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Do tramway tracks have anything "special" to cope with thermal expansion..?

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As the title says basically - is anything special or different done to cope with thermal expansion/contraction of the rails for "tramway" track buried in road surfaces..?
 
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bassmike

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I would have thought that tramway tracks buried int the street surface need less allowances for expansion and contraction?
 

DJ_K666

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Depends on the ground. I do believe tram lines which are similar to railways have expansion joints (The DLR has them) but I do think the ground might conduct heat away.
 

507 001

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Not really, hence cracked rails are far more common in street running areas.
 

Bald Rick

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As the title says basically - is anything special or different done to cope with thermal expansion/contraction of the rails for "tramway" track buried in road surfaces..?

The issue with thermal expansion on the normal railway is the risk of rails buckling. This is much less of an issue when the rail is embedded in the road surface, as there is nowhere for the rails to buckle to without moving the road as well.
 

Pakenhamtrain

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The issue with thermal expansion on the normal railway is the risk of rails buckling. This is much less of an issue when the rail is embedded in the road surface, as there is nowhere for the rails to buckle to without moving the road as well.
As shown here in Riversdale Road Camberwell in 1991:
ayUav83.jpg
 
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Thanks for that photo.

The thought had occurred to me that, if they do go, the direction of least resistance would be upwards!

Another thought I had was that maybe because less surface is exposed to direct sunlight (ie just the crown and not the webs and feet) maybe they would heat up less than rail on sleepers/bearers.

Thanks all for your insights.
 
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DJ_K666

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As shown here in Riversdale Road Camberwell in 1991:
ayUav83.jpg
I'd imagine the problem might be more pronounced in a climate like Australia's. I read somewhere that LR55 rail is like a cartridge, maybe 15ft long that's dropped into a trench in the road surface and so if the track does buckle then the affected sections could be lifted out and replaced rather than doing all that chopping of long rails.
 

edwin_m

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I'd imagine the problem might be more pronounced in a climate like Australia's. I read somewhere that LR55 rail is like a cartridge, maybe 15ft long that's dropped into a trench in the road surface and so if the track does buckle then the affected sections could be lifted out and replaced rather than doing all that chopping of long rails.
That would surely mean a huge number of rail joints that would probably cause more problems than whatever they are trying to solve. As far as I know LR55 was never used beyond a short test section in Sheffield, though Prague does something similar and the VLR people may well be doing the same.
 

bassmike

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Depends on the ground. I do believe tram lines which are similar to railways have expansion joints (The DLR has them) but I do think the ground might conduct heat away.
The D L R does not use 'Tram lines' but ordinary ballasted flat-bottom rail.
 

WatcherZero

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Here they are usually laid in a concrete trough essentially becoming slab track, sometimes with a flexible polymer surround to the steel to allow a bit of flex.

Ultralight rail they are just laid on the ground without foundations though.
 

DJ_K666

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That would surely mean a huge number of rail joints that would probably cause more problems than whatever they are trying to solve. As far as I know LR55 was never used beyond a short test section in Sheffield, though Prague does something similar and the VLR people may well be doing the s

The D L R does not use 'Tram lines' but ordinary ballasted flat-bottom rail.
I was referring to the expansion joints which look like a short point blade and a bent piece of rail pointing out from the 4 foot. They use a combination of ballasted, sleeper ed track and slab track but yes flat bottom rail too.
 

Pakenhamtrain

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Here they are usually laid in a concrete trough essentially becoming slab track, sometimes with a flexible polymer surround to the steel to allow a bit of flex.

Ultralight rail they are just laid on the ground without foundations though.
We lay down concrete sleepers with rebar then pour the concrete or asphalt over it:

About the only place I can think of that expansion joints exist is over bridges:
Everywhere else it's just welded rail.
 
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