KiwiRail construction executive general manager Robert Gibbes said the two long rail lengths now visible in the yard were known as back shunts, and would provide "roads" in the South Dunedin yard once the redevelopment was complete.
One of the rail lengths was intended for KiwiRail rolling stock asset services and the other for KiwiRail infrastructure teams, Mr Gibbes said.
The back shunts were expected to be completed around the end of the year, he said.
The KiwiRail operations team would bring in assets, including locomotives, wagons, and carriages from the Main South Line.
The KiwiRail rolling stock back shunt was required for operating and moving the assets around the new yard and into the new buildings.
The rolling stock asset services team would use small electric shunt vehicles to move assets through what were holding roads, operational roads and into and out of the new mechanical workshop by way of a "traverser", a sideways-moving platform for transferring a railway vehicle from one set of rails to another parallel set.
The long length of the back shunts was essential to be able to safely shunt multiple assets at once, improving efficiency, Mr Gibbes said.
"The KiwiRail infrastructure team will use the other road for testing plant and equipment, including the national tampers when they are in the south of the country.
"The road is located in this area so that those teams can perform maintenance tasks away from the operational shunting areas."
The state-owned enterprise is building a wagon assembly facility, where two wagons can be assembled a day, and replacing the mechanical workshop, where up to 21 locomotives, wagons or carriages will be worked on at a time.
KiwiRail’s redevelopment of the site is expected to be complete next year, with parts of the new workshop to begin operation early in the new year.
