Whilst fire pumps may be used for other duties such as ballast or general service they should not normally be used for pumping oil. Changeover arrangements may be fitted allowing a pump to be used for oily bilges,
Emergency fire pump
This equipment is of the utmost importance to the safety of the ship and due care and attention is to be given to both maintenance and training of the equipment.
Instructions are to be clearly posted on start-up procedures and valves are to be clearly marked with their correct operating positions.
The emergency fire pump is to be run and tested weekly for at least five minutes, ensuring that remote starts are working and that the required pressure can be maintained at the furthest away fire hydrant.
If any defects are noted, including insufficient water pressure, then the Company is to be notified and an urgent plan agreed to rectify the situation as quickly as possible.
By regulation cargo vessels are provided with emergency fire pumps because a fire in the engine room could put all of the other pumps out of action. Such a pump is indicated in Figure below and is located away from the engine room in the shaft tunnel, steering gear or in the forward part of the ship.
The suction lift of any pump is limited and for this reason emergency fire pumps are restricted to being at a maximum of 6 m from the water level at light draught conditions. Ideally they are installed below the waterline to guarantee avoidance of suction problems. There have been difficulties in the past with some steering gear located emergency fire pumps when the ship was in the ballast condition.
If the location of a centrifugal type emergency fire pump is the steering flat then, because of the high suction lift involved, a priming pump is fitted. This may be friction driven from the fire pump flywheel and once the fire pump is running the priming pump drive wheel, normally held away from the flywheel by a spring, must be held against it until the fire pump is primed. The fire pump (centrifugal type) discharge valve is shut while the pump is being primed and opened gradually as the suction is taken up. On large vessels a special two stage pump arrangement may be used .
(Figure below) The first stage below the waterline is driven by a hydraulic motor. The second stage and the hydraulic power unit are driven by a prime mover (or electric motor from the emergency supply) which can be positioned at more than the normal distance from the waterline. If the fire pump is driven by a water-cooled diesel engine supplied with cooling water from the fire pump a header tank will be provided to ensure that the engine is cooled while the fire pump is being primed. The engine could have a closed circuit fresh-water system, with the water being cooled in a radiator. It is usual however, to fit an air-cooled diesel engine.
Where a closed-circuit fresh-water cooled engine is installed anti-freeze may be needed for the radiator in cold weather. An emergency pump has an independent diesel drive or some alternative such as an electric motor powered from the emergency generator.
Where steel pipes are used, they are galvanized after bending and welding. Their diameter is between 50 mm and 178 mm depending on the size and type of ship. Engine room hydrants must have hoses and nozzles for jet and fog or dual purpose nozzles.
International shore connection
The international shore connection (Figure below) is a standard sized flange with nuts, bolts and washers and a coupling for the ship's fittings. The dimensions are shown. The fitting and joint must be suitable for a working pressure of at least 10.5 bar. Four bolts are required of 16mm diameter and 50mm length, also eight washers.
Fig:International shore connection
Hoses and nozzles
Fire hoses must be of approved materials. They are positioned adjacent to hydrants together with suitable nozzles. Dual purpose nozzles can be adjusted by rotation of the sleeve to produce a jet or spray. These are an alternative to having available separate jet and spray or fog nozzles.
Types of portable fire extinguisher
There are four principal types of portable extinguisher usually found on
board ship. These are the soda-acid, foam, dry powder and carbon dioxide
extinguishers. Details as below :
Fixed fire extinguishing installations
- Soda acid portable fire extinguisher
The container of this extinguisher holds a sodium bicarbonate solution.
The screw-on cap contains a plunger mechanism covered by a safety
- Foam type portable fire extinguisher
The main container is filled with sodium bicarbonate solution and a long
inner polythene container is filled with aluminium sulphate
- Dry powder fire extinguishers
The outer container contains sodium bicarbonate powder. A capsule of
carbon dioxide gas is located beneath a plunger mechanism in the
- CO2 portable fire extinguisher
A very strong container is used to store liquid carbon dioxide under
A variety of different fixed fire fighting installations exist, some of
which are specifically designed for certain types of ship. A selection of
the more general installations will now be outlined.
Other important fire & safety equipments
- Fire main system for cargo ships
An outbreak of fire requires a source of ignition, the presence of combustible material and ample oxygen. Of the three factors, oxygen is provided in large quantities in machinery spaces, accommodation, dry cargo holds and tanker pumprooms by ventilation fans. Air supply trunkings are not only a source for a supply of oxygen to feed the fire but also have potential for carrying smoke from one area to another....
- Automatic water spray & water mist system for machinery protected area
The automatic spray or sprinker system provides a network of sprinkler heads throughout the protected spaces. This system may be used in accommodation areas, and in machinery spaces with certain variations in the equipment used and the method of operation. ....
- Automatic foam induction system for machinery space fire
Foam spreading systems are designed to suit the particular ship's requirements with regard to quantity of foam, areas to be protected, etc. Mechanical foam is the usual substance used, being produced by mixing foam making liquid with large quantities of water. Violent agitation of the mixture in air creates air bubbles in the foam. ...
- CO2 fire extinguishing installations for machinery spaces
Fire extinguishing installations employing CO 2 stored under pressure at ambient temperature are extensively used to protect ships' cargo compartments, boiler rooms and machinery spaces. When released the CO 2 is distributed throughout the compartment, so diminishing the relative oxygen content and rendering the atmosphere inert....
- Inert gas systems, inert gas generator
Inert gases are those which do not support combustion and are largely nitrogen and carbon dioxide. Large quantities suitable for fire extinguishing can be obtained by burning fuel in carefully measured amounts or by cleaning the exhaust gases from a boiler. ....
- Fire fighting Halon system
A Halon storage system would be very similar to one using carbon dioxide except that fewer cylinders would be required. The liquefied Halon is usually pressurised in the cylinders with nitrogen in order to increase the speed of discharge. ....
Marine machineries - Useful tags
Marine diesel engines
- Use of Breathing apparatus
Compressed air cylinders are of various sizes, usually of either 9 or 6 litre water capacity.
The fully charged pressure of cylinders also varies. Some types are charged to as high as 300 bar (4500 p.s.i.). The maximum charging pressure is always stamped on either the neck or the shoulder of a cylinder.
- Emergency Fire pump cargo ships machinery spaces
Two independently powered pumps must be provided in all cargo ships of 1000 tons gross and over and in passenger ships of less than 4000 tons gross. Larger passenger vessels and passenger ferries must have three such pumps.
- Foam adapter for machinery space fire
Foam branch pipes which operate in a similar manner to those used in deck installations for tankers, are fitted for use with the hydrants in some machinery spaces and in particular for passenger ferry car decks.
- Various fire detectors working principle
The main function of a fire detector is to detect a fire
as quickly as possible; it must also be reliable and require a minimum of
- Fire detection system
The fire detection system is to be classed as Critical Equipment and must be maintained in good working order.
- Fire fighting strategy for cargo ships
A basic strategy should be followed in all fire fighting situations. This
will involve four distinct aspects, which are locating, informing, containing
and finally extinguishing a fire.
||Steam generating plant
||Air conditioning system
||Emergency power supply
||Exhaust gas heat exchangers
||Feed extraction pump
|| Four stroke engines
|| Fuel injector
|| Fuel oil system
|| Fuel oil treatment
Lub oil filters
MAN B&W engine
Oily water separator
Overspeed protection devices
Piston & piston rings
Sewage treatment plant
Starting air system
Two stroke engines
Drydocking & major repairs
Deck machineries & cargo gears
|| Control and instrumentation
||Engine room safety