A networking engineer envisions a new way to get water to the flames — by applying networking technology to a traditional hoselay.
Relay pumping can supply water over long distances, but existing equipment requires continuous monitoring of pressures and flows at each booster pump. A firefighter must be dedicated to monitoring and controlling each pump. In addition, each firefighter must be able to communicate with all of the other firefighters on the relay to ensure that pump pressure and flow changes are coordinated. On a long relay, a firefighter or a crew may be forced to remain at a location that might become dangerous. If they leave the location, the relay may fail.
Adding a data network to a relay system changes this scenario. The data network enables a single firefighter using a personal computer, or a touch-screen device connected to the computer, to monitor and control all of the pumps. The data network requires the addition of a small gauge wire pair onto the hoses used in the relay.
This article will explain how a ground-based data network system can be implemented as well as adapted for use in a helicopter.
ON THE ROAD
If existing fire roads are used, the hose can be deployed from reels mounted on 4WD vehicles (Fig. 1). The vehicles also carry a diesel or gasoline booster pump that is monitored and controlled by the network. Alternatively, if existing fire roads are not available, the hose can be deployed from reels mounted on tractors or plows (Fig. 2). Each tractor or plow would also carry a diesel or gasoline pump.
The relay system can be cached near a high-value facility and be rapidly deployed when there is a fire threat. There is no apparatus limit on the length of the relay, and the wire pair network can be added to both large- and small-diameter hoses.
All American Hose (which recently acquired Snap-Tite Hose) currently sells a fuel-carrying hose with a single embedded wire that is used to ground static electricity, according to Bob Harcourt, president. He explains that placing two wires in a hose is not a problem. Additionally, the voltages and currents in the data network wires are very small and harmless.
Many pump companies are using microprocessors to control the engines and pumps on firefighting vehicles. Mike Laskaris, engineering manager of Hale Pumps, says that it is possible to connect the microprocessors on his pumps to a data network that runs on the wire pair in the hoses. That hose data network can extend for many miles.
One example of a low-cost network is the LonWorks System from Echelon Corp. (http://www.echelon.com/). It was used in an application for Motorola in Scottsdale, Arizona, several years ago. An explanation of proposed uses for the system follows.
DETAILS OF THE PROCESS
The data network electrical signals in the wire pair on one hose must pass through the hose couplers to the wire pair in the adjacent hose. Fig. 3 shows a proposed new Storz-type hose coupler for connecting hose sections together. The proposed coupler does not require exposed electrical contacts that might be affected by dirt and water.
Each coupler contains an electrical coil that forms one half of an electric transformer. When the two couplers are connected, data network signals are transmitted across the coupler via magnetic fields. No metallic contact is required.
A small-diameter wire pair (24 to 16 AWG) will allow the Echelon Data Network to send its signals over long distances. Electrical repeaters at each pump allow the network to support any number of pump/hose sections.
A proposed new type of hose has two separate fluid-carrying chambers (Fig. 4).
One chamber is used for transporting the fluid to the next pump, and the other chamber is used to create a water curtain by placing small holes along the length of the hose. The hose is designed to lie flat to ensure that the holes point upwards for a proper water curtain spray. The transport section of the hose can use a percolating design to protect the hose from fire.
The enabling of the water curtain flow in each segment is done by remote control from the system computer. A valve at each pump in the relay determines whether water will enter the water curtain section of hose.
The remote-controlled water curtain feature makes the system useful for surrounding a prescribed fire before ignition. The water curtain option can be selectively enabled in hose segments where the fire is nearing the hose. No water is wasted on sections that are not at risk of escape.
A GPS unit can measure the altitude of a vehicle location and be connected to the data network. If the terrain is hilly, the data network can be used to communicate the elevation of the vehicle as it travels. The vehicle might carry a variety of hose lengths on different reels. A program on the system computer could use topographic maps and the tractor location/elevation to determine the best hose length selection for the next leg of the relay. A shorter hose would be required if the next leg had a large increase in elevation.
The hose data network can enhance crew safety by providing an alternate system for communication between the vehicles and the base. Radio communication can be lost because of obstacles to radio wave propagation.
Since vehicle crews and nearby firefighters have access to water from a hose relay, they might carry a protective shelter tent that can be filled with water from the hose. The water should give enhanced thermal protection to firefighters trapped in a burnover (Fig. 5).
A long relay might be used to fill a portable pool near a fire that could supply water to helicopters carrying buckets. The relay would then reduce the distance that the helicopters would have to fly to refill their buckets. In addition, if the tractor-based relay system reaches an obstacle it cannot go around, a helicopter could be used to continue the relay over the obstacle.
In other uses, a helicopter could carry one or more reels of hose, with each reel containing an electric pump at its center (visit www.electric-fluid-pipeline.com). The hose would be deployed as the helicopter flies over the ground. When a reel has deployed all of its hose, it would be lowered to the ground.
The electric pumps in the helicopter reels would be powered by wires that are embedded in the hose and connected to the data network for monitoring and control. The electric power would come from an electric generator on the last vehicle of the ground relay. The helicopter could be used to continuously spray water onto a fire.
Another version of the proposed relay system has large-diameter electric power wires embedded in all of the hoses. These wires would have high voltages and currents that power electric pumps. No diesel or gasoline pumps would be used. The advantage of an electric pump system is that there is no need to refuel the pumps. Once they are deployed, they can run unattended for days or weeks.
In all walks of life, digital data networks like Ethernet have become widely used. People have Ethernet and WiFi networks in their homes, and the devices are low in cost and high in performance. With further research, a similar data network might be added to a relay pumping system, providing many useful firefighting services at a modest cost.
Steve Shoap is a retired electrical engineer who has been working with digital data networks for a very long time. He has worked for Bell Telephone Labs, MIT Lincoln Lab, and Motorola Semiconductor; been a member of an NFPA technical committee for electronic devices; and spent many hours reading about fighting wildfires in the library of the NFPA headquarters near his home in the Boston area. You can contact him firstname.lastname@example.org.
Note: The inventions in this article are protected by U.S. Patents 7,819,345, 7,942,350, and Australian Patent 2008-302-447. A Canadian patent is pending. Additionally, a PCT Patent Application has been filed.