The choice of fire protection solutions for hangars is often one of the most contentious issues facing the owner, and therefore the engineering firm designing the infrastructure. In a previous article we looked at the particular case of hangar extinguishing systems based on NFPA 409 (See post).
The selection of fire protection means in hangars should be based on purely economic criteria, by means of a detailed investment analysis.
In my opinion, such a choice should be based exclusively on economic criteria, by means of the application of investment analysis techniques.
To this end, and given that taking out insurance is taken for grantedThe initial cost of the fire protection equipment, as well as its maintenance and operation (periodic testing), must be weighed against the cost of the risk premium to be paid for it. should include both the building and the aircraft it houses, as well as the losses caused by not having such means of production operational..
Does this mean that the means of fire protection in hangars are not standardised and are therefore free to choose? Not at all, the national regulatory framework establishes minimum standards as set out in the Fire Safety Regulation for Industrial EstablishmentsThe door is also open to the application of other international standards of recognised prestige, in particular the NFPA 409.
So how much freedom is there really in such a choice?
In fact, it is virtually total, given that national legislation prescribes This is coupled with a very low weighted and corrected fire load for the building resulting from the application of the table with the aircraft based activity fire load. This is coupled with a very low weighted and corrected fire load for the building resulting from the application of the table with the fire load of the aircraft-based activity. This results in very low means of fire protection.
So who decides which means of fire protection are the most suitable? If the choice is to be made by strictly economic reasonsThe participation of the insurance companyThe insurance company is able to provide risk premium valuations based on the fire protection measures to be installed. For this purpose, insurance companies usually have their own standards, the best known case being that of FM Global.
Another aspect that may seem important at first sight is the fuel content of the tanks. As fires based on flammable liquids, which are the type of fires for which hangars in particular are protected, develop very quickly, a small amount of fuel will have a negligible influence on decisions (see Figure 1).NFPA 409 defines unfuelled craft as those that have less than 0.50% of their capacity.).
The conclusion of all these disquisitions is obvious, the result will vary widely depending on the cost of the hangar, but above all, on the cost of the aircraft it houses.
As an example, two ratios are provided for military transport aircraft:
- One-position aircraft/one-position hangar cost ratio for the C295 model: 3/1.
- Ratio aircraft/one-position hangar cost for the A400M model: 30/1.
The ratio of the cost of the fire protection means depending on the regulations applied:
- PCI NFPA 409/National Standard cost ratio: 100/1. (Including fire fighting water supply cistern).
