sentences:  Without these centers, rail communication between Polish Silesia and the Baltic Sea was virtually impossible.As coal was one of the main Polish exports, and transit through Germany was not allowed (due to the German–Polish customs war in the late 1920s and early 1930s), construction of the new line was necessary.On February 17, 1928, the President of Poland Ignacy Mościcki signed a bill which ordered construction of the 255-kilometer line Herby – Inowrocław.