Preconnects: Selecting the Right Hose for the Job

BY DOUG LEIHBACHER

During the initial moments of a fire re-sponse, the engine company officer must make several speedy decisions that will have a significant effect on the outcome of the firefighting effort. Beginning with the receipt of the alarm, the officer must anticipate the approach patterns of the other responding engines and ladders and decide from which direction to respond into the scene, taking into consideration speed of response and apparatus placement. Next, he must decide which hydrant to select and whether a stretch is warranted. If a stretch from the hydrant is necessary, the apparatus must be positioned where it will be out of the collapse zone and will not interfere with ladder company placement. Once all this is taken care of, it is time to make the most important decision of all: which hoseline to stretch to the fire.

Selecting the right hoseline for the job is a pivotal determining factor in the outcome of the fire, and the decision must be made in a split second. If the right line is called for, the stretch will go smoothly, and the extinguishment process will begin in a timely manner. If the wrong line is selected, the extinguishment process will be delayed, the fire may get away, and all other firefighters and civilians in the building will be in greater peril. Luckily, the question of which line to stretch is multiple choice. It is either

  • the short preconnect,
  • the long preconnect,
  • the 21/2-inch,
  • the standpipe hose pack,
  • the deck gun, or
  • the booster line.

Let’s examine the indicators that help in the selection process and discuss the benefits and potential exigencies of each choice.

THE SHORT PRECONNECT

A 13/4- or two-inch preconnect is an effective line for use in low-rise residential structures, whether private or multiple dwellings. In these buildings, compartmentalization reduces the need for extensive reach capabilities. As long as hose teams can get into the fire floor, they will usually be able to get water onto the seat of the fire. For the purposes of this discussion, the short preconnect should be considered to be a 150- to 200-foot line. If the engine is parked in front of or at the corner of the fire building, the short preconnect is the right choice for a fire on the first or second floor of a normal-sized residential building-a 25- by 75-foot or a 50- by 75-foot structure on a city building lot. In such a building, stretching a long preconnect (250 to 300 feet) to the first or second floor will leave excess hose in the foyer, stairwell, and landings, leading to plethoric kinking. The 150-foot preconnect would also be appropriate for a moderate fire in the basement provided that the access point is in the front. If access is at the rear or on the side of the building, you will need the long preconnect.

In estimating the right amount of hose to use, it is first necessary to estimate the number of lengths needed from the apparatus to the front door. Second, it is necessary to estimate the number or lengths needed inside the building from the front door to the seat of the fire. For this, it is essential to first know what floor the fire is on and where the fire is in relation to the stairwell. The standard rule of thumb for estimating the amount of line necessary to reach the fire in a residential building has been to allow one length per story plus one “working length” for the fire floor. This guideline errs on the side of safety: You might stretch long, but rarely will you stretch short. Strictly speaking, the vertical distance from one floor to the next is 10 to 12 feet, not 50 feet. If a building with an open well hole is encountered or if a fire escape stretch is used, one length of hose will reach to the fourth or fifth floor.

The reason one length per floor is given is to accommodate all multiple dwellings, including those that have narrow well holes or 1/4-turn stairs that wrap around an elevator shaft. In buildings such as these, the line must be laid around the perimeter of the stairwell rather than straight up through the well hole. As a result, 25 to 30 feet of hose may be needed to get from one landing to the next in buildings with narrow well holes.

Moreover, a full 50-foot length will be needed if the stairs wrap around an elevator. In most districts, the number of buildings that have 1/4-turn stairs that wrap around an elevator is so limited that they can be targeted and preplanned.

A far greater number of multiple dwellings have wide or open well holes that allow the line to be stretched up the center of the railings without any obstruction. In these buildings, again, only 10 to 12 feet of line is needed per floor so that one length will reach from the base of the stairwell to the fifth or sixth floor.

The remainder of multiple dwellings have narrow well holes where the railing crosses the landing with 41/4 inches or less clearance. In these buildings, the line must be carefully stretched around the newel posts to prevent a coupling from becoming wedged. If a narrow well hole is encountered, figure approximately 25 to 28 feet of line per story, or two floors per length.

The type of well hole is one of the primary factors in determining how much hose to call for. With the expansion of medical assistance responses, engine companies are sent to the buildings in their districts more frequently than ever before. This creates an opportunity to gain greater familiarity with the buildings. When operating at a medical call in a multiple dwelling, the company officer should make a mental note of the type of staircase well hole. This will assist in selecting the proper length preconnect if the next call to the building is for a fire.

