RISK AND RELIABILITY CRITERIA FOR SELECTING FIRE-FIGHTING RESCUE EQUIPMENTS

Hydraulic survival instrument (HSI) can be used as the main equipment used for operations on unblocking casualties when wrecking and fire-rescue units (FRU) works. Currently, more than ten domestic and foreign firms produce various sets of HSI with different functional characteristics. Selection of a particular set HSI by decision maker on completing their FRU is very difficult. Previously, it was shown that for estimation the level of technical risk when using this or that sophisticated equipment can be used the integrated index — the expectation of damage from termination of his work and, further, relative overall benefit indicator (in this case, brought by a set extinguish), which may be estimated by the formula: W = V/(G + B), where V— the value of avoided damage, rub., estimate of the value of avoided damage from mortality and injuries during the liquidation aftermath of accidents; V = Y; Y — damage caused by a fault HSI (during wrecking); G — the cost on preventing and reducing technical risk (primarily operating costs for attendance of HSI), rub.;B— level of technogenic risk, rub., which can be interpreted as the expectation of damage from individual risk. Here, the level of technogenic risk B in terms of value (the expectation of damage) is calculated as follows: B = QY, where Q — the probability of failure HSI. The higher the value of W, the more reliable and efficient (relatively) set. Statistically reliable performance data on failures HSI in relevant system of accounting such events cannot be received. Therefore, realization calculations of value W, as well as in cases of choosing a particular set HSI when determining the probability of adverse events (failures), the method of constructing and analyzing “fault trees” (AFT) process can be used — as the most commonly used and intuitive. On the assumption that the worst event during the wrecking is a temporary loss of performance (failure) HSI and probable slowdown at rescue operations, the damage from failure Y depends on mortality and severity of disease associated exactly with slowdown on unblocking (at a cost life in Russia 4.5 mln. rub.). We examined samples sets of HSI — “Prostor”, “Sprut”, “Medved”, “Kombitech” for performing operations on unblocking and rescue of victims. The calculation results show that the decision-makers should not take to consider options for purchasing sets HSI “Prostor” and “Medved” without bringing their reliability indexes to an acceptable level. And although the set “Sprut” is cheaper (16 %) the set “Kombitech”, the value of expectation of damage is lower (on 71 % or 3.5 times) at last one, but the overall benefits W is higher than another sets. Therefore, the option of purchasing the set “Kombitech” seems preferable. The proposed approach to reliability evaluation of HSI using risk indicators and overall benefits for selecting particular set, can be added with results of certification tests by manufacturers — for management decisions to include
not include in the standard package of HSI used by fire-rescue units.