the train itself.
From 1895, especially in Prussia and Saxony (but also to a lesser extent in Baden, Bavaria and Alsace-Lorraine), eight-wheeled compartment coaches were built. They were predominantly used in the semi-fast trains or "Eilzüge" introduced in 1907 and in the so-called fast passenger trains. Over 3,500 coaches were built in several batches starting in 1898. The compartments in the coaches were sometimes linked to provide access to the toilets. In third class coaches the privies lacked flushing facilities until some time later.
Initially the window frames on compartment coaches - like the coach bodies themselves - were made of wood, which very quickly warped. After 1900 they were made of a brass alloy based on a patent by the Julius Pintsch AG firm. The upper part of the window frame on these coaches was rounded.
From 1910 the paraffin lighting was replaced by more efficient gas lighting. After 1900, rising wood prices forced a switch to steel construction and then to lower value materials during the First World War.
Prussian state railways coaches were equipped with standard bogies with two and later three spring systems. Most coaches were 18.55 m long. Initially "Westinghouse brakes" were used, but after 1900 they were fitted with standard Knorr brakes. The hand brake was housed in a separate brakeman's cabin at one end of the coach. These were removed in 1930.
Of the 21,000 compartment coaches of all types that were built, 14,000 were handed to other countries after the First World War as reparations. Of these, 5,000 went to the re-emergent Poland.
Development by the Deutsche Reichsbahn.
In order to rationalise wagon maintenance the centre axle was removed from 1920 on many of the six-wheeled compartment coaches, because it had been established that this had no negative impact on the riding qualities. In addition, in order to overcome the pressing shortage of coaches following the ceasefire reparations of 1918/19, another 500 four-wheeled compartment coaches of Prussian design were ordered (50 seconds and 450 Wagen third class coaches). In addition, due to the great shortage of wagons, many former Prussian coaches were reallocated to the south German railway divisions so that they could now be seen across the entire German Empire.
In the mid-1920s the brakeman's cabin was removed on those coaches that now ran on electrified routes. With the demise of the fourth passenger class in 1928, many compartment coaches were converted to coaches with heavy luggage sections ("Traglastenwagen") by combining of compartments. After the DRG had introduced new four-door Typs E 30 "Eilzugwagen" (semi-fast coaches) in 1930, still more coaches had passenger compartments knocked into larger compartments which were classed as heavy luggage compartments ("Traglastenabteil").
Several of these compartment coaches were used for express services along the Ruhr ("Ruhrschnellverkehr"). They were given the DRG's red and beige livery used for multiple-unit trains. The window sections of second class coaches were painted in Stadtbahn blue-green (RAL 6004) as on the Berlin S-Bahn. Even 18 new compartment coaches were bought for this purpose.
Post-war development.
Most of the compartment coaches were rebuilt by the Deutsche Bundesbahn (DB) in the 1950s into "Umbauwagen" (rebuild coaches). The compartment coaches that remained in the East German Reichsbahn (DR) had several compartments combined and, as on the six-wheeled coaches, every second door was removed. In the 1960s the compartment coaches were converted to the so-called "Rekowagen" (rebuilds).
Since the Second World War compartment coaches have largely died out in Germany, as in other European countries, and have been largely replaced by corridor coaches and, increasingly nowadays, open coaches.