Pipe diameter upgrading from existing 150mm to 200mm diameter at Service Lane for No. 24& 24B Granville Road

2025-2026

Before

After

Project Overview

Trenchless upsizing of an existing 150mm sewer to 200mm diameter within a constrained urban service lane. The works utilised a purely mechanical pipe breaking method to fracture the host pipe and simultaneously install a new HDPE replacement pipeline — all carried out from just the two access manholes, with no open‑cut excavation along the pipe route.


Key Equipment

 

  • Hydraulic Jack (upstream manhole) – push / pull operation
  • Conical Bursting Head – fractures existing pipe and expands the cavity
  • Gantry (downstream manhole) – guides and supports the pulling assembly

Work Process

  1. Flow diversion and manhole preparation to accommodate equipment

  2. Drill rods advanced through the existing pipe from upstream to downstream manhole

  3. Bursting head and new HDPE pipe attached to the leading rod at the downstream end

  4. Hydraulic jack pulls the assembly back, breaking the old pipe and pulling in the new pipe in a single continuous operation

  5. Manhole equipment removed, works area reinstated, and post‑installation CCTV survey completed to verify alignment and integrity

Why This Technique?

    • Zero surface disruption along the pipe run – ideal for the narrow service lane.

    • Minimal footprint: only the two manholes served as work points.

    • Efficient upsizing without the cost or risk of full open-trench excavation.