‘B’ Class Division Sign

‘B’ Class Division Sign – IMO Fire Control Symbol FS0143

The ‘B’ Class Division sign is a mandatory IMO fire control symbol used on fire control plans and shipboard bulkheads to indicate the location of a ‘B’ class fire division. Recognised under IMO Resolution A.654(16) and reproduced to ISO 17631, this pictogram allows crew, surveyors, and shore-based emergency responders to identify the fire-resisting boundary instantly, regardless of the language they speak.

The symbol is shown as a single horizontal band across a photoluminescent square background, distinguishing ‘B’ class divisions from the double-band symbol used for ‘A’ class divisions elsewhere on the fire control plan. This design forms part of the internationally standardised library of fire control symbols found on fire control plans, damage control plans, and general arrangement drawings across commercial vessels, offshore installations, and naval ships.

Why the ‘B’ Class Division Symbol Matters

‘B’ class divisions are constructed from approved non-combustible materials and are designed to resist the passage of flame for at least 30 minutes under standard fire testing, providing a critical barrier that slows the spread of fire and smoke between compartments such as cabins, corridors, and public spaces. Correctly marking these divisions on the fire control plan allows the crew and attending firefighters to understand the vessel’s compartmentation strategy at a glance during an emergency.

Because accurate identification of fire divisions is so important for effective firefighting and damage control, SOLAS Chapter II-2 and the Fire Safety Systems Code require the fire control plan to clearly indicate the class of every structural fire division throughout the vessel. This symbol is reproduced on the printed fire control plan posted at the gangway and bridge, alongside the full suite of IMO fire-fighting equipment and fire control symbols.

Compliance and Certification

This ‘B’ Class Division sign is manufactured to comply fully with IMO Resolution A.654(16) and ISO 17631 symbol requirements, ensuring the pictogram, colour scheme, and proportions match the standard expected during port state control inspections, classification society surveys, and SOLAS compliance audits. Non-standard or incorrectly proportioned signage is a common source of survey deficiencies, so every FS0143 sign is checked against the current IMO symbol register before it leaves our warehouse.

Manufactured from durable photoluminescent, self-adhesive vinyl, this sign charges under normal ambient lighting and glows for an extended period in the dark, ensuring the fire division marking remains identifiable even during a blackout or power failure. This self-luminous performance is especially valuable when fire control plans need to be read quickly during an emergency.

Installation Recommendations

For best results, this symbol is typically reproduced on printed fire control plans, damage control plans, and deck plans rather than fitted directly to the structure itself, so it should be applied wherever the vessel’s official fire control documentation requires a clear indication of ‘B’ class fire divisions. Ensure the plan is updated consistently across all copies held at the gangway, bridge, and engine control room.

Vessels undergoing a fire control plan update, newbuild fit-out, or SOLAS compliance retrofit should ensure this symbol is included alongside the complete suite of IMO fire control symbols so that the printed fire control plan accurately reflects the fire divisions built into the vessel. Surveyors routinely cross-check the fire control plan against the vessel’s actual construction, making accuracy here a key focus area during flag state and classification inspections.

Key features of this ‘B’ Class Division sign include:

• Complies with IMO Resolution A.654(16) and ISO 17631 fire control symbol standards
• Photoluminescent vinyl construction for visibility during power loss or low-light conditions
• Self-adhesive backing for fast, permanent installation on plans and documentation boards
• Waterproof and saltwater resistant for long-term use throughout the vessel
• Matches the standard pictogram used fleet-wide on fire control plans for consistent crew recognition

Order your ‘B’ Class Division sign today to keep your vessel’s fire control plan accurate and fully compliant, supporting crew safety, SOLAS compliance, and a smooth outcome at your next port state control or classification survey.

For more information on the international symbol standards referenced above, see the International Maritime Organization resolution library. Browse our full range of Fire Fighting Signs for more IMO-compliant fire control signage for your vessel.