BY BILL GUSTIN
Rural, suburban, and many big-city fire departments use preconnected attack hoselines because they are easy to use and can be deployed quickly. Preconnects hasten fire attack because they eliminate the time it takes to uncouple the hose used for the stretch to the fire from the remaining hose in the hosebed and then connect the line to a pump discharge. Preconnects lead out rapidly because most of them are relatively short, generally 200 feet. Moreover, under ideal conditions, one firefighter can pull the hose from the apparatus and stretch it.
Preconnects simplify pump operations because their length remains constant, eliminating the friction-loss calculations needed for varying lengths of hoseline. Preconnects can be charged rapidly at a predetermined pressure, requiring only an allowance for elevation. For easy reference, place a label indicating the discharge pressure for each preconnected line on the discharge valve handle, or indicate the discharge pressure on the line’s pressure gauge with a grease pencil or reflective tape.
FLOW TESTING IS ESSENTIAL
Some departments establish and post two operating preconnect pressures that are possible with fog nozzles capable of variable flows. Miami-Dade (FL) Fire Rescue, for example, marks two pressures on the discharge gauges for the 1 3/4-inch preconnects. A red stripe on the gauge marks the pressure required to flow 180 gpm. This application rate is recommended to achieve rapid control of two or more rooms of fire filled with modern household furnishings made with plastics and other synthetic materials. A blue stripe on the same gauge marks the pressure required to flow 220 gpm.
When determining pressures for preconnected hoselines, there is absolutely no substitute for actually flow testing each preconnect on every make and model of apparatus. With fog nozzles, this means that a flowmeter is necessary. Before testing, make sure the device is properly calibrated. Do this by first flowing a solid-bore nozzle, measuring the flow with a pitot gauge, and then comparing the pitot gauge reading with the flowmeter gpm reading. Simplify flow testing by connecting the flowmeter to an intake instead of trying to “rig” it to the discharge of each preconnect.
Flow testing is essential. There are too many variations in friction loss across brands of hose and in pump discharge piping to arrive at predetermined discharge pressures based on theoretical hydraulic calculations or friction loss charts. We have found as much as a 10-psi difference in 1 3/4-inch hose friction loss calculations among various manufacturers.1
LOCATIONS FOR PRECONNECTS
You can specify modern pumpers with discharges and hose compartments for preconnects just about anywhere on the apparatus. Preconnects can also be improvised on existing apparatusfor example, departments that have eliminated booster lines commonly connect a 100-foot “trash line” of 1 1/2- or 1 3/4-inch hose to a side discharge and lash it to a running board with old seatbelts.
Front-bumper preconnects facilitate safer operations at fires along roadways because firefighters do not have to step outside the traffic lane blocked by the apparatus as they may have to do when pulling hose from the side or rear of the apparatus. Hose preconnected in a front bumper tray is easy to disconnect and carry in a bundle. This makes it handy to use as an extension for other hoselines or as a “skid” or “leader line,” connected to 21/2-inch or 3-inch hose.
Generally, front-bumper preconnects are limited to 100 feet, ideal for most rubbish and auto fires. There are exceptions, however; my department recently purchased five pumpers equipped with 150- and 200-foot preconnect crosslays in the front bumper. Firefighters working on these new pumpers praise the bumper preconnects because of their accessibility, making them easy to deploy and reload.
CROSSLAYS: ADVANTAGES AND DISADVANTAGES
A significant number of engines, quints, and specialized apparatus built within the past 20 years are equipped with transverse “crosslay” preconnects. Crosslays are connected to pump discharge piping fitted with a swivel that allows the hose to be deployed from either side of the apparatus.
Years ago, nearly all crosslays were located above the pump panel, at the top of the apparatus. This location, however, led to excessively high crosslays as fire departments ordered pumpers with progressively larger booster tanks and side compartments. This is a common problem with today’s multitask fire/advanced life support/rescue/haz-mat “urban response vehicles.”
Excessively high crosslays are an invitation to injury. I wonder if statistics have been compiled on how many firefighters have sprained their ankles or hurt their backs as a result of falling while pulling hose from an excessively high crosslay. I’m surprised that the National Fire Protection Association or the Occupational Safety and Health Administration has not set standards on the height of crosslays. As safety-conscious as today’s fire service is, it’s hard to believe that apparatus are still being built with crosslays that are so high that a firefighter who is off balance because of the SCBA cylinder he is wearing on his back has to step up on a running board and reach over his head to pull a preconnect. Pull an excessively high preconnect from the opposite side of the nozzle, and watch out! That nozzle can fly uncontrollably off the top of the crosslay, smash on the pavement, or take out a few of the nozzleman’s teeth.
