A One-pass lining consist of solid reinforced concrete segments manufactured in accordance with the Civil Engineering Specification for the water Industry. It provides a finished shaft or tunnel in one operation. By eliminating the need for a secondary lining, it can offer a significant reduction in overall construction time with consequent savings in costs.
Lining design takes advantage of the full section thickness, avoiding local weaknesses at bolt pockets. Shafts can be built using underpinning, caisson or jacking techniques. The units are reinforced to withstand normal handling and erection stresses. They are suitable for all ground conditions. Special units can be fabricated to support platforms and landings in shafts.