BY BILL GUSTIN
Part 1, “Locations, Loads, and ‘Lead Outs,’ “ was published in the April 2002 issue. Part 2, “Hose Loads,” was published in the May 2002 issue.
Few things are more embarrassing and unprofessional than an engine company that stretches a preconnect, charges it, and then finds that it is too short to reach the fire. A long stretch beyond the reach of preconnects should never catch firefighters off guard. Disciplined, well-trained firefighters stretch hoselines in accordance with a size-up, not on impulse. An engine officer who is not absolutely certain of how to reach a fire and how much hose to stretch should order his company to stand by until he conducts a size-up. In certain situations, such as fires in a motel or an apartment complex, the officer may find a closer access point and order the pumper to relocate to another side of the building.
Fire companies must identify and preplan those occupancies that are beyond the reach of their preconnects. Garden apartments, for example, are commonly surrounded by landscaping and can be situated a considerable distance from streets and parking lots. Apartment complexes that have all units facing a center courtyard may also require a stretch longer than the longest preconnect.
Train for fire scenarios that require extension of preconnects, such as the stolen car burning in a field or along railroad tracks hundreds of feet off the street. For mobile home fires, an engine company may have to extend its preconnects when a large apparatus cannot get close to the fire because of the narrow driveways commonly found in trailer parks.
A 13/4-inch preconnect flowing 180 gpm has the capability to rapidly control fires in residential occupancies filled with modern, synthetic household furnishings-if it is long enough to reach the fire.
OPTIONS FOR EXTENDING THE PRECONNECT
When a fire is within the extinguishing capabilities of a 13/4-inch preconnect but is beyond its effective reach, the engine company officer has to decide whether to extend the preconnect by adding more 13/4-inch hose or stretch 21/2- or three-inch hose from the main hosebed (and reduce it to 13/4-inch hose at the fire).
 Stretch a triple-layer load into a courtyard. (Photos by Raul Torres.) |
Let’s look at the advantages and disadvantages of each option. The 2 1/2- or three-inch hose will definitely supply more water than 1 3/4-inch hose and flow it at lower pressures and for much greater distances. Additionally, stretching the larger hose gives the company the ability to operate two 1 3/4-inch handlines by connecting a 2 1/2x 1 1/2x 1 1/2-inch gated wye. But, there is a drawback: Stretching 2 1/2-inch or three-inch hose can be physically draining and time-consuming and may require more personnel (roughly 100 feet per firefighter) than may be available in the initial stages of an incident.
Extending a 1 3/4-inch preconnect with additional 1 3/4-inch hose is much faster and easier than stretching larger hose from the hosebed, and it will take fewer personnel to do it. Granted, it doesn’t give a company the ability to operate a second handline. That second line is great if there are sufficient personnel to rapidly stretch 2 1/2- or three-inch hose. Do not attempt this, however, at the expense of delaying getting the first handline into operation, especially when the fire is well within the suppression capabilities of a single1 3/4-inch hoseline.
 Fully extend a 200-foot preconnect (carry extra sections of hose over the SCBA cylinder). |
There is, however, a limit to how far 1 3/4-inch hose can be extended before friction loss and pump discharge pressures become excessive. Some textbooks set this limit at 300 feet, but the rules have changed somewhat, thanks to two recent developments in the fire service. The first is the improved flow possible with modern hose made with smooth synthetic linings and jackets that expand to increase the cross-sectional area of the waterway. These improvements remarkably lower friction losses. For example, the 1 3/4-inch hose currently in use in my department has a friction loss of 40 psi per 100 feet at 180 gpm. This is a vast improvement over our previous hose that had a loss of 50 psi at the same flow. The second factor is the trend toward replacing 100-psi fog nozzles with nozzles that flow the same gpm at 75 to 50 psi.
 Unscrew the nozzle; connect a 100-foot, 13/4-inch high-rise pack and, if necessary, extra 50-foot sections. |
These two develop- ments, less friction loss and lower nozzle pressures, leave more pressure available to overcome friction loss in longer stretches of hose. My department limits the maximum length of 1 3/4-inch hose to 400 feet. This requires a pump discharge pressure of 210 psi, allowing for a friction loss of 160 psi (40 psi per 100 feet) and a nozzle pressure of 50 psi. This pump pressure, although considered high by some standards, achieves a flow of 180 gpm, sufficient for most of our residential fires.
You should set your own limits for extending 1 3/4-inch hose. Data for arriving at the maximum allowable length of hose should be based on actual flow tests conducted by your department using its own pumps, hose, and nozzles, not from a manufacturer’s friction loss tables, theoretical figures, or mathematical calculations. A lot depends on how many gpm your department wants to pump through its 1 3/4-inch lines. A lower flow means lower friction loss, which makes more pressure available to push water through a longer hoseline. Your department should set a maximum allowable pump pressure for hand-lines such as 225 psi.
