Marine Single-Leaf Steel Weathertight Door with Dogs | Deckhouse & Superstructure Access

Marine Single-Leaf Steel Weathertight Door with Dogs | Deckhouse & Superstructure Access

Product Overview

The marine single-leaf steel weathertight door with dogs is a hinged closing appliance for access openings in exposed superstructures and deckhouses above the freeboard deck. A welded steel frame, stiffened door leaf, resilient perimeter gasket, hinges, and permanently attached dog handles work together to provide a compressed weather seal when the door is correctly installed and fully secured.

Selection is governed by more than the clear opening size. The vessel designer and shipyard should confirm the installation position, required door class, opening direction, sill or coaming arrangement, surrounding bulkhead strength, corner form, gasket system, dog arrangement, and class or flag requirements. This door should not be described as a watertight subdivision door or a fire-rated door unless a separate approved design and certificate are provided.

Quick Specifications

• Current standard references: GB/T 3477-2023 and ISO 6042:2015 → directly relevant to marine weathertight single-leaf steel doors.
• Application location: superstructure and deckhouse access above the freeboard deck → final suitability depends on the approved load-line arrangement and installation position.
• Clear opening range in the supplied series: 1000 × 500 to 1800 × 900 mm → covers compact service openings and full-height personnel access.
• Closing arrangement: multiple manually operated dogs around the leaf perimeter → distributes gasket compression instead of relying on a single latch.
• Door operation: hinged single leaf with local operation → opening hand, outward/inward direction, and operation from both sides must follow the approved vessel drawing.
• Frame and corner options: R80 and R150 cutout references appear in the supplied table → exact F/Y corner type and door class must be confirmed from the original standard drawing.
• Surface preparation: abrasive blast cleaning to Sa 2½ plus epoxy shop primer for carbon-steel construction → final coating system and dry-film thickness follow the vessel paint specification.
• Inspection and tightness verification: hose, chalk, or air testing as applicable → test method, pressure, duration, and acceptance criteria are confirmed in the approved inspection plan.

Main Technical Parameters

Selection & Inquiry Guide

Step 1: Confirm the governing standard and door class. For a current Chinese-standard steel door, identify the required GB/T 3477-2023 designation; for an international project, confirm whether ISO 6042:2015 or a class-approved project drawing governs.

Step 2: Provide the vessel type, installation deck, superstructure or deckhouse location, exposure position, and whether the opening protects access to spaces below. Confirm sill or coaming height and surrounding bulkhead arrangement.

Step 3: Confirm clear opening H × W, door-leaf size, steel-wall cutout, square or rounded corner form, left-hand or right-hand opening, and the required outward or inward opening direction.

Step 4: Confirm material and construction: shipbuilding steel grade, frame profile, leaf thickness, stiffener arrangement, hinge and pin material, gasket type, dog material, and corrosion-protection system.

Step 5: Confirm closing and access features: individual dog handles or linked quick-acting mechanism, operation from both sides, hold-open arrangement, internal locking, external padlocking, or anti-intrusion provision where required.

Step 6: Provide quantity, class society or flag requirement, certificate scope, inspection and test plan, approved drawing, delivery destination, and required delivery time.

Structure

Welded steel frame | Stiffened single door leaf | Hinges and pins | Continuous perimeter gasket | Multiple dog handles and wedges | Internal and external operating handles | Hold-open device | Primer or project coating system

Weathertightness, Installation & Quality Advantages

• Multiple dogs provide distributed compression around the gasket perimeter, helping maintain a continuous seal at the top, sides, corners, and sill when the door is fully secured.
• A correctly aligned hinge axis and controlled leaf-to-frame clearance reduce uneven gasket loading, difficult operation, and local leakage caused by fabrication or welding distortion.
• The welded frame forms part of the surrounding boundary. Frame fit-up, bulkhead flatness, welding sequence, corner details, and nearby stiffening should be checked before final welding.
• Gasket grooves, landing faces, dog wedges, and hinge components remain accessible for inspection, cleaning, adjustment, and replacement during vessel service.
• Where the applicable load-line rule requires it, gaskets and clamping devices are permanently attached and the door is arranged for operation from both sides of the bulkhead.
• Weathertight performance is verified only after installation and adjustment. A shop test does not replace the shipyard’s final inspection of frame welding, gasket compression, door operation, and boundary tightness.

