Welded SteelWelded Steel Double Bitt Bollard with Wide Base Plate | ISO 13795

Product Specification

Welded Steel Double Bitt Bollard with Wide Base Plate | ISO 13795 Type B for Ship Mooring and Towing

Product Overview

The ISO 13795 Type B welded steel bollard is a shipboard double-bitt fitting with a wide base plate for mooring and approved towing arrangements. It is welded to the vessel deck or an engineered foundation, where the twin bitts receive rope force and the enlarged base interface transfers the resulting reaction into the reinforced ship structure.

The supplied range covers nominal sizes 150 to 600, including A and B capacity variants at several common bitt diameters. Selection must distinguish figure-of-eight mooring with one-rope or two-rope use from towing with an eye-splice arrangement. The tabulated SWLs are reference values from the supplied data; final load marking, deck reinforcement, weld details, rope arrangement, and certificate scope should follow the approved vessel drawing and project requirements.

Quick Specifications

• Product type: Welded steel double bitt bollard with wide base plate → larger deck welding footprint for ship mooring and project-approved towing stations.
• Standard and type: ISO 13795:2020 Type B → reference for Type B geometry, nominal-size designation, welding details, and separate mooring / towing SWL columns.
• Nominal size range: 150 / 200 / 250A / 250B / 300A / 300B / 350A / 350B / 400A / 400B / 450A / 450B / 500A / 500B / 550A / 550B / 600 → A and B suffixes identify different capacity constructions at the same nominal diameter.
• Mooring SWL, one-rope use: 54 to 1,401 kN → applies to the one-rope figure-of-eight condition stated in the supplied standard table.
• Mooring SWL, two-rope use: 49 to 948 kN → use the dedicated two-rope column; values must not be added together or replaced by the one-rope rating.
• Towing SWL: 98 to 1,893 kN → separate eye-splice towing condition requiring confirmation of towing lead, dynamic duty, foundation, and approved vessel arrangement.
• Installation: Deck-welded wide base plate → local deck thickness, supporting structure, welding procedure, load direction, and access for inspection should be confirmed before production.
• Material and finish: Weldable shipbuilding steel with Sa 2.5 blasting and epoxy shop primer as reference → stainless steel, low-temperature steel, galvanizing, or special coating requires project-specific confirmation.

Main Technical Parameters

Selection & Inquiry Guide

Step 1: Confirm ISO 13795 Type B with wide base plate and select the nominal size / A-B variant from the approved vessel mooring and towing arrangement.

Step 2: State the operating duty separately: one-rope mooring, two-rope mooring, towing by eye splice, or a project-defined combination. Provide required SWL, rope type, rope diameter, rope MBL, belaying method, and expected lead direction.

Step 3: Provide the deck plan, installation position, foundation and reinforcement drawing, deck plate thickness, available clearance, and the required load-transfer direction. The wide base plate does not replace a structural foundation check.

Step 4: Confirm the weldable material grade, minimum design temperature, toughness requirement, stainless-steel or ice-class option, material traceability, and whether the project requires low-temperature impact testing.

Step 5: Confirm welding details, WPS / PQR, NDT scope, dimensional inspection, SWL marking, maker documentation, class survey, and any witness or approval requirement before quotation.

Step 6: Confirm surface preparation, primer and final coating system, quantity, vessel type, newbuilding or replacement status, delivery destination, required delivery time, and reference drawing or photos.

Structure

Twin cylindrical bitts | Wide welded base plate | Top closure plates | Internal / external supporting plates according to size | Rounded rope-contact surfaces | Deck welding interface | SWL marking area | Project-specified coating

Mooring, Towing, Welding & Engineering Advantages

• The wide Type B base plate provides a larger welded interface than a narrow-base configuration, helping distribute the fitting reaction into the supporting deck area; the surrounding deck structure still requires project-specific strength verification.
• Separate one-rope, two-rope, and towing SWL columns support correct selection for different belaying arrangements and reduce the risk of treating the highest towing value as a universal bollard rating.
• A and B variants at the same nominal diameter use different plate thicknesses, welding leg lengths, and reference SWLs, allowing the capacity class to be selected without relying on diameter alone.
• Rounded bitt surfaces, top transitions, and rope-contact edges should be dressed smooth and kept free from harmful weld spatter, sharp edges, or coating irregularities that may abrade synthetic mooring or towing ropes.
• Weld volume and joint geometry should follow the approved design. A different welding method may be considered only when equivalent strength / weld volume is demonstrated and accepted under the project welding procedure.
• Material grade, weldability, heat input, distortion control, and NDT are important for the thick A-variant constructions and for low-temperature or ice-class projects.
• The fitting, wide base plate, deck insert, and reinforcement should be reviewed as one load-transfer system rather than as an isolated catalog component.

Custom Attributes

• Standard: ISO 13795:2020 → controlled standard copy and project specification govern final dimensions, load notes, marking, and acceptance.
• Type: Type B → welded double-bitt bollard with wide base plate for a larger deck connection footprint.
• Nominal Size: 150 to 600 → choose the full designation, including A or B suffix where listed.
• Mooring Load Basis: Figure-of-eight belay, one-rope or two-rope use → select the corresponding SWL column and do not combine tabulated values.
• Towing Load Basis: Eye-splice arrangement → towing SWL is a separate condition and requires confirmation of towing lead and vessel structural design.
• Material: Weldable shipbuilding steel / high-strength steel / stainless steel / project-specified low-temperature steel → exact grade and component schedule to be confirmed.
• Installation: Deck welded wide base plate → foundation, reinforcement, weld detail, load direction, and inspection access are part of the approved vessel design.
• Surface Treatment: Sa 2.5 blasting plus epoxy shop primer as reference → final coating follows vessel specification; polished finish applies to stainless steel, and galvanizing is subject to size and fabrication feasibility.
• Certificate Requirement: Available according to order scope → material certificates, maker documents, class survey, and witness inspection are not automatic unless specified.

How It Works

One or two mooring lines are belayed in the approved figure-of-eight arrangement, or a towing eye splice is engaged according to the vessel towing plan → Rope tension acts on the twin bitts → The bitt structure and wide base plate distribute the reaction → Welds, deck insert, and reinforcement transfer the load into the ship structure

Applications

Ship mooring stations | Harbour towing arrangements | Tugboats | Workboats | Cargo vessels | Tankers | Research vessels | Ice-class vessels subject to approved low-temperature design | Newbuilding and engineered replacement projects

Certifications & Advantages

Certificates, material traceability, inspection records, calculation review, and class survey can be arranged according to project requirement, approved drawing, test / inspection scope, and classification society procedure.

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

Drawing & Photos

FAQ

Q1: What is the practical difference between ISO 13795 Type B and Type A?

A1: Type B is identified by the wide base plate arrangement. The larger foundation interface can provide a broader welding footprint and different load-transfer geometry, but it does not eliminate the need to check the deck insert, reinforcement, welds, and load direction. The vessel drawing should specify the required type.

Q2: Can the towing SWL be used as the mooring SWL, or can the two-rope values be added?

A2: No. The table provides separate load conditions for one-rope mooring, two-rope mooring, and towing. Use only the column corresponding to the approved rope arrangement. Do not add two-rope values or substitute the towing value for mooring unless the project design and class approval explicitly permit it.

Q3: What information is required before quotation?

A3: Confirm ISO 13795 Type B, complete nominal designation, required mooring / towing duty, SWL, rope details and MBL, line lead, deck foundation drawing, material and minimum temperature, coating, WPS / NDT scope, class requirement, quantity, destination, and delivery schedule.