A fire hose is a high-pressure hose

Hose (tubing)

A hose is a hollow tube designed to carry fluids from one location to another. Hoses are also sometimes called pipes , or more generally tubing...

 used to carry water

Water

Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...

 or other fire retardant

Fire retardant

A fire retardant is a substance other than water that reduces flammability of fuels or delays their combustion. This typically refers to chemical retardants but may also include substances that work by physical action, such as cooling the fuels; examples of these include fire-fighting foams and...

 (such as foam) to a fire

Fire

Fire is the rapid oxidation of a material in the chemical process of combustion, releasing heat, light, and various reaction products. Slower oxidative processes like rusting or digestion are not included by this definition....

 to extinguish it. Outdoors, it is attached either to a fire engine

Fire apparatus

A fire apparatus, fire engine, fire truck, or fire appliance is a vehicle designed to assist in fighting fires by transporting firefighters to the scene and providing them with access to the fire, along with water or other equipment...

 or a fire hydrant

Fire hydrant

A fire hydrant , is an active fire protection measure, and a source of water provided in most urban, suburban and rural areas with municipal water service to enable firefighters to tap into the municipal water...

. Indoors, it can be permanently attached to a building's standpipe or plumbing

Plumbing

Plumbing is the system of pipes and drains installed in a building for the distribution of potable drinking water and the removal of waterborne wastes, and the skilled trade of working with pipes, tubing and plumbing fixtures in such systems. A plumber is someone who installs or repairs piping...

 system. It was invented by Hero of Alexandria

Hero of Alexandria

Hero of Alexandria was an ancient Greek mathematician and engineerEnc. Britannica 2007, "Heron of Alexandria" who was active in his native city of Alexandria, Roman Egypt...

  in the basis of Ctesibius

Ctesibius

Ctesibius or Ktesibios or Tesibius was a Greek inventor and mathematician in Alexandria, Ptolemaic Egypt. He wrote the first treatises on the science of compressed air and its uses in pumps...

' double action piston pump.

The usual working pressure of a firehose can vary between 8 bar (800 kPa; 116 psi), while its bursting pressure can be up to 83 bar (8,300 kPa; 1,204 psi).

After use, a fire hose is usually hung to dry as standing water that remains in a hose for an extended period of time can deteriorate the material and render it unreliable or unusable. As such, the typical fire station

Fire station

A fire station is a structure or other area set aside for storage of firefighting apparatus , personal protective equipment, fire hose, fire extinguishers, and other fire extinguishing equipment...

 often has a high structure to accommodate the length of a hose for such preventative maintenance.

On occasion, fire hoses are used for crowd control

Crowd control

Crowd control is the controlling of a crowd, to prevent the outbreak of disorder and prevention of possible riot. Examples are at soccer matches, when a sale of goods has attracted an excess of customers, refugee control, or mass decontamination and mass quarantine situations . It calls for gentler...

 (see also water cannon

Water cannon

A water cannon is a device that shoots a high-pressure stream of water. Typically, a water cannon can deliver a large volume of water, often over dozens of metres / hundreds of feet. They are used in firefighting and riot control. Most water cannon fall under the category of a fire...

), including most notably by Bull Connor

Bull Connor

Theophilus Eugene "Bull" Connor was the Commissioner of Public Safety for the city of Birmingham, Alabama, during the American Civil Rights Movement...

 in Alabama

Alabama

Alabama is a state located in the southeastern region of the United States. It is bordered by Tennessee to the north, Georgia to the east, Florida and the Gulf of Mexico to the south, and Mississippi to the west. Alabama ranks 30th in total land area and ranks second in the size of its inland...

 against civil rights protestors in 1964. While still a common practice in many countries, it is no longer used in the U.S.

History

Until the middle 19th century most fires were fought by water transported to the scene in buckets. Original hand pumpers discharged their water through a small pipe or monitor attached to the top of the pump tub. It was not until the late 1860s that hose became available to convey water more easily from the hand pumps, and later steam pumpers, to the fire.

In Holland, the Superintendent of the Fire Brigade, Jan van der Heyden

Jan van der Heyden

Jan van der Heyden was a Dutch Baroque-era painter, draughtsman, printmaker, a mennonite and inventor who significantly contributed to contemporary firefighting. He improved the fire hose in 1672, with his brother Nicolaes, who was a hydraulic engineer...

, and his son Nicholaas took firefighting to its next step with the fashioning of the first fire hose in 1673. These 50-foot lengths of leather were sewn together like a boot leg. Even with the limitations of pressure, the attachment of the hose to the gooseneck nozzle allowed closer approaches and more accurate water application. Van der Heyden was also credited with an early version of a suction hose

Hard suction hose

Hard suction hose is a specific type of fire hose used in drafting operations, when a fire engine uses a vacuum to draw water from a portable water tank, pool, or other static water source. It is built to withstand vacuum, rather than pressure, abrasion, and heat...

 using wire to keep it rigid. Early fire hose was fabricated of leather, fastened together with copper rivets and washers and, as can be imagined, it was heavy, stiff, and commonly leaked.

