Trespassers 'reach summit of shard'

We believe this is an incident which took place around December 2010 when we were undertaking both ground and structure works.

The breach was discovered very soon afterwards and security immediately tightened.

Today security on the site is tight with 14 night-time security guards on duty continuously who cover all areas, as well as 25 CCTV cameras in operation together with a ground floor level laser alarm system.

It took a few minutes of lingering before the walkway was clear of people - we grabbed onto the scaffolding pipes and swung off the bridge.

Hanging on the freezing pipes, we pulled ourselves on top of the walkway and laid down out of view, waiting for a reaction in case anyone had seen or heard us. It didn't seem so.

Staying low, we then descended the other side of the scaffolding, right behind the security hut where we could see the guard watching TV, not the cameras.

Quickly, we scampered across the yard and found the central stair case, again pausing to see if there was any reaction from the yard, phones ringing or doors opening. It was silent.

We were so high, I couldn't see anything moving at street level. No buses, no cars, just rows of lights and train lines that looked like converging river systems, a giant urban circuit board.