Extreme heat house damage?

They don't in India or Australia need to cope wth below zero temperatures.

I don't know your gate, but steel is an excellent conductor, so the bottom may be almost as hot as the bit in the sun.

If there's a problem with buckling rails, just split them into 60' sections with gaps between them to allow for expansion. Then you also get a nice deedlidum sound as the carriages go over the gaps. You know it makes sense.

(To hold then ends together you bolt strips of metal between the ends, with slotted holes to allow for expansion. Then you think of a silly name for these metal strips - say, um, *fish plates*.)

The cut ends have to be pulled together before welding so that the rail is in tension most of the time.

No, it does not. If it is sufficiently constrained, is simply builds up the stress in the rail without any corresponding strain.

That is the whole point. A steel rail is a very long spring as it were.

And the buckling is controlled by Eulers rule (

Bear in mind that the loss of *just one* tie down will *quadruple* the chance of buckling in that section of rail, So a quarter the temperature difference between the buckling temperature and the 'temperature of no stress', in the rail will do the job.

I.e compared with a freshly laid track , a track that has *just one* tie down missing or loss, will buckle at one quarter the temperature change it would otherwise buckle at . If there are two missing, its one sixteenth.

If you have a very high summertime temperature and a very low winter temperature, you need to do a lot more track maintenance. Or accept lower speeds

If there is a problem with buckling rails consult a basic text book on Eulers buckling criteria and realise that you other possible ways to stop it beyond reducing the stress in the rail by using expansion joints (which smash the train wheels at speed).

Or you can save loads of money by restricting maintenance, and skimping on design, and limiting train speeds so that when the rail does buckle, no one gets killed.

Those who work on the railway safety reckon Euler’s critical load cannot be used directly: there's too much complexity from the multiple elements. And it does seem to me rather unlikely that thousand of miles of track around the world would be left at risk of catastrophic buckling from the failure of a single one of many millions of ties.

The felt won't melt but the glue holding it down might well. I doubt if it will lift though since it is intrinsically quite rigid.

Not a chance - the house would have to be on fire to melt lead or even to soften it.

Expansion of various plastics constrained by metal fittings could well lead to cracking in sheets held by some less well designed glazing bars.

Probably already in progress if you are on land that is susceptible. I haven't seen cracks in the clay going this deep for many years.

When I was a platelayer, the main overnight weekend task was replacing the short sections with long rails, but IIRC these had expansion joints in the form of very long overlapping taper joints. I believe that this did limit the 'wrong way' speed, but that wasn't a particular issue on the Paddington westwards stretch.

This was about 48 years ago. I seem to recall these joints were a few metres long, but that may be inaccurate. I don't know when or why these were changed for continuous pre-stressed rails.

I just found this...

Steel is quite poor compared to copper, maybe 20x worse. Pokers are made from steel.

My brother found some melted slots in the side of his printer like someone had stuck a soldering iron through and dragged it along. It was caused by a glass paperweight focussing the sun as it moved across the sky.

Bollocks

You are inventing an authority to avoid admitting you havent a clue

Ther are only a few elements. sleepers, ties and track.

And it does seem to me rather unlikely that thousand of miles

No, only the length of track where the tie has failed is at risk and then only if the weather is extreme.

In short there is certainly a margin for failure. In normal temperatures you probably are inside Euler limits with two adjacent ties missing But its marginal at three ties missing or two ties and a very hot rail.

So in order not to be blamed. since you don't know how good the track condition is, because you haven't the money to test it, you impose a speed limit so that a train wont jump the buckled section

I don't think it's THAT bad, but it is worse certainly

"The thermal conductivity of steel is measured at approximately 45 W/(mK), which is extremely low compared to copper and aluminium that exhibit a thermal conductivity value of 398 W/(mK) and 235 W/(mK) respectively."

That's an erroneous assumption. I was relying on stuff I'd been pointed to - though I admit freely I cannot follow the details let alone the formulae.

Anyhow, I'll show you mine if you show me yours.

I'll even start with a couple of examples:

Grissom, G. and Kerr, A. 2006. Analysis of lateral track buckling using new frame-type equations, Int J Mech Sci, 48:21-32.

"In the past several decades, many lateral track buckling studies have been conducted in an effort to determine an allowable safe temperature increase for preventing the occurrence of buckling. The present analysis builds on some of these studies, but uses recently derived frame-type equations that more accurately represent the response of the rail-tie structure in the lateral plane. The presented analysis takes into account the effects of the torsional stiffness of the rail fasteners, the lateral bending stiffness of the cross-ties, and the track gauge to model more accurately the lateral response of the track panel to temperature increases. It determines effective ways to raise the allowable safe temperature increase, whether by increasing the axial and lateral resistances or by increasing the rotational stiffness of the fasteners. Also, the effect of lateral tie-stiffness on the safe temperature increase is examined."

"Meanwhile, the critical force, which can buckle the structure, was first proposed by Leonhard Euler in 1757 for a column structure (Timoshenko and Gere, 2009). This formula evaluates the critical load that causes the sudden change in the lateral deflection of the column. This causes the loss of stability, ...It is important to note that a railway track can also be treated as a column structure with more elements and much complexity; therefore, Euler’s critical load cannot be used directly as a rail buckling force."

You stated "the loss of *just one* tie down" means "a quarter the temperature difference between the buckling temperature and the 'temperature of no stress'" will cause buckling.

Now it seems to be 2 ties missing *and* "a very hot rail" before it buckles.

The problem areas with flat roofs is where there are joints, typically the edgeing that laps up and over the upstand. Unless the joint is properly protected with solar chippings, this is where the failure starts.

There will be thunderstorms on late tuesday/wednesday for somw, and flat roofers will be in demand.

My younger son moved into a newbuild house last autumn. Yesterday one of two patio doors shattered into fragments, inner pane only. The door faces west so afternoon sun only. He rang the builder's maintenance company to get it replaced under warranty and they said it happened to several houses on his estate. Picture: