Tag Archives: Fire Fighting

FIXED FIRE FIGHTING SYSTEM

ADVANCED FIRE FIGHTING, Fire & Life Safety Education, Fire Fighting System, FIXED FIRE PROTECTION, Innovation, , , , , ,

Trust my readers are Happy and Healthy and are slowly but steadily returning to normalcy. We need to be careful not only during this period but at all times. In this blog of mine we shall discuss a very important aspect of firefighting which is called the Fire Hydrant system. A lot of money is spent on that all over the world but many are unaware what it is and how it can help in firefighting. We have seen them in the factories and buildings we work and have always wondered how they work? Let me tell you all about it.

We know that there are 3 stages of Fire. 1. Incipient stage 2. Growth stage 3. Fully developed or Fully involved stage. To fight the fire and extinguish it in the incipient stage and to some extent in the growth stage we can use the fire extinguishers and hose reels. But when the fire advances to the next stage these are simply not enough. Here we need the Hydrant system or the Fire Water Hose system. Automatic Sprinkler Systems too help here. But the sprinkler is more internal and the hydrant takes care of the external factor.

A hydrant system is a special outlet fitted on water mains for firefighting purpose. The definition is very clear and it says that this system cannot work without the abundance of water. To put this in proper perspective the fire trucks or fire engines carry a limited supply of water and it is exhausted very fast. Therefore, if a system with abundant water is provided fire can be fought till the fire services arrive and they too can use the system. Fire can be brought under control soon and structural damage can be limited .

JOCKEY PUMP, MAIN PUMP, DIESEL PUMP.

Let us study the system in detail. The heart of the system is called the pump room and it consists of 3 pumps. 1. Jockey Pump. 2. Main Pump and 3. Diesel Pump. This is a system under pressure and the entire network of complex piping is charged. Depending on the design requirements pressure is set. It usually starts at 7BAR and can go till 10BAR. Manual firefighting is not feasible at a pressure beyond 11BAR. The pumps are necessary to take care of the pressure and to ensure the correct pressure is maintained at all times during Fire Fighting.

  1. Jockey Pump : This pump gets switched on when pressure in the line drops below 5BAR. The pump when on increases the pressure levels to the optimum levels already set. The pump functions as per the pressure setting and rating.
  • Main Pump : This pump switches on when the pressure drops below 4.5BAR. This usually happens when more outlets are operated. Hence this pump increases the pressure to the original set levels and can sustain the pressure for longer periods, even when multiple outlets are operated. But both the Jockey and Main Pump operate on Electricity and the Electricity for the pump house should be independent of the supply to the premises. 
  • Diesel Pump :  This pump is the backup system for the Main and Jockey pumps. When there is a power failure this can be switched on and the firefighting operations can be continued. In some systems the technology is so designed that the pump can switch on automatically if there is a drastic drop in pressure and can bypass the main and jockey pumps.

All the pumps are interlocked for automatic operations through a MCC panel and pressure switch integration.

Every inlet needs an outlet and the outlets will be all around and the water flows through a maze of pipes and valves. Let me describe in brief about them.

Hydrant Post ,Hose Box, Fire Service Inlet

Hydrant Post : This is the main outlet and usually this is mounted on a pipe which looks like a lamp post. The outlet contains a Wheel to open and a coupling where the hose can be attached to it. The hydrant post is of either a single head or a double head and the heads are installed depending on the design requirement.

Hose Box or Hose Station : Next to the hydrant post we find a box where 2 hoses are kept. The hoses are called delivery hose or the fire hose. There are different types of hoses and the widely used Hose today is called RRL Hose (Reinforced Rubber Lining). There are 3 lengths of hoses and these are same across the world. They are 7.5mts, 15mts, and 30mts. For firefighting in the yard 15mts is the standard length and for using inside 7.5mts are used. In some places the hose box may be a little away from the Hydrant post. The delivery hoses have couplings which are universal sizes of 63mm diameter. The hose box contains a branch pipe or a nozzle along with the delivery hose. The box is locked and there will be a key in a small glass enclosure which can be easily broken. In the hose box a Branch pipe or normally called a Nozzle is placed along with the hoses.

Fire Service Inlet : This too looks like a hydrant post but the difference is this will be an inlet which can be used by the firefighters to fill the tank of the fire truck. As the water in the fire truck gets exhausted too quickly the firefighters can use the water provided. The fire service inlet is usually located near the entrance of the building.

Universal Branch Pipe, JET Branch Pipe, Foam Branch Pipe

Branch Pipe : This is one of the essential accessory without which fire fighting cannot be done. There are various types of branch pipes and describing each one of them in this blog would be too elaborate. But for information some of them are

  1. Jet Branch Pipe.
  2. Universal Branch Pipe.
  3. Curtain Branch Pipe.
  4. Foam Making Branch Pipe. And so on

To operate this system during fire ground operations 3 persons who are well trained are needed. In the case of civilian fire fighters 4 persons can too be there. As the system throws out water at a high pressure one needs to be trained to use it. Persons who are not trained should never operate the system as life can be lost if something goes wrong. The designated persons operating the hydrant are called

  1. Branch Man.
  2. Support and Signal Man.
  3. Hydrant valve opening man.

To operate the communicate during the operation the firefighters use simple voice and hand signals. The Signals are used to open the water, increase the pressure, maintain the pressure and close the water after firefighting. 

A typical position of the branch man with his support will look as follows.

