Oh dear! Can physically isolating the rails from each other have a significant effect on noise and vibration? I really would have expected tie bars somewhere in the design.
A tie bar wouldn‘t make any difference with the forces involved. What would be the benefit anyway? LVT is used everywhere in the world, including the channel tunnel, the east london line etc.
Maybe a tiebar wouldn't have made any difference, but it appears the blocks holding each rail fastening have parted company with the main slab at what I presume a rubber/plastic "boots" that provide some vibration isolation. This might not have happened if the fastenings had been set into the main slab. Or at least it would only have happened at a higher impact force than it did here. We don't know whether the impact forces in this accident were in the range where it would have made a difference, or whether there would have been any change to the accident sequence if it had.
Not just some isolation, the rubber boot replaces the dampening of the ballast on conventional track. The whole point of the system is, that the concrete blocks are not connected to the base plate.
Noted thanks. There are other slab track systems which don't have this isolation, so I guess the dampening isn't fundamentally necessary.
but I am surprised that the damping would be unacceptably jeopardised by having a tie bar between the concrete pads, effectively making them back into single sleepers. There used to be lots of these in France a few decades ago, an angle iron across the centre. I don't know whether that was to save weight or materials.
It saves both, plus it provides an extra face on the sleeper to resist lateral movement in hot weather, plus it helps to prevent a sleeper becoming centre bound.
...as you could if it was bridged by a tie-bar.
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The diversion was a recent bonus for me, mirrorring a trip of years sgo.From this article, it seems the Gotthard Base tunnel is open again for a very limited passenger service - the undamaged eastern bore is otherwise dedicated to freight.
Passenger service resumes through Gotthard Base Tunnel
SWITZERLAND: Swiss Federal Railways has reintroduced a limited passenger service through the 57 km trans-Alpine Gotthard Base Tunnel. The world's longest railway tunnel was badly damaged when a freight train derailed on August 10, affecting 8 km of one of the two running bores, and one of ...
Repairs to the western bore will take several months, with a detailed plan available by the end of October.
Diversions of most passenger trains via the 1882 mountain route will continue, with double-deck trains not cleared on this route.
