The proposal to develop a direct line from Düren to Aachen was discarded due to the geological conditions of the northern Eifel and a curve to the north was adopted between Düren and Aachen that is still used by the line. The share capital of 9 million marks was raised to enable the Rhenish Railway to build the line by the issuing of shares. But due to the difficult route, construction costs increased to 21 million marks. The additional costs of 12 million marks were raised by issuing additional shares worth 4.5 million marks and bonds worth 7.5 million marks. The Belgian government alone acquired bonds for 3 million marks.