Although the fire floor level is a significant factor when estimating the number of lengths needed, the size of the building and the distance the apparatus is from the front door are equally important conditions to consider when selecting the best preconnect to use. As mentioned above, the short preconnect is effective for fires on the first and second floors, provided that the apparatus is located in close proximity to the front door and the fire building is standard size residential. If the officer is uncertain of these factors, it is better to take the long preconnect and leave the excess line in front of the building.

An additional use for the short preconnect is for vehicle fires. Booster lines are no longer considered adequate for use on automobile fires. Given the quantity of plastics and flammable liquids found in automobiles nowadays, 20 gallons per minute is not nearly enough. The short preconnect provides an adequate flow rate to effect a quick knockdown and allows the pumper to be placed a safe distance from the fire.1

THE LONG PRECONNECT

The long preconnect (five or six lengths/250 to 300 feet) should be used for fires on the third floor or above at a normal-sized multiple dwelling. Use it also for fires on the first floor or second floor or in the basement when there is an extended distance from the apparatus to the front door or where entry must be made from around the back of the building. This is often the case with garden apartments, condominium complexes, and private dwellings set well back from the street.

If the building is set back from the road, it may take one or two lengths to reach the front door, depending on the size of the yard. Similarly, if the apparatus is parked several doors down the block from the fire building, one, two, or more lengths may be needed just to reach the front door, even in the absence of a front yard. A quick way to estimate the horizontal distance to the front door in an urban setting if you are parked down the block is to count the number of building fronts. Most city building lots are 50 feet across, the same size as a length of hose. They either contain one double wide building (approximately 50 feet) or two single wide buildings (approximately 25 feet) per lot. By counting the number of fronts, it is possible to estimate the number of lengths from the apparatus to the front door. In suburban settings, this is not as practicable unless the size of lots is known. In many areas, telephone poles are spaced approximately 50 feet apart and can be used in the estimate. In many areas, however, the utility poles are spaced about 50 feet apart and can be similarly used to estimate how many lengths are needed to reach the front door.

The long preconnect can also be used for fires on the lower floors of a high-rise residential structure. At a fire on the ground floor or the first or second floors of a high-rise, the long preconnect can provide an alternative to a standpipe stretch. However, the volume of potential fire must be considered. The long preconnect requires no assembly and thus can be stretched more rapidly than the standpipe hose pack. However, the pumper must be reasonably close to the front door, and the stairwells should be located close to the center core. This information comes only from knowing the building through experience or preplanning.

STRETCHING LONG VS. STRETCHING SHORT

In estimating horizontal and vertical distances, it has long been the pandemic conviction of engine officers that it is better to stretch too long and have extra hose than to stretch too short and only have enough hose to make it to the front door of the fire occupancy. However, to automatically call for the long preconnect at every building fire just to be on the safe side can lead to excessive kinking and inadequate water delivery. In many cases, it is easier to recover from stretching short than it is to overcome stretching long, especially when a breakaway nozzle is used.

When in doubt, an extra length of hose (a donut) can be brought in with the preconnect and attached before the line is charged if needed. The use of a breakaway nozzle can further lessen the impact of stretching short. With a breakaway, even after the preconnect is charged, if an additional length is needed, it can be added expeditiously on the fire floor at the nozzle without necessitating a call to the pump operator to shut down the line.

Note that in some districts, the nature of the buildings requires longer than normal preconnects. However, when more than five or six lengths of 11/2- or 13/4-inch preconnects are used, excessive friction loss is generated. To alleviate this problem, instead of adding a sixth or seventh length of 13/4-inch hose, you can incorporate a length of 21/2-inch hose into the preconnect at the bottom of the hose load. This length, which is the last length to come off the pumper, is attached to the 13/4-inch hose with a reducer.

THE 21/2-INCH handline

Because of its versatility, which allows it to be used as a supply line or a handline, the 21/2-inch hose is usually stored on the engine in a static hoseload containing approximately 10 lengths. There are several indicators for stretching the 21/2-inch as a handline:

  • A heavy fire condition in a large commercial occupancy such as an auto repair shop, a taxpayer, a warehouse, a commercial building basement, a department store, a factory, a lumberyard, or a supermarket. The common denominator here is “commercial” occupancy. Because of the lack of compartmentalization; large, open areas; and high ceilings, the added reach of the 21/2-inch line is needed to penetrate into the seat of the fire. In addition, the added capacity of the 21/2-inch line can better handle the heat production (Btus) created by the heavy fire loading of these occupancies.
  • As an exterior exposure line at a large fire or a heavily involved, unoccupied vacant building. In both of these scenarios, a defensive attack is warranted. The greater reach and flow capabilities of a 21/2-inch line make it effective for use as an exposure line. When used as such, it is most efficient to lay the water on the upper sections of the exposure, allowing the water to flow down the side of the building, blanketing it with a heat-absorbing coating of water. Streams aimed directly into the main body of fire are less effective because they cannot readily extinguish it. They fail to penetrate to the seat of the fire either because of interior collapse that deflects them or thermal columns that cause them to dissipate and rise up as steam.

