‘B’ Self-Closing Semi-Watertight Fire Door Sign

‘B’ Self-Closing Semi-Watertight Fire Door Sign – IMO A.654(16) Fire Control Symbol FS0232

This ‘B’ Self-Closing Semi-Watertight Fire Door sign identifies a door built to B-class fire integrity, the lower-duration fire rating typically used within accommodation spaces, that also provides semi-watertight closure and self-closes automatically to maintain both functions without depending on crew action. The pictogram shows the “SWT” designator in yellow above the door-and-arc symbol with a self-closing arrow, distinguishing it from the red A-class version and matching exactly what appears on the vessel’s fire control plan for this opening. As SKU FS0232 in the Fire Fighting Signs range, it is designed for permanent fixing on or beside B-class semi-watertight fire doors in accommodation alleyways, cabin blocks and similar internal openings.

B-class fire doors provide a shorter fire integrity period than A-class doors and are generally used to subdivide accommodation and public spaces rather than machinery or structural fire zones, but this self-closing semi-watertight fire door remains just as important to maintaining the vessel’s overall fire and water ingress strategy. Because the door closes automatically, it restores its rated protection every time someone passes through without needing to be manually shut, which is particularly valuable in busy accommodation alleyways where doors are used constantly throughout the day. The photoluminescent background keeps the door’s function identifiable during a blackout, when accommodation escape routes matter most.

Why B-Class Semi-Watertight Fire Door Identification Matters

Crew and passengers moving through accommodation spaces need a fast, reliable way to identify a self-closing semi-watertight fire door so it is never propped open, since doing so undermines the compartmentation the vessel’s fire safety plan relies on. Correct signage also helps fire wardens and safety officers quickly distinguish B-class doors from the higher-rated A-class doors elsewhere on the ship during rounds, since the two ratings serve different purposes and appear in different locations. This distinction is particularly relevant on passenger vessels with extensive accommodation areas where B-class doors are numerous and closely spaced.

Compliance and Certification

This sign reproduces the fire control symbol set derived from IMO Resolution A.654(16) and continued under the current ISO 17631 standard for fire control plan graphics, matching what flag-state surveyors and classification societies expect to see when identifying this self-closing semi-watertight fire door. SOLAS Chapter II-2 sets the fire integrity standard for B-class divisions used in accommodation spaces, and correctly labelled self-closing arrangements are checked during Port State Control inspections, class surveys and internal fire door testing rounds. Fitting SKU FS0232 keeps your accommodation door signage matched to the fire control plan surveyors will review.

Installation Recommendations

Fix this sign directly on or beside the door frame at eye level, using the pre-drilled fixing holes for a permanent mechanical fixing on steel or composite doors, or the self-adhesive backing on painted surfaces where a mechanical fixing is impractical. In accommodation alleyways, position the sign clear of door closers, kick plates and other hardware so it remains fully visible, and inspect it periodically alongside the self-closing mechanism during routine fire door testing rounds. Replace any sign that has become faded or illegible from repeated cleaning of accommodation surfaces.

• Standard IMO/ISO 17631 fire control symbol – yellow “SWT” designator with self-closing arrow
• Photoluminescent base for visibility during blackout or power failure
• 150x150mm rigid or self-adhesive format to suit steel, composite and painted door surfaces
• Durable finish suited to frequent cleaning in accommodation environments
• Matches fire control plan symbols exactly for fast, confident door function identification

Order the FS0232 ‘B’ Self-Closing Semi-Watertight Fire Door sign to keep every accommodation fire boundary on your vessel correctly identified before your next drill or survey. Safety Sign Hub stocks the complete IMO fire control symbol range and ships marine-grade signage across Australia and to vessels in port.

Browse the full Fire Fighting Signs range for every fire control plan symbol your vessel needs, or see our Hazard Signs for ISO 7010 warning pictograms to complete your safety signage programme.

This self-closing semi-watertight fire door sign identifies the correct door type at a glance, helping crew and class surveyors confirm the fitting matches the vessel’s fire safety plan during drills and inspections. See our full range of fire fighting signs for complete vessel fire safety marking.