Civil Engineering September 2022 | Vol 30 No 8

Civil Engineering September 2022 53 to the SBM 3 km offshore. Three product pipelines were put into one carrier pipeline ashore. A PLEM was piled into the seabed which connected the carrier pipeline to the SBM. The SBM was anchored into position next to the PLEM. The volume outside the product pipelines but within the carrier pipeline was filled with an inhibiter fluid. These pipelines are still in operation within the port limits of Mossel Bay. Onshore and offshore pipeline to the CALM A 12-inch pipeline was installed from the PetroSA storage tank farm to the CALM 2 km offshore and 2 km to the PetroSA alcohol terminal. A PLEM was piled into the seabed, which connected to the pipeline and to the CALM. The CALM was anchored on the seafloor next to the PLEM. This pipeline is still in operation and within the port limits of Mossel Bay. DURBAN ONSHORE (PRIVATE) There are pipelines from both the Engen and SAPREF refineries that connect the refineries with the tankage in the harbour. They are bi-directional since product can be pumped to the harbour for export, for injection into the MPP24 for transport inland, or to move imported product or blend stocks from the harbour to the refineries. The integrity of these lines is maintained to ensure they are available for daily operation when the refineries are in operation. The Engen refinery has not been in operation since December 2020 after an explosion that resulted in the facility being shut down. Engen has subsequently decided not to restart the refinery. However, the pipelines now bring imported product back to the loading Figure 10 Onshore and offshore pipeline to the CALM Figure 9 Mossel Bay offshore pipelines being laid using the S-lay method The Engen refinery has not been in operation since December 2020 after an explosion that resulted in the facility being shut down. Engen has subsequently decided not to restart the refinery. However, the pipelines now bring imported product back to the loading terminal at Wentworth, adjacent to the refinery, so they are still operational.