Ship-to-Ship Mooring Analysis for Haizhou Bay Star and Pontoon

Ship-to-Ship (STS) Coupled Mooring Project

Project: Haizhou Bay Star

Project Type: Mooring system design and CCS approval for a floating hotel vessel and pontoon facility.

Location: Haizhou Bay, China

Classification Society: China Classification Society (CCS)

Applicable Rules: CCS Rules for Classification of Mobile Offshore Units (2023)

Haizhou Bay Star is China’s first CCS-classed near-shore floating recreation facility. The project combines a floating hotel vessel with a separate pontoon that provides passenger access from shore.

Because the facility is located in a shallow-water harbour basin, a conventional anchor-based mooring arrangement was not suitable. The project therefore adopted a special mooring system using suction piles as the seabed anchoring points.

The main engineering challenge was to control the movements of both Haizhou Bay Star and the pontoon within an acceptable operating range, allowing the shore-connected gangway to remain accessible and safe under the specified environmental conditions.Project Overview

STS Mooring Analysis and Engineering Scope

Final class approval support: Updated the analysis and documentation to reflect the as-installed mooring arrangement and supported the project through final CCS approval.Scope of Work
Engineering Basis and Outcome
Need Mooring Analysis Support

Access feasibility assessment: Worked with the client during the early project stage to evaluate different passenger boarding and access arrangements for Haizhou Bay Star.

Mooring concept development: Developed and evaluated the concept of mooring Haizhou Bay Star together with a separate pontoon, which provides the connection between the floating hotel vessel and the shore-based gangway.

Mooring system design: Designed and refined the combined mooring arrangement for Haizhou Bay Star and the pontoon, including the suction-pile anchoring concept, mooring line arrangement and connection details.

Vessel modification: Designed additional padeyes on Haizhou Bay Star for the mooring connections between the vessel and the pontoon.

CCS submission and technical clarification: Prepared the mooring analysis and supporting documentation for CCS review, and responded to technical comments concerning environmental load selection, damping assumptions and other calculation parameters.

Site-condition design revision: Revised the mooring line arrangement after the installed suction piles experienced significant positional deviations due to site geotechnical and construction constraints.

CCS Approval Outcome for the STS Mooring Analysis Report

The mooring analysis was performed with reference to the applicable requirements of the CCS Rules for Classification of Mobile Offshore Units (2023). The assessment covered both operating and survival conditions, with particular attention given to verifying the mooring system under the survival environmental condition.

The engineering model considered the combined response of Haizhou Bay Star and the pontoon, the environmental loads, damping assumptions, mooring line characteristics and the suction-pile anchoring arrangement. Following installation, the analysis was revised to reflect the actual positions of the suction piles and the corresponding changes to the mooring line arrangement.

The final calculation report demonstrated that the movements of Haizhou Bay Star and the pontoon could be maintained within the required range under the assessed conditions. This enabled the shore-connected gangway to remain functional and provided a practical boarding arrangement for the floating facility.

The submitted mooring analysis and the final as-installed arrangement were reviewed and approved by CCS.