Appendix 3 – Thermal Radiation Test Supplement to Fire Resistance Test Procedures for Windows in “A”, “B” and “F” Class Divisions

  1.1 This appendix specifies a procedure for measuring heat flux through windows as a basis for characterizing their ability to limit the heat radiation in order to prevent the spread of fire and to enable escape routes to pass near the windows.

  1.2 This procedure is an optional requirement and may be requested by some Administrations for windows in specific areas of a ship.

  2.1 The window shall be tested in accordance with appendix 2 of this part using the additional instrumentation as described below.

  2.2 The term "window" includes windows, side scuttles and any other glazed opening provided for light transmission or vision purposes in a fire resistant division. The term "fire resistant division" includes bulkheads and doors.

  3.1 Additional instrumentation consists of a restricted-view total-heat flux meter calibrated with the restricted view to indicate incident heat flux. The flux meter shall be water-cooled and capable of measuring heat flux 0 kW/m² to 60 kW/m². The flux meter should be calibrated at least once a year against a standard device.

  3.2 The flux meter should be placed perpendicular to the centre of the window being tested, and in a position such that the centre of the flux meter's view coincides with the centre of the window^footnote (see figure). The flux meter should be located at a distance greater than 0.5 m from the window, such that the view of the flux meter just includes part of the frame. However, the flux meter should not be located more than 2.5 m from the window. The dimension of the boundary and window frame seen by the flux meter, which remains outside the window, should not exceed 10% of the total width seen by the flux meter on the surface of the sample. It should be calculated on the basis of restricted view angle of the flux meter and its distance to the sample surface.

  3.3 For windows whose greater dimension is less than 1.57 times the smaller dimension, only one flux meter is needed.

  3.4 For oblong windows whose greater dimension is more than 1.57 times the smaller dimension, additional flux meters should be provided. The distance of the flux meters from the window should be adjusted such that the flux meters' view covers at least 50% of the window. However, the flux meters should not be located less than 0.5 m nor more than 2.5 m from the window.

  4.1 The peak heat flux (E_w) should be measured for the first 15 min of the test, for the first 30 min of the test, and for the entire duration of the test (i.e. 60 min for class "A" and 30 min for class "B" boundaries).

  4.2 The peak heat fluxes (E_w) measured in accordance with paragraph 4.1 should be compared against the reference value (E_c) from table 1 below.

  4.3 If (E_w) is less than (E_c) , the window is acceptable for installation in a boundary of the corresponding fire resistant classification.

Table 1 – Criteria for heat flux