Poland took over 2,627 miles (4,228 km) of railway lines in the territory formerly under Prussian rule, 2,707 miles (4,357 km) from the former Austrian territory and 4,575 miles (7,362 km) from the Russians. The country received 4,762 locomotives of 164 types, 10,379 passenger carriages and 111,092 freight wagons. Most of them were in a poor or disastrous technical condition. The railway network in the newly formed country was in ruins. During the war the occupying forces destroyed 41% of bridges, 63% of railway stations, 31% of warehouses, 48% of workshops and engine houses, 81% water stations and water towers, and 22% of houses. They transported away equipment, machines and resources required for the operation of the railways. The Treaty of Versailles did not provide for respective indemnification to Poland. The largest scale of destruction was recorded in territories administered by the new directorates: in Vilnius, Warsaw, Radom, Lviv and Stanyslaviv. The Ministry of Railroads commenced the construction of provisional wooden bridges, replacing them gradually with steel structures using reusable elements. The process of reconstruction continued over the entire interwar period.
The occupying forces left behind tracks consisting of 66 types of rails of different quality and with different degree of wear and tear. The first deliveries of new rails and bonds were ordered from Belgium in 1922, and from 1923 supplies were sourced from 4 steel and iron works in Upper Silesia. As late as after 1925 the first Polish rail – S26 (weighing 42.5 kg/m) – was introduced. The rail bond structure was standardised and stronger steel was used for the manufacturing of trackway elements. The rails supplied by steel and iron works were 12- and 18-metres long, and from 1938 – their length was 30 metres. In the interwar period all sleepers were replaced, that is, 50 million pieces of new railway sleepers were laid! This involved an enormous amount of labour. More and more often intermediate rail fasteners were used: first the rails were screwed onto sole plates, and then the sole plates were fastened to sleepers.
In 1922 the entire railway network in Poland was divided into 9 districts: Warsaw, Radom, Vilnius, Kraków, Lviv, Stanyslaviv, Katowice, Poznań and Gdańsk (including railways in the territory of the Free City of Danzig).
Each of the invaders introduced different rules of traffic and signalling. For example, Austrians required left-hand traffic and time-based departures, while Prussians determined the time of departure based on distance travelled. They used different railway signalling and train traffic security equipment. In September 1926 the President of the Republic of Poland established an enterprise called the Polish State Railways (Polish acronym: PKP) which assumed the task of administering and using real property owned by railways, and became the owner of all movable assets.
The organisation of services was slightly different in each of the formerly partitioned territories. Only in 1931 was a uniform structure, divided into traffic and commercial, road and mechanical sections, introduced. The following central units were established: the State Railways Studies and Design Bureau (1926), Central Wagon Counting Bureau, Central Bureau for Material Supplies for the State Railways, Warsaw Railway Junction Electrification Bureau and Motor Transport Bureau of the Polish State Railways. In 1934 the Railroad Guard Service (Polish acronym: SOK) was formed.