Dr Alun Thomas has a broad experience of many types of tunnelling methods from immersed tubes to segmental linings, from closed face TBMs to hand excavation under compressed air. He is a specialist in sprayed concrete lined (SCL/NATM) tunnels and numerical modelling. He has been involved in promoting the use of permanent sprayed concrete, fibre reinforcement and spray-applied waterproof membranes. More recently he has championed sustainability and carbon management. Over more than 30 years he has been involved in many of the major tunnelling projects in the UK. He is currently the Carbon manager at the Copenhagen metro.