Around 1895, unlined fire hose made of circular woven linen yarns began to replace leather hose. It was certainly much lighter. As the hose fibers, made of flax, became wet, they swelled up and tightened the weave, causing the hose to become watertight. Unlined hose, because of its lack of durability, was rapidly replaced with rubber hose in municipal fire service use. It continued to be specified, however for use on interior hose lines and hose racks until the 1960s, and is still used in some areas for forestry applications.

Following the invention of the vulcanization

Vulcanization

Vulcanization or vulcanisation is a chemical process for converting rubber or related polymers into more durable materials via the addition of sulfur or other equivalent "curatives." These additives modify the polymer by forming crosslinks between individual polymer chains. Vulcanized material is...

 process as a means of curing raw soft rubber into a harder, more useful product, the fire service slowly made the transition from bulky and unreliable leather hose to the unlined linen hose, then to a multi-layer, rubber lined and coated hose with and interior fabric reinforcement. This rubber hose was as bulky, heavy, and stiff as leather hose but was not prone to leaking. It also proved more durable than unlined linen hose. Its wrapped construction resembled some hose used today by industry, for example, fuel delivery hose used to service airliners.

Modern Usage

Modern fire hoses use a variety of natural and synthetic fabrics and elastomer

Elastomer

An elastomer is a polymer with the property of viscoelasticity , generally having notably low Young's modulus and high yield strain compared with other materials. The term, which is derived from elastic polymer, is often used interchangeably with the term rubber, although the latter is preferred...

s in their construction. These materials allow the hoses to be stored wet without rotting and to resist the damaging effects of exposure to sunlight and chemicals. Modern hoses are also lighter weight than older designs, and this has helped reduce the physical strain on firefighters. Various devices are becoming more prevalent that remove the air from the interior of fire hose, commonly referred to as fire hose vacuum

Fire Hose Vacuum

A Fire Hose Vacuumis a small pneumatic device that removes residue air from the inside of a fire hose, thereby making it smaller and somewhat rigid, thus allowing more hose or other equipment to be stored on a fire apparatus as well as making loads or packs deploy with increased ease....

s. This process makes hoses smaller and somewhat rigid, thus allowing more fire hose to be packed or loaded into the same compartment on a fire fighting apparatus.

Types

There are several types of hose designed specifically for the fire service. Those designed to operate under positive pressure are called discharge hoses. They include attack hose, supply hose, relay hose, forestry hose, and booster hose. Those designed to operate under negative pressure are called suction hoses.

Types

Name	Definition
Attack	hose is a fabric-covered, flexible hose used to bring water from the fire pumper to the nozzle. This hose ranges in nominal inside diameter from 1.5 to 3 in (38.1 to 76.2 mm) and is designed to operate at pressures up to about 400 psi (2,757.9 kPa). The standard length is 50 ft (15.24 m).
Supply and relay hoses	are large-diameter, fabric-covered, flexible hoses used to bring water from a distant hydrant to the fire pumper or to relay water from one pumper to another over a long distance. These hoses range in nominal inside diameter from 3.5 to 5 in (88.9 to 127 mm). They are designed to operate at pressures up to about 300 psi (2,068.4 kPa) for the smaller diameters and up to 200 psi (1,379 kPa) for the larger diameters. The standard length is 100 ft (30.48 m).
Forestry hose	is a fabric-covered, flexible hose used to fight fires in grass, brush, and trees where a lightweight hose is needed in order to maneuver it over steep or rough terrain. Forestry hose comes in 1 and 1.5 in (25.4 and 38.1 mm) nominal inside diameters and is designed to operate at pressures up to about 450 psi (3,102.6 kPa). The standard length is 100 ft (30.48 m).
Booster hose	is a rubber-covered, thick-walled, flexible hose used to fight small fires. It retains its round cross-section when it is not under pressure and is usually carried on a reel on the fire pumper, rather than being stored flat. Booster hose comes in 0.75 and 1 in (19.1 and 25.4 mm) nominal inside diameters and is designed to operate at pressures up to 800 psi (5,515.8 kPa). The standard length is 100 ft (30.48 m).
Suction hose Hard suction hose Hard suction hose is a specific type of fire hose used in drafting operations, when a fire engine uses a vacuum to draw water from a portable water tank, pool, or other static water source. It is built to withstand vacuum, rather than pressure, abrasion, and heat...	sometimes called hard suction, is usually a rubber-covered, semi-rigid hose with internal metal reinforcements. It is used to suck water out of unpressurized sources, such as ponds or rivers, by means of a vacuum. Suction hose ranges in nominal inside diameter from 2.5 to 6 in (63.5 to 152.4 mm). The standard length is 10 ft (3.05 m).