Moreover, the heavy volume of fire at exposure fires makes collapse an everpresent danger. Companies need to maintain a safe distance from the fire building and collapse zone. This necessitates either a 21/2-inch handline with greater reach or a master stream. Exterior fire streams are subject to wind currents, thermal columns, and air resistance, which act to break up the solid stream of water into a spray. This reduces the stream’s reach before it can penetrate far enough to do any good. A smaller handline is more vulnerable to these vagaries than a 21/2-inch handline. A 21/2-inch line with a 11/4-inch smooth bore tip (at 50 psi NP) can be expected to reach a horizontal distance of approximately 70 feet with a moderate breeze countering it and up to twice that distance if the wind is calm. If a greater distance is needed, the line should be shut down and placed into a portable deluge appliance.

The 21/2-inch handline also makes an effective exterior stream for flanking a heavily involved open rear porch fire. When a vacant side yard or driveway allows the necessary leeway for the 21/2-inch line to be directed at a 90-degree angle to the side of the building, it can be used to quench the heat generated by the porch fire. This will take the force out of the main body of fire and make it easier for companies operating inside to cut off the fire.

  • A heavy fire in a high-rise building. The use of 21/2-inch lines in high-rise buildings is becoming more and more prevalent. The high-heat/high-wind/low-water-pressure conditions encountered on the upper floors of high-rise buildings oblige the use of 21/2-inch line. The reduced friction loss in 21/2-inch hose can make the difference in whether the operations are successful or not.

Consider these numbers: A flow of 150 gpm through a 13/4-inch hoseline creates approximately 35 pounds of friction loss per 100 feet. Assuming a 150-foot stretch, a residual (flowing) pressure of approximately 150 psi would be required at the standpipe outlet to supply a 100-psi fog nozzle (or 100 psi to supply a smooth bore nozzle). Such pressures can be difficult to achieve, especially when pressure-regulating devices are present.

Most fire codes modeled from NFPA 14, Standpipe, Private Hydrant and Hose Systems-2000, require the use of pressure-regulating devices at standpipe stations whenever the pressure at the standpipe outlet is in excess of 100 psi. According to requirements, the pressure is to be reduced from 100 psi to 80 psi. Unless removed or overridden, they can prevent proper pressures, even when the system is augmented with a pumper feeding the siamese. However, to supply a 21/2-inch line with 225 gpm., there is only 10 psi of friction loss per 100 feet, or a total of only 15 psi friction loss in a 150-foot stretch. Thus, a pressure at the standpipe outlet of only 65 psi would be sufficient to supply a 21/2-inch line with a smooth bore nozzle.

  • As a supply line to a wye gate or water thief. Often the specific circumstances encountered on the fireground require that the engine be placed a substantial distance from the fire building, out of the reach of the long preconnect-for instance, the fire building may be set well back from the street, a reverse or back stretch may be required, or the fire building may be located on a narrow street blocked by traffic, preventing the apparatus from getting in. Another possibility is that a dead hydrant may be encountered, necessitating that the pumper continue down the block in search of a water source. In circumstances like these, a 21/2-inch line can be stretched to the front of the building to supply a wye gate or water thief from which smaller handlines can be operated. When stretched by the pumper, a three-inch or 31/2-inch line will supply even greater water.

When selecting the 21/2-inch handline, you must consider several factors. Because of its weight (approximately 150 pounds per length when charged), the decision to use the 21/2-inch handline must be made carefully. The officer must weigh its flow and reach capabilities against its deficit of mobility. When staffing is limited, the decision to take the 21/2-inch should be communicated to the chief officer so that a second company can be assigned to assist with stretching and advancing the line. In most fire departments, the use of a 21/2-inch line requires the teaming of two companies to effect the line’s stretch and operation. Company officers should avoid coordinating such operations without going through the chief. The pairing of two companies is virtually essential to effectively use this line.

