The abbreviation AC on a fire truck means "Tank Vehicle", which directly indicates the presence on board the vehicle of a stationary water container or fire extinguishing substances. The presence of a tank is a key difference between this type of equipment and specialized hose or gas-dimming vehicles, allowing the crew to immediately start extinguishing the fire without waiting for water supplies from hydrants or natural reservoirs. It is this parameter that determines the tactics of using the machine in a fire and its place in the combat calculation.
Constructively tanker-vehicle It is a complex engineering structure, where the chassis of the truck is adapted for the installation of special equipment and a tank with a volume of 1.2 to 12 cubic meters. The weight of fully refueled equipment significantly exceeds the weight of the basic chassis, which requires strengthening the frame, installing additional springs and using more powerful braking systems. The water in the tank when moving creates a dynamic load, so the inner part of the tank is always equipped with special breakwaters that prevent sharp shifts in the center of gravity during maneuvers.
The main task that is being solved tanker-vehicleThe purpose of the project is to ensure the autonomy of the fire department in the first minutes after arrival at the call site. The crew is able to supply the trunks for extinguishing directly from the tank, in parallel organizing the intake of water from an external source through a pump or by gravity. Such a dual system of fire extinguishing agent supply makes the ATS a universal tool both in urban development and in the absence of a developed infrastructure.
Design features and construction of tanker vehicles
The central element of the design is the tank itself, which can be made of various materials, each of which has its own performance characteristics. Modern models are most often equipped with stainless steel or fiberglass containers, which avoids corrosion and significantly reduces the weight of the equipped machine compared to traditional carbon steel. The internal space of the tank is divided break-cutter - sealed partitions with holes that extinguish the inertia of the liquid during acceleration and braking of the car.
The most important part of the system is the centrifugal fire-pump, which is powered from the chassis engine through the power take-off box (COM). The pumping equipment provides the necessary pressure to supply water to the sleeve line and allows for the intake of liquid from open reservoirs through the suction sleeves. A complex system of piping, valves and distribution manifolds is used to control the flow of the extinguishing agent, usually located in the rear compartment or on the sides of the body.
⚠️ Note: Operation of the pump without water ("dry") is strictly prohibited, as this leads to instant overheating of the sealing rings and jamming of the working wheels, bringing expensive equipment out of order.
The crew cockpit is also undergoing significant changes to accommodate combat crew and stock of special equipment. In the compartments located along the sides, fire hoses, barrels, branches and personal protective equipment are stored. The bays are designed to provide quick access to tools at any time of the day and in all weather conditions, which is critical to reducing deployment time.
To prevent freezing of water in winter, the tanks and pump compartment are often equipped with engine exhaust heating systems or electric shades.
Classification of fire tankers by capacity
The division of fire trucks of the ATS type into classes is made depending on the volume of the tank, which directly affects their tactical and technical characteristics and scope of application. Light tankers based on the chassis of medium-duty trucks (for example, GAZ or ZIL), have a tank capacity of up to 2.5 cubic meters and are designed to work in dense urban areas or hard-to-reach places. The average models that form the basis of the parks of most fire departments, hold from 2.5 to 5 cubic meters of water and have high cross-country ability.
Heavy tankers installed on the chassis of KamAZ, Ural or MAZ carry on board from 5 to 12 cubic meters of water. Such machines are often used to extinguish large industrial sites, forests and in situations where the water source is at a considerable distance. The increased weight requires the use of a chassis with a wheel formula 6x4 or 6x6, as well as reinforced stabilization systems when driving.
- 🚒 Light class: up to 2.5 m3, high maneuverability, work in the city center.
- 🚛 Middle class: volume of 2.5-5.0 m3, universal purpose, main combat crew.
- 🏗️ Heavy class: volume of over 5.0 m3, extinguishing large fires, working in industrial zones.
The choice of a specific type of tanker for the fire department depends on the characteristics of the object to be protected. For residential areas with a developed network of hydrants, middle-class machines are enough, while for the protection of warehouse complexes or suburban areas, heavy ATS with a large reserve of fire extinguishing agent are required. Design engineers always take into account the range of the sleeves and the time of arrival to the nearest water source.
Pumping and sleeve equipment system
The heart of any fire tanker is a pumping unit, the reliability of which depends on the effectiveness of extinguishing. Most modern models use centrifugal pumps of normal pressure (NC), capable of creating a head of up to 100 meters of water column. High pressure pumps or combined installations combining both operating modes may be installed for the supply of special fire extinguishing agents or for work on high-rise buildings.
The pump is controlled from the rear panel of the operator, where the pressure gauges, valve control levers and vacuum apparatus are located. Vacuum system It is necessary for the initial filling of the pump with water when installing from open reservoirs, creating a vacuum in the suction line. Modern automated systems allow the operator to control pressure in the pressure line and, if necessary, to discharge excess water back into the tank or to the ground through drain valves.
| Type of pump | Serve (l/s) | Pressure (m) | Application |
|---|---|---|---|
| NCN-40/100 | 40 | 100 | Basic extinguishing |
| NCN-60/100 | 60 | 100 | Large hearths |
| NPVN | 10-20 | 200+ | High-rise buildings |
| Combined | 40/10 | 100/200 | Universal. |
Pipeline strapping is made of corrosion-resistant materials and passes through the heated compartment to prevent freezing of water residues in winter. All connections are equipped with quick-removal couplings, which allows you to quickly connect additional sleeves or trunk sleeves of large diameter. The system is regularly checked during maintenance and after each exit.
