1 3/4-INCH HOSE: THE BOOSTER LINE OF THE ’90s?
The origin and development of the use of small-diameter hose for interior attack dates as far back as the 1950s in some areas of this country and to the 1960s and 1970s in other areas. During my younger years, while living in a New England city, the engine company officer had only two choices for handlines—the ¾-inch booster line and the 2 1/2-inch “big line.” One-anda-half-inch hose was used strictly for overhaul. These limited choices were not viewed favorably by firefighters, since the flow available from the booster was approximately 16 gpm and that from the 2’/2-inch line was about 250 gpm. Quite a spread! Often the booster came off first because of its mobility and the speed with which it could be deployed. The small line had other advantages, as well. It didn’t have to be hung to dry or repacked. But the dismally low flow rate was a marked weakness; more often that not, the fire “got away” from the small line.
Many of the larger urban departments did not equip their engines with water tanks until the 1970s. Until this point, the only option was to drop the big line and pump from the hydrant-even for a rubbish or auto fire. When booster reels with the larger one-inch hose, capable of flows of from 30 to 50 gpm, came on the scene, they were greeted with great enthusiasm. Unfortunately, the low flow cycle repeated itself on too many occasions. The “fast” booster was being used its the initial attack line on structural fires, with the same results.
(Photos by author.)
One-and-a-half-inch hose was the next step up the ladder of interior attack lines. Whether preconnected or attached to the end of a largerdiameter line, l ‘/2-inch hose was considered an improvement over the toosmall booster and the bulky, hard-tomancuvcr 2 1/2-inch. The flow available from the 1 1/2-inch line varied from 95 to 1 20 gpm, depending on the nozzle used and the nozzle pressure. Not all departments went this way, however, lor many of the larger, urban departments. the big 2 1/2-inch line was still the rule for both interior and exterior use at structural fires. As late as 1967, the City of New York (NY) Fire Department prohibited the use of 1 ½inch hose at a structural fire except during the overhaul stage.
During this period of increased use of 1 1/2-inch hose, fire service personnel in the larger cities were becoming polarized into two groups —those who were staunch advocates of its use, and those who felt the 1’/2-inch had little to offer over 2’/2-inch.
DEVELOPMENT OF 1 ¾-INCH HOSE
In the late 1960s and early 1970s, the major urban areas of the United States were witnessing dramatic increases in fire activity. America’s cities literally were being consumed by flames. In those days, it was common for the busier engine companies to clock tens of runs in a tour, with many working structural fires. The mandated use of 2 1/2-inch hose was very timeconsuming and debilitating—but 1 ½inch hose didn’t have the knockdown capability that was needed. It commonly flowed about 100 gpm.
FDNY began a program that evaluated the different sizes of attack lines. The program’s objective was to maintain the maneuverability and light weight of 1 1/2-inch hose, while obtaining increased water flow. Under the leadership of the late Battalion Chief Milton Brodey, the testing program evaluated the speed, maneuverability, and kinking characteristics of different diameter hoselines. One of the main factors considered was the ease with which a charged line could be moved into a building.
FDNY decided on l-Vi-inch hose. Evaluation continued and was expanded to various areas of the city. Flows in the range of 180 gpm were attainable using either a ‘VWinch smooth-bore tip or one of the new generation of automatic nozzles. This hose offered a quantum leap forward. The flow being delivered increased by as much as 80 percent over 1 ‘/2-inch hose, and the maneuverability benefits of 1 ‘/2-inch hose were retained.
New York also was experimenting with a new friction loss-reducing agent that could permit even greater flows with the 1 3/4-inch line. This agent, which was metered into the fire stream, reduced friction loss so much that 250 gpm could be delivered through lVTinch hose. While it was used extensively for a number of years, the use of the agent eventually fell, and 180 gpm was accepted as the flow rate from 1 Vi-inch hose.
1 3/4-INCH USE EXPANDS
Throughout the 1970s and 1980s, the use of 1%-inch hose grew significantly in this country. Some proponents advanced the theory that it could do everything a 2½-inch line could do at lower cost and with none of the disadvantages of 2 1/2-inch hose. This theory’ expanded the use of 1 Viinch hose to the extent that some departments removed 2 1/2-inch hose from their apparatus completely, replacing it w ith 1 3/4-inch hose for handlines. As an example, a brand-new 1,500-gpm pumper recently was being loaded with hose and placed in service. As a length of 2’/2-inch hose was being uncoiled, the chief commented, “I don’t know what I’m going to use that for!”
While 1 Vi-inch hose was being put to very good use in many instances, some officers seemed to lack a clear understanding of its proper utilization or benefits. One training officer stated that the purpose of 1 Vi-inch hose was to reduce wear and tear on the apparatus by permitting lower engine pressures with the same flow as 1 ½inch hose. The original purpose for developing this new diameter hose seemed to be fading from memory.
The benefits of 1 Vi-inch hose cannot be discounted, however. Regardless of the misconceptions that may have arisen, my belief is that the typical lVi-inch handline is flowing approximately 150 gpm on the fireground. This is a significant improvement over what could be obtained from 1’/2-inch line. It meets many departments’ need for an interior attack line. When viewed in that context, its development and use have been successes.