When using a 21/2-inch line inside a structure, it is advisable not to call for water until the line is completely stretched into position and flaked out with kinks removed. Of course, always charge the handline in a safe area before calling for water. Once charged, a 21/2-inch line becomes cumbersome and arduous to move. If water is called for prematurely, it can kink up in the hallway or stairwell and be very tough to get it into place after the fact, particularly if it is being used on an upper floor. Later-arriving companies will stretch hoselines on top of it, rendering it immobile. Keep in mind, even firefighters in top physical condition can become fatigued quickly on the nozzle of a 21/2-inch line. Backup firefighters must be rotated in frequently.

THE STANDPIPE HOSE PACK

It is usually easy to decide when to hook up to a standpipe. On arrival, if you have a fire in a high-rise or standpipe building, you call for the standpipe hose. However, a careful size-up is needed. What type of high-rise building is it? Is it a residential high-rise or an office building? On which floor is the fire? As mentioned above, a fire on the first or second floor may be easier to handle with a preconnect. How large is the building? Where are the hose outlets located on each floor? How many lengths will be needed to reach the fire apartment from the hose outlet? How large is the fire? What are the wind conditions? Is the fire on the windward or leeward side of the building? Are the wind or fire conditions great enough to require the services of a 21/2-inch line? The answers to these questions will assist you in deciding what size hose and how many lengths to bring.

As a general rule, three lengths or 150 feet of hose are usually sufficient to reach the majority of high-rise fires. With reference to the spacing of standpipe risers, NFPA 14 states that all portions of the floor must be within 30 feet of a nozzle attached to 100 feet of hose. However, some older standpiped buildings constructed prior to the code requirement and some newer exempted structures do not necessarily comply. To comply with this requirement, some other buildings may place standpipe risers in public hallways, where it may be unsafe to hook up on the fire floor. Such buildings may need longer stretches (an extra 50 to 100 feet) to enable you to hook up to a distant standpipe on that floor or one in the hallway on the floor below. This information should be noted during building inspections so that additional hose can be brought when needed.

Not all apartments or offices on a given floor are the same distance from the standpipe riser. Whereas the fire apartment can be at the far end of the hall, requiring all three lengths of hose, it could also be right next to the stairwell door and require only one or two lengths. In the latter case, if all three (or four) lengths are connected, there will be far too much hose, and the excessive hose kinking in the stairwell will obstruct egress and render the hose stream ineffective. Therefore, whenever conditions permit, the officer must determine which apartment is the fire apartment, estimate the horizontal distance from the riser, and decide how many lengths should be connected. Standard operating procedures recommend connecting to the standpipe on the floor below the fire. While crew members are setting up there, the fire officer can take a quick look at the distance to the apartment on the floor below that is in line with the fire apartment and estimate how much hose will be needed.

As mentioned above, most buildings will require only 150 feet of standpipe hose, but some buildings may require an extra length. The company officer should know which buildings they are ahead of time. Additionally, it is a good idea for second- and third-due units to bring additional hose in with them, as it may be necessary for them to hook into the standpipe riser on a lower floor. When heavy winds and fire conditions are present, additional units should consider bringing larger-diameter backup lines.

In general, engine companies should use the same riser and work together to advance on the fire from the same direction. Operating from separate risers can lead to a crossfire in the hallway. In addition, designate one stairwell as the attack stairwell and reserve the other for evacuation of the floors above. For the evacuation stairwell to remain tenable, the stairwell door on the fire floor must remain shut. A company stretching in from that stairwell will charge it with heat and smoke and endanger residents and members working above. Once everyone is removed and ladder companies have been able to open the roof bulkhead, the evacuation stairwell can be designated as the ventilation stairs.

Notwithstanding these points, on occasion, it may be necessary to use a separate riser from the one taken by the first-due engine. This would be the case if the initial riser were inoperable because of mechanical failure or repair work or became clogged with debris. In this instance, reverse the stairwell designation.

It is imperative to flush the standpipe outlet before hooking in and charging the line. Standpipes are notorious for collecting all manner of flotsam and jetsam and passing it through the standpipe outlet and down the hose, where it readily clogs the nozzle. Take a few seconds to thoroughly flush the standpipe outlet before shutting it down and connecting the hose to it. While doing so, look closely at the hose outlet, and note any pressure-regulating devices located there. If any are present, immediately notify the officer.2

When supplying a standpipe, the pump operator must consider the friction loss on the fire floor, the system loss in the standpipe, and the head loss between the siamese and the fire floor. The friction loss in the handline will be the same as it is in any preconnect of that length. Therefore, assuming 150 feet of 13/4-inch line with a 100-psi fog tip at 150 gpm, the friction loss would be approximately 50 psi. System loss would be a constant of 25 psi (some newer installations are 15 psi). Thus, a rule of thumb for standpipe pumping operations in this case would be 175 psi + 5 psi per story. If the pumper is distant from the siamese, it may also be necessary to consider friction loss to the siamese. However, friction loss in large-diameter siamesed supply lines is usually negligible. During preplanning, make sure that the system can handle the anticipated pressure.