Another suction hose, called a soft suction, is actually a short length of fabric-covered, flexible discharge hose used to connect the fire pumper suction inlet with a pressurized hydrant. It is not a true suction hose as it cannot withstand a negative pressure.

Raw Materials

In the past, cotton was the most common natural fiber used in fire hoses, but most modern hoses use a synthetic fiber like polyester or nylon filament. The synthetic fibers provide additional strength and better resistance to abrasion. The fiber yarns may be dyed various colors or may be left natural.

Coatings and liners include synthetic rubbers, which provide various degrees of resistance to chemicals, temperature, ozone, ultraviolet (UV) radiation, mold, mildew, and abrasion. Different coatings and liners are chosen for specific applications.

Hard suction hose consists of multiple layers of rubber and woven fabric encapsulating an internal helix of steel wire. Some very flexible hard suction hose uses a thin polyvinyl chloride cover with a polyvinyl chloride plastic helix.

Connections

Hose connections are often made from brass, though hardened aluminum connections are also specified. In countries which use quick-action couplers for attack hoses, forged aluminum has been used for decades because the weight penalty of brass for Storz couplers is higher than for threaded connections.

Threaded hose couplings are used in the USA, Canada, and Britain. Each of these countries uses a different kind of threading. Many other countries have standardized on quick-action couplings, which don't have a male and female end, but connect either way. Again, there is no international standard: In Central Europe, the Storz Connector is used by several countries. Belgium and France use the Guillemin connector. Spain, Sweden and Norway each have their own quick coupling. Countries of the former Soviet Union area use the Gost coupling.

In the USA, a growing number of departments use Storz couplers for large diameter supply hose, or other quick-action couplings. Because the usage isn't standardized, mutual aid apparatus might have a small compartment dedicated to a multitude of hose adapters.

The different styles of hose couplings have influenced fireground tactics. Apparatus in the USA features "preconnects": Hose for a certain task is put into an open compartment, and each attack hose is connected to the pump. Time-consuming multiple connections or problems with male and female ends are avoided by tactics. In countries where Storz (or similar) connectors have been used for attack hoses for generations, firefighters drop a manifold at the border of the danger zone, which is connected to the apparatus by a single supply line. As a result, the tiny item "hose coupler" has also influenced the looks and design of fire apparatus.

Design

A fabric-covered fire hose has one or more layers of woven fabric as a reinforcement material. A hose with one layer is called single jacket hose and is used where light-weight is important or where the hose is expected to have infrequent service. A forestry hose is single jacket for light-weight. An industrial fire hose is single jacket because it sees infrequent use. A hose with two layers is called a double jacket hose and is used where weight is not as critical and where the hose is expected to have frequent, sometimes harsh use, as in urban fire service.

A jacketed hose is usually lined with a thin-walled extruded tube of rubber or another elastomer material that is bonded to the inside of the hose. This prevents the water from seeping through the hose jacket. Some forestry hose is made with a perforated rubber liner to allow it to "weep" a little water through the jacket as a protection against embers that might otherwise burn the hose.

Another type of fabric hose construction is called through-the-weave extrusion. In this design a single fabric jacket is fed through a rubber extruder. The extruder coats both the inside and outside of the fabric with a rubber compound to form both an inner liner and an outer coating at the same time. The extruder forces the rubber into and through the jacket weave to form an interlocking bond. This construction produces a lighter weight hose and is primarily used for larger-diameter supply hoses.

Manufacturing Process

Fire hose is usually manufactured in a plant that specializes in providing hose products to municipal, industrial, and forestry fire departments. Here is a typical sequence of operations used to manufacture a double jacket, rubber-lined fire hose.

Preparing the yarn

• There are two different fiber yarns that are woven together to form a hose jacket. The yarns that run lengthwise down the hose are called warp yarns and are usually made from spun polyester
  Polyester
  Polyester is a category of polymers which contain the ester functional group in their main chain. Although there are many polyesters, the term "polyester" as a specific material most commonly refers to polyethylene terephthalate...
  
   or filament nylon
  Nylon
  Nylon is a generic designation for a family of synthetic polymers known generically as polyamides, first produced on February 28, 1935, by Wallace Carothers at DuPont's research facility at the DuPont Experimental Station...
  
  . They form the inner and outer surfaces of the jacket and provide abrasion resistance for the hose. The yarns that are wound in a tight spiral around the circumference of the hose are called the filler yarns and are made from filament polyester. They are trapped between the crisscrossing warp yarns and provide strength to resist the internal water pressure. The spun polyester warp yarns are specially prepared by a yarn manufacturer and are shipped to the hose plant. No further preparation is needed.
• The continuous filament polyester fibers are gathered together in a bundle of 7-15 fibers and are twisted on a twister frame to form filler yarns. The plied and twisted yarn is then wound onto a spool called a filler bobbin.

