A Serious Question

[Bound2Please]

I have 4 by 60ft lengths of steel, that weight in at just over a ton each, all 4 have 2 by 7/8in diameter holes in each end.

The serious question here is how do I stop 2 of them expanding in 70f temperatures more than the other 2?

No silly replies like paint the ends white, or spray with water, as that's not an option. Scientific replies please.

[BrundallNavy]

Ask network rail, I think they have similar problems too 

[Guest]

1 hour ago, Bound2Please said:

I have 4 by 60ft lengths of steel, that weight in at just over a ton each, all 4 have 2 by 7/8in diameter holes in each end.

The serious question here is how do I stop 2 of them expanding in 70f temperatures more than the other 2?

No silly replies like paint the ends white, or spray with water, as that's not an option. Scientific replies please.

Have you got the Summer Rails?

[MauriceMynah]

3 minutes ago, Philosophical said:

Have you got the Summer Rails?

I understand there's a cream you can apply for that.

[TheQ]

Spend a few million on an under rail refridgeration system... they have the oposite for turnouts (points) with heaters to stop them freezing up in the winter...

[ExSurveyor]

Build a canopy over the affected area,  keep the sun off and you keep the heat off. 

[JanetAnne]

File the ends down on all four rails the relevant amount to compensate for the expansion when hot? 

When the rails are cool you will need to get all three passengers to jump as their carriage passes the gap.  If that isn't enough get the driver to jump at the same time. 

[grendel]

paint the whole piece white, not just the ends - better still polish them to a mirror finish.

[ChrisB]

3 hours ago, Bound2Please said:

I have 4 by 60ft lengths of steel, that weight in at just over a ton each, all 4 have 2 by 7/8in diameter holes in each end.

The serious question here is how do I stop 2 of them expanding in 70f temperatures more than the other 2?

No silly replies like paint the ends white, or spray with water, as that's not an option. Scientific replies please.

Is this because you are bolting them together and you want them all to remain stable? If you could describe the application that you intend doing with them.

[Guest]

7 minutes ago, JanetAnne said:

File the ends down on all four rails the relevant amount to compensate for the expansion when hot? 

When the rails are cool you will need to get all three passengers to jump as their carriage passes the gap.  If that isn't enough get the driver to jump at the same time. 

You have the basis of a good idea, file the ends in summer "brilliant". it is the winter solution that needs some work so why not have some short infill sections to "bridge the gap" (so to speak), no hang on that would cause too many track joints, ahh, why not have one long infill section? 

[JanetAnne]

Is this a modern problem?

I cant remember whether the bridges were out of action in the summer of 1976.... must have been too busy bathing with a friend!

[Bound2Please]

Strange isnt it, that every one bar one assumes I was talking about railway track.

[Timbo]

10 minutes ago, Bound2Please said:

Strange isnt it, that every one bar one assumes I was talking about railway track.

I know Charlie...it's because they are amateurs.  I realised straight away you were building a guide rail to be fastened to the bed of the River Ant for a self-steering system for your boat. A log flume but with no wash, ideal for a Theme Park! 

[Paul]

steel rail expands at a rate of 0.00000686 per unit length per degree farenheit. Assuming an ambient temperature of 60f then a 60ft rail has an maximum expansion of 0.00000686ft x 80, assuming a maximum rail temperature of 140f (the rail will be considerably hotter than air if in direct sunlight) x 60ft for the length of the rail then the maximum expansion will be in the region of 0.3951 inches or 10.04mm. The maximum expansion gap on rail track in the UK varies dependent on rail type, fixing type and dimensions etc between 14.28 and 14.31mm.   

I fail to see a problem?

 

[Cockatoo]

You could always get another 4 slightly shorter and use those during the summer. You might even find some suitable ones laying around.

[Guest]

17 minutes ago, Timbo said:

I know Charlie...it's because they are amateurs.  I realised straight away you were building a guide rail to be fastened to the bed of the River Ant for a self-steering system for your boat. A log flume but with no wash, ideal for a Theme Park! 

At first I thought he was building a greenhouse from the lengths of steel, but was worried that the expansion of the metal would cause the glass to crack.

[Guest]

19 minutes ago, SteveDuk said:

You could always get another 4 slightly shorter and use those during the summer. You might even find some suitable ones laying around.

Would these shorter ones have a name  by chance?

[Cockatoo]

2 minutes ago, Philosophical said:

Would these shorter ones have a name  by chance?

I think they are called "higher ambient temperature operating condition substitution lengths of steel"

 

[Maxwellian]

Well Charlie at least you got one scientific answer.

[Regulo]

That's one more than I thought he'd get!

[Bound2Please]

1 hour ago, Maxwellian said:

Well Charlie at least you got one scientific answer.

But from a practical response it was well out, as I have known rails so hot, sausages have been cooked on them, that are in direct sunshine.

Back to the question, how do two get to expand less than the other two.

[Cockatoo]

They don't, the other two are shorter to begin with :)

[JanetAnne]

Now if it was rails we were talking about, though it seems we are possibly not, I would drill a cooling hole down the length of the two rails intended to remain to size and pump cooling water along the inside of said metal. 

If I was fortunate enough to have a local source of water like, for example, a river below and the water was not the wrong type of water then I could potentially keep my steel cool and to size.

[grendel]

is the steel of all 4 pieces the same composition, there must be steels with a lower expansion coefficient.

[Guest]

15 minutes ago, grendel said:

is the steel of all 4 pieces the same composition, there must be steels with a lower expansion coefficient.

I believe I read somewhere that with different metal grain compositions resulting from modified forming and rolling processes, it is possible to get long sections of steel to expand somewhat width ways rather than predominantly length ways.