Single-Lever Quick-Action Marine Weathertight Steel Door | GB/T 3477-2023

Product Specification

Single-Lever Quick-Action Marine Weathertight Steel Door | GB/T 3477-2023

Product Overview

The single-lever quick-action marine weathertight steel door is a manually operated, single-leaf hinged closing appliance for exposed access openings in superstructures, deckhouses, forecastles and similar boundaries above the freeboard deck. A central operating lever moves the linked clamping points so that the door leaf is drawn evenly against the frame gasket, allowing faster closing than individual dog handles while maintaining a continuous weathertight seal.

This page covers a weathertight external door, not a watertight bulkhead door and not a certified fire door. The current Chinese standard is GB/T 3477-2023, which replaced GB/T 3477-2008 and is related to ISO 6042:2015. Installation in Load Line Position 1 or Position 2 must be confirmed against the vessel arrangement, sill or coaming height, opening direction, surrounding structure, flag requirements and classification-society approval. The dimensions below reproduce the user-supplied table and require confirmation against the selected approved drawing before production.

Quick Specifications

• Standard reference: GB/T 3477-2023, with ISO 6042:2015 as an international reference → the exact door type, standard edition and approved drawing should be stated in the purchase order.
• Door configuration: single-leaf hinged steel door with single-lever quick-action clamping → one operating movement actuates the linked securing points around the leaf.
• Nominal opening range: 1000 × 600 to 1600 × 700 mm → selection should consider clear passage, escape access, equipment movement and available door-swing space.
• Corner radii: R100 nominal opening, R150 cut-out and R200 overall outline → rounded corners simplify fair structural transitions and reduce local stress concentration at the opening.
• Leaf plate thickness: 8 mm shown as a common value in the supplied table → applicability to every listed size and final stiffening arrangement must be confirmed from the approved drawing.
• Installation location: exposed superstructure or deckhouse boundaries above the freeboard deck → Position 1 / Position 2 designation alone does not determine the complete sill and structural requirement.
• Closing and sealing: linked clamps, gasketed frame and hinged leaf → frame flatness, hinge alignment and uniform gasket compression are key to reliable hose-test performance.
• Inspection and options: functional, chalk-contact, hose or air testing as applicable; security device, stainless-steel version and special coating are project options → exact scope is subject to class, flag and approved design.

Main Technical Parameters

Selection & Inquiry Guide

Step 1: Confirm the governing basis: GB/T 3477-2023, ISO 6042:2015 reference, shipyard drawing, class rule and flag / Load Line requirement. State whether a standard or project-specific door is required.

Step 2: Select nominal clear opening and opening hand. Provide the required outward or inward swing, hinge side viewed from the weather side, inside / outside lever arrangement, clear escape path and available swing clearance.

Step 3: Provide the installation boundary: vessel type, exact deck and frame position, Load Line Position 1 or 2 where applicable, sill or coaming height, bulkhead plate thickness, cut-out, surrounding stiffeners and welding access.

Step 4: Confirm construction materials and corrosion system. This page primarily covers mild-steel construction; stainless-steel supply requires grade and galvanic-isolation details, while aluminium should be treated as a separate approved door design rather than assumed under the steel-door standard.

Step 5: Confirm the sealing and operating package: gasket material and section, number and adjustment range of linked clamps, hold-open device, operating-force requirement, anti-piracy or internal security arrangement, and any restriction affecting emergency escape or operation from both sides.

Step 6: Confirm inspection and documentation: dimensional and functional checks, chalk-contact test, hose or approved air test, coating inspection, material certificates, maker certificate, class witness / product certificate, quantity, packing, destination and delivery time.

Structure

Welded steel door frame | Rounded-corner ship-structure cut-out | Single-skin steel leaf with stiffening to approved drawing | Heavy-duty hinges | Single operating lever | Mechanical linkage | Adjustable perimeter clamps / dogs | Continuous replaceable gasket | Inside and outside operating arrangement as approved | Hold-open and security devices when specified

