Double Bitt Mooring Bollard with Optional Horns | ASTM A27 Grade 70-36 Cast Steel

Product Overview

The cast steel double bitt bollard is a ship mooring deck fitting used to secure and control mooring ropes at deck mooring stations. This page covers the 8 inch and 10 inch double bitt configurations manufactured from ASTM A27-70-36 C-Mn cast steel or equivalent, with optional horn arrangements for projects that require additional rope-retention support around the bitt area.

Compared with a large inland-barge bollard page, this product page focuses on the compact 8 inch and 10 inch ship mooring range, the optional horn structure, controlled cast-steel surface quality, and project-based inspection such as dye penetrant testing, magnetic particle examination, localized X-ray inspection, FEA strength review, and pull test verification when required by the order specification.

Quick Specifications

• Product type: Cast steel double bitt bollard → deck mooring fitting for ship mooring arrangements, not a lifting product.
• Nominal types: 8 inch and 10 inch → suitable for projects where the vessel drawing specifies this compact double bitt bollard range.
• Horn arrangement: available with or without horns → horned type can help rope retention and handling around the bitt area when specified.
• Material grade: ASTM A27-70-36 C-Mn cast steel or equivalent → selected for cast-steel bollard body strength and mechanical property control.
• Heat treatment: heat-treated cast steel before delivery → supports mechanical property stability and casting quality control according to the supplied specification.
• Surface condition: smooth and free from burrs that may cut mooring rope → rope-contact finishing is a key acceptance point for mooring use.
• Inspection options: material mechanical test, heat treatment record, dye penetrant test, magnetic particle examination, and localized X-ray test → inspection scope should be confirmed before quotation.
• Engineering verification: FEA strength calculation and pull test verification can be arranged according to project requirement → load direction, test load, fixture, and witnessing scope must be agreed in advance.

Main Technical Parameters

Selection & Inquiry Guide

Step 1: Confirm double bitt bollard size: 8 inch or 10 inch, and whether the project requires the horned or non-horned configuration.

Step 2: Confirm vessel type, deck mooring arrangement, rope lead direction, rope wrap condition, and installation position according to the vessel drawing.

Step 3: Confirm material requirement: ASTM A27-70-36 C-Mn cast steel or equivalent material grade acceptable to the project specification.

Step 4: Confirm surface treatment: sandblasting, shop primer, final coating system, color, and any special corrosion-protection requirement.

Step 5: Confirm quality control and inspection scope: mechanical property test, heat treatment record, dye penetrant test, magnetic particle examination, localized X-ray test, FEA report, and pull test verification if required.

Step 6: Confirm certificate scope before quotation: ABS approval, mill certificate, maker certificate, class witness inspection, or other approval requirement according to order and project procedure.

Step 7: Provide quantity, delivery destination, required delivery time, GA drawing, deck foundation drawing, and reference photos if available.

Structure

Cast steel double bitt body | Optional horn arrangement | Smooth rope-contact surface | Heat-treated C-Mn cast steel | Deck mounting base | Force-concentration transition area | Sandblasted / shop-primed surface

Casting, Inspection & Engineering Advantages

• The cast-steel body is suitable for forming an integrated double bitt shape with rounded transitions around the rope-contact and force-concentration areas.
• Surface dressing after casting focuses on removing burrs and sharp edges that may damage mooring rope during repeated ship mooring operations.
• Heat treatment before delivery supports mechanical property control for ASTM A27-70-36 or equivalent cast steel, with material property test report available according to order scope.
• Casting quality control can include visual inspection, dimensional checking, mechanical property test, and heat treatment record review before surface treatment.
• Dye penetrant testing or magnetic particle examination can be arranged when the project requires surface or near-surface discontinuity checking.
• Localized X-ray inspection can be focused on critical areas where force concentration is expected around the bitt root, base transition, and horn connection area, subject to project requirement and agreed acceptance criteria.
• FEA-based strength calculation can be used to review stress distribution and optimize local transition areas when the vessel design office or class approval process requires additional engineering verification.
• Pull test verification can be arranged according to agreed loading direction, test load, fixture method, and witnessing scope; the required test procedure should be confirmed before production.

Custom Attributes

• Model Type: Double Bitt Bollard → compact ship mooring bollard arrangement for deck mooring stations.
• Size Range: 8 inch / 10 inch → selected according to vessel drawing, deck layout, and rope handling requirement.
• Horn Option: with or without horns → select horned type when the project drawing requires additional rope-retention geometry.
• Material: ASTM A27-70-36 C-Mn cast steel or equivalent → final equivalent grade should be confirmed before order release.
• Surface Treatment: sandblasting and shop primer painting → final coating system should follow vessel painting specification.
• Casting Quality Control: mechanical test, heat treatment, NDT options → inspection items should be stated in the purchase order.
• FEA Review: available according to project requirement → used to check stress concentration and verify local structure when required.
• Pull Test Verification: available according to project requirement → test load, load direction, fixture, and witness requirement must be confirmed.
• Certificate Requirement: ABS approval / mill certificate / maker certificate according to order scope → class approval is subject to project procedure and class society acceptance.

How It Works

Mooring rope is led around the double bitt → Smooth cast-steel surface supports rope contact → Horned type helps rope retention when specified → Mooring force is transferred through the bitt body and base into the deck foundation → Inspection and coating are completed according to project requirement

Applications

Ship mooring stations | Deck mooring arrangements | Cargo vessels | Tugboats | Workboats | Inland and coastal vessels | Shipyard newbuilding projects | Replacement of existing 8 inch or 10 inch double bitt bollards

Certifications & Advantages

Certificates can be arranged according to project requirement, inspection scope, material traceability, ABS approval procedure, and class society review. Certificate wording and witness scope should be confirmed before order release.

Certification: CCS, NK, BV, ABS, DNV, LR, KR, IRS, RS, RINA, CRS, Makers Test Certificate.

Drawing & Photos

FAQ

Q1: What is the main difference between the horned and non-horned double bitt bollard?

A1: The main bollard body and nominal size range are the same, while the horned type adds horn dimensions K, L, and M. The horned type should be selected only when the vessel drawing or rope-handling arrangement requires this additional rope-retention geometry.

Q2: Can NDT, FEA calculation, and pull test verification be supplied?

A2: Yes, these items can be arranged according to project requirement. The inspection method, acceptance criteria, FEA load case, pull test load, loading direction, fixture method, and witness scope should be confirmed before quotation or production.

Q3: Does this page provide a fixed SWL for the bollard?

A3: No fixed SWL is added because the supplied data provides model type, dimensions, material, inspection items, and weight only. Final mooring load basis should be checked with the vessel mooring arrangement, deck foundation design, rope wrap condition, and project approval requirement.