 Under the Railways Act 1921 , the NSR was one of the eight major companies designated to form the North Western , Midland and West Scottish Group . This group became the London , Midland and Scottish Railway ( LMS ) . The act came into force on 1 January 1923 but along with the Caledonian Railway , the NSR amalgamation into the LMS was delayed until 1 July 1923 due to certain legal requirements not being completed by the due date . 
