THE VOLUNTEERS’ CORNER
Long Driveways— More Solutions
MAINTAINING a constant supply of water is a headache of rural fire fighting. Tank trucks can make up for the lack of a close-by static source of water only if they can provide a steady flow to hose lines.
The use of a clapper (swing-check) siamese at the main road end of a hose line stretched into a long driveway or rural lane is the key to a satisfactory water supply where tankers are employed. This will enable the heavily loaded tanker to remain on a firm roadbed and prevent bogging-down.
While the first tanker is discharging water into one inlet of the clapper Siamese, a second is connecting to the other inlet. The clappers prevent backflow of water and permits tire second tanker to take over the job of discharging water into the supply fine without a break as the first tanker starts to run dry. If two lengths of hose are left attached to the clapper inlets, each tanker can quickly hook up the Siamese (Figure 1).
No. 1 tanker can then leave to refill and permit another truck to take its place at the end of the supply line— ready to take over from No. 2 tanker. The number of tankers needed is gaged by the time it takes a tanker to obtain a load of water and return to the fireground.
All this presumes, of course, that the tankers are equipped with discharge pumps capable of forcing at least 200 to 250 gpm a moderate distance through 2 1/2-inch hose to a pumper at the fire.
Another system is to use a portable tank. Each tanker dumps its load into the collapsible tank, which can hold 500 or more gallons, and leaves to refill. This is where a tanker’s ability to drop water quickly will pay off. The drop should exceed the gallonage being removed by the pumper at the fire so that the reservoir is full when the tanker leaves. A pumper drafts from the tank and supplies the pumper at the fire.
If the supply line is not too long and the number of gallons required is not too great, a portable pump can be used to supply the engine at the fire. Testing the portable pump through various lengths of hose will show what can be expected on the fireground.
It should be remembered that the size of the supply line has a direct bearing on the number of gallons per minute that a pump at the portable tank can send to the pumper at the fire. The use of 3-inch —or even 3 1/2-inch—hose will permit the pump to supply a much larger volume of water than it can through 2 1/2-inch hose.
Sometimes it is feasible to provide a water source for tankers or start a relay with a portable pump and a portable tank. If an engine cannot get close enough to a river or pond to drop in its suction hose, a portable pump can be placed at the water’s edge. It can then pump through three or four lengths of 2 1/2-inch hose to the portable tank. Then an engine can draft from the tank and the relay is in business. This is when it pays to have a portable pump designed for volume rather than pressure.