Torres Strait Condition Assessment – Application of Inspection Manuals

Abstract

Torres Straight Island Regional Council manages the maritime infrastructure on 14 islands (15 communities) across the Torres Strait. The infrastructure comprises jetties, barge ramps and dolphins, which are an integral part of the goods and services supply chain and provide recreational boating access. The majority of the maritime infrastructure was constructed in the late 1980s and early 1990s. A condition inspection was undertaken in 2004 and significant deterioration was noted in the proceeding years. RHDHV were engaged to undertake a condition assessment of the infrastructure in 2021. The condition assessment included recommend actions for remediation and prioritization of the works. The condition assessment was undertaken in accordance with the TMR Bridge Inspection Manual (now Structures Inspection Manual) and the Port Australia Wharf Structures Condition Assessment Manual (WSCAM). The TMR Manual is applicable to infrastructure in Queensland. However, it is not specific to maritime infrastructure. WSCAM is specific to maritime infrastructure and offered a number of benefits. Implementation of the two manuals allowed for a condition assessment in accordance with TMR requirements, which was tailored to maritime infrastructure. The maritime infrastructure is nearing the end of its design life. Combined with overloading, a lack of tailored maintenance and high corrosion rates in a tropical environment, the infrastructure was generally in poor condition with limited remediation options available to extend the service life. Safety risks were identified at most locations. Suitably frequent condition assessments are recommended to allow for identification of defects and implementation of remediation actions, before the infrastructure becomes unsafe and unrepairable. Due to the condition of the infrastructure, broad scale replacement of the marine infrastructure is recommended. The presentation outlines failure mechanisms, explores lessons learnt in undertaking condition assessments in accordance with TMR Manual and WSCAM and provides recommendations for undertaking affordable and economical condition assessments in remote locations.