Michael Tomlinson has a lifetime's experience in piling and foundations. He worked for George Wimpey Ltd for nearly 30 years on the design and construction of foundations and earthworks. Since 1976 he has been an independent consulting engineer. He has worked in many parts of the world and is the author of a number of technical papers on piles and their behaviour in different soils. He was the first recipient of the Skempton Gold Medal inaugurated by the British Geotechnical Society in 1998.John Woodward has undertaken the design and construction of a wide variety of geotechnical work in the UK and overseas. For the past 10 years he has acted as arbitrator and adjudicator resolving contractual disputes concerned with piling, drilling and contaminated land. In addition he works as an independent consultant and lectures on foundation design and construction. He is the author of several papers and An Introduction to Geotechnical Processes (Taylor and Francis, 2005).