Shoalhaven Pumped Hydro Expansion

Project Overview

The project entails building a new pipeline adjacent to a current one at the Shoalhaven Hydropower plant. This encompasses the excavation of a downstream tunnel and undertaking subterranean drilling to create a chamber for accommodating the required mechanical machinery. In a decision rooted in Value Management, CPB opted for the Drill and Blast method of boring instead of using a Tunnel Boring Machine (TBM).

TBH’s Role

TBH was engaged to support the bidding process to provide a Quantitative Cost and Schedule Risk

Assessment to inform the TOC contingency allowances, which included:

• Undertaking a comprehensive review of the base schedule and cost to ensure their robustness.
• Facilitating workshops to establish and define both the inherent and contingent risk profiles.
• Implementing industry-leading practices in both Quantitative Cost Risk Analysis (QCRA) and Quantitative.
• Schedule Risk Analysis (QSRA), which encompasses the identification of correlation and prolongation costs.
• Confirming the accuracy of the results, including an assessment of various application scenarios.

The TBH Difference

The project faced challenges related to the availability of specialist contractors, environmental issues, unpredictable ground conditions, and the choice of tunnelling technique. Nevertheless, through meticulous collaboration with the project team, TBH successfully affirmed that the established contingency allowances were not only suitable and competitive but also accurately reflected the project’s risk profile and were in accordance with the type of contract in place. This collaborative effort also aided the alliance in evaluating various scenarios while formulating the Target Outturn Cost (TOC).