It was transferred to the Jubilee line on May 1 1979 . It connected to the main line at Baker Street . The branch remained part of the Bakerloo line until 1 May 1979 , when similar congestion problems for the Bakerloo line caused by two branches converging at Baker Street led to the opening of the Jubilee line , initially created by connecting the Stanmore branch to new tunnels bored between Baker Street and Charing Cross .