Selection Guide for Marine Heavy-Duty Double-Post Mooring Bollards

Step 1: Confirm Compliance Prerequisites 

1. Core Standard Matching
   • For domestic vessels & global export: Priority is given to GB/T 554-2023 Ships and marine technology—Ship mooring and towing equipment—Steel welded bollards for sea-going ships (replacing the former shipbuilding industry standard CB/T 554-96), the current mandatory standard for marine mooring bollards in China.
   • For international export: Simultaneously comply with ISO 13795 Ships and marine technology — Mooring and towing equipment — Bollards. EU-bound vessels shall meet EN standards, and US-bound vessels shall comply with ASTM standards.
   • For special vessels: Offshore platforms and engineering vessels shall additionally meet relevant industry specifications (such as IMO MSC.1/Circ.1619 Guidelines on Mooring Equipment for Ships).
   
   
2. Classification Society Certification Requirements
   
   
   Only products with approval certificates from the classification society where the target vessel is classed are acceptable. Mainstream societies include CCS, DNV, LR, BV, NK and ABS. The certificate must include: product model, Safe Working Load (SWL), material report, Welding Procedure Specification (WPS), Non-Destructive Testing (NDT) report. Each bollard shall be marked with the corresponding classification society steel stamp and traceable serial number.

Step 2: Determine Core Selection Parameters (Top Priority)

1. Core Indicator: Safe Working Load (SWL)

• Step 1: Calculate the vessel's Equipment Number (N) based on the vessel's length overall, breadth, moulded depth, draft, and superstructure area (a unified calculation formula for Equipment Number is adopted by all classification societies).
• Step 2: Look up the minimum breaking load, quantity and diameter of the mooring lines required for the vessel according to the Equipment Number (N).
• Step 3: The minimum breaking load of the mooring bollard shall be ≥ the minimum breaking load of the corresponding mooring line. Classification societies mandate a minimum safety factor of 4, i.e. SWL = Minimum Breaking Load of the Bollard / 4.
• Selection Margin: For vessels operating in ocean-going areas, harsh sea conditions, or multi-working conditions, it is recommended to reserve a margin of 1.2~1.5 times the calculated SWL value.

Quick Selection Reference Table (Compliant with GB/T 554 Standard)

2. Quantity and Layout Requirements

• Conventional sea-going vessels: At least 2 sets of heavy-duty double-post mooring bollards shall be arranged at the bow and stern respectively, with 1 set arranged every 20~30m along the ship's side on the deck, symmetrically distributed.
• All mooring bollards shall correspond one-to-one with fairleads and chocks, to avoid excessive deflection angle of the mooring line (optimal deflection angle ≤15°), preventing line wear and uneven stress on the bollard.
• Sufficient operating space shall be reserved at the installation position, avoiding deck equipment, pipelines and passages, to ensure the safety of personnel operation.

Step 3: Match Working Conditions and Confirm Structural Type

Supplementary Structural Selection Details

1. Base Type: For heavy-duty bollards on sea-going vessels, priority is given to welded integrated base. Bolted flange base (only applicable to small inland waterway vessels) is strictly prohibited, to ensure that the load can be completely transmitted to the hull strong structure after welding.