"Drills break through into busy London rail tunnel"

[muckymotor]

I suspect someone is in for an almighty bking

http://www.bbc.co.uk/news/uk-england-london-217153...

[Megaflow]

Somebody is going to need a lot more than the yellow pages down his pants for that one!

[12v3pot]

Feet vs metres? Wouldn't be the first time. :-)

[Mr_B]

Looks like a piling rig drill. If they broke through and were piling in the right place, then the foundations of whatever they are building will be right on that tunnel ?

[Chrisgr31]

My dad had that in Newcastle, where they tried to pile through the metro line. Of course it shouldnt happen and someone will have to explain what went wrong

[MOTORVATOR]

Mr_B said:

Looks like a piling rig drill. If they broke through and were piling in the right place, then the foundations of whatever they are building will be right on that tunnel ?

Continous flight auger piles. They won't necessarily gain their bearing capability from end bearing and rely heavily on skin friction. Install enough of them for what is beig supported and the loading on a tunnel can be negliable.

This isn't as uncommon as you might expect as it is down to the tunnel owner to determine the location and the accuracy of some of their records isn't all that.