On Sunday morning Transdev/Kiwirail conducted a large scale test of our electric trains. I understand the trains had been creating harmonics through the lines. This wasn’t affecting trains but was creating impacts outside the network – although I’m not sure of the full extent of the issue. The test saw seven 6-car EMUs running between Papakura and Britomart via the Eastern Line which I believe is the most electric trains that have run on the network at any one time so far. When two EMUs are joined together they have the capacity to comfortably carry 750 people although during an event or during a busy peak I suspect that number could be closer to 1,000.

These photos were taken by Patrick Reynolds taken from the Pt Resolution Bridge.





And this one is from Alex Burgess of one crossing the Orakei Basin

Double EMU Orakei Basin

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  1. Alex does have one of an EMU 6 car set with traction motor issues outside Homai. Thankfully this was discovered in testing rather than revenue services.

    Also I was wondering if it was the EMU’s I heard through Papakura on Sunday morning. So it was

        1. Thats not what happened. There was a faulty jumper cable between the two units – this resulted in the brakes remaining applied on the trail unit.

    1. LOL Patrick is a Professional photographer. You can be sure that anything you see in those photos is that way because of conscious choice on his part.

    2. Haha, wanting to show motion, not just freeze the moving trains. See I’m not a real foamer, I don’t get that excited by the things in themselves; much more interested in what they do.

  2. Wow, great photos. They look fantastic when joined up, especially with the eastern line scenery in the background. Excuse my amateurness, but what is meant be ‘creating harmonics’?

  3. Harmonics are where basically high frequency signals are generated by the train in this case and fed into the overhead wires and they radiate out and cause interference on radio receivers. The overhead wires become one long radio aerial and cause interference to all manner of equipment. I’m not sure how much of the results of testing is in the public domain so I can’t comment further.

    1. Harmonics can also refer to multiples of the basic 50 Hz imposed on the power supply and fed back into the grid. It can be fixed with filters but better not to impose them on the supply in the first place.

      1. Marvellous!

        That’s a good harmonic generator. It appears that the EMUs are bad harmonic generators. Hope it can be resolved quickly.

  4. I think there were six sets of six cars (12 EMU’s) at the start, but fewer by day’s end, with several returning to the depot early (and some of the test trains cancelled) due to developing faults.

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