Bulkhead Class Divisions

         As per SOLASChapter II-2, Part A Regulation 3 there are three class divisions for structural fire protection requirement of bulkheads and decks. 

        The administration has required a test of a prototype bulkhead or deck under the FIRE TEST PROCEDURES CODE to ensure that it meets integrity and temperature rise requirements. 

        Before we move on to the types of class divisions you must know that is a non-combustible material

Non-combustible Material:

        It is a material that neither burns nor gives off flammable vapours in sufficient quantity for self-ignition when heated to approximately 750-degree Celcius, this being determined under the Fire Test Procedures Code.

Types of Class Divisions:

• 'A' Class Divisions

• 'B' Class Divisions

• 'C' Class Divisions

'A' Class Divisions:

        'A' class divisions are those divisions formed by bulkheads and decks which comply with the following criteria:

• They are constructed of steel or other equivalent materials

• They are suitably stiffened

• They are insulated with approved non-combustible materials such that the average temperature of the unexposed side will not rise more than 140-degree Celsius above the original temperature, nor will the temperature, at any point, including any joint, rise more than 180-degree Celsius above the original temperature, within the time listed below.

• Class "A-60" 60 min

• Class "A-30" 30 min

• Class "A-15" 15 min

• Class "A-0" 0 min

• They are constructed to be capable of preventing the passage of smoke and flame to the end of the one-hour Standard Fire Test

• The administration required a test of a prototype bulkhead or deck under the Fire Test Procedures Code to ensure that it meets the above requirements for the integrity and temperature rise.

 

'B' Class Divisions:

         'B' class divisions are those divisions formed by bulkheads, decks, ceilings or linings which comply with the following criteria:

• They are constructed of approved non-combustible materials. 

• Materials used in the construction and erection of the 'B' class division are non-combustible, except that combustible veneers, may be permitted provided they meet other appropriate requirements.

• They have an insulation value such that the average temperature of the unexposed side will not rise more than 140-degree Celcius above the original temperature, nor will the temperature at one point, including any joint, rise more than 225-degree Celcius above the original temperature, within the time listed below. 

• Class "B-15" 15 min

• Class "B-0" 0 min

• They are constructed to be capable of preventing the passage of flame to the end of the first half-hour of the Standard Fire Test

• The administration required a test of a prototype bulkhead or deck under the Fire Test Procedures Code to ensure that it meets the above requirements for the integrity and temperature rise.

'C' Class Divisions:

• 'C' class divisions are those divisions constructed of approved non-combustible material. 

• They need to meet neither requirements relative to the passage of smoke and flame nor limitations relative to the temperature rise.

• Combustible Veneers are permitted provided they meet the requirements.

Reference: IMO Publications & Documents - International Conventions - SOLAS Ch-II-2