In order to transfer sewage from the eastern to the western side of the Connaught St ridge, Sydney Water had the choice of constructing a Sewerage Pumping Station (SPS) and rising main or drilling through the ridge and lay a gravity Ø400 PE carrier for a distance of 500m. Economic modelling showed the gravity option to be the better choice.

Blackheath Microtunnelling Pezzimenti Free Pipe by Freebore method

Blackheath Microtunnelling pezzimenti 500m in Sandstone PE Pipe

Staged Microtunnels

The 500m was split into 2 sections 152m and 337m. A 16m deep shaft was constructed at Ch 152. The 152 m x Ø530mm microtunnel was constructed first, and then the 337m intercept bore was completed in 2 stages- 173m from the upstream end and 164m from the deep 16m shaft on the downstream end.

Intercept Microtunnel – 35m Below

The intercept microtunnel met within 40mm at the breakout point some 35m below the Connaught St ridge. The PE pipe was pulled in in one continuous length by the client and the annulus grouted by Pezzimenti Tunnelbore.

Blackheath Microtunnelling Pezzimenti Tunnelbore Loading a Rod

Blackheath Microtunnelling Pezzimenti Tunnelbore operator

Blackheath Microtunnelling Pezzimenti Tunnelbore microtunnelling in progress

Blackheath Microtunnelling Pezzimenti Tunnelbore end of stroke

Blackheath Download Microtunnelling Project PDF