Illustration 138693218 © Kkssr - Dreamstime.com
Illustration: Funtap P/Dreamstime.com
Drones have been used to undertake surveys on Crossrail sites
Clockwise from top left: Paul Surin (Wienerberger); John Bedford (Ark Consultancy); Terry Stocks (CDBB); Jaimie Johnston (Bryden Wood); Tim Thomas (BASF); Jeff House (Baxi)
Image: Kevin Christensen/Dreamstime.com