fire suppression systems and fire fighting equipment
Operating as Pliszka Fire Protection Engineering, we designed and installed fire protection systems on ships of the Polish Navy. The scope of work which we executed and the solutions which we implemented on different ships varied depending on individual technical and tactical parameters. At the end of last year, we completed tests of the fire protection systems on one of these ships, a Polish patrol boat. All of the fixed fire suppression systems using inert gasses and halon substitutes as well as foam-based extinguishing systems which were a part of the tactical and technical plans for this unit were designed and installed by our company. As Pliszka Inżyniering Przeciwpożarowy, we were also responsible for developing and implementing a fire suppression control system, pressure-release flaps, and a pressure monitoring system in extinguishing agent reservoirs.
Gas fire suppression systems
In compliance with the technical and tactical parameters of the ship, a full 27 compartments were fitted with automatic gaseous fire suppression systems. These included the Engine Control Centre, the main engine room as well as the fore and aft engine rooms, the CIC Combat Information Centre, the turbine rooms, the fore main control panel, the sidearms storeroom, the torpedo storeroom, and electrical equipment compartments. Depending on the investor’s requirements and the size of the spaces, FK-5-1-12 (the chemical name for NovecTM 1230) or an inert gas, Inergen IG-541 was used. Both extinguishing agents are completely safe for people within the area subject to fire suppression and for the natural environment. FK-5-1-12 is mainly intended for extinguishing group A and B fires, including high-voltage electrical equipment. The extinguishing process using FK-5-1-12 involves the removal of heat energy from the flames, a phenomenon which completely blocks the combustion reaction and prevents further ignition. Inergen IG-541 on the other hand is a mixture of nitrogen, argon, and carbon dioxide, gases which occur in the natural atmosphere. It effectively suppresses fires of the A, B, C and D groups by reducing the oxygen content of the surrounding air to a level which does not permit the continuation of the combustion reaction.
Control systems for gas fire suppression systems
The control systems for these gaseous fire suppression systems was designed and constructed based on two linked and redundant central extinguishing control panels. Each of these meets the requirements for control panels for warships. They feature increased resistance to vibration and electrical shorts, and also are supplied by 3 independent power sources – from the on-ship power grid, an emergency UPS power system, and an individual battery.
All of the gaseous fire suppression systems installed on the ship can be initiated from four different locations. Release of the extinguishing agent can be initiated from either of the control panels as well as from localised fire extinguishing stations installed next to each system, and also manually by using a lever on the reservoir valves. In order to increase the reliability of these systems, every element is monitored and information is transmitted to each control panel along two paths, one running along the starboard side of the ship and the other along the port side. This solution eliminates the risk of the connection being broken if the unit is partially damaged.
The fire suppression system is integrated into the ship’s IPMS system. Its design and execution were developed in consultation with the Polish Register of Shipping. The system makes it possible in future to connect additional smoke, temperature and flame detectors. In the expanded version, it will be possible to obtain a full visualisation of the state of the system presented on any device, including mobile devices such as tablets or telephones.
Automatic pressure-release flaps
All spaces protected by fire suppression systems were also fitted with automatic pressure-release flaps. The purpose of these is to prevent damage to the spaces which could occur as a result of excessive pressure increase caused by the sudden release of gas from the reservoirs. To prevent this, at the moment that the extinguishing process is initiated, in addition to appropriate visual and audio signals, pressure-release flaps are automatically opened. After a pre-set pressure release period has lapsed, whose length depends on the type of extinguishing agent used, the flaps are automatically closed and the compartment sealed in order for effective fire suppression to proceed.
Every reservoir in the gaseous fire suppression system is monitored for pressure. A signal is generated if there is an increase or drop in pressure inside the monitored reservoir. Any type of damage to the reservoir is also signalled, as are cases in which the cables attached to manometers and relays in the reservoirs become disconnected. Due to the risk of persistent low temperatures onboard the ship, all reservoirs filled with FK-5-1-12 extinguishing agent are protected by a special cover made of austenitic stainless steel. These are intended to prevent a drop in temperature to below -10°C, thus preventing a drop in the pressure of the gas in the reservoirs.
A foam-based system was designed for fire suppression at helicopter landing pads. A system of nozzles built into the surface of the landing pad makes it possible to rapidly cover the entire area with foam. The foam spraying nozzles are adapted for use with heavy foams. The system can be triggered manually from a station near the extinguishing agent reservoir, the bladder tank.
A foam system was also designed for local extinguishing of fires between bulkheads of the ship. Portable foam-based systems were also planned for horizontal deck areas where there is a risk of fire related to oils and hydrocarbons during normal operation of the ship or during fuelling and oil transfer operations in port, as well as for extinguishing fires in storage and living areas. The local fire extinguishing system and the portable foam extinguishers were designed to work together with the water-hydrant systems on the ship.
All foam extinguishing systems designed for and installed on the ship use the AFFF 3% extinguishing agent, suitable for use with A and B group fires.
Local fire suppression system for the galley
The scope of works which we were entrusted with also included a local fire suppression system for the galley, designed to deal with grease fires. This system can be initiated automatically after detection by temperature sensors. It can also be initiated manually using start/stop buttons located at the entrance hatches to the galley. After the extinguishing process is initiated, the system immediately applies an extinguishing agent to the source of the fire as well as to the ventilation hood. At the same time, power is cut off to kitchen equipment, to the in/out ventilation in the galley, flaps in the ventilation conduits are closed, and the appropriate visual and audio signals are given.
All extinguishing agent reservoirs and other elements of the systems and portable devices were mounted in such a way as to guarantee their stability during storm weather.
Additionally, operating as PLISZKA Inżyniering Przeciwpożarowy, we were responsible for the development of:
a fire protection and evacuation route plan
a fire protection inventory list
a plan for the distribution and mounting of fire protection equipment
a design for fire protection storerooms
We also conducted training for the ship’s crew on the use of the fire protection systems which we installed.