Improved Ladder Pipe Operations Speed Knockdown, Increase Safety
Since last August, the Milwaukee Fire Department has been training its 20 aerial ladder companies in new evolutions, enhancing safety of fire fighters while increasing their ability to knock down blazes more quickly through upper windows, particularly in dwellings.
The first evolution is the removal of the ladder pipe operator from the ladder and the use of ropes to control the nozzle position from the platform. The second, made possible by high-volume fog nozzles, is stream operation without shutdown as the ladder is extended and retracted in and out of windows from floor to floor.
Various methods have been used elsewhere for ground control of aerial streams. Some trucks come equipped with cable controls. Electric operating mechanisms are available. All have their disadvantages, chiefly the necessity for the pipe to be an optional appliance—out of the way when the ladder is needed as a people-mover, yet able to be put into action quickly when water is called for.
Two ropes on pipe
The procedure adopted in Milwaukee uses two colored 3/8-inch ropes, 85 feet long, with a 15-foot length of 3/16-inch stainless steel cable attached with snaps at the free ends. The green rope is coiled in the bottom of a green bag about 2 feet long, stored on the rig, with the cable coiled on top of it and snapped to the drawstring end of the bag. To use it, the cable is unsnapped, pulled free of the bag, then snapped to the ladder pipe handle for elevating the stream by pulling the handle down.
An identical red rope with cable, coiled in a red bag, is snapped to the pipe barrel. It serves to lower stream elevation. Normally, the nozzle drops freely if the green rope is slacked off, but there can be times when an extra pull is needed.
The green rope is brought down above the rungs and the red one, beneath the ladder. The lower ends of both ropes are snapped to each other so neither end gets “lost.” Whoever has hold of one rope can quickly grasp the other.
With these controls, two men can operate the stream, one manning the platform and the red rope if necessary, the other handling the green rope. This second man wears a safety belt hooked to a convenient portion of the ladder turntable structure so that any sudden change in pull or even a rope breakage will not throw him to the ground.
With older straight stream nozzles, discharging in the 500 to 1000-gpm range, nozzle reaction is so great that aerial ladder manufacturers normally require the stream to be shut down while the ladder is being retracted or extended. This means any change in ladder reach requires shutdown. That, in turn, means considerable loss in fire attack flexibility, especially at relatively small but threatening and fast-spreading blazes in crowded residential neighborhoods.
However, with high-volume adjustable spray nozzles such as the Akron Turbojets now in service on Milwaukee aerials, manufacturers have agreed that the lower nozzle reactions permit full stream flow with a fully hydraulic aerial while the ladder sections are moving up or down.
Stream placed in window
At the discretion of the officer in charge, therefore, ladder companies are now prepared to start the stream with the flow set for 350 to 750 gpm, aim the ladder tip at a window from the second to fifth floor and extend the tip directly into the window with the stream in operation.
Said Motor Vehicle Operator Instructor Harlan Knem, “Normally you stop extending the ladder when the nozzle is just out of sight inside the window—about a foot. This allows you to get penetration without risking snagging the ladder tip on debris inside. It’s easy to spot the position with the stream working, even at night, because you can easily see the spray pattern.”
Once the spray is inside the window, its wide cone pattern insuring optimum saturation of the room, the operator uses the ropes to raise and lower the stream for complete coverage, then retracts the ladder. If knockdown by the fog and steam is sufficient, water can then be shut off—typically after only about 15 seconds. This allows other companies to proceed with interior attack. Or the ladder may be swung continuously from window to window for more extensive fires, or from floor to floor, repeating the rapid knockdown process with operator safety.
This evolution requires detailing men to keep the 3-inch hose supplying the pipe from tangling or interfering with other operations below while the ladder is extending or retracting.
Learning by experience
Whenever the ladder is moving in or out a window, the pipe is held horizontal so the nozzle will not get hooked or jammed into sash or other obstructions.
“In one of our first trials,” says Knem, “the pipe was tipped up as the ladder went into the room. As the fly was extended, it shoved the pipe against the ceiling and broke it right off the ladder. We learned from this.”
“Also,” he added, “the cable fittings and snaps have to be strong. We had to make several changes there after one of the snaps broke under the pull needed to elevate the nozzle. The stuff used for flag halyards won’t do the job. We went to stainless steel fittings with double compression splices at the cable eyes.”
A few of the city’s aerials cannot fully utilize the continuous stream operation because of their extension-retraction mechanisms are of a type which can be overriden by nozzle reaction forces if the ladder is not locked while water is on. Others will adopt the procedure fully as soon as training is completed.