When firefighters hear the term engine company operations, we often think of hoses and nozzles, advancing hoselines, and applying water to the fire. As exciting as that all sounds, and it is, there is more to engine company operations than just those items.
One of the areas of this discipline is establishing water supply. This can be from a pressurized source such as a hydrant or from a static source such as a portable water tank or body of water. Hitting a hydrant is going to be the easiest and quickest form of establishing a water supply, but not all hydrants are going to be the best solution to the problem.
In certain districts, municipalities, and response areas, there may be hydrants, but they may on supply low pressure and flows. If we refer to the NFPA hydrant coding chart, a red hydrant is going to be one that supplies less than 500 gpm. A blue hydrant will be the best supplying at least 1,500 gpm or more, with green supplying between 1,000-1499 gpm, and orange supplying between 500-999 gpm.
The key is to color code the hydrant, and this requires testing the hydrants on an annual basis to determine flow rates and pressure rates. Some fire departments will do this along with the local water department or public works department. When the responding fire department knows what their hydrants are going to supply, this will be beneficial in determining whether to hit the hydrant or maybe supply their own water with a draft water operation.
Drafting Options
There are times when drafting water from a static source is better than using a low-flowing hydrant. Drafting operations are not considered sexy or fun but they can be a valuable way to supply water. When it comes to drafting water, there are multiple ways of setting up the operation to best suit the department’s operations and resources and meet the demands of the incident scene.
One option is to employ a single portable water tank that may be able to hold 1,000-1,500 gallons right next to the engine. This can easily be set up by one firefighter with water being dumped in from another water tender or tanker (depending upon local terminology). The one porta-tank can supply two handlines flowing 150 gpm each for about five minutes if using a 1,500-gallon tank. If only one handline is being used initially, the flow time will increase taking into consideration the initial engine’s on-board water supply.
Another option is to use multiple porta-tanks to supply water. In photo 1, two porta-tanks are set up to allow for a more efficient operation. In photo 2, we can see three porta-tanks set up. There is no limit to the number of portable water tanks that can be set up except for the space available to set up multiple tanks, the availability of water tanks, and the ability to have enough water tankers or tenders shuttling water from fill site to dump site.
The benefit to having multiple porta-tanks is the amount of water available to draft from to supply the overall operation and the ease in keeping them filled during the operation. Depending on the location of the incident and the water supply site, dumping the water into the porta-tanks will be dictated by the water tankers dump chutes and the access to the porta tanks.
In photo 2, you can see how the three porta-tanks have been set up. This allows for the tanker to back in (due to the location of the incident) and dump the water either to the side tanks or the tank right behind it. In other situations, the porta-tanks can be set up to allow for simultaneous tankers to stop and dump their water into the porta-tank.
Sometimes drafting the water from the rear of the engine or from the front of the engine will be the best approach. As pictured in photo 3, two porta-tanks are located side by side behind the engine. In this situation, water tanker shuttles can proceed with ease given the laneway serving the house in question.
Additional Considerations
A fire department must be proficient with setting up these types of operations, which includes the ability to transfer water from the dump tank into the drafting tank. In photo 1, you will see a simple but effective way to transfer water from one tank to the other. Using a jet siphon at the bottom of the red tube creates a vacuum to siphon the water to draw it up from one tank into the other. There are other ways to create or set this up with different configurations from other manufacturers that will provide the same result.
The jet siphon can be controlled to by the pump operator to be a slow, constant refill or a quicker refill based on the amount of water being drafted. The one consideration is to ensure that the drafting tank isn’t overflowing with water, wasting it on the ground. When there are multiple porta-tanks lined up next to each other, each one can have a jet siphon operation set up so that constant water is being transferred from one tank to the other as it is being re-supplied.
In photo 1, notice also that there’s a hoseline with a nozzle on the end of it positioned at the corner of the water tank. This is to allow the pump to flow water constantly when the handlines are shut down so as not to overheat the pump.
This month the focus is on engine company operations, and even though supplying water from a portable water tank is not the most exciting topic to look at in this discipline, it is just as essential to knowing how to maximize the flow from a hydrant. Drafting water operations will benefit firefighters when they know how to set it up and operate it—and this comes only with regular, consistent training.
Mark van der Feyst has been in the fire service since 1999 and is a firefighter with the Fort Gratiot (MI) Fire Department. He is an international instructor teaching in Canada, the United States, and India, and at FDIC. He is also the lead author of Residential Fire Rescue (Fire Engineering Books & Video). He can be contacted at Mark@FireStarTraining.com.
