A question for the train enthusiasts out there

[kenj]

F. I. L. said when he was driving steam goods trains on that line, at the right time of the year, he used to stop the train and him, the fireman and guard would pick mushrooms from the farmers paddocks. Wouldn't be able to do it these days.

Ken

[Roscoe]

Possibly either new rails waiting to go in, or old rails that were just replaced and waiting to be picked up.

Yes, you could be right. A mad friend of mine said that all the rails are delivered pre rusted.

[Roscoe]

I have another question for you clever train enthusiasts:

As you know, the railways now have welded rails. I understand to make that possible the rails are pre stressed.

Firstly, I don't know what is meant by pre stressed.

Secondly, do they remove all the rails and replace them with pre stressed rails before they weld them? If not how do they do it?

Thanks for your help.

[1101]

If hundreds of miles of steel track is welded together
How do they deal with the expansion & contraction . Do they have expansion gaps along the rail ?

[Roscoe]

If hundreds of miles of steel track is welded together
How do they deal with the expansion & contraction . Do they have expansion gaps along the rail ?

No. They do not have expansion gaps these days as they used to. Apparently the pre stressed rails eliminate the need for expansion gaps. I'm waiting for someone to tell me why that is.

[pheonix]

https://en.wikipedia.org/wiki/Rail_stressing has an explanation.

[1101]

a good vid of showing how stressing is done.
Im surprised at the amount of stretch

https://www.youtube.com/watch?v=I8EZ6pEAyLc

[kenj]

https://youtu.be/_LoXgN1QWZM

Ken

[Brucem]

I seem to recall that there was a railcar that left Christchurch late in the evening 10pm? for Greymouth, it carried the next day's Press. I remember going to the railway station th buy a copy to check on University exam results (1959). This was also used extensively by trampers/mountaineers to get to Arthurs Pass. I think these were th old Vulcan? railcars.

[kenj]

I seem to recall that there was a railcar that left Christchurch late in the evening 10pm? for Greymouth, it carried the next day's Press. I remember going to the railway station th buy a copy to check on University exam results (1959). This was also used extensively by trampers/mountaineers to get to Arthurs Pass. I think these were th old Vulcan? railcars.

Father in Law drove the 88 seater RM (Rail Motor) railcars on the Napier Gisborne run. They were the last ones NZR used from memory. They had FIAT
horizontally opposed underfloor diesel engine which he said gave lots of problems. Overheating? I think. Memory could get it wrong from 55+ years ago when he told me.

Ken