Offshore operations in shallow waters often create operational trade-offs for vessel owners. Subsea infrastructure maintenance demands heavy-duty mission equipment, including Dynamic Positioning (DP2), integrated diving systems, deck cranes, and compliance with the Special Purpose Ships (SPS) Code. Existing vessels commonly feature drafts that restrict them from accessing shallow water. To address this operational constraint in the Gulf Region, Zamil Offshore contracted Conoship International to design a cost-effective Dive Support Vessel (DSV) with a shallow draft of 2.5-meter without sacrificing operational capabilities and fuel efficiency. Conoship executed both the Concept and Basic Design phases of the design
Hydrodynamic Efficiency and Shallow Water Access
Designing a DSV with a limited draft requires close attention to structural weight, stability, and
resistance. Carefully balancing these aspects resulted in a vessel that combines low fuel consumption
with a high level of operational performance and versatility.
Conoship mainly focused on hull line optimization and spatial configuration to maintain operational
standards:
- Hull Line Optimizations: CFD analysis and tank testing have been applied to minimize hull
resistance and optimized flow to the propulsion gear. - Deck and Equipment Layout: The versatile design features a clear working deck of 360 m2
that has been reinforced for the carriage of heavy deck cargo. A knuckle boom crane with a
reach of 22 m and 20 ton load capacity enables offshore lifting operations. Dive support
capabilities are centered around a dedicated diving deck and control room featuring
equipment including LARS, ROV and dive support systems. - Operational Capabilities: Station keeping can be achieved by the class 2 Dynamic Positioning
system or by twin spud-poles in shallow draft scenarios. Adding versatility, 5 dedicated dry
bulk tanks allow supply of cargo to offshore operations. - Fuel Efficiency: Lower hull resistance and optimized engine load distribution reduce fuel
consumption per operational hour compared to standard alternatives.
Tailored Design for Zamil’s Fleet Requirements
Zamil Offshore required a modern, highly specialized asset to support subsea infrastructure operations, including maintenance for regional oil and gas installation. Rather than adapting an ‘off the shelf’ design, Zamil sought a state-of-the-art vessel built around low fuel consumption, efficient maintenance, and high operational reliability.To meet these requirements for subsea infrastructure work, Conoship designed a light-weight hull structure and optimized hull shape giving unique performance in shallow waters. Combined with an efficient diesel-electric propulsion arrangement for DP operations, the vessel burns less fuel. This gives Zamil a specialized asset that cuts daily operational costs and lowers emissions without sacrificing capability
Class Approval and Engineering Execution
The design complies with ABS Class rules and the SPS Code. This confirms that specialized operational capabilities can be integrated into a shallow draft profile. Conoship’s scope covered the full Concept and Basic Design packages, delivering a complete engineering package suited for yard selection and
construction.This collaboration reinforces Conoship’s experience in custom naval architecture and specialized
offshore vessel engineering.
Main Characteristics of the Dive Support Vessel
- Length: 76.20 m
- Beam: 17.00 m
- Draft maximum: 2.50 m
- Deadweight: approx.. 950 tons
- Dynamic positioning: DP class 2
- Accommodation capacity: 76 persons
- Propulsion: 2 x Azimuth thruster
- Deck equipment: 22m – 20 t knuckle-boom crane
- Dive equipment: LARS, ROV, and dive support systems