Principle of operation of centrifugal pump
The rotating working wheel captures water and, under the action of centrifugal force, throws it to the periphery, creating pressure. The inlet dilution ensures a constant influx of new liquid.
Foaming systems and combined extinguishing
Many modern tankers are equipped with an additional foaming tank, which expands their functionality. The presence of a foam tank allows you to extinguish flammable and combustible liquids, where the use of clean water is ineffective or even dangerous. Mixing of the foaming agent with water occurs in special dosing devices installed on the pressure line of the pump, ensuring an accurate concentration of the solution.
The foam extinguishing system can operate in automatic or manual mode, allowing the operator to choose the type of foam (heavy, medium or light) depending on the type of burning substance. For the generation of foam, special barrels or generators are used that are connected to pressure sleeves. The effectiveness of foam extinguishing is much higher, since it isolates the fire from oxygen access and cools the surface of the burning material.
- 💧 Heavy foam: used to fill rooms and basement floors.
- 🫧 Medium foam: used to extinguish oil spills.
- ☁️ Light foam: effective for localizing vapors and gases in closed volumes.
Maintenance of the foam tank requires special attention, since the remnants of the foaming agent can crystallize and clog pipelines. After each use, the system is necessarily washed with clean water, and in winter the foaming agent is merged or replaced with frost-resistant analogues. Control of the level and quality of the foaming agent is included in the mandatory daily check of the combat readiness of the machine.
⚠️ Attention: When mixing different types of foaming agents, a chemical reaction with precipitation can occur, which will cause the dispensing system and the pump to fail.
Maintenance and readiness check
The constant readiness of the fire truck to leave is ensured by strict maintenance regulations and daily checks. Mechanics and drivers are required to monitor the level of oil in the engine and pump, tire pressure, the condition of the braking system and the charge of the batteries. Particular attention is paid to the density of the adjoining hatches of the tank and compartments in order to exclude the entry of dust and moisture on the equipment.
A pump with water circulation in a “circle” (from tank to tank) is tested weekly to check the operability of all units. During this procedure, the absence of extraneous noise, vibration, oil and water leaks, as well as the correctness of the readings of the control and measuring devices are checked. All results of inspections are recorded in the travel list and the log of technical condition of the equipment.
☑️ Daily inspection of the ATS
Seasonal maintenance includes replacement of lubricants with the appropriate temperature regime, checking of the heating system of compartments and anti-corrosion treatment of the body. In anticipation of the winter period, water utilities are conserved, seals are replaced and engine preheaters are checked. Untimely performance of these works can lead to defrosting of the pump and failure of the machine at a critical moment.
Regular lubrication of the pump drive shafts and COM prolongs the life of the transmission and prevents jamming with prolonged downtime.
Tactics of use and combat deployment
Arriving at the scene of the fire, the tanker driver takes a position that ensures the safe operation of the crew and convenient water withdrawal. The machine is installed at a distance that excludes the collapse of structures on the equipment, but allows you to feed the barrels directly to the hearth. If it is at a distance, the ATC can work in a “pumping” by supplying water from the hydrant or pond to the fire site through intermediate tanks or sleeves.
Combat deployment is carried out by calculation in the standard time, which for modern tanker trucks is from 40 to 60 seconds. Firefighters quickly lay trunk and work lines, connect trunks and supply water under the necessary pressure. The coordinator of actions (the head of the guard) manages the pump, adjusting the pressure depending on the number of connected barrels and the change in the situation at the fire.
In water-scarce conditions, the tanker can operate in recycling mode or use foam to increase the fire-extinguishing efficiency of a small amount of water. Maneuverability and permeability of the machine allow you to get close to the burning object, which is especially important when extinguishing forest fires or fires in the private sector. After the fire has been eliminated, the equipment is assembled and the tank refueled to return to standby mode.
What is the standard amount of water for the city?
For urban fire departments, the de facto standard is tanker trucks with a volume of 4-5 cubic meters. This volume allows you to carry out initial actions to extinguish and localize the fire until the arrival of additional equipment or uninterrupted water supply.
Can a fire tank be used for drinking water?
Absolutely not. The inner surface of tanks and pipelines of fire engines is not intended for contact with drinking water and may contain residues of foaming agents, products of corrosion or pollution. The use of such water for domestic needs is prohibited by sanitary standards.
Why are tanks made of stainless steel?
Stainless steel is not susceptible to corrosion when in contact with water, which guarantees a long service life and the absence of rust that could clog the pump and sprinkler systems. In addition, it is lighter than conventional steel, which allows you to increase the payload of the chassis.
How often should I change the water in the tank?
Water in the tank is recommended to be updated at least once a month, and in the summer - more often to prevent flowering and the appearance of an unpleasant smell. Before winter conservation, the water is completely drained to avoid breaking the tank with ice.
What is a “dry passage” for a fire pump?
This is the work of a centrifugal pump without fluid flow. Unlike bulk pumps, centrifugal pumps cannot work “dry” even for a short time, since water performs the function of lubricant and cooler for end seals of the shaft.