Branch Man Holding the Branch Pipe
Ready Position

A part of the system is also a water Monitor which are fixed in one location and throw water with great force and to a long distance. They are easy to use and are strategically placed where the fuel load is high.

To conclude I would say that

“TACTICS WITHOUT TECHNOLOGY IS HELPLESS. TECHNOLOGY WITHOUT TACTICS IS USELESS”

WISH ALL MY READERS A MERRY CHRISTMAS AND A HAPPY AND SAFE NEW YEAR.

Till my next blog stay safe and be safe.

Seshadri Varadarajan.
9840814353.


Complete Fire Fighter – I

Fire & Life Safety Education, Innovation, , , ,

Trust all my readers are staying safe.  We have discussed a lot on Fire safety in the past year. A lot of aspects were covered and I trust the information has been helpful to understand the dynamics of Fire and its character. We all know that fire fighting is dangerous and not to be done by untrained people. In this blog let us discuss the dangers faced by the Fire service personnel while battling the fire and how to ensure they return back safely to their families.

Fireman ready for Battle

There are 5 common hazardous situations most fire fighters find themselves during a fire ground operation.

  1. Elevated Temperature
  2. Smoke
  3. Oxygen Deficiency
  4. Toxic Atmosphere
  5. Structural Collapse

All the above situations present different challenges and are life threatening conditions. Though the fireman in advanced countries are highly trained it is not so in developing countries. To face these situations, rescue people and still coming out alive is a huge task. Hence a fire fighter needs to be properly equipped before he can even fight the fire.

Let us start with the dress of the fire fighter. This is called the fireman suit and it consists of the following.

  1. Helmet with Neck Protector
  2. Protective Flash Hood
  3. Jacket
  4. Gloves
  5. Trousers
  6. Boot

Helmet: The helmet protects the head, neck and face. It consists of a cap shell, cap hoop, the buffer layer and chin strap. It has an anti-scratch outer coating and anti-fog visor. The shell is made of TPE (Thermo Plastic Elastomer) material for resisting high temperature. The visor is polycarbonate. The neck protector has to be made of genuine leather. The interior of the helmet should have ventilating channels for sweat absorption and a shock absorber made of Poly Ethane foam. The chinstrap should be made of flame retardant cotton.

Protective Flash Hood: The protective hood provides thermal insulation to the sensitive parts of the head. It should have an elasticated face opening with comfortable seams. The hood should be flame and abrasion resistant. The flash hood should be double layered and made of 50% Meta-aramid and 50% viscose fabric and manufactured as per the latest fire safety standards.

Fireman jacket and trouser: These are the largest and most important parts of dressing up a fireman. Both the jacket and the trouser should consist of 4 layers.

1.Outer Layer
2.Moisture Barrier Layer
3.Heat Barrier Layer
4.Inner Lining

The outer layer is the most important layer which is exposed to heat and flame. It should be made of molecular engineered fire resistant fabric. The outer layer is made of 60% Para-aramid and 40% Meta-aramid. The outer layer should be 245 GSM fabric.

The moisture barrier layer protects the firefighter against water, chemicals, blood borne pathogens and microorganisms. It should be made of 80% Meta-aramid 20% Para-aramid coated with PTFE (Teflon). The moisture layer must be made of 110 GSM fabric.

 The heat barrier layer provides protection from heat. The material should be non-woven spun laced fire resistant material. It should comprise of 80% Meta-aramid and 20% Para-aramid fabric. The heat barrier layer fabric should be 70 GSM.

It is common knowledge that a firefighter would sweat a lot and hence absorption of sweat is important too.  The inner layer should made up of 50% Meta-aramid and 50% Para-aramid fire resistant viscose material. The inner layer fabric should be 150 GSM.

A wrist guard is sewn into the jacket, which protects the exposed skin between the edge of the sleeve and the glove. The collar is designed to protect the throat and the back of the neck. The special elbow guards protect the fireman’s elbow while crawling.

The special reinforced knee guards protect the knees while fighting fire. The trouser also consists of cargo pockets, suspenders, and stretch waistbands.

Gloves: Fireman gloves provide protection to the hands from heat and is also water repellent. It should be made of leather and lined with Cotton and a split leather cuff, stitched with fire resistant threads. The glove is Gunn cut designed with winged thumb, gauntlet type.

Boot: The fireman boot comes in black and yellow colour. It has vulcanized rubber uppers and soles and is lined with Woven Cotton material. It has Epoxy toe caps and has lacquer coating for weather protection.

 It is thermal resistant, waterproof, puncture resistant, chemical resistant, anti-crush and electrically insulated. The soles are slip resistant, highly durable and have minimum heel impact. The steel midsole provides protection from pins and sharp objects.

Every Fireman suit made should pass the following tests as per the world standards.

  1. Flame Spread
  2. Heat Transfer (Flame)
  3. Heat Transfer (Radiant Heat)                                              
  4. Residual Strength of Material (All Layers)
  5. Heat Resistance (All layers)
  6. Tensile Strength (Outer layer)
  7. Tear Strength (Outer layer)
  8. Penetration by Liquid Chemicals
  9. Resistance to Water Penetration
  10. Water Vapour Resistance

By donning the fireman suit a firefighter is ready for fire ground operation but to fight the oxygen deficiency and smoke he needs a Self Contained Breathing Apparatus (SCBA). We shall discuss about it in the next blog.

Till then stay safe and be safe.

Seshadri Varadarajan – 9840814353
For more information on Fire Man Suit, visit www.ushafire.com and www.resguardo.com