Patrick Stevedores required certification of all aspects of operation of a new mobile harbour crane at their Fisherman Islands container terminal. This was necessary in order to gain approval to operate the crane from the Port of Brisbane Corporation (PBC), the owner and lessor of the wharf. At the time of CGR being commissioned for the work, the crane had already been ordered and was being shipped to Brisbane.
CGR was responsible for the analysis and assessment of the capacity of the wharf as well as for making recommendations and compiling a report for submission to PBC.
A start up meeting was held with PBC to obtain the necessary information and to discuss their concerns. Until that time, Gottwald, the crane manufacturer, had indicated that they believed the crane loading, particularly the travelling loads, would be acceptable. The manufacturer’s assessment was based on the travelling loads being calculated by distributing the total crane load uniformly over the whole plan area of the crane, rather than just over the actual contact area of the tyres. It was agreed with PBC that this was not an appropriate consideration.
CGR therefore undertook a finite element analysis of the wharf in order to obtain the most accurate results for the client. The wharf is a flat slab construction between the crane beams with a relieving slab behind the rear crane beam.
The results showed that certain restrictions would be required for operation of the crane as well as for traverse / travel of the crane on the wharf.
After discussion with operations personnel at both Patrick’s and Gottwald, recommendations were made regarding load limitations and travel area restrictions. This discussion was undertaken to ensure that the proposed limitations would allow maximum use of the crane for Patrick Stevedores while at the same time maintaining safe operations on the wharf for PBC.
After delivery of the crane and once the required modifications had been made, CGR was present for a trial traverse of the crane to the front of the wharf. Although this was successful, the difficulty of the operation for the crane driver was noted. CGR subsequently reviewed the analysis regarding the travel for the crane to the front of the wharf and a new access method was then proposed which simplified the traverse procedure.
The mobile crane was safely operated on Berths 1, 2 and 3 for several months before being relocated by the operator to a new berth at the terminal.