The "Wairarapa Mail" was hauled by a diverse range of motive power. Until World War II, WW class steam locomotives were typical motive power between Wellington and Summit at the western end of the Rimutaka Incline, while H class Fell engines handled the train over the Incline, and from Cross Creek at the eastern end through to Woodville, A class locomotives were normal. Passenger carriages were often older wooden mainline carriages displaced from premier services by new rolling stock; some of these carriages were gas-lit into the 1930s and even later.