Obviously these are only indicative and maximum values; for a lot of persons, in fact, to respire at 65°C constitutes difficulty; while it is liquidated that respiration at 100°C determines completely death。

CFAST valuates the temperatures and the reference height of two zones (superior and lower) in which it is pided the compartment, that are possible to happen during the fire develop。

The interface height (that is the separation of ideal surface between the hot zones with smokes) allows verifying in the different locations the risk presents。

For the exposure to the heat, besides, it is possible to determine specific locations values, with the entity of the incident thermic flux。

As far as the tenability coefficients is concerned, CFAST carried out three distinct values of the inherent exposure to heat:

1。the temperature of the inhaled gas;

2。the fraction, in comparison with the determinant dose of incapacity, of the convention heat accumulated; including values between 0 and 1; the reaching of the maximum value 1 is to indicate the happen of incapacity;

3。the heat total flux incident ( Kw min/m^2)。

-the smoke species; 3)

-the indicators of danger conditions for passengers and crews (tenability coefficients)。

The indicator conditions of danger, as the exposure to the heat and the inhalation of gases, are that elements, which present more directly relate to the characteristics and physiologic of the human body。

For this, it has been employed tests on pigs。 The pigs have been used to the analogy existing between theirs cutis and those human。

The utilization of the rats, from the consolidated tradition of valuing the toxicity of chemical element by such animals, has given a reinterpretation, in various modes, to relate it to the man。

Anyway, the resulted obtained, though not exhausted, have determined a useful cognitive base for the evaluations of fire risk and they have allowed of determining an assembly of "indicative" coefficients tenability。

The judgment of the paper author, then, for the evaluations  of  such  safety  indicators,  is  that  will  be

Numerical Simulations

They are considered two examples concerning a fire evolution in a typical passenger cabin of a cruise ship (see plant of fig。 1)。

It is well known that, as suggested by MSC/circ 1003, in case of moderate fire risk accommodation area, the max value of the combustible mass material per unit deck area is 35 kg/m^2。

According to the SOLAS fire class of the cabin (B0) the final fire safety objective is to keep the fire contained in the space boundary for the time prescribed  (30 minutes)) with an increased amount of combustible material, without additional fire protection。

The simulation analysis has regarded the cabin with or without  sprinkler installation。

Fig。 1: plant of typical passenger cabin

Passenger cabin without sprinkler head installation

It is considered as first example of the fire growth in a passenger ship cabin (passenger cabin of cruise ship) without sprinkler installation (or in the case that the sprinkler doesn’t work), and with fire beginning in the matrimonial mattress。

For the cabin it is consider a typical configuration:

-a room of 2。8x3。7 with matrimonial bed;

-an entrance of 1x2。3 m with wardrobe;

-a bath of 1。8x2。3;

with internal altitude of m 2。7, internal doors of 0。7x2。1 m, exit door (on the balcony) of 1。7x2。1 m

The furniture of the room included besides the matrimonial bed:

1)a bedside table with light;

2)a shelf with television set and light table;

3)an easy chair;

4)two chairs;