Rural Water Supply: the Vacuum Tanker, the Better Way

By Jason Estep

There is always a better way, and those who are most successful in all walks of life are consistently looking to become better, to get an edge, to become the best. This is applicable to all industries, to life in general, and especially to rural fireground operations using tankers.

Let’s look at what we are doing now. We use apparatus with large tanks, usually with a capacity of 1,250 to 4,000 gallons of water. They may or may not have a fire pump. If a pump is present, it generally will have a three-inch tank-to-pump valve along with a 1¼-inch tank fill valve from the pump. It would have a dump valve at the rear. Some have the ability to dump off the side and usually have a 2½-inch direct tank fill valve. Some of the more progressive tankers have five-inch direct tank fill valves. The theory is, bigger is always better, and most counties have one unit named the “Super Tanker.”

(1) Conventional tanker fill sites can be a resource-draining operation. A fully staffed engine company is needed. (Photo by author.)
(1) Conventional tanker fill sites can be a resource-draining operation. A fully staffed engine company is needed. (Photo by author.)

A pressurized water source is needed to refill the tank, whether it is a fill-site pumper or a fire hydrant. The basic tanker design has really not changed in 70-plus years. Sure, safety items and the chassis have improved, but the basic concept is the same. The technology is outdated, yet 99 percent of rural fire departments are still using these tankers on the fireground.

The fire service has been conditioned to believe that the time it takes to dump the water from the tank determines the “efficiency” of the tender. Although dump times are a factor in determining efficiency, the ability to efficiently fill the tanker is what increases gallons per minute (gpm) at the fireground. You cannot dump what has not been loaded. The difficulty in sustaining adequate fire flow in rural communities is often a direct result of the inability to fill tankers efficiently. We’ve already stated that a fill-site pumper must be used to fill the tanker along with three to four firefighters to staff the fill site to hook and unhook lines, pump the truck, and so on. Fill sites must be set up in areas from which the pumper can draft adequate water and that are large enough to maneuver tenders, lay out lines, and so forth. Fill site setup can be time consuming and is often handed off to a mutual-aid company, adding to the time delays. By the way, did I mention that the fill rate must not exceed 1,000 gpm and 100 pounds per square inch, which is the maximum fill rate for a polytank? Failure to abide by this can void the lifetime warranty of the tank.

(2) The ability to self-fill at more than 1,000 gallons per minute eliminates the need for a fill-site engine and the associated personnel. (Photo by Charles Clark.)
(2) The ability to self-fill at more than 1,000 gallons per minute eliminates the need for a fill-site engine and the associated personnel. (Photo by Charles Clark.)

This all takes place to deliver around 95 gpm per tanker to the fireground on a two-mile round trip, so it will take four or five tankers to deliver 500 gpm to the fireground. A fill-site pumper can usually handle only three or four tankers, so another fill-site pumper will have to be used with another three firefighters at the fill site. It can become a logistical nightmare really quickly if not properly managed. It is perfectly understandable that many departments take the “easy” way out and travel back to the nearest hydrant to fill up, wasting travel time and often driving by usable water sources.

For argument’s sake, I know that there are some departments that are very proficient at filling tankers, but if they are open-minded, they will admit that these operations can drain resources quickly. There is a better way!

If we could accomplish and often exceed the same goals with fewer resources, shouldn’t we seriously consider a transition? The technology to do this has existed for the past 25 years and has proven to be successful. What is it? It is the vacuum tanker.

The Vacuum Tanker

A vacuum tanker is unique to the fire service; its roots were in the industrial world. This tanker fills itself by pulling water into the tank using vacuum. These trucks were designed and tailored to the fire service and meet all of the National Fire Protection Association 1901, Standard for Automotive Fire Apparatus, requirements.

(3) A 3,000-gallon vacuum tanker was filling through 120 feet of suction hose during this training session. This water was previously unobtainable in this community. <i>(Photos 3 and 4 by author.)</i>
(3) A 3,000-gallon vacuum tanker was filling through 120 feet of suction hose during this training session. This water was previously unobtainable in this community. (Photos 3 and 4 by author.)

The baffling is constructed so that it not only controls the force of moving water but also strengthens the tank. The vacuum system is designed to allow fill rates that average 1,200 gpm and can approach 1,500 gpm.