Weathertight Design, Installation and Quality Advantages

• The single-lever mechanism closes several linked clamping points in one movement, reducing closing time and helping the operator apply more consistent compression than separately adjusted dog handles.
• A continuous gasketed seating line is only effective when the frame remains flat after fabrication and shipboard welding. Frame distortion, uneven weld sequence or poorly aligned hinges can create local leakage even when the operating lever moves correctly.
• The R100 / R150 / R200 corner progression provides a practical transition between clear opening, cut-out and outer frame outline. The shipyard should retain the approved corner radii and reinforcement geometry rather than square-cutting the opening.
• For Load Line applications, the door assembly should be permanently and strongly attached to the boundary, have strength appropriate to the surrounding structure, use permanently attached gasket and clamping arrangements, and be operable from both sides in the approved configuration.
• Doors at exposed superstructure ends normally open outwards unless the Administration or approved vessel design permits another arrangement. Opening direction, hinge side, handrail interference, escape route and sea impact direction should therefore be reviewed together.
• Hose testing checks the completed sealing line under water spray, while chalk-contact testing helps identify uneven gasket contact before the final test. Air testing may be used only when accepted by the project specification and attending authority.
• An anti-piracy or additional security device must not be added as an uncontrolled obstruction to escape. The exact arrangement should be reviewed against the vessel security plan, operational procedure, flag requirement and class approval.
• No fire rating is claimed for this standard weathertight door. A-class or B-class boundaries require a separately tested and certified fire-door construction with compatible frame, insulation, hardware and penetration details.

Custom Attributes

• Standard: GB/T 3477-2023 → current Chinese standard for marine weathertight single-leaf steel doors; selected configuration must match the approved drawing.
• International Reference: ISO 6042:2015 → covers main dimensions, materials, quality and manufacturing conditions for weathertight single-leaf steel doors.
• Door Type: Single-leaf hinged, single-lever quick-action → manual linkage operates multiple securing points around the gasketed leaf.
• Nominal Size: Eight listed openings from 1000 × 600 to 1600 × 700 mm → custom dimensions require structural and approval review.
• Installation Position: Superstructure, deckhouse, forecastle or machinery-casing access above freeboard deck → exact Load Line location and sill requirement must be confirmed.
• Material: Mild steel as the main page basis → stainless steel can be considered with grade and corrosion details; aluminium requires a separate approved design basis.
• Surface Treatment: Project-specific marine coating system → blast-cleaning grade, primer, intermediate coats, finish colour and dry-film thickness are to be confirmed.
• Testing: Functional, gasket-contact and weathertightness tests → method, pressure / nozzle condition, duration, acceptance and witness scope follow the approved specification.
• Security Option: Anti-piracy or internal securing arrangement available subject to review → must remain compatible with emergency access, operation from both sides and vessel procedures.
• Certification: Maker documentation, material certificates, type approval or individual class certification as applicable → exact scope must be agreed before quotation.

How It Works

Operator moves the single lever → Mechanical linkage drives the perimeter clamps → Door leaf is pulled evenly toward the frame → Continuous gasket is compressed along the seating line → Weathertight closure is confirmed → Reverse lever movement releases the clamps for opening

Applications

Exposed superstructure end bulkheads | Deckhouse external access | Forecastle access | Companionway and machinery-casing access where approved | Cargo vessels | Tankers | Tugboats | Workboats | Offshore support vessels in marine service | Newbuilding and replacement projects

Certifications & Advantages

Certificates and inspection documents can be arranged according to the exact product design, project specification, flag requirement, class approval route and agreed witness scope. Type approval or EC MED documentation must not be assumed unless a valid certificate covers the exact door model, size, material, closing mechanism and intended application.

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

Drawing & Photos

FAQ

Q1: Is this product a watertight door?

A1: No. It is a weathertight external door intended to prevent water penetration from weather and sea exposure when properly closed. It is not designed or certified as a pressure-resistant watertight subdivision door unless a separate approved watertight design is supplied.

Q2: What information is required to select a door for Load Line Position 1 or Position 2?

A2: Provide the vessel GA, exact deck and frame location, clear opening, sill or coaming height, opening direction, hinge side, surrounding structure, class society and flag requirement. Position designation alone is not enough because the applicable sill, boundary strength and access rules depend on the actual arrangement.

Q3: Which tests and certificates are normally confirmed before ordering?

A3: Confirm dimensional and operating checks, gasket-contact verification, hose or approved air test, coating inspection, material traceability, maker certificate and any class witness or product certificate. Test conditions and certification scope must be agreed before manufacture rather than assumed as standard delivery.