Anyone know what the critical temperature may be before damage occurs to rolling stock and locos? My loft is currently 49'c most I can take is 5 minutes before I have to come down... got me wondering

Quote from: Spanners70 on July 11, 2026, 05:36:03 PMAnyone know what the critical temperature may be before damage occurs to rolling stock and locos? My loft is currently 49'c most I can take is 5 minutes before I have to come down... got me wondering

I vaguely recall a lower limit being advised, but I don't think any manufacturer has ever stated an upper limit...

What some do panic over in hot weather is the expansion of track, but even those concerns are over-blown - the Coefficient of Expansion for Nickel Silver is 16 × 10^-16 /1 degree C, so you need around a 64°C temperature change, for a 1 metre length of flexitrack to expand by 1mm!

Well I'd certainly bring locos and stock down and out of that heat, I'd be concerned about plastic warping or cracking due to expansion of the metal chassis within.

I've always maintained that "raw" lofts, garages, shed etc. are no place for a model railway.

How hot does stuff get in a container on a ship passing through the tropics?
I suspect that's more of a test than a loft.

Quote from: PLD on July 11, 2026, 06:24:18 PMWhat some do panic over in hot weather is the expansion of track, but even those concerns are over-blown - the Coefficient of Expansion for Nickel Silver is 16 × 10^-16 /1 degree C, so you need around a 64°C temperature change, for a 1 metre length of flexitrack to expand by 1mm!

That may be the theory based on the material properties, but believe me I've had fiddleyard track start to snake in my conservatory at 30 degrees (only in there for testing before a show), and in hot exhibition halls.  It's only loosely pinned compared to the fully glued and ballasted track on the scenic parts of the layout - that's never suffered.

My stuff including my 25+ year old current layout have always been in my W. Texas garage with yearly swings from about 0 to 43 degrees.

Things are sluggish in the Winter and need more warming up, but things still work.

For what that's worth.

49 might be a different animal!

I don't have a thermometer to hand in the 'train room', but in preparation for an open day today, I ran some trains successfully yesterday morning (Friday). The locos all come to rest in an isolated section ahead of each red signal, before I 'power off'.
On power up this morning (Saturday) a Class 47 immediately proceeded to run into the train in the next section. The cause? The rails had expanded so much that the isolated rail had come into contact with the 'live' bit! Guess I should have used Peco Insulated joiners!
ps 'running day very successful!
Kev E.

Quote from: ntpntpntp on July 11, 2026, 07:04:21 PM

Quote from: PLD on July 11, 2026, 06:24:18 PMWhat some do panic over in hot weather is the expansion of track, but even those concerns are over-blown - the Coefficient of Expansion for Nickel Silver is 16 × 10^-16 /1 degree C, so you need around a 64°C temperature change, for a 1 metre length of flexitrack to expand by 1mm!

That may be the theory based on the material properties, but believe me I've had fiddleyard track start to snake in my conservatory at 30 degrees (only in there for testing before a show), and in hot exhibition halls.  It's only loosely pinned compared to the fully glued and ballasted track on the scenic parts of the layout - that's never suffered.

Agreed, the track on our club test track in the Clubroom (in a metal portable office) got very wibbly wobbly in hot weather. Also it isn't just about temperature it is about extremes of temperature too I would say. I have had very few split gears in my Farish diesel fleet, but then the temperature in my modelling room (in the house) is comparatively stable and I reckon that is a factor.

Quote from: ntpntpntp on July 11, 2026, 07:04:21 PM... believe me I've had fiddleyard track start to snake in my conservatory at 30 degrees (only in there for testing before a show), and in hot exhibition halls.

Found this shot of expansion problems on my son's narrow gauge layout a few years ago.  Granted he was still mastering track laying and soldering etc. but clearly he forgot to leave any gap at all at this board joint and this was the result @ 36 degrees in our conservatory    This joint had been perfectly fine until then.



The layout's subsequently been dismantled as tbh it was too ambitious, and as parents we had to point out we would need the room sometimes, there would be nowhere to store the layout, and it would be too large to ever take to a show in our car!

It is my unscientific observation that Farish diesel loco gears tend to split more if the layout room is hot. I used to have a lot of problems in NZ summers when my layout was in a shed in the garden.
A lot fewer since we moved house and the layout moved into a room in the house, double glazed and well insulated.

I agree with post #1 above.

Here in Australia my layout in the garage experiences large temperature differences, but the effects on the layout are minimal. Keeping track clean is the biggest problem out there.

As @PLD says, I think expansion problems are exaggerated.

You either experience them or you don't. I'm not sure you can say they're exaggerated, people are literally posting photos of the damage which has resulted from temperature related expansion. Bizarre comment.

I don't see anything bizarre about it at all, but we'll leave it at that.

I've over 700 items of rolling stock so dragging them all up and down depending on temperature is a no go. Had no issues with track, all laid with 0.5mm gap between lengths last summer nothing has moved despite -8 to +50.
One day I will get the wiring finished and start running stock at last

https://www.ngaugeforum.co.uk/SMFN/gallery/160/5079-120726094526-1607962474.jpeg

https://www.ngaugeforum.co.uk/SMFN/gallery/160/5079-120726094522-160795837.jpeg

Strewth!!
That's one helluva fiddle yard