Marine Cast Steel Mooring Roller Button | CB/T 3861 Type B Open Type Single Roller

Marine Cast Steel Mooring Roller Button | CB/T 3861 Type B Open Type Single Roller

Product Overview

The CB/T 3861 Type B cast steel roller button is an open-type single roller used in ship mooring equipment. It is installed at mooring line guidance positions where the vessel arrangement requires a rotating rope-contact surface instead of a fixed edge. The roller helps guide PP rope or steel wire rope, reduce local friction, and support smoother rope movement during berthing, shifting, and harbor mooring operations.

This page covers Type B roller diameters from 150 mm to 450 mm with SWL from 127 kN to 617 kN according to the supplied parameter table. The supplied technical requirement states that the assembled roller should withstand a horizontal load equal to two times the SWL without permanent deformation, cracks, or other strength-affecting defects, and the roller assembly should rotate flexibly without jamming. The structure is described as similar to NS 2585 roller arrangements; dimensional interchangeability should be confirmed by drawing when replacement is required.

Quick Specifications

• Standard and type: CB/T 3861 Type B open type → suitable for standard ship mooring roller-button arrangements using one rotating roller.

• Roller diameter range: 150 to 450 mm → select according to rope size, SWL, and available mooring station layout.

• SWL range: 127 to 617 kN → used as the product load basis for horizontal strength verification; it is not a rope breaking load.

• Maximum cable diameter: PP rope 32 to 80 mm / steel wire rope 16 to 44 mm → initial compatibility reference for rope selection.

• Steel wire rope reference: 1770 MPa, 6×37 → use the project rope specification to confirm final selection.

• Assembly performance: horizontal 2×SWL load capacity without permanent deformation, cracks, or strength-affecting defects according to supplied requirement.

• Rotation requirement: assembled roller should rotate freely without jamming → important for rope protection and maintenance inspection.

• Bearing / bush options: stainless steel, copper, or bronze → selected according to corrosion exposure, maintenance plan, and project requirement.

Main Technical Parameters

Selection & Inquiry Guide

Step 1: Confirm CB/T 3861 Type B open type and required roller diameter D from 150 to 450 mm.

Step 2: Check the required SWL, rope type, and maximum rope diameter. Do not replace SWL with rope breaking load or rope MBL.

Step 3: Confirm material requirement, such as cast steel, stainless cast steel, or other project-specified material. Material grade should be confirmed before quotation.

Step 4: Confirm bearing or bush material, such as stainless steel, copper, or bronze, and confirm whether grease access is required by the maintenance plan.

Step 5: Confirm surface treatment: Sa 2.5 blasting with epoxy shop primer, galvanizing, polishing for stainless parts, or customized coating system.

Step 6: Provide quantity, vessel type, installation position, classification society requirement, drawing or reference photo, delivery destination, and required delivery time.

Structure

Open-type single roller | Cast steel roller body | Roller shaft / pin arrangement | Stainless steel, copper or bronze bearing/bush option | Grease maintenance point | Base / support structure according to drawing | Coated or stainless finished surface

Design, Load and Maintenance Advantages

• The single rotating roller provides a controlled rope-contact surface and helps reduce sliding friction compared with a fixed rope guide edge.

• The Type B range covers SWL 127 to 617 kN, giving several standard sizes for different mooring station layouts and rope diameters.

• The supplied performance requirement uses a horizontal 2×SWL load condition, helping shipyards check the roller assembly against permanent deformation, cracks, and strength-affecting defects.

• Free rotation after assembly is a key inspection point. Smooth rotation reduces rope wear and makes maintenance issues easier to identify before operation.

• Stainless steel, copper, or bronze bearing/bush options can be selected to match corrosion exposure, lubrication practice, and maintenance preference.

• Grease maintenance access supports regular lubrication so that the roller can continue moving smoothly in marine service.

• Casting surface, rope-contact radius, shaft fit, and coating preparation should be checked carefully because they directly affect rope protection, rotation, and inspection acceptance.

Custom Attributes

• Standard: CB/T 3861 → use when the vessel specification or shipyard drawing calls for this Chinese marine roller standard.

• Type: Type B open type → single exposed roller arrangement for mooring line guidance.

• Roller Diameter: 150 / 200 / 250 / 300 / 350 / 400 / 450 mm → select by SWL, rope diameter, and installation space.

• SWL: 127 to 617 kN → product load rating reference from the supplied table; not a lifting SWL and not rope breaking load.

• Applicable Rope: PP rope and steel wire rope → steel wire rope reference in the table is 1770 MPa, 6×37.

• Material: Cast steel as product basis → stainless cast steel and other listed material options should be confirmed by drawing and project specification.

• Bearing / Bush: Stainless steel, copper, or bronze → selected according to corrosion resistance and lubrication requirement.

• Surface Treatment: Sa 2.5 blasting + epoxy shop primer, galvanized, polished, or customized → final coating should follow the vessel coating specification.

• Certificate Requirement: Maker certificate or class certificate according to order → class inspection scope should be confirmed before quotation.

How It Works

Mooring line approaches the roller → Rope contacts the rotating roller surface → Roller turns with rope movement → Friction and local rope wear are reduced → Horizontal load is transferred through the roller assembly to the supporting ship structure

Applications

Ship mooring stations | Deck rope guidance positions | Fairlead and roller guide arrangements | Newbuilding projects | Ship repair and replacement | Cargo vessels | Tugboats | Barges | Workboats | Harbor mooring equipment

Certifications & Advantages

Certificates can be arranged according to project requirement, inspection scope, material traceability, load verification requirement, and class society approval procedure.

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

Drawing & Photos

FAQ

Q1: How should the correct CB/T 3861 Type B roller size be selected?

A1: Select the roller diameter according to required SWL, PP rope or steel wire rope diameter, installation space, and the vessel mooring arrangement drawing. The SWL and maximum cable diameter should both be checked before quotation.

Q2: Is the SWL in the table the same as rope breaking load or lifting SWL?

A2: No. The listed SWL is the product load rating reference for the mooring roller button. It should not be treated as rope breaking load, rope MBL, or lifting equipment SWL.

Q3: What should be checked before production or class inspection?

A3: Confirm the standard type, size, material grade, bearing or bush material, surface treatment, drawing, inspection scope, and certificate requirement. If a class certificate or witnessed inspection is required, it should be confirmed before quotation.