THE DECK Gun

The deck pipe or gun is a preconnect without hose. As such, it can be put into operation more rapidly than any other device. Its primary use is to take the intensity out of a heavy fire condition. Use of the deck gun is indicated when the magnitude of the fire initially precludes an interior attack or when there is no life hazard present. The deck gun is particularly advantageous at fires in vacant buildings that are in dangerous disrepair or where collapse is anticipated.

The deck gun can be a superior device for protecting exposures. To be effective, however, the engine must be positioned in line with the alleyway so that the stream can be directed onto the side of the exposed building. This requires careful placement.

In cases where a vacant building fire is threatening an occupied building in close proximity, the first-due engine company may find it necessary to use the deck gun to protect the exposure on arrival, while an interior handline is being stretched into the occupied building. When used in this manner, the pump operator (who often directs the deck gun) must bear in mind that with 500 gallons of water onboard, the tank will be entirely depleted in just 30 to 60 seconds. If all the onboard water is used up, the crew inside will be delayed in getting water and initiating an interior attack. In instances such as this, the pump operator will have to hustle to get them water and should concentrate on getting one supply line into the pump so that the interior line can be charged.

THE BOOSTER LINE

The booster line has a long history in the fire service, owing to its versatility. It is the line to use for average brush, dumpster, and outside rubbish fires. It can also be used for overhauling debris that has been removed to the exterior of the fire building. Constructed of 3/4-inch- or one-inch-diameter, hard rubber jacketed hose, booster lines are subject to trifling back pressure and consequently are easy for one firefighter to operate. Moreover, they are fast and easy to stretch and equally easy to repack. The ease with which it can be deployed and handled by one firefighter has also made the booster line an effective tool in the hands of the pump operator attempting to cool an apparatus subject to severe radiant heat.

In recent years, the booster lines have been disappearing from many newer apparatus, partly because of financial considerations and partly because of a fear that they will be inappropriately used inside structure fires. Booster lines are not suitable for automobile or structure fires. Their capacity is too limited.

The excessive friction loss created in the narrow waterway limits their effective delivery to 20 or 30 gpm maximum. As such, they cannot render an expeditious knockdown. To attempt to get greater volume from a booster line would require excessive engine rpm and potentially damage the pump. For autos and structures, 13/4-inch lines should be the minimum diameter of hose used. Inside a structure, handlines should be supplied with at least 150 gpm. When limited water is sufficient, however, the booster line is the least fatiguing, most rapidly deployable choice of handlines.3

The booster line, which is 200 feet or more, is particularly effective at brush fires and can cover a lot of ground. The water discharged is adequate to quickly douse flames without overkill. This conserves water, which is an important consideration when working in wooded areas where hydrants are not present. Moreover, the hard rubber jacket is more resistant to burns when dragged over hot spots than woven jacketed hose. It is also lighter and less fatiguing to move in rough terrain.

Selecting the right hoseline on the fireground can be a crucial decision. The company officer needs to become familiar with the capabilities and reach of the various preconnects carried on the apparatus. The preceding discussion provides some general guidelines; however, given the myriad of buildings and architectural styles found throughout the country, it is impossible for any one guideline to work in all areas. Therefore, do not construe any of the above as hard-and-fast rules. Calling for the right hoseline on the fireground is ultimately a matter of practice. As with most skills, hands-on training and experience are the preferred approaches to learning. The best idea is to get out in your district with a tape measure and some hose and see just how long your stretches should be.

Endnotes

  1. For a thorough discussion of car fire tactics, see Bill Gustin’s article, “Expect the Unexpected at Vehicle Fires,” Fire Engineering, August 1997, 87.
  2. For an in-depth discussion of standpipe pressure reducers, see “Standpipe Operations” by David Fornell, Fire Engineering, August 1991, 71.
  3. For an in-depth discussion of interior handline flows, see David Wood’s article, “Nozzles and Handlines for Interior Operations,” Fire Engineering, April 1999, 63.

DOUG LEIHBACHER, a 20-year veteran of the fire service, is captain of Engine 303 in the Yonkers (NY) Fire Department. He has a bachelor’s degree in education and is a New York state-certified fire instructor and municipal training officer. He is currently completing requirements for an associate’s degree in fire technology.

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