1000 GPM in Inline Pumping With 500 Ft. of 4-In. Hose
The Rialto, Calif., Fire Department has been using 4-inch hose for supply lines from hydrants to engines for two years. When we began using it, we had in mind a large gasoline tank farm and a number of other large and combustible buildings in our city.
We have 500 feet of 4-inch, doublejacket, 600-psi-test hose loaded on each engine along with 1200 feet of 2 1/2-inch hose loaded so that we can also lay parallel 2 1/2-inch lines. This arrangement has proven itself invaluable twice in the last six months and has more than justified the extra cost of the 4-inch hose. Hydrants within our city are generally able to supply at least 1000 gpm through 500 feet of 4-inch hose and one of our standard hose lays is a forward lay using only the 4-inch hose.
As good as this lay is, we have begun using 4-inch hose while also laying a single or parallel 2 1/2-inch line. The effect of these added lines is to eliminate our dependence on a single 4-inch line while increasing flow and residual pressure at the engine. It is our belief that these added lines laid going in to a working fire allow the fireground officer a greater latitude in determining what lines to use to attack the fire.
We have also devised plans for relaying water in the event 500 feet of 4-inch is not enough to reach an involved building. We have found that it is quite reasonable to piece out to 1000 feet of 4-inch line and still be able to move 1000 gpm. Our evolution requires our first engine to lay 500 feet of 4-inch hose and return to the hydrant. The second engine picks up where the first engine leaves off and lays to the fire. On arrival, it places the 4-inch line into an intake and the engine at the hydrant begins to supply the lay with engine pressures of about 175 to 200 psi.
We have also begun using 4-inch hose to supply our deluge gun. This is accomplished by placing a 2 ½ X 4-inch increaser on a 2 ½-inch discharge and thert placing a 50-foot length of 4-inch hose between the discharge and a 4 X 2 ½-inch reducer on the deluge gun. This operation is extremely fast and we have found no problems in supplying large volumes of water through a single 2 ½ -inch discharge. We are aware that traditionally we have relied on a 2½inch discharge to supply 250 gpm, but we have had very good results with flows of 1000 gpm.
Servicing sprinklers
Another quick operation is to lay from a hydrant with 4-inch hose into a fire department sprinkler connection. This has proven a real time saver and produces a much greater supply than two 2 ½ -inch lines. It also allows the engine laying the 4-inch line to use its 2½-inch hose for attack lines from another hydrant or the same hydrant if we know that the hydrant is capable of flows in excess of 1500 gpm. Normal policy, however, is to supply the sprinkler system with a pumper solely responsible for that assignment.
The Rialto Fire Department also operates a trailer which carries 700 gallons of AFFF. This unit has four 2 ½-inch intakes and four 2 1/2-inch discharges and has a motor to proportion AFFF concentrate with water at up to 1000 gpm. Originally, we supplied this trailer with 2 ½-inch lines, but more recently we have begun to lay 4-inch hose. Doing this has again increased our efficiency while reducing the amount of extra lines around this unit. By initially laying a 4-inch supply line, we have reduced by several minutes the time required to put this unit into service at flammable liquid fires.
We believe we have only scratched the surface for the uses of large-diameter hose in our department and feel that many small departments may be able to greatly increase the effectiveness of each of their engines by expanding their use of large-diameter hose.
