Flow Field Investigation for a Cable-Burying Jet Trenching Tool

Abstract Post Lay Burial of underwater cables is a well-spread protection method for the cable assets in most cases. In certain types of soil, Jet Trenching tools are used for cable burial. Such tools are Asso.subsea’s AssoJet III series of jet trenchers with swords baring cutting nozzles, custom made and tailored for Asso.subsea project needs, with in-house design, engineering and construction by the company itself. This tool is investigated in terms of its flow field under operating conditions. The flow field induced post the jetting nozzles is crucial for the effective cutting ability of the tool, especially in cohesive soils with higher Undrained Shear Strength (Su/Cu), thus the knowledge of the flow field characteristics is important for assessing many operational parameters and optimizing them. The present study displays the investigation of the flow field for AssoJet III tool under steady state conditions for 2 individual approaches under Project specific configuration for the tool. Results give insight for operational optimization, are in agreement with relevant literature, while match with in-situ observations during operation on the field.