The author traces the history of electrical transmission for locomotives in which steam or Diesel engines have been the prime movers, and refers to the important contributions made by his firm in this direction. Although there are over 1,000 exhaust and gas turbines in service, the locomotive forming the principal subject of the paper is the first example in which this form of power is applied. The author, after dealing with the design of the turbine in general, takes the reader for an imaginary trip with the driver of the gas turbine locomotive, and explains the principles of operation, and the method by which the system of governing enables the machine to adapt itself to various running conditions. The safety devices are described in detail, and some attention is given to the opportunity afforded by a locomotive of this type for the adoption of power braking, which the author has been quick to utilize. The paper concludes with an analysis of the economic prospects of gas turbine locomotives, which comprises some useful comparisons with other types of motive power, including valuable information in graphical and tabular form.