Classification of Fire bulkheads inside Accommodation

The bulkheads are classified as A B & C class. The classification is based on fire resistance.

A Class Division

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

1. They are constructed of steel or other equivalent material;
2. They are suitably stiffened;
3. They are insulated with approved non-combustible materials such that the average temperature of the unexposed side will not rise more than 140ºC above the original temperature, nor will the temperature, at any one point, including any joint, rise more than 180ºC 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
4. They are constructed as to be capable of preventing the passage of smoke and flame to the end of the one-hour standard fire test.

B Class Divisions

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

1. They are constructed of approved non-combustible materials  
2. They have an insulation value such that the average temperature of the unexposed side will not rise more than 140ºC above the original temperature, nor will the temperature at any one point, including any joint, rise more than 225ºC above the original temperature, within the time listed below:
   • Class”B-15″ 15 min
   • Class”B-0″     0 min
3. They are constructed as to be capable of preventing the passage of flame to the end of the first half hour of the standard fire test.

C Class divisions

“C” class divisions are divisions constructed of approved non-combustible materials. They need meet neither requirements relative to the passage of smoke and flame nor limitations relative to the temperature rise. 

What is a non-combustible material as per SOLAS

Non-combustible material is a material which neither burns nor gives off flammable vapours in sufficient quantity for self ignition when heated to approximately 750°C, this being determined to the satisfaction of the administration by an established test procedure. The other materials are considered as combustible materials.