G44 sleeper query

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Ploughman

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THe NYMR PW dept has just bought in some second hand G44 sleepers as we have done in the past few years.
However this time round at least 2 of the sleepers have these 25 mm approx studs embedded in them. They will be cut off before we lay them though.

This got me wondering what they were used to fasten down.
Any ideas ?

I am very familiar with G44's having used them many times on NWR Relays around the country but do not recall them of this size.

Initial thoughts were for mounting AWS ramps but that would be a pair of smaller bolts.
Could they be for S+C Stress beams?
 

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Trog

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G44EX used either side of two concrete bearers that carry the blades of an adjustment switch, the studs would have held down the strap rails.
 
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Ploughman

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Thanks for the replies.
Looks like query answered.
Especially as the 2 sleepers in the photo are black painted on the end with EX written on.
Why didn't I see that before?
Couple of hundred of these and about 800 steels going in this winter.
 

a_c_skinner

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"adjustment switch"

I've seen these, assumed they relieved thermal stress, but from the name I imagine I'm wrong.

AS
 

civ-eng-jim

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"adjustment switch"

I've seen these, assumed they relieved thermal stress, but from the name I imagine I'm wrong.

AS

Trog may correct me but the terms expansion switch and adjustment switch are used to describe the same thing.

This photo is a structural adjustment switch on the Medway viaduct on the Channel Tunnel Rail Link to cater for expansion/contraction of a bridge deck.

Much longer than a thermal adjustment switch.
 

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Trog

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Adjustment and breather switch are the terms I have heard used most often, but the names of P-Way components can vary from place to place. So expansion switch may be equally valid. Either way it is a device used to take up thermal expansion of the rails where the track or the structure the track is on is such that the track can not just be left to absorb/resist those forces. There are several designs and they can be found on timber, concrete and steel sleepers.
 

Ships

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Trog may correct me but the terms expansion switch and adjustment switch are used to describe the same thing.

This photo is a structural adjustment switch on the Medway viaduct on the Channel Tunnel Rail Link to cater for expansion/contraction of a bridge deck.

Much longer than a thermal adjustment switch.

Normal breathers are used for structures too
--- old post above --- --- new post below ---
THe NYMR PW dept has just bought in some second hand G44 sleepers as we have done in the past few years.
However this time round at least 2 of the sleepers have these 25 mm approx studs embedded in them. They will be cut off before we lay them though.

This got me wondering what they were used to fasten down.
Any ideas ?

I am very familiar with G44's having used them many times on NWR Relays around the country but do not recall them of this size.

Initial thoughts were for mounting AWS ramps but that would be a pair of smaller bolts.
Could they be for S+C Stress beams?

I would love to know how you've gotten hold of 800 odd of these, were supposed to specify serviceable on cat 3 and below routes but you can never get serviceable g44s. If your mixing steels and concs don't forget your transition woods ;)
 
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Trog

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If you are mixing steels and concs don't forget your transition woods ;)

Minimum of four in case anyone was wondering, you can use more but as they are more expensive than steel or concrete and do not last as long you should only use more if you have good reason.
--- old post above --- --- new post below ---
Normal breathers are used for structures too


I think the channel tunnel rail link is built more to French standards than our own, hence the strange design of breather, which looks like a modernised version of the sort of thing we were using in the 1960's.

Interesting that the two switches face in opposite directions, it has always been British custom and practice to lay breathers in so that trains running in the predominant direction of travel run off the inside blades rather than on to them. So if the blade tip were to break off, trains feel a bump as they go over the missing bit, rather than a bang as the wheels hit the broken end of the blade.
 
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