Comparison of Dynamic Response of Chinese Lantern and Lazy S Riser Configurations Used in CALM Oil Terminal

The risers are one of the most important components of the CALM oil terminal during the unloading/loading operations of tankers, which are used in two common configurations, including Chinese Lantern and Lazy S. It is common to not consider the interaction between these riser configurations and the mooring system. Therefore, the purpose of this paper is to compare the permissible horizontal displacement range or SAFOP of each of these risers in interaction with the mooring system and also to compare the dynamic response of these risers under operating conditions using OrcaFlex software with Persian Gulf environmental conditions in 16 coordinate directions. The results show that the Chinese Lantern configuration performs better in terms of SAFOP than Lazy S. The results also show that in the most critical case, the maximum tension created in the PLEM is 7% higher in the riser with the Lazy S configuration than in the riser with the Chinese lantern configuration. However, the maximum bending moment created in the riser with the Chinese Lantern configuration is 73% higher than the riser with the Lazy S configuration.