If you look in the gallery there is a photo of an old pnuematic hammer which was used, its still there in one of the buildings that are waiting for demolition.
As for the theft, it was an inside job, the security firm employed some new lad, he was only there 3 weeks when it happened, as well as the propelor apparently they tried to steal 2 brass proppelors from outside the offices.
I work there and know the security gaurds, this is inside info so its true.
The security gaurd involved was not checked before recruitement and it turned out he had previous for deception.
Maybe next time they will vet their staff properly!
Btw, if you want pics of the proppelors you are best asking as EVERY vehicle that enters and exits is logged, everything is also recorded via 24/7 CCTV and security is 24/7.
They won`t mind if you ask politely