The union was wrong
In Jan 2021, Stuff reported:
Alby Barr, Northland chairman of the Rail and Maritime Transport Union, said the upgrade has been a long time coming and there is a lot of interest in using rail from Northland businesses. …
Just two trains a day use the North Auckland Line but Barr said the trains can be 2km long.
When I read this article, I thought the assertion the trains were sometimes 2 km long was unlikely. So I asked Kiwirail. They took a while to answer, but they now have. My thanks to them.
The longest train in 2019 was 1070 metres. There are no 2 km long trains. In fact only three out of 494 trains exceeded 800 metres. The average was 409 metres.
I’m not against the North Auckland line upgrade. I just think the facts are important.