EXPERT RESEARCH OF AUTOMOBILE BRASS CABLE LUG WIRE WEIGHT
Contained in article fire statistics shows that today the main cause of ignition of cars is the failure of its systems, mechanisms and units. Wherein, the proportion of the number of fires due to a technical failure increased from 15.7 % in 2001 to 34.0 % in 2010. And in 2012 the total number of fires that have occurred due to a malfunction of systems, mechanisms and units of the vehicle and the vehicle wiring fault is equal to 7718 (40.0 %),25% higher than the number of fire for the same reason in 2011. Thus, the development of measures to prevent fire on a vehicle is essential. One of the types of preventive measures is fire investigation. The article indicates that the overwhelming number of fire engineering conclusions regarding the technical reasons of fire in vehicles are likely that does not allow to implement and design specific engineering solutions. This can be explained by many factors, including the lack of evidence-based practices. In particular, methods of analysis of the reflow of live products from brass in forensic fire technical expertise are not available, although the need for expert research of brass contacts is very high. The article gives examples of actual research of brass cable lug wire weight for Lada RSO 15L-02U-41, Lada KS0Y5-02D-42, Lada 21144 cars, completely burnt in the fire. To conduct the study a scanning electron microscope JSM-6392LV was used with energy dispersive microanalysis system INCAEnergy. In the course of the study there were confirmed and specified on the actual examples of diagnostic features, experimentally determined by specialists of the Research Center of Expertise Fires (All-Russian Research Institute for Fire Protection of Emercom of Russia), and the identity of the process of destruction of the brass contact-electric or thermal. It is proved that on the surface of the brass contacts there can be fixed as the classic signs of a large transient resistance and highly specific for brass contacts signs in the form of separation of zinc in the form of spherical particles. It has been established that the identified signs are stable and unaffected in the natural conditions of storage of thermally damaged car. The given data may be used by specialists with expert study of brass contacts vehicles, seized from fire, establishing the nature of their damages and, ultimately, cause of the fire. In addition the materials contained in the article can be useful to the manufacturer Lada RSO 15L-02U-41, Lada KS0Y5-02D-42, Lada 21144 in preventing fires by improving technological discipline and improvement of the design of the contact nodes.