Tanker Shuttle Techniques For Supplying Large Flows
The Volunteers Corner
If you are going to supply fireground flows of as much as 600 gpm with a tanker shuttle, then you must start with a plan of operation and follow through with adequate training.
The plan of operation should describe how tankers will be filled at the water source, define the options for maintaining a water supply on the fireground and—most important of all—designate the selection of a water supply officer.
A simple but effective way to designate the water supply officer is to state that the second chief officer who arrives on the fireground shall be in charge of water supply—the tanker shuttle. In a mutual aid area, the second chief officer arriving on the fireground might not be a member of the department responsible for extinguishing the fire, but he would still take charge of the water supply operation. The exception would be if the chief of department who is responsible for command of the fire is the second chief officer to reach the fireground.
Obviously, the fire departments that provide mutual aid for each other must all have a hand in the development of the plan of operation and must participate in multi-department drills if their tanker shuttles are to supply the maximum amount of water to the fireground. Fire departments that frequently supply mutual aid to each other should also train with each other as much as possible.
Developing the plan: It is necessary for all departments that help each other with tanker shuttles to be involved in the development of a plan of operations because standardization of filling and dumping techniques is a vital part of an effective tanker shuttle operation. Effectiveness depends on all units having the necessary fittings for filling as well as everyone understanding the fireground dumping operation, whether it be into portable tanks or a large tanker used as a reservoir.
Development of an operations plan should start with a survey of the available tankers. Find out how each tanker is designed to be filled and determine whether alternate filling methods are practical. From that you should develop a list of fittings and hose sizes that should be available on the pumper at the drafting site.
The most important move you can make after obtaining this information is to start an effort to standardize all accessory equipment. This can’t be done in a few weeks, but it is a goal to shoot for in the next few years. For example, if 4-inch hose is carried by some companies and a couple of tankers have 4inch fill valves, you might wish to standardize on using this large diameter hose for filling tankers. You can start by first using an adapter system, such as a 4X2 1/2X2 1/2-inch wye on the end of a 4-inch line from the pumper and 2 1/2-inch parallel lines to a Siamese on the 2 1/2-inch fill valve on a tanker. Some tankers have two 2 1/2-inch fill valves and a Siamese is not needed. Explore the present possibilities and make use of them. Then determine what specification changes are needed for tankers that will be bought in the future to improve the filling operation.
Filling tankers: There are two basic positions in a tanker shuttle operation. The first-in attack pumper, or tanker-pumper, begins an immediate attack on the fire. The second pumper goes to the static water source—pond, river or other body of water—and is dedicated to filling tankers for the duration of the shuttle. Some departments like to have a front-mount pump available for this assignment because of the ability to nose the pump close to the water. Lines are laid out from this pumper so that as one tanker is being filled, a line (or lines) can be coupled to the next tanker to be refilled.
Stretching fill lines long enough to attach to a second tanker while the first is being filled saves time and that’s the big objective at the fill site. Road conditions establish a static travel time that cannot be cut safely. However, time for a tanker round trip can be saved both at the fill site and the dump site on the fireground. Hooking up the second tanker while the first is being filled is one way to save time. Another way is to design tankers so that the baffles have openings that allow the maximum flow rate for filling while still small enough to provide safety against dangerous water surge on the road.
Dumping the load: The one most important common error in the design of tankers is the failure to provide a large enough dump valve. Fortunately, we are making progress and 4-inch valves are now rather common. The 8-inch-square valve with an attached trough that can drop about 1000 gpm is the best we’ve seen. Such a valve can cut the dump time of a 4-inch butterfly valve in half.
The use of two folding, portable reservoirs with a siphon between them also reduces dump time because a tanker does not have to wait for water to be used from a single reservoir. The additional reservoir also provides a greater margin of safety for the attack pumper’s water supply. While waiting for another tanker, the attack pumper is less likely to run out of water with two folding tanks holding 4000 or more gallons of water than with a single reservoir of half that capacity. If a large tanker is used as a reservoir it should have a rapid-fill capability.
The water supply officer should assign officers to take charge of the filling site and the dump site. These officers must control traffic to these sites—by radio or messenger—so that tankers don’t get bottled up.
Whenever possible, return tankers to the fill site by a route that is different from the one to the fireground. That also will save time by eliminating the need to slow down for oncoming tankers on narrow roads.