Crux Substructure EPC and Offshore Installation Project
Project
Crux Substructure EPC and Offshore Installation Project
Client
Shell Australia
Contractor
PT McDermott Indonesia (PTMI)
Location
Batam, Indonesia
Project Period
February – March 2025
OCS was awarded the subcontract to carry out dredging services at the PTMI North Yard in Batam, Indonesia, to provide sufficient water depth for the Crux Jacket transportation barge which based on the bathymetric survey results at the PTMI North Yard, the water depth in certain areas did not meet the required keel clearance for the jacket transportation barge and require to conduct the dredging.
OCS Scope:
OCS’ scope of work included the provision of dredging services within the designated North Yard dredge area to achieve the target depth of 8.5 metres. The excavation requirement in the North East corner was close to a hard layer of Conglomerate Rock Layer with a compressive strength ranging from 22.4 to 32.4 MPa, as identified in the borehole logs.
The cornerstone of OCS’ execution plan was the UB-01 “Miss Pennie” barge, which was equipped with a centrally controlled 8-point mooring system, four independent spuds, a 90-tonne crane, and two units of CAT390 long-arm excavators. The operation was supported by the Multicat AHT “Miss Bee.”
The CAT390 excavators were equipped with 2.0 m³ buckets to perform dredging and cleaning operations until the hard layer was exposed. Subsequently, one of the excavators was reconfigured by replacing the bucket attachment with a drum cutter to excavate the hard layer.
The excavated materials were loaded onto a hopper barge and transported to a pre-approved disposal location.
Project Outcome:
The dredging works were completed successfully, achieving the required target depth to meet the keel clearance requirement for the Crux Jacket transportation barge in timely manner. OCS’ deployment of specialised dredging equipment, combined with experienced marine construction personnel and effective execution planning, ensured that the works were carried out safely and efficiently while overcoming the challenges posed by the hard rock layer.
