Sunday, December 10, 2006

Self-Education ~ Hot Summer = Slow Speeds

With a seemingly long hot summer ahead of us, unfortunately I think us commuters had better get used to longer train journeys. I browsed the V/Line website and found the following article:

High temperatures in many parts of Victoria provide a timely reminder that V/Line services can be affected when the mercury climbs into the 30s.

As a safety precaution track operator Pacific National imposes speed restrictions on V/Line trains when the forecast temperature is 36 degrees and above (32 degrees and above for some sections of track in outer regional areas).

This has been standard operating procedure in the Victorian rail industry for more than 10 years.

High temperatures can affect rail track and the speed restrictions are designed to ensure trains are able to continue to operate safely.

Pacific National has advised that when speed restrictions are imposed during the summer, V/Line trains will not be able to operate above 90 km/h

Hooray, this fills me with joyful anticipation and not only do we have to worry about carriages that have defective air-con (even the new V'locity's suffer this issue, especially when left standing in the sunlight in the yards all afternoon), but commuters will enjoy the extra 10~15 minutes added travel time.

Anyway, this led me to read up on railway tracks and I learnt about "sun kink" which is an issue that can cause derailments.

Engineers try to heat the rail to a temperature roughly midway between the average extremes of hot and cold (this is known as the 'rail neutral temperature'). If temperatures reach outside normal ranges however, welded rail can buckle in a hotter than usual summer or can actually break in a colder than anticipated winter.

From: ""

So I'm thinking that as soon as temperatures get above 32~36 this is the 'rail neutral temperature' that our new tracks between Geelong & Werribee (were the new tracks were laid), are rated for. You learn something new every-day.

It still doesn't make me happy, but you can't argue with science & engineering and safety precautions!


Anonymous Anonymous said...


11/12/06 2:59 pm  
Anonymous Cooper said...

1 Billion Dollars well spent.

Vline Fast Train. What a joke!!!!!

11/12/06 3:43 pm  
Anonymous Anonymous said...

good to see people class safety as a joke...

11/12/06 5:58 pm  
Blogger vlinewhinger said...

Well to be fair, I don't think he was referring to safety as a joke.

Even so, I dare say the 90 km/h is erring reasonably on the far side of cautious, particularly when on the same day on the other narrow gauge track the goods train overtook us running at speeds at least 20 km/h more.

I'm no engineer but I'd wager the track is probably able to sustain higher speeds in higher temps, given it's newness & concrete sleepers.

I stand to be corrected by someone with more knowledge, however I would have thought the temperature extremes would be taken into account when methods of construction etc were considered.

11/12/06 7:51 pm  
Anonymous Anonymous said...

Vline are looking to appeal tp Pacific National (rail maintainer- till the labor government takes it back-election promise) to increase the speeds on the A grade tracks.

11/12/06 9:53 pm  
Anonymous Cooper said...

anonymous, firstly good name. Makes it easy to reply to you.

Secondly it is not a safety issue but for the money spent you would think that they could run the trains at speed. If you look at that Wiki article you can see that the design can take expansion if it is installed right. It is just another chink in the Vline chain and I have to tell you there is a sh!t load of them. For the money spent they could have probably developed some sort of hover train!!!!

Still with all this quality of service we can expect another ticket price increase next year.

12/12/06 9:35 am  
Anonymous Anonymous said...

Well maybe the narrower track is less sceptical to spread in the warmer weather? Its easy to say why go slower for the heat it should this and that. If you were on a train that derailed due to the track conditions wouldnt you than ask why werent they going slower? That sort of stuff is all science and even though the sleepers are concrete the rails are still metal and we all know that metal expands when heated

13/12/06 3:46 pm  
Anonymous Anonymous said...

remember vline doesn't own the track. they just use it like a motorist on the highway.

13/12/06 9:09 pm  

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