HISTORY REPEATS ITSELF
On the negative side, history does seem to be repeating itself. The 1 Viinch interior attack handline now is being used more and more for initial exterior attack—a purpose its original proponents never intended. While it is possible to obtain a 250-gpm flow through a 1 ¾-inch line (roughly equivalent to a 2‘/2-inch line with a l’/s-inch tip), the line kinks and is rock-hard. The maneuverability advantage is diminished. In addition, to achieve this flow through a long stretch of hose, engine pressures in excess of 200 psi often are required. Some view this pressure as excessively high and a safety concern. The result, in the real world of field operations, is that the 1 Vi-inch attack line is unlikely to be flowing 250 gpm. It is more likely, particularly when controlled by a single firefighter, to be flowing somewhere around 120 gpm.
FDNY’s rule of thumb is that if a single firefighter can control and operate a 1 Vi-inch line, the line is not flowing at the desired 180 gpm (see chart). While not much testing has been done on the subject, it is generally believed that a nozzle reaction force in the range of 55 to 60 pounds is comfortable for one firefighter to control. Reaction forces higher than this require more personnel, and maneuverability is markedly decreased.
Unfortunately, this supports what we have seen more often than we would like —a small-diameter attack line being used on a fully involved structure and having practically no effect. Little wonder—the flow most likely is less than 150 gpm.
DESTRUCTION OF A MYTH
We have seen 1 ‘/4-inch hose used as a replacement for 2’/2-inch hose in fireground situations that the original proponents and developers of the small-diameter hose did not contemplate and, in all likelihood, would not support. In the 25 years since 1 ¾-inch was developed, the fire load in structures has increased significantly, due to the increased use of hydrocarbonbased synthetics in almost every facet of our society. A large volume of fire on arrival may necessitate a highvolume knockdown from the exterior prior to an aggressive interior operation. Arson fires in vacant or partially occupied structures often have a good head start and also require a quick, exterior “dash” before a line is moved inside. If l/t-inch hose is the only handline available on the rig, successful control could be dubious.
COMPARISON OF REACTION FORCES
To be prepared for both exterior and interior operations, one large department uses 150 feet of 1 ¾-inch as a leader line, attached to a 1 ‘/4-inch smooth-bore nozzle, on a 2’/2-inch line. If the volume of fire and occupancy warrant an exterior attack, the 1 ‘/4-inch tip can flow 330 gpm at 50psi nozzle pressure. Then the 1 ¼-inch line is attached for interior operations flowing 1 50 gpm through a low-pressure combination nozzle.
I’he 1 ‘/4-inch tip provides essentiallv twice the flow of the 1 VVinch line. Maneuverability is sacrificed, but this is not the major issue when a large volume of water is needed. The 2½inch line still can be moved, if necessary. The next step up the fire stream ladder would be a master stream, which greatly sacrifices speed and mobility in exchange for increased flow. The arrangement this department utilizes seems ideal for its application.
The use of 2’/2-inch line need not necessarily be restricted to exterior operations. Although this size line is less maneuverable than a smaller-diameter line, maneuverability and speed may be outweighed by the demand for increased water flow. The flow from a single 2‘/2-inch line may equal or exceed that available from two smaller lines, depending on the nozzle used.
The construction, age, and occupancy of the building; exposures involved; and the volume of fire may dictate the use of 2‘/2-inch line in the interior. The increased flow, reach, and penetration of the fire stream may be needed. It is being used with success where fire is in the basement or first floor of multiple dwellings, where the stretch is short; as expected in industrial and commercial occupancies; and particularly well in fully involved residential garages, where the volume of fire is high and the exposures oftentimes severe.
BOOSTER LINE OF THE ’90s?
It is unfortunate to have to conclude that 1 ¾-inch hose is being used as the booster line of the ’90s. Firefighters of the past often did not have the option of using small-diameter hose for interior firefighting. This set the stage for potential misuse of the booster line. Many departments— both large and small —have removed the booster reel entirely from their apparatus in response to this misuse and the limitations of the line itself. Lacking a clear understanding of the reasons for the development of 1¾inch hose, others have implemented it as a complete replacement for 2½inch line. In cases where this has occurred, the net result has been a decrease in fire flow from exterior handlines.
A POTENTIAL SOLUTION
The tools available to firefighters today far exceed the most far-fetched dreams of their predecessors. Unfortunately, when we think of tools, we often think first of hand or hydraulic tools.
The various sizes and types of hose and nozzles are as much tools to the firefighter as are the axe, pike pole, and circular saw. Using the right tool for the job means getting the task done quickly and efficiently. One-andthree-quarter-inch hose was researched, developed, and implemented to improve fire flow and retain maneuverability for interior firefighting. It accomplished exactly that. It was intended to replace 2‘/2-inch hose in the difficult, arduous stretches of New York’s tenements.
While 1 ¾-inch may have some use in exterior applications when water volume is not a factor and speed is of the essence, it was not intended to replace the larger-diameter line for all of its well-suited uses. One-and-threequarter-inch line is a great tool —use it for its intended purpose *
The author gratefully acknowledges the assistance of First Deputy Fire Commissioner William M Feehan and Assistant Chief Donald F. Devine of the City of New York (NY) Fire Department and Captain David P. Fornell of the Danbury (CT) Fire Department in the preparation of this article.
