For electric locomotives the second letter often referred to where the locomotive was based, such as EC in Christchurch, EO in Otira and EW in Wellington.
It is on the northern approach to the pass, a saddle between the Otira and Bealey Rivers high in the Southern Alps.
Otira |
Generally the DXC sub-class is assigned to the South Island, as the modified air intakes were designed to assist in are useful for working the Midland Line, coal trains (see above) particularly in the formerly electrified Otira Tunnel section, whereas the DXB sub-class were predominantly assigned to the North Island.
A further seven locomotives were assembled at the Hutt Workshops and two at Addington Workshops for use on the Otira - Arthur's Pass section of the Midland Line.