RAILforum: Why are rails warping in Europe when they don't in Arizona?

This is topic Why are rails warping in Europe when they don't in Arizona? in forum Western US at RAILforum.

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Posted by Konstantin (Member # 18) on :

I have seen a few times on the news that warped rails are a common problem right now in Europe, because of the heat wave they are experiencing.

The heat in Europe is still quite low compared to the heat we have in Arizona and I rarely hear of warped rails here.

I realize that with modern technology, the tracks in areas with known high temperatures are desinged for it. But how about 100 years ago? Trains ran through Arizona where the winter temperature was in the 30's, sometimes even the 20's. Then in the summer, the temperature was routinely from 110 to 115, sometimes in the low 120's. I am sure that sometimes the rails warped, but I have not read that it was a common problem. What is the difference with the rails in Europe?

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Elias Valley Railroad (N-scale)
www.geocities.com/evrr

Posted by RRCHINA (Member # 1514) on :

I don't know about proceedures Europeans use but track on 1st class RR's in the US is laid with knowledge of local conditions, ie,
what is the average temperature in the local.
They try to simulate this as they lay rail.
Sometimes they lay rail at night, or use dry ice to cool it, or even artificially heat it to achieve, as nearly as possible, the mean
temperature in each location.

Additionally, there are rail anchors applied
which attach to the rail and fit snugly up
against both sides of the ties. This forces the expansion to make the rail fatter and taller rather than to become longer, which is the normal and easiest way to expand.

Today rail is welded. Pre 1950's 39 foot rails were connected with a device called a joint. These had a small gap between the rails which absorbed some of the expansion
but also created a weak spot in the track that created substantial maintenance costs.
You can still see this on branch lines and in yard tracks where operating speed is slow.

Hope this brief explanation helps.

Posted by Konstantin (Member # 18) on :

I appreciate your response. I am not sure this really explains the problem. I still don't fully understand. Over 100 years ago, they were able to build track that could withstand a temperature difference of 100 degrees, then I wonder why today the European railroads cannot withstand the weather.

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Elias Valley Railroad (N-scale) www.geocities.com/evrr

[This message has been edited by Konstantin (edited 08-15-2003).]

Posted by RRCHINA (Member # 1514) on :

There have always been "sun kinks" on railroads. They do not always become public knowledge, but a recent ( last year) event
in Maryland caused a derailment of an Amtrak train. That one was explained by recent maintenance that had not been completed.

The ballast that is the part of the track structure beneath and surrounding the ties
not only cushions the impact of a trains
weight and speed but also served to hold the tie in place. When track maintenance is done
the ballast is disturbed and must be properly reinstalled (RR's call this tamping) or the complete track structure is weakened, which is what happened in MD.

These events happen occasionally, yes even on the 1st class US RR's, but are seldom
publicized. Some of the freight train derailments that we occasionally hear about are caused this way. Perhaps the Europeans
had underdesigned for the weather anomalies
they are experienceing, but more likely they are getting publicity because everything associated with this unusual heat in Europe
is getting more media play. And we should never underestimate the willingness of the media to over-dramatize events. Sometimes the
story is more to get attention for the writer or his employer than to give us the information without "garnish" or a bias.

Once more, I hope this is helpful.

Posted by Konstantin (Member # 18) on :

I remember that Amtrak derailment in Maryland because of the "sun kinks". I tend to also remember one in Florida.

You are probably correct in your last paragraph about it getting more publicity than it really deserves.

------------------
Elias Valley Railroad (N-scale)
www.geocities.com/evrr

Posted by MPALMER (Member # 125) on :

My guess...Could any of it have to do with "modern" welded rail?
In years past most rails were short lengths (39 ft as discussed above), so there were a lot more expansion gaps for this kind of thing.

[This message has been edited by MPALMER (edited 08-16-2003).]

Posted by Geoff Mayo (Member # 153) on :

Modern rails are laid according to the average local conditions +/- a suitable factor. The rails are actually stretched when laid so that in theory they are in tension when cold and in compression when warm. Temps in Europe have been AIUI abnormally high, ie even beyond the overload factor. You can only design for so many conditions.

Geoff M.

Posted by RRCHINA (Member # 1514) on :

Welded rail has been used in the US since the 1950's. As discussed above, it is achored so that it must expand fatter and taller rather than the least resistance horizontally.

Welded rail, in the US, is laid in 1/4 mile strings and then those are weled together in the field to make even longer continuous welded rail. This is the standard on all major railroads principal routes. That is where their primary revenue sources are serviced so they obviously cannot tolerate problems with sun "kinks". Yes, they happen
occasionally, almost always as a result of maintenance errors.