This European Standard is applicable to all types of shield machines and associated back up equipment, thrust boring machines, auger boring machines and lining erection equipment. It specifies the essential safety requirements for the design, installation, maintenance, and information for use of such machines. Shield machines and associated back up equipment include: - open shields for both manual and mechanical excavation; - shielded tunnel boring machines; - micro tunnelling machines; - towed or stationary back up equipment; - pipe jacking equipment. All shield machines provide lateral and radial ground support. In addition they may provide various types of face support and ground water control (see Clause 3).