Friday, January 27, 2012

Some spark plugs for the diesel electric

I like trains. They are a marvellous way to travel. I have a vague understanding of electric trains, they have electric motors and electric bits and the power comes from an overhead wire or a rail on the ground. It is all I need to know.

Steam trains are so cool. All that smoke and steam, shovelling coal into a boiler, pressured steam moving pistons to drive wheels. Not too hard.

Modern diesel electric trains just seem to work without a problem. They are high tech beasts and there is nothing really to see. They just work.

But old diesel trains have become quite fascinating to me, especially the starting up of them. It is not a simple process of pushing a button and the engine starts.

There is a long whirring I think of a starter motor. There is what looks like steam belching out, and then the steam is combined with black smoke and lots of putt putt noises. Sometimes the engine settles to a regular beat, but not always. Is that a fail to start?

Like cars, of course of diesel engine needs a starter motor. What powers it? Batteries? How many and what voltage are they usually? How long does the starter motor engage?

What is the steam? Or is it not steam but white smoke?

Do the engines kind of start, but don't really, and hence the starter motor has to keep turning? They seem to start a bit, like firing, but don't really start for quite a long time.

In the probably forlorn hope that I have reader who understands old diesel electric trains. I might have to go to a website forum and ask questions there.


  1. That locomotive is raring to go, isn't it!

  2. So many questions, so little time. :)

  3. Victor, one wonders if it ever did move again.

    Rubye, I started writing that post ages ago. I have actually found out some answers. It is all there on the net.

  4. I know nothing about trains. Do some googling and find an old railway engineer who can probably explain it to you.

  5. River, the ideal would be for someone to explain it all verbally. I should go to a train museum.

  6. I am not the reader you seek. But there ARE some fine loco experiences still to be had around the country - and a fine Train museum in Adelaide! Did you miss it when you were here??

  7. We saw it Red.

  8. I know this is old (I found it while googling Bondi 1980's).
    That's an old British Railways 26 class. Back when these were built, diesel was so cheap that they would leave engines running almost all the time, so they wouldn't cool down. What you're seeing here is a big engine starting from cold. The whir is the starter and possibly (if fitted) electric oil primer pumps. White smoke is unburnt fuel and the black is just diesel clag. The speeding up and slowing down is caused by the engine governor (the thing that controls steady engine speed)as it is controlled by oil pressure and as the oil going to it is cold, it's too thick to do the job properly. If you let it run for about three minutes, it'd start to even out and after a full warm up, it just run at a pretty constant speed.
    Here's more about those locos:

    1. Thanks for the information Nick. I've seen quite a few more videos of old diesels starting since then and they can be quite spectacular. Yes, I have heard diesel engines are quite happy to idle away for extended periods.


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