30
Consulting Matters Project case studies
Kimberley Ports Authority: Wharf Extension Underdeck Access Involving the conceptual development, detail design and installation of an access system for the routine inspection and maintenance of underdeck assets, including piles, headstocks and services along the full length of the Broome Port Wharf in the northwest of WA, the wharf consists of the original portion, constructed in the 1960's, and the later extension constructed in 2007. A simple access system is installed to the soffit of the original wharf deck but not to the wharf extension. Wave International was commissioned to perform the detailed structural and mechanical engineering design for the wharf extension access system and develop solutions to numerous challenges arising from the client’s design brief, the operational environment, existing constraints, and the contractor’s execution methodology.
Figure 1 – Elevations of new underdeck access trolley – boom arms extended
Significant for numerous stakeholders, in addition to the extension of asset life for the client, further economic, safety and environmental benefits were to be realised. For example, prior to the new installation, all inspection and maintenance works under the wharf extension had to be completed using cantilevered / hanging scaffolding, top-side mobile cranes, boats and barges, attracting additional overhead costs and increasing the risks to maintenance crews. The new access system sought to mitigate these risks and the design requirement for full encapsulation, further enhanced safety and ensured any negative environmental impacts, particularly from blasting and painting operations, were minimal. The design portion of the project, though small in scale and dollar value as far as engineering projects are concerned, was big on innovation combined with solid, firstprinciples engineering. The final design of the access system (shown in Figures 1 to 3), is, put simply, a travelling personnel basket. It allows for complete access to all areas of the headstocks and piles within the tidal zone for up to four people and tools, under various combinations of dead, live, wind and wave loading conditions. It consists of an upper steel frame to house the main driving components, wheel bogies and slewing frame, with aluminium framing for the walking deck, driving cabin and extending boom arms to help reduce the overall weight.
Figure 2 – Plan view of new underdeck access trolley
