Tunnel Seal — AVN 1200

The seal a microtunnel machine drives through at the shaft wall, so ground water, soil and slurry stay out of the shaft around the machine. A 94-1/2 in square headwall plate (2,400 mm) anchors to the wall round its edge. On it sits a steel ring, then a 20 mm SBR rubber ring with its bore under the machine's OD, then 32 finger plates bolted through the rubber on its bolt circle. Each finger is slotted, so it slides in to back the rubber as the drive wears it. Lugs top and bottom take the rigging. About 1,970 lb of steel. We draw each seal to your headwall and your machine, for the launch or the reception shaft. The AVN 1200 seal in our work gallery is this build. Built in our shop by CWB-qualified welders, painted grey.