Heathrow Structure
 

At Heathrow, UK, there is a strange, gantry-like structure which can be seen just inside the south perimeter, between Terminal 4 and the BA Cargo building. It has four legs forming a box-like structure, with something suspended between. I would estimate the height to be about 15 metres. It looks similar to the crane system used to pull small yachts out of the water, but obviously is not that. Anyone know what it is.........???

Ah Ha, rumours ( crew) over the months and years have ranged from it being a new roof for the nearby security check point to it being a engineering mock up for the T5 roof structure.......so yes, I'd also like to hear the truth........