Custom Attributes

• Product Type: Hinged single-leaf steel weathertight door with dogs → intended for exposed superstructure and deckhouse access.
• Current Standard Basis: GB/T 3477-2023 / ISO 6042:2015 → exact designation and project edition to be confirmed before quotation.
• Clear Opening: 1000 × 500 to 1800 × 900 mm in the supplied series → customized sizes require an approved drawing and structural review.
• Corner Configuration: R80 / R150 reference cutouts → exact square-corner or rounded-corner type must match the vessel opening.
• Material: Shipbuilding steel as the normal basis → stainless-steel or aluminium versions require separate material, welding, strength, and corrosion details.
• Closing System: Multiple individual dogs as the page configuration → dog count, spacing, wedge geometry, and linkage option follow the selected door class.
• Gasket: Continuous marine-grade resilient seal → material, section, bonding method, compression, and replacement specification to be confirmed.
• Surface Treatment: Sa 2½ blast cleaning + epoxy shop primer → final paint system, color, and DFT according to project specification.
• Testing: Hose / chalk / air test as applicable → method and acceptance criteria according to the approved inspection and test plan.
• Certificates: Maker documentation or class certificate according to order → available upon request and subject to class approval and survey scope.

How It Works

Door leaf closes against the welded frame → Dog handles engage the wedges → Distributed clamping compresses the perimeter gasket → The sealed boundary limits weather-water entry → Dogs are released locally to reopen the access

Applications

Forecastle access | Exposed deckhouse entrances | Superstructure end bulkheads | Accommodation deck access | Machinery-casing access above the freeboard deck | Workboats | Cargo vessels | Tankers | Tugboats | Newbuilding and replacement projects

Certifications & Advantages

Material certificates, dimensional inspection records, tightness-test records, and classification inspection can be arranged according to project requirement, approved drawing, inspection scope, and surveyor involvement.

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

Drawing & Photos

FAQ

Q1: What is the difference between a weathertight door and a watertight door?

A1: A weathertight door is used to prevent weather water from entering an exposed boundary when closed and secured. It is not automatically suitable for a watertight subdivision bulkhead or hydrostatic pressure. The installation location and required door rating must be confirmed from the vessel’s approved drawings.

Q2: How is the correct number of dogs selected?

A2: Dog quantity and spacing depend on door size, class, leaf stiffness, gasket section, corner form, and the approved standard drawing. More dogs should not be added or removed without checking the designed compression pattern and operating arrangement.

Q3: Which inspection and test documents should be requested?

A3: Typical documents may include the approved or maker drawing, material certificates, dimensional report, coating record, operation check, and the specified hose, chalk, or air tightness-test record. Class witnessing and certificate format must be agreed before production.

Zhongyuan Ship Machinery Manufacture (Group) Co., Ltd. was founded in the 1990s and has developed into an integrated marine equipment manufacturer and project supply partner combining manufacturing, technical support, and export services. The group consists of four factories and one export trading company, with more than 300 employees, including over 20 experienced technicians and engineers. Our export company supports global customers with project communication, technical documentation, logistics coordination, and after-sales service.

Our factories are certified to ISO 9001, ISO 14001, ISO 45001, and related occupational health and safety management standards. We also hold type approval certificates from major classification societies such as DNV, LR, BV, and ABS, as well as works approval certificates, class-approved WPS procedures, and qualified welders. Our products can be supplied with certificates from IACS classification societies including DNV, ABS, LR, BV, CCS, RINA, KR, NK, IRS, and RMRS, depending on project requirements.

We manufacture a wide range of marine and offshore equipment, including deck equipment and machinery, mooring and towing equipment, deck outfitting, shafting components, rudder stocks, shaft and rudder systems.

In addition to our manufactured products, we also supply selected marine equipment through qualified partner manufacturers, including hydraulic cylinders, hydraulic power units, marine hardware, lifting and lashing equipment, hoisting and rigging products, lifeboats, rescue boats, launching appliances and davits, life-saving equipment, fire-fighting equipment, rubber fenders, rubber packing, marine pumps, valves, pipe fittings, multi-core pipes and accessories, steel wire ropes, mooring ropes, rope nets, anchors, anchor chains, and various marine chains.

Our main production facilities include CNC machining centers, CNC machine tools, CNC cutting machines, boring and milling machines, hydraulic presses, plate rolling machines, welding robots, welding equipment, shot blasting equipment, and dust-free painting workshops. These facilities enable us to support customized manufacturing and project-based production for shipbuilding, ship repair, offshore, and marine engineering projects.

We are committed to providing reliable, high-quality, and cost-effective marine equipment to customers worldwide. With our manufacturing capability, technical support, qualified supply network, and export coordination experience, Zhongyuan aims to be a trusted partner for shipyards, shipowners, offshore companies, and marine equipment distributors.