 (3) Crosslays may not be the ideal location for preconnects in cities with narrow streets, parallel parking, and fences in front of homes with small front yards. (Photo by Bob Pallestrant.) |
Modern fire apparatus can be specified with lower, user-friendly crosslays that make it easier and much safer to pull and reload preconnects. Low-profile crosslays put the nozzle within reach so the nozzleman can carry it when pulling the preconnect from either side of the apparatus. It’s also easier to grasp flakes of hose and place them on your shoulder or carry them over your forearm.
The size and dimensions of crosslay hosebeds are extremely important considerations. You should not have to cram hose into a crosslay to get all of it to fit. We had this problem with a fleet of apparatus we purchased a few years ago. I’m confident the manufacturer met our specifications for a certain quantity of hose, but I have to think that the crosslay hosebeds were built to contain thinner, more compact hose than what we are using today. As a result, companies using these apparatus, now in our spare fleet, must use rollers designed for large-diameter hose to squeeze the air out of their 1 3/4-inch preconnects so they will fit in the crosslay beds.
If your department uses pistol-grip nozzles, make sure the crosslay beds are wide enough to pull the nozzle through to the other side of the apparatus. Narrow crosslay hosebeds, only as wide as one section of hose laid flat, are fine if you intend to stack the hose so that it can be pulled as a bundle and placed on your shoulder. This is perfect for a “minuteman” and some flat loads. However, hose stretched out of a narrow crosslay is likely to jam if it isn’t pulled directly in line with the hosebed. This can require an extra firefighter to stand at the crosslay and clear it while it is being stretched.
Even though crosslay preconnects work well for many departments, that doesn’t necessarily mean they will work well for yours. Don’t spec an apparatus with crosslays just because other departments have them. Find out if they are right for your department. Improvise a crosslay on one of your present pumpers by connecting a hoseline to a side discharge and laying it above the pump panel, or flake hose over the engine cover on an open-cab apparatus. Go out in your community and stretch this improvised crosslay under realistic conditions. Naturally, any hoseload will lead out nicely in a smooth, empty parking lot; you have to put it to the test by stretching around corners and obstacles commonly found on the fireground. Experiment also with different hoseloads. Try them in fire scenarios that are likely to occur in your jurisdiction. See which one works best for you.
If your tests are valid and realistic, you’ll probably find that crosslays work great under certain conditions, but those conditions may not be present in your response district.
Crosslays work best when they can be pulled and stretched directly at right angles from the side of a pumper. That is one reason they are so popular in rural and suburban areas, where homes tend to have large front yards and long driveways to stretch out hose.
No doubt, many urban fire departments use crosslays effectively. Big-city firefighters usually pull a portion of the preconnect hoseload and place it on their arm or shoulder. Crosslays facilitate a shoulder carry because, when bedded, the hoseload can’t be any longer than the width of the apparatus. This allows the preconnect to be carried and led out from a shoulder without dragging on the ground and snagging on obstacles.
Crosslays can be used safely and effectively on incidents along roadways if the apparatus is positioned properly. Spot the pumper diagonally across two lanes of traffic or the shoulder and one lane. Placing the apparatus between firefighters and oncoming traffic provides firefighters with a protective barrier. Spotting diagonally facilitates pulling the crosslay toward the fire without stepping outside the area protected by the apparatus. 2
Crosslays, however, may not be the ideal preconnect if they cannot be pulled straight from the side of the apparatus. Consider a community with narrow streets and alleys, parallel parking, fences in front of buildings, and homes with little or no front yard. Under these conditions, there can be very little, if any, space at the side of an eight-foot-wide pumper for pulling and advancing a crosslay. In this case, the crosslay will have to be stretched or carried directly toward the front or rear of the apparatus. This generally requires two firefighters: a nozzleman to stretch or carry the hose and a second firefighter to clear the crossway bed and keep the hose from catching on ladders, grabrails, or any other projections.
 (5) A preconnect master stream deploys rapidly and is more effective than apparatus-mounted devices for ground-floor fires. (Photo by John Ferraro.) |
It can be tempting to position an apparatus with crosslays so that it lines up with a driveway, an opening in a fence, or a space between two parked cars. This position may allow the crosslay to be stretched in a straight line from the side of the pumper, but it can place the apparatus too close to the fire and block access for aerial apparatus.
The keys to using crosslays effectively are, first, find out if they work for your department; then, choose a hoseload that deploys preconnects smoothly, and train personnel to stretch them proficiently under realistic fireground conditions. Be sure to specify an apparatus with crosslay hosebeds of the proper height, width, and hose capacity. Know when to use crosslays and when not to use them. Recognize situations where crosslays do not work wellfires that call for stretching hose from the rear of the pumper, for example.
