David has over 50 years of experience in tunnel engineering, mining and geotechnics. His work has involved the design of tunnels, underground excavations and slopes in rock; sprayed concrete support design; cut-and-cover tunnels; invention and design of geotechnical products; tunnel refurbishment; underground mining development and capital works design; ground investigation; assessment of subsidence from underground activities; environmental, economic and contractual aspects of construction. He has undertaken numerous appointments on peer review and expert advisory panels and as expert witness in Parliamentary Committee, Public Enquiry and in the High Court. David is a retired Colonel in the Engineer & Logistics Staff Corps, a volunteer reserve group within 77th Brigade of the Royal Engineers regiment.