Testing of the new electric trains is well underway with the first train out on the lines near Wiri six nights a week.
Testing starts at 9.30pm each night and continues until 4 in the morning, with a team of engineers from Spain and New Zealand on board.
The train being tested has been loaded with sandbags to simulate a full passenger load.
EMU Project Director Lloyd Major says: “We have 1776 sandbags on board, each weighing 20 kilograms; this is the train at close to full weight. It has thrown up a couple of interesting things like some of the older station platforms will need work because they are slightly too high for a full train.”
The train is reaching speeds of 110 km/h, which is the maximum speed allowed on the Auckland rail network.
"Testing has been going well and we are on target to take paying passengers in the second quarter of next year," says Lloyd.
Four of the fleet of 57 trains have now arrived in Auckland from Spain. Testing of the new trains will also be done during the day over the holiday rail shutdown.