Fire-fighting System Research Articles

Computer simulation of the trajectories of large water jets

A three-dimensional computer simulation of the motion of a water jet is described which includes the effects of wind from any direction. The simulation is useful in the design of fire-fighting systems, particularly those used in offshore situations. The equations of motion are presented in vector form and the problem of the fluid dynamic drag variation is discussed. Semi-empirical approximations for the drag components along and across the jet are presented which involve four unknown constants. These are reduced to three by using previous data on the efficiency of vertical jets. To fix the remaining constants, information was available from a series of large jets tests carried out to prove an offshore fire fighting system. In these tests different nozzle shapes were tried and, using the best of these shapes, a large number of trajectories were measured photographically. These were used to fix the simulation drag constants and good agreement is shown between measurements and predictions. The simulation enables the effects of flow-rate, pressure, nozzle size, elevation and wind strength to be evaluated in the system design

Halogen-Free Fire Resistive Cable Splices

Cables for power supplies, signals and communications have to be considered as very important and possibly weak points in the fire fighting and prevention systems. They rarely cause fires but may supply combustible material and assist flame propagation as they penetrate floors and walls.

Fire Protection Systems on (WMATA) Metro

Smoke and fire detection, fire alarm and fire fighting systems for the Washington Metropolitan Area Transit Authority (WMATA) Mass Rapid Transit System, including some alternate fire fighting system designs, are presented. A combined rate-of-rise/fixed temperature fire detector is used in areas where rapid temperature changes are abnormal. Fixed temperature fire detectors are used in the other areas requiring protection. The below grade passenger stations have a wet pipe standpipe system. This system also includes a dry pipe and siamese connection to increase the volume and pressure of the water above the nominal city water pressure. The aerial and surface stations have a dry pipe standpipe system. All passenger station standpipe systems provide water to a hose valve within each fire equipment cabinet and to each angle hose valve located under manhole covers on the platform. The train tunnels also have a dry standpipe system.

A heat stress monitoring system for fire fighters

A portable lightweight seven-channel radiotelemetry system has been developed, which is capable of monitoring environmental stresses and physiological response of fire fighters exposed to heat stress during fire fighting operations.

Drag Reduction Application in Fire Fighting Systems

Predictions concerning the maximum friction reduction by drag reducing polymeric additives are presented. It was found that in rough firehoses, a reduction of about 60% in friction losses can be obtained. Polymeric additives can be used in fire fighting systems in order to increase the flow rate. However, it seems that 1-1/2 in. firehoses cannot be made as effective as 2-1/2 in. firehoses by the addition of drag reducing polymers. Polymeric slurries can be used as drag reducing agents; however, in common firehoses about 400 pipe diameters are required to activate the polymers injected as polymeric slurry to the water flowing in the firehose.

Organisation of the National Rescue and Firefighting System in Poland

National Firefighting and Rescue System (NFRS) has been created to protect population, property and environment within the territory of the Republic of Poland by the following activities: extinguishing fires, fighting against the local threats, chemical and ecological rescue operations, technical rescue operations and first medical aid. NFRS, as an integral part of the internal security system of the country, is financed by the Government. The Chief Commandant of the State Fire Service is the central body of the state administration responsible for organization and managing the NFRS. The system operates on three administrative levels corresponding with the administrative structure of the country: district (main executive level, where interventions are carried out by the district’s resources), regional (coordination and assistance to the rescue operations when resources in the district are insufficient) and national (rescue operations assistance and coordination when resources in the region are insufficient). The main purpose of this article is to present : tasks performed by the NFRS (National Firefighting and Rescue System), functioning of the system at three levels (district, regional and national), cooperation of the NFRS with subjects like Police, Border Guard, units of Voluntary Fire Brigade and many others.

Cross-Connection Hazards and Protection

40 waterborne epidemics recorded since 1907 in Illinois have resulted in 13,000 known cases of illness and 200 deaths. Eighteen of the epidemics, almost half the total, were caused by some type of faulty piping or plumbing arrangement that permitted sewage or contaminated water to enter a safe water system either at the source or in the distribution facilities. This type of defect resulted in 4,406 cases of illness and 92 deaths, 34 and 46 per cent of the respective totals. Cross connections between safe and raw or unsafe water systems have been the greatest single cause of waterborne epidemics in this period of nearly 50 years. Cross connections can be classified as direct or indirect. In the former, the safe water system is physically joined to a system containing unsafe water, sewage, or other waste for example, a fire-fighting system utilizing raw water from a polluted river. In indirect cross connections, contaminated water or waste may be sucked or blown across a space to a safe water system. The most common example of this type of cross connection is found in the ordi-