The fourth of 57 new electric trains for Auckland has arrived from Spain.
Auckland Transport is switching its fleet from refurbished diesel trains to new $7 million electric trains, and is also building new stations and signalling systems.
The new trains are not in service yet, but engineers are testing them most nights on a section of the southern line.
Project manager Lloyd Major says the tests are to ensure the technology and mechanics perform exactly as they are meant to.
The trains can travel at up to 110km per hour.