Division .4 F1

Fire doors in main vertical zone bulkheads and stairways enclosures other than power-operated sliding watertight doors and doors normally locked, shall satisfy the following requirements:

1. .1

   The doors shall be self-closing and be capable of closing with an angle of up to 3,5° opposing closure. The speed of closure shall, if necessary, be controlled so as to prevent undue danger to persons. In new ships the uniform rate of closure shall be no more than 0,2 m/s and no less than 0,1 m/s with the ship in the upright position.