16–400 kN Manual-Release Spring-Type Towing Hook for Tugboats | CB/T 637-1995

Product Overview

The 16–400 kN manual-release spring-type towing hook series is intended for tugboats and towing vessels to retain the towing connection during operation and permit deliberate local release through a mechanical operating arrangement. The supplied configuration uses a double-spring mechanism to assist hook opening after the retaining device is disengaged. This page covers the manually operated spring type and does not represent a hydraulic or pneumatic remote-release system.

CB/T 637-1995 covers product classification, technical requirements, test methods, inspection rules, marking, and packing for spring towing hooks used in ship towing. The supplied series includes 16, 25, 40, 63, 100, 160, 220, 320 and 400 kN models. The supplied dimensional table uses the term “Max. Load”; the contractual designation as allowable load, SWL, safe towing load, test load or another load term must be confirmed from the approved project drawing and order specification before manufacture.

Quick Specifications

• Product type: Manual-release spring-type towing hook → local mechanical release for tugboat and ship-towing arrangements.
• Standard reference: CB/T 637-1995 → applies to spring towing hooks for ship towing and covers technical, test, inspection, marking, and packing requirements.
• Load range: 16–400 kN in the supplied series → nine model sizes allow selection according to the approved towing arrangement and required load basis.
• Spring arrangement: Double-spring mechanism → assists hook opening after the retaining device is disengaged; spring details and release-load capability follow the approved design.
• Release arrangement: Manual local operation → hydraulic and pneumatic remote-release equipment are not included in this configuration.
• Model range: 16 / 25 / 40 / 63 / 100 / 160 / 220 / 320 / 400 → overall dimensions and calculated weight vary by selected model and must be checked against the installation space.
• Material basis: Mild steel / C-Mn steel → exact grades for the hook body, base, pivot pin, bushes, latch components and springs are to be confirmed.
• Surface treatment: Sa 2.5 blasting + one epoxy shop-primer coat as reference → final marine coating follows the vessel painting specification.

Main Technical Parameters

Primary dimensions for the supplied 16–400 kN manual-release spring-type towing hook series. Dimensions are in millimetres unless otherwise stated. Load terminology follows the supplied table and requires project confirmation.

Selection & Inquiry Guide

Step 1: Select the required model from the 16–400 kN series and confirm the contractual load designation used by the project.

Step 2: Provide towing-line type, towing eye or connection dimensions, expected lead direction, operating angle, and required clear hook opening.

Step 3: Confirm the installation foundation, load path, under-deck reinforcement, fastening / welding interface, and available operating clearance by drawing.

Step 4: Confirm the manual release arrangement, local operator position, lever or release-wire route, required release load, and reset procedure.

Step 5: Confirm material grades, minimum design temperature, corrosion environment, ice-class or low-temperature requirement, and final coating system.

Step 6: State test and certificate scope, classification society, witness points, quantity, delivery destination, required delivery date, and provide GA or installation drawings.

Structure

Towing hook body | Retaining and latch assembly | Double-spring assisted release mechanism | Manual operating lever / release linkage | Pivot pin and bushes | Base and foundation interface | Reset and locking arrangement | Marine protective coating

Release, Installation & Quality Advantages

• The manual mechanism provides local mechanical operation without relying on a hydraulic power pack or pneumatic supply; operator position and safe access must be checked in the vessel arrangement.
• The double-spring arrangement assists hook opening after the latch is disengaged, while the permitted release load must be demonstrated by the approved design and test procedure rather than inferred from the model load value.
• The nine-model 16–400 kN series provides a practical range for matching towing-hook size, installation envelope, foundation arrangement, and project load requirement.
• Towing force is transferred through the hook body, pivot, base, and supporting hull structure; foundation strength and under-deck reinforcement are therefore part of the complete towing arrangement.
• Pins, bushes, latch contact areas, springs, and release linkages should remain accessible for inspection, lubrication, wear checks, and functional testing.
• Load testing, release-operation testing, material traceability, and class witnessing can be arranged according to the approved inspection and test plan.

Custom Attributes

• Standard: CB/T 637-1995 → standard reference for spring towing hooks used in ship towing.
• Model Range: 16 / 25 / 40 / 63 / 100 / 160 / 220 / 320 / 400 → select by approved towing arrangement and project load requirement.
• Load Rating: 16–400 kN maximum load in supplied data → final contractual load definition and marking are to be confirmed.
• Release Method: Manual local release with double-spring assistance → remote hydraulic or pneumatic release is outside this configuration unless separately designed.
• Material: Mild steel / C-Mn steel → exact component grades and low-temperature requirements to be confirmed.
• Surface Treatment: Sa 2.5 + epoxy shop primer as reference → final paint system follows project specification.
• Installation: Deck / foundation mounted → load direction, fastening details, deck reinforcement, and access clearance require approved drawings.
• Inspection & Certification: According to order scope → test loads, release test condition, class witnessing, and certificate type must be agreed before quotation.

How It Works

Towing connection is placed on the hook → Retaining mechanism secures the hook in the working position → Towing load is transferred to the base and supporting hull structure → Operator actuates the manual release arrangement → Latch disengages and the double springs assist hook opening → Connection is released → Hook is reset, locked, and function-checked before reuse

Applications

Harbour tugboats | Coastal towing vessels | Ship-assist tugs | Workboats with approved towing arrangements | Newbuilding projects | Replacement of compatible spring towing hooks

Certifications & Advantages

Certificates and inspection can be arranged according to project requirement, approved test scope, material traceability, and classification society procedure. Availability is subject to class approval and the agreed order scope.

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

Drawing & Photos

FAQ

Q1: Can the hook be manually released while carrying its full rated load?

A1: The supplied table gives a model maximum load, but it does not independently confirm the permitted release load. Release under load must be defined in the approved specification and verified by the required release-operation test. Full-rated-load release must not be assumed.

Q2: Does this series include wheelhouse remote release?

A2: No. This page describes a manual-release, double-spring towing hook. A hydraulic or pneumatic remote-release system requires a different approved configuration, control philosophy, fail-safe review, and test scope.

Q3: What information is required to select the correct model?

A3: Provide the required load designation, towing-line or eye dimensions, pull direction, foundation and installation drawing, manual release arrangement, material and coating requirements, class society, test scope, quantity, destination, and delivery schedule.: No. This page describes a manual-release spring towing hook. A hydraulic or pneumatic remote-release system requires a different approved configuration, control philosophy, fail-safe review, and test scope.

Q3: What information is required before quotation?

A3: Provide the required load designation, towing-line or eye dimensions, pull direction, foundation and installation drawing, manual release arrangement, material and coating requirements, class society, test scope, quantity, destination, and delivery schedule.