Humber - Feeder 9

Humber Feeder 9 Gas Pipe line replacement project, a world record project involving a 5km 4.5m dia bored tunnel with a 1.2m concrete coated steel pipe inserted by thrusting - a world record.

The tunnel traversed the Humber Estuary at a maximum depth of 35m which required the compressed air interventions to be performed at low tides only. It featured the first use of MSV's in the UK due the steep vertical alignment

The tunnel boring machine was a HK mix-shield requiring 5 booster stations in the tunnel. Geology was chalk with the occasional flint nodule

The breakthrough was into a water filled shaft due to the soft, flowable nature of the ground in the shaft location