sentences:  The Dunedin-Invercargill run was treated as an extension of the Christchurch-Dunedin express, and the train was sometimes called the Invercargill Express.In March 1914, it was possible to travel from Christchurch to Invercargill in thirteen hours.AB class locomotives capable of speeds of 107km/h took over from the A and Q locomotives from 1915, but in the 1930 and wartime, maximum SIMT speed was limited to 80km/h and track and running conditions did not allow the acceleration of the late 1940s when the express, at its zenith, reached sustained higher speeds on the Canterbury Plains and became the "South Island Limited".