Rear preconnects, separated by a divider from the main hoseload, remain the attack line of choice for many fire departments. Consider again the factors of narrow streets, parallel parking, and fences in front of homes with little, if any, front yards. Here, an engine equipped with rear preconnects has to pull slightly past the fire building to stretch back toward the fire. This is good positioning for an engine: Passing the fire allows the officer and crew to get a view of three sides of the fire building and adjacent exposures before they get out of the cab. Pulling past the fire also leaves the space in front of the fire building open for aerial apparatus.
The versatility of rear preconnects is increased when they are connected to discharge piping at the rear of the apparatus instead of up in front of the hosebed. This makes it easy to disconnect the preconnect and pull it as a skid load, dropping it at the fire when an engine reverse lays to a hydrant.
Of course, any preconnect can be disconnected and used as a skid, but climbing up in the hosebed and disconnecting it from its discharge can be difficult. This task can be eliminated by connecting a 10- to 15-foot “pigtail” of hose between the preconnect and the discharge. In this way, you will be able to disconnect the preconnect at the pigtail instead of up in the hosebed.
It’s hard to avoid a high hosebed on a pumper with a 750- or 1,000-gallon booster tank. The West Palm Beach (FL) Fire Department made its rear preconnects safer and easier to pull by lashing the nozzle and a loop of hose where it can be reached by a firefighter standing on the ground.
A rear preconnect hosebed is, of course, much longer than a crosslay, but that doesn’t mean the hose load has to be as long as the hosebed. If your department stretches all or a portion of a preconnect from a shoulder load or carries flakes of hose, mark the hosebed six to eight feet from the rear, and load the preconnect, or at least the last 100 feet, to this point. This will keep the hose folds short enough to carry so the hose doesn’t become snagged on obstacles.
So, what’s better, crosslays or rear preconnects? That’s a question each department must answer for itself. The size and length of preconnects and how they’re configured on an apparatus must be decided on the basis of the following factors: staffing, occupancies, size and height of buildings, structures’ setback from the street, width of streets and alleys, parking conditions, and fences around structures.
The type of apparatus may be the deciding factor. Quints, for example, usually don’t have rear preconnects because the rear of the apparatus is too busy with ladders, a basket, or a turntable.
Apparatus, of course, can be equipped with crosslays and rear preconnects. This is common in the Southeast, where many pumpers have 150- and 200-foot 1 3/4-inch crosslays as their primary attack hoselines for single-family dwelling fires. In addition, pumpers may have a rear preconnect containing up to 300 feet of 1 3/4-inch hose for longer stretches, such as garden apartments.
Of course, larger hose can also be preconnected. A 2 1/2-inch preconnect is a very powerful and versatile weapon; it is capable of delivering more than 300 gpm into a storefront or heavily involved wood-frame structure. A 2 1/2-inch preconnect is also an excellent way to begin a long stretch of 1 3/4-inch hose when it is connected to a breakaway nozzle or a gated wye with 1 1/2-inch thread.
My department has taken the impressive knockdown power of the 2 1/2-inch preconnect to a higher level by issuing to select engine companies a highly portable master stream device that is preconnected to 100 feet of three-inch hose. This ground-operated monitor has proven to be more effective than apparatus-mounted deck guns for two reasons. The first is that an engine operating its deck gun in front of a fire building may steal the most strategic position for an aerial apparatus. Second, apparatus-mounted, heavy-stream devices are great for fires above the first floor, but they can be fairly ineffective on ground-floor fires because of their height on the apparatus. They are generally too high to direct a stream into the overhead; consequently, most of the water strikes the floor. A ground-mounted monitor, on the other hand, is low enough to penetrate and direct a powerful stream up into the ceiling. This new preconnect monitor can be rapidly deployed and relocated and is equipped with a safety feature that automatically shuts off water flow if the device should move uncontrollably because of nozzle reaction.
Endnotes
- For a detailed explanation of flow testing, see “Nozzles and Handlines for Interior Operations,” David Wood, Fire Engineering, April 1999.
- For a detailed explanation of how to position apparatus safely along a roadway, see “Safe Placement of Apparatus on Roadways at Nonstructual Fire,” Doug Leihbacher, Fire Engineering,April 1994.
BILL GUSTIN is a captain with Miami-Dade (FL) Fire Rescue (formerly Metro-Dade) and lead instructor in his department’s officer training program. He began his 29-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. He is an editorial advisory board member of Fire Engineering.or a detailed explanation of how to position apparatus safely along a roadway, see “Safe Placement of Apparatus on Roadways at Nonstructural Fires,” Doug Leihbacher, Fire Engineering, April 1994.