Preconnects can be extended by adding hose at the nozzle end of the line or back at the pumper. If the additional hose is larger than the preconnect (say you’re extending a 1 3/4-inch line with 2 1/2- or three-inch hose), of course it must be added at the pumper. Adding hose at the pumper, however, can take more time and personnel because the entire stretch of hoseline will have to be moved up toward the fire. It is easier to extend preconnects at the nozzle end of the line by adding rolls or bundles of hose. My company extends 1 3/4-inch preconnects by connecting a high-rise hose pack that consists of 100 feet of 1 3/4-inch line. If more hose is needed, we add 50-foot sections of 1 3/4-inch hose that are folded into horseshoes and bound together with straps. The 50-foot bundles are easily carried over the SCBA cylinder.
 Stretch the high-rise pack. |
Breakaway nozzles facilitate adding hose because the ball shutoff controls the water flow and allows you to remove the tip and connect additional lines. It is critical, however, to tie the valve handle in the open position to keep it from accidentally being closed when the nozzle is dragged along the ground.
Breakaway nozzles are a good idea, but I have to wonder, Why charge a line in the first place if it was too short to reach the fire? I think it’s easier to simply unscrew the nozzle from the end of the line, connect more hose, and then call for water.
For most fire departments, a fire beyond the reach of preconnects is not an everyday occurrence. Engine companies must, therefore, compensate for a lack of actual experience by preplanning occupancies that could require a longer than usual stretch and keeping their skills sharp by frequently training in hose evolutions.
An officer who has conducted an intelligent size-up before his company goes to work must decide whether the engine company should extend a preconnect with the same size hose or stretch larger hose from the main hosebed. The officer’s size-up must take into account the following factors: how to reach the fire, the length of the hoseline needed, the number of handlines, and the gpm necessary to control the fire. Staffing is also an important consideration, but remember that the fire doesn’t care how many firefighters are on the scene: Either you control it with a sufficient rate of flow or wait for it to consume fuel until it burns down to your capabilities.
DON’T BE A
Firefighters gain most of their experience fighting fires in relatively small, compartmented dwellings. A residential one- or two-room fire is usually no match for a well-trained, adequately staffed, and determined engine company flowing 180 gpm from a 1 3/4-inch preconnected hoseline. Firefighters who repeatedly experience the impressive knockdown capability of 1 3/4-inch preconnects on residential fires can un-knowingly become “slaves” to these hoselines and out of habit use them ineffectively and dangerously at larger fires, such as those in commercial occupancies. Firefighters who seldom get a chance to experience a volume of fire that exceeds the suppression capabilities of their 1 3/4-inch preconnects may fail to recognize those fire situations, however, rare, that have the potential to intensify beyond their control.
 The nozzleman arrives at the entrance with the slack hose to advance into the structure. |
There are, of course, larger preconnects, including master stream devices that are capable of controlling a large fire, but using them is not always the answer because they, too, can cause problems that are inherent with all preconnects.
Fire departments that depend too heavily on preconnects tend to spot their pumpers in the same way at every fire-at or very close to the fire building so they can reach the fire with their preconnects. This can create some problems. First, a large fire scene can become a parking lot of engines, which can block access for aerial apparatus and expose pumpers to falling walls, power lines, or radiant heat. Second, engines positioned at the fire are usually supplied by an “in-line” stretch-that is, from a supply line laid from a hydrant to the fire. Hoselines, even those of large-diameter hose, supplied directly with hydrant pressure can severely limit the amount of water an engine can receive, especially at large fires, where long hoselays and low hydrant pressures are commonly encountered.
Preconnects are great for initiating a quick attack by the first-arriving engine. At large fires, however, later-arriving engine companies should seriously consider leaving their preconnects in the hosebed and instead secure an adequate water supply. This is most effectively achieved by reverse laying hoselines from the fire to a hydrant. Engines connected directly to a hydrant with a short section of large-diameter suction hose take maximum advantage of the hydrant’s flow and the apparatus’ pump capacity.
The information in these articles is certainly not new or cutting edge. It is nothing more than a review of basic firefighting tactics and fire stream hydraulics. Unfortunately, it is easy to forget the basics when we must continuously reinvent ourselves to provide an ever-expanding range of services. We must not forsake the basics of our profession. Of all the services fire departments provide, firefighting is and will continue to be the one service the public most expects and depends on us to provide.
Special thanks to Chief Paul Martin, Chicago (IL) Fire Department, and Broward County (FL) Fire-Rescue Engine Co. 32 for help with this article.
BILL GUSTIN is a captain with Miami-Dade (FL) Fire Rescue and lead instructor in his department’s officer training program. He began his 28-year fire service career in the Chicago area and teaches fire training programs in Florida and other states. He is a marine firefighting instructor and has taught fire tactics to ship crews and firefighters in the Caribbean countries. He also teaches forcible entry tactics to fire departments and SWAT teams of local and federal law enforcement agencies. Gustin is an editorial advisory board member of Fire Engineering.
