Upgrades
With the EF class being relatively young there have been very few upgrades to the locomotives. Significant maintenance is undertaken at the main Hutt Workshops near Wellington which, due to the unelectrified section between Palmerston North and Waikanae (and Wellington's electrification being DC rather than AC), the locomotives must be towed to by a diesel engine to access the workshops.
An upgrade programme was undertaken over 1993 and 1994 which saw the 20 remaining locomotives receive a full overhaul including transformer work and new traction motors. This work was undertaken at the Hutt Workshops with EF 30007 the first to be treated after having been out of action for some time prior.
From June 2006, the locomotives have been fitted with AAR style couplers, each weighing over 400 kilograms (880 lb), to allow them to pull heavier trains.
In July 2010 it was announced by KiwiRail that EF 30065 and EF 30128 were to be assessed to see if they are able to be made ready to again enter service on the NIMT, having been held in open storage (along with EF 30186) for many years at Palmerston North as surplus to operational requirements. It is hoped that reinstating the locomotives will help to ease pressure on the working fleet, especially as locomotives are currently regularly out of service for maintenance, modification and re-branding. EF 30065 was placed on second-hand bogies and moved to Hutt Workshops in August 2010 to begin the assessment, followed by EF 30186 in September, though it was not mentioned in the original announcement. EF 30128 followed to Wellington in April 2011. It is anticipated that one of the locomotives will serve as a parts source to return the other two to service and the remaining hulk scrapped.
Read more about this topic: New Zealand EF Class Locomotive