It's this one in Epsom.
During excavations for gas works last month, one such joist was exposed, roughly a foot below the surface, and more or less where the white van is. It's roughly 18 inches by 18 inches square in section, so a really enormous beam and it appeared to be perpendicular to the wall on the left of the picture, but with no obvious way of reaching the wall on the right - it was aiming roughly at the middle of where the billboard is. Based on the position relative to the bridge itself, I would expect there to be four in total although only this one was exposed.
The interesting thing is that the gas men had to abandon their plans to re-lay the main along this road "because of engineering difficulties encountered", which I suspect - and which they haven't denied - was due to the state of the joist. ( NB Network Rail are aware of it so there is no need for anyone reading this to alert them. )
It appears that, obviously many years ago, another utility - not the gas - seems to have considered it a good idea to cut out a large section of the joist, about 90% of it in fact, to pass some pipes through below it. At that section, almost two feet long, only the top two or three inches or so thickness of the joist remains! As the pipes would have been run level, it's a fair bet that any other joists at this bridge - likely four in total - will have been similarly damaged, so probably very wise that the gas aborted their works pending further examination of the structure rather than expose the lot of them.
My obvious question is, will this damage to the joists be likely to result in some extensive and disruptive remedial works at some point? On the one hand the joists have obviously been in this state for many years already and the bridge has clearly been fine, but on the other hand with such damage having come to light, presumably it cannot be ignored, particularly since the gas main in the road in question will have to be replaced which would mean extensive excavation along the road there.
