M2 Motorway -- Stockbury Valley Viaduct. These slender pillars of reinforced concrete will carry the new Stockbury Valley viaduct 800 feet across the valley, south-west of Sittingbourne, Kent. The viaduct will have ten spans, the longest of them 85 feet, and will cross the A249 at a height of 80 feet. Christiani and Nielson are the reinforced concrete engineers and J.L Kier & Company are contractors for the bridge. Kent, England. 05 June 1962.