Weaving the jackets

• The warp yarns are staged on a creel, which will feed them lengthwise down through a circular loom
  Loom
  A loom is a device used to weave cloth. The basic purpose of any loom is to hold the warp threads under tension to facilitate the interweaving of the weft threads...
  
  . Two filler bobbins with the filler yarn are put in place in the loom.
• As the loom starts, the filler bobbins wind the filler yarn in a circle through the warp yarns. As soon as the bobbins pass, the loom crisscrosses each pair of adjacent warp yarns to trap the filler yarn between them. This weaving process continues at a high speed as the lower end of the jacket is slowly drawn down through the loom, and the bobbins continue to wrap the filler yarns around the circumference of the jacket in a tight spiral. The woven jacket is wound flat on a take-up reel.
• The inner and outer jackets are woven separately. The inner jacket is woven to a slightly smaller diameter so that it will fit inside the outer jacket. Depending on the expected demand, several thousand feet of jacket may be woven at one time. After an inspection, the two jackets are placed in storage.
• If the outer jacket is to be coated, it is drawn through a dip tank filled with the coating material and then passed through an oven where the coating is dried and cured.

Extruding the liner

• Blocks of softened, sticky, uncured rubber are fed into an extruder. The extruder warms the rubber and presses it out through an opening between an inner and outer solid circular piece to form a tubular liner.
• The rubber liner is then heated in an oven where it undergoes a chemical reaction called vulcanizing, or curing. This makes the rubber strong and pliable.
• The cured liner passes through a machine called a rubber calendar, which forms a thin sheet of uncured rubber and wraps it around the outside of the liner.

Forming the hose

• The jackets and liner are cut to the desired length. The inner jacket is inserted into the outer jacket, followed by the liner.
• A steam connection is attached to each end of the assembled hose, and pressurized steam is injected into the hose. This makes the liner swell against the inner jacket and causes the thin sheet of uncured rubber to vulcanize and bond the liner to the inner jacket.
• The metal end connections, or couplings, are attached to the hose. The outer portion of each coupling is slipped over the outer jacket and an inner ring is inserted into the rubber liner. A tool called an expansion mandrel
  Mandrel
  A mandrel is one of the following:* an object used to shape machined work.* a tool component that grips or clamps materials to be machined.* a tool component that can be used to grip other moving tool components.- Variants :...
  
   is placed inside the hose and expands the ring. This squeezes the jackets and liner between the ring and serrations on the outer portion of the coupling to form a seal all the way around the hose.

Pressure testing the hose

• Standards set by the National Fire Protection Association require that each length of new double jacket, rubber-lined attack hose must be pressure tested to 600 psi (4,136.9 kPa), but most manufacturers test to 800 psi (5,515.8 kPa). Subsequent to delivery, the hose is tested annually to 400 psi (2,757.9 kPa) by the fire department. While the hose is under pressure, it is inspected for leaks and to determine that the couplings are firmly attached.
• After testing the hose is drained, dried, rolled, and shipped to the customer.

Quality Control

In addition to the final pressure testing, each hose is subjected to a variety of inspections and tests at each stage of manufacture. Some of these inspections and tests include visual inspections, ozone

Ozone

Ozone , or trioxygen, is a triatomic molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that is much less stable than the diatomic allotrope...

 resistance tests, accelerated aging tests, adhesion tests of the bond between the liner and inner jacket, determination of the amount of hose twist under pressure, dimensional checks, and many more.

Future

The trend in fire hose construction over the last 20 years has been to the use of lighter, stronger, lower maintenance materials. This trend is expected to continue in the future as new materials and manufacturing methods evolve.
One result of this trend has been the introduction of lightweight supply hoses in diameters never possible before. Hoses up to 12 in (30.5 cm) in diameter with pressure ratings up to 150 psi (1,034.2 kPa) are now available. These hoses are expected to find applications in large-scale industrial firefighting, as well as in disaster relief efforts and military operations.

Fire hoses come in a variety of diameters. Lightweight, single-jacket construction, ¾, 1, and 1½ inch diameter hose lines are commonly used in wildland firefighting applications. Heavy duty double, double-jacket, 1½, 1¾, 2, 2½, and on occasion 3 inch lines are used for structural applications. Supply lines, used to supply fire apparatus

Fire apparatus

A fire apparatus, fire engine, fire truck, or fire appliance is a vehicle designed to assist in fighting fires by transporting firefighters to the scene and providing them with access to the fire, along with water or other equipment...

with water, are frequently found in 3, 3½, 4, 4½, 5 and 6 inch diameters.