Does anyone know what happened this morning? it was closed both ways and the cab I was in had to try and turn around and go over tower bridge. I know they had closed for maintenance 10pm to 6am. but it was open yesterday..
Yesterday morning there was a pile of wall tiles about 1/3rd of the way through. I heard that during the night or early morning a further number fell from the roof of the tunnel onto the carriageway. Not sure whether this is related to cold or moisture or both. I imagine that it's both although the tunnel has not generally been as cold as the upper ground areas, water or moisture trapped in the plaster freezes and expands causing slippage and this is exacerbated as it freezes, defrosts, refreezes etc (look up the "peculiar expansion of water" if you fancy more technical detail).
Exactly the same reason we have cracks in the carriageway although these are made much worse by vehicles running on them. Hopefully it's not anything more ominous.
Thank you Marcusm for giving me another thing to remember that I find interesting.:-) it's a wonderful old tunnel which was built with skill a hundred years or so ago, I wonder if anything that is built today that has such heavy daily use will last that long?
going off now to read up on 'the peculiar expansion of water'...