No water ever enters the pump; all of the vacuum is created by air flow out of the tank. This air flow can be reversed to slightly pressurize the tank while dumping, allowing the vacuum tanker to efficiently dump 97 percent of its tank capacity. Studies have proven that conventional gravity dump tankers can efficiently dump only 80 to 90 percent of their tank capacity.

Advantages

The major advantage of the vacuum tanker is that it does not require a fill-site pumper. Think of the operational advantages of eliminating an engine company from fill-site duties. With the personnel shortages that departments across the nation are facing, wouldn’t it be great to use that engine and the firefighters at the fireground instead of having them fill tankers? The vacuum tanker makes it a reality.

Fill sites are simple to set up. All you need is suction hose. The cam-lock-style fittings are easy to connect to establish the fill line. I have seen a fill site set up and a 2,000-gallon tank filled in less than four and a half minutes with just one firefighter. (For safety reasons, I recommend a two-person setup; in a pinch, one can handle it.) This paragraph by itself should be enough to justify the superiority of the vacuum tanker.

Think of it in terms of the private business world. We have eliminated the need for a high-dollar capital asset (fill-site pumper) along with the personnel to operate it while improving operational efficiency. This would surely get someone a promotion in the business! The advantages do not stop here.

(4) The vacuum tanker allows you to take advantage of the water sources in your community, many of which often are close to the fire. This vacuum tanker provided all the water for this residential structure fire from this shallow stream.
(4) The vacuum tanker allows you to take advantage of the water sources in your community, many of which often are close to the fire. This vacuum tanker provided all the water for this residential structure fire from this shallow stream.

You can use water you could not use before. You are limited only by the suction hose you carry on the truck. Streams and ponds that lie up to 100 to 120 feet from the road are now usable water sources. Think of the importance of being able to get the water from the farm pond one-quarter mile from the fire instead of driving three miles back to town to fill at a hydrant. This puts adequate water on the fireground quickly, when you need it, allowing you to flow high gpm. This is a game changer for rural fire operations.

Using water sources that are closer to the fire eliminates the need to run an excessive number of tankers on a long tanker shuttle, which makes for a safer operation. Being able to achieve higher flow rates should also equal quicker knockdown, resulting in less property loss and less exposure for firefighter injuries.

The system also allows you to access water in shallow streams without worrying about losing draft if a gulp of air gets into the strainer. A properly constructed strainer will allow you to fill very efficiently in three to four inches of flowing water. This is ultra-important in that you can use the water sources in your community that you may now be driving past.

(5) This shallow water source was used on arrival to supply water to the fireground while another nearby stream was being developed as a water source. Being able to fill from small streams without the fear of losing prime because of sucking air is a great advantage. <i>(Photo by Jordan Kirby.)</i>
(5) This shallow water source was used on arrival to supply water to the fireground while another nearby stream was being developed as a water source. Being able to fill from small streams without the fear of losing prime because of sucking air is a great advantage. (Photo by Jordan Kirby.)

The vacuum tanker can also be designed so that it can perform the same function as a normal fire apparatus. A fire pump can be added, if needed. It can operate from a hydrant, compartments can be configured, and hosebeds can be added. The bottom line is that you can retain the same functionality as your current apparatus while gaining the operational advantage of the vacuum tanker. A normal fire apparatus will never be able to perform with the capabilities of a vacuum. These units are also very competitively priced with conventional tankers.

This is the better way. The efficiencies of filling more quickly, with fewer personnel, eliminating the need for a fill-site engine, dumping seven to 10 percent more water on each dump, and making water accessible in your community set the vacuum tanker apart. A 2,000-gallon vacuum tanker will consistently perform at 170 gpm or greater on a two-mile shuttle, compared to 95 to 110 gpm for a conventional tanker. This has been proven in multiple studies.

This technology has proven to be reliable. It is up to the fire service to learn about it and embrace it. The next time you are in the market for a mobile water supply apparatus, research the vacuum system and the manufacturers that build them. You owe it to yourself and your community to find the better way.

JASON ESTEP is a firefighter with the Morrisvale (WV) Volunteer Fire Department, which has an extensive history of operating on rural firegrounds through the use of tanker/tender operations. Estep has a mechanical engineering degree from Fairmont State University. He developed a course on rural water movement that focuses on moving more water with fewer people.

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