The Main North Line between Picton and Christchurch and the Main South Line between Lyttelton and Invercargill, running down the east coast of the South Island of New Zealand, are sometimes together referred to as the South Island Main Trunk Railway (SIMT). Construction of a main line running the length of the east coast began in the 1860s, not completed all the way from Picton to Invercargill until 1945.