Civil Engineering May 2022 | Vol 30 No 4

Civil Engineering May 2022 11 “A hallmark of this massive project was how smoothly it ran from start to finish. This was a complex mega project in West Africa with a very compressed timeline, so it was quite an achievement for everyone involved to deliver as much as we have. Fortunately, Covid-19 only really impacted the de-mobilisation phase, as marine contractor CHEC still had marine equipment on site,” he adds. CONSTRUCTION CHALLENGES Any project of this scale is bound to encounter challenges. On this project, these included contractual, weather, technical, logistical, social, and even language barriers due to Chinese, Ghanaian and French contractors being on site, aside from the multinational client and consulting teams. The construction aspect of the project was also not without its challenges. To support the construction schedule, certain aspects were altered. The quay wall, for example, was originally conceived as a conventional gravity blockwork wall, but after detailed plan- ning was undertaken, it was found that the required number of blocks to be placed would delay the schedule. To ad- dress this, a decision was taken to design and construct the quay wall using 2 700 t caissons which significantly saved time and kept the marine works on schedule. Ghana also experiences unsuitable sea conditions for marine construction for several months each year. In order to safely place the caissons and carry out the hard rock dredging, the advance of the breakwater was carefully planned and constructed. The advancing breakwater provided enough sheltered water for year- round marine operations. Furthermore, Ghana is a seismically active zone, which required that special attention be given to the design of the marine and land infrastructure. The design needed to address liquification of marine sediments and the reclamation materials, and the structural stability of the breakwater, quay wall and buildings. Solutions included the removal of lique- faction-prone materials, consolidation of marginal foundation materials and detailed analysis and structural design of major elements. SAFETY FIRST A robust safety culture was established between the employer, engineer and con- tractors early in the project. Close coop- eration between all parties and common project-wide HSE protocols were vital in supporting the objectives of the share- holders and funders. These resulted in excellent track records for health, safety, environment and social performance. The project recorded over 16 million hours with only three lost time injuries (LTIs). A further five million hours were worked after the last LTI, resulting in an LTI frequency rate of 0.04 and a total recordable incident rate of 0.46. Some specific measures were instituted such as weekly management safety walks, safety rewards and recognition, integration of the construction and safety teams and limiting the use of divers during works checks when using eco-scopes and bathy- metric surveys. Thorough risk-related assessments and investigation reporting processes were implemented and accepted by the contractors to report all incidents, regardless of severity. This aided the risk management and development of the lessons learnt. This remarkable record was achieved despite cultural and experience differences between the multi-national team. Another tribute to the excellent safety record was the awarding of the ENR Global Best Projects Award 2021 for Best Airport/Port for the Tema Port Expansion Project Phase One. Entries could only be made for projects that did not have any construction-related fatalities, and construction had to be completed between January 2020 and May 2021. ENR’s annual Global Best Projects competition identifies and honours the project teams behind outstanding design and construction efforts. At least one firm involved in the project must be working outside of its home country, and projects are partially weighted by how globally diverse those teams are. ENVIRONMENTAL CONSIDERATIONS “A construction project of this magnitude has significant scope for the degradation of the environment and the local com- munities, mainly fishermen. It was vital to carry out all construction works and subsequent operations in a manner that minimised any negative impact on the community, as well as the on and offshore environment. From an environmental perspective, AECOM was at the forefront of mitigating, offsetting, and ensuring environmental compliance to the highest standards,” says Simpson. Full-time environmental special- ists ensured International Finance Corporation (IFC) compliance, which relates to environmental and social performance standards that define responsibilities for managing environ- mental and social risks. For example, “A hallmark of this massive project was how smoothly it ran from start to finish. This was a complex mega project in West Africa with a very compressed timeline, so it was quite an achievement for everyone involved to deliver as much as we have.”