 In 1846 the line obtained an authorising Act of Parliament; it was to be called the "Caledonian and Dumbartonshire Junction Railway" (C&DJR).The Caledonian expressed interest in the line and offered to lease the line on its completion, and subscribed to some shares.The C&DJR decided that the Caledonian Railway would be a better partner than the E&GR, and in 1847 successfully presented another Bill to Parliament, proposing an alteration of the terminal in Glasgow so as to connect with the Caledonian.