HIGH-RISE STANDPIPE FLOW TEST
BY GERALD A. TRACY
Can firefighters fighting a fire in a high-rise structure take for granted that they are operating with an adequate supply of water from the standpipe? When attack teams are making “the push,” moving in on an advanced fire, is their safety affected when other teams “open up” and begin using water from the same standpipe? When officers make that call to “start water” and the hoseline is bled and ready, we expect that tool of extinguishment to operate with efficiency and effectiveness, but that can only be expected when the volume of water is sufficient for the given situation.
Standpipes (six or eight inches in size) supply water in large building complexes and high-rise buildings, and the system design can limit water supply and pressure. FDNY procedure is that after the first line is hooked up and operating, a second line, the backup line, generally will advance out of the same stairwell and, in most cases, will be connected to the same standpipe. Obviously, operating that second line will have some effect on the first line. What we did not know was the extent and duration of the effect. To determine this information, FDNY conducted a flow test in a high-rise building, using our standard equipment.
Our choice of handlines for attacking fires is dictated by the type of operation, the occupancy, the size of the area involved, and the volume of fire encountered. Our mandated tool of choice for standpipe operations is a 212-inch hose with a 118-inch open bore tip. This combination of nozzle and hose enables an attack team to deliver 250 gallons of water onto a fire with nozzle pressures as low as 50 pounds. A valid reason for this combination is a high volume of water delivery with low pressures in the equipment being used.
THE TESTS
We conducted the tests in a building that was under construction. The building had an eight-inch dry standpipe riser supplied by a 1997 pumper (Engine 40), equipped with an automatic governor to regulate pump pressures.
The tests assessed the amount of water flow and pressure lost to the open and operating first handline when a second and then a third handline are put into operation. The resulting pressures and flows in gallons revealed by the tests are shown below.
THE RESULTS
The results of the test revealed that on the initial operation of the second handline, 53 gallons were lost in the first line flow–approximately 20 percent of the line`s effectiveness and extinguishing power. When the third line was in operation, the loss was 65 gallons.
Consequently, attack teams must be notified when additional lines are going to start water. The loss of water will affect their safety as they are moving in on an advanced fire. A firefighter must remain at the standpipe outlet to reregulate the proper pressures for the line being supplied. Incident commanders or the operations post chiefs must coordinate the operations of additional lines after the initial attack line is in operation. Members operating in the fire operations area (fire floor and floor above) must monitor radio transmissions affecting the implementation and operation of additional handlines.
Engine pump operators must monitor the output of pressure and flows when supplying standpipe systems. Incident commanders must be notified when it appears no water is flowing into the system. This is probably due to a closed valve in the standpipe riser or a section being supplied in the system. Notification would also be required when an excess flow is observed, which could indicate that many valves are open or there is a break in the system.
MASTER STREAMS OPERATED FROM WITHIN HIGH-RISE BUILDINGS
There will be a day that any given fire department will experience an advanced fire in a high-rise building beyond the capability of handlines, a fire that is also high above the reach of outside master streams. Having a means to place a portable master stream in operation may make the difference between giving up the building to a fire or containing and controlling the beast in its den.
A ram set gun was used to shoot a threaded lag into the concrete floor of this high-rise to provide a means of securing the master stream appliance from the back pressures incurred with water flowing and the nozzle elevation below 35 degrees above horizontal. This allows the versatility to place this appliance in areas such as in a stairwell, in a hallway, or on an open floor.
Two types of portable master stream appliances were tested. The ground base of a portable master stream appliance should be provided with a means of securing it to a substantial object. One was secured with a hook and chain mounted to the ground base, the other with a safety strap and hook. The hook or strap was placed onto the ram set lag, securing the appliance from back pressure movement. When the nozzle of portable master streams is lowered below 35 degrees above horizontal, the pressure and velocity of the stream exert a back pressure force. The rule of thumb is that for every gallon leaving the nozzle tip, a force of one-half pound of pressure is forcing the appliance backward. The results of flow using different size tips are shown on page 109. The method of securing the appliance can be seen in the photographs below.
MASTER STREAMS: LESSONS LEARNED AND REINFORCED
The flow test revealed that with only one 212-inch line supplying this appliance, a flow of almost 500 gpm was reached. When a second line augments the appliance, flows in excess of 600 gpm can be reached. Opening the standpipe outlets fully will allow flows in excess of 700 gpm.
To place a lag in the floor of the fire area, a handline is needed as protection for the member shooting the lag. The protection line can be the second line stretched initially. A third line can be stretched to act as the protection line while the second line is used to augment the master stream appliance.
A single gate must be placed one length back in each of the supply lines to the appliance. This will allow the appliance to be shut down for repositioning or conclusion of multiversal operations. These supply lines can then be reverted into handlines by attaching controlling nozzles with open bore tips.
The reach of this master stream, 100 feet-plus, will offer safety in distance. The power of this solid master stream can be used to penetrate drop ceilings and gypsum board walls shielding a fire. n
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Measuring the nozzle pressure to establish the flow. (Photos by author.)
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(Left) Appliance No. 1 was secured by hook and chain. (Right) Appliance No. 2 was secured by a safety strap.
GERALD A. TRACY is unit commander of Fire Department of New York Squad 18 located in the borough of Manhattan, is an instructor for the department`s Captain`s Development Course and Firefighters Professional Development Program, and was one of the developers of the “Back to Basics” training course. He lectures extensively on various subjects including strategy and tactics in high-rise structures and multiple-occupancy and private dwellings.
