 However, the underframes were not designed to be towed in the long term and they deteriorated rapidly, bringing about their demise by 1985.The introduction of the EM class "Ganz-Mavag" electric multiple units to the Wellington suburban system meant eleven 56-foot carriages became available, and the cancellation of the unnamed daylight successor to the New Plymouth Night Express that ran between New Plymouth and Taumarunui freed more.A wooden 50-foot Z bogie box wagon was refitted with bogies that enabled it to run at passenger-train speed and was painted the same shade of bright red as the cars it accompanied.