cctv at the o2 arena in london

A.t.t was recently called to carry out a CCTV survey at the o2 in London, we had to survey 3 runs in total all 450mm diameter, we used out state of the art crawler unit from AMI, a fantastic system with a great picture, we found one length was full of concrete one which had a few cracks and displacement's and another which had a few crack's. we have recommended patch lining so you never know we my be back there in the near future. unfortunately the run that is 100% full of concrete needs to be