By Wayne L. Eder
Published Friday, April 1, 2011
| From the April 2011 Issue of FireRescue
Regardless of fire service advances in equipment and training, some fire departments still struggle with the concept of moving water in non-hydranted areas. In this article, we’ll explore the basics of the rural water shuttle and how it can benefit your community. I will use the term “water tender,” as outlined in the resource definitions of the Incident Command System (ICS)—not the term “water tanker.”
Before we delve into the different types of water shuttle operations, we should at least briefly address safety issues. First, I strongly recommend that all agencies that operate water tenders review the FEMA/U.S. Fire Administration (USFA) publication FA248, Safe Operation of Fire Tankers. Water tenders are one of the most common fire vehicles involved in accidents, and such accidents often result in firefighter fatalities. Prior to operating a water tender, you should initiate proper training and licensing to prevent injury or death to your personnel.
Be extremely cautious of homemade or modified apparatus that are used as water tenders, as they are often not designed to transport water. Remember: A gasoline tanker is designed to carry a substance that’s lighter than water, so if you fill it with water, it could easily become overloaded. (Gasoline’s weight per gallon is 6.07 lbs.; water’s weight per gallon is 8.34 lbs.) On a 2,500-gallon modified tender, we’re adding approximately 5,675 lbs. to the weight that the vehicle was designed to carry. This can make a significant impact on braking and maintenance issues.
Additionally, shuttle operations often take place along narrow roadways. Setting up to fill and dump on the front and rear of apparatus will help with firefighter safety. Dump valves off two sides and the rear provide additional flexibility in traffic situations. When speccing apparatus, consider two direct-fill valves on the rear of your tender. This allows firefighters to be protected from traffic during fill operations, and it increases your flow rates during filling. Protecting the scene by closing a roadway and using the mandatory Department of Transportation (DOT) traffic vests and other traffic safety devices will provide additional safety to your personnel.
The Nurse Tender
Many progressive and well-trained fire departments still rely on the antiquated “nurse tender” concept, in which a water tender pulls in and pumps directly to an engine company, providing a continuous supply of water until the tender runs dry and must go refill.
There’s a basic formula for water shuttle that must be addressed to help us understand the weakness of the “nurse tender” concept:
Unload or Dump Time (UT) + Travel Time to Fill Site (TTF) + Fill Time (FT) + Return Time (RT) = Total Fill/Dump Cycle
Using this equation, with a fill site two miles away, and basing the travel time on a conservative 35 mph, the total time to shuttle water on a 2,000-gallon tender would work out as follows:
UT (pumped off in 22 minutes) + TTF (6 minutes) + FT (5 minutes) + RT (6 minutes) = 39 minutes
If the pumping engine is using a 500-gallon tank and flowing 100 gpm, it will be empty long before the “nurse tender” returns, thus allowing the fire to spread and placing the lives of both firefighters and victims in jeopardy. This is an extremely inefficient and dangerous process that can be corrected through the use of portable tanks.
The Portable Tank
Many firefighters avoid the use of portable tanks for a variety of reasons (weight, deployment, fear of drafting, etc.), but in the rural environment, the portable tank is your best friend. In the aforementioned scenario, we can improve operations dramatically by deploying a 2,000-gallon portable tank alongside the attack engine. Our new formula would look something like this:
UT (through the dump valve in 2 minutes) + TTF (6 minutes) + FT (4.5 minutes) + RT (6 minutes) = 18.5 minutes
By using a portable tank, we’ve reduced our time by 20.5 minutes and come closer to the 25 minutes of 100 gpm that we actually have on scene. (Note: This is an average and does not take spillage into account.) By adding a second water tender, we can maintain our water supply indefinitely. We can also reduce fill time through the use of a fill station. By using dual fills, we can cut our fill time, saving valuable minutes. By adding a second portable tank or by using a larger portable tank, we can continue to increase our water delivery efficiency.
There are two basic types of portable tanks, the rigid style with a frame and the collapsible “pumpkin” style. Each has its advantages and disadvantages, but for structure fires or large flow operations, it’s hard to beat the framed tanks. By connecting these tanks and using some simple tools, you can greatly enhance your ability to move water.
The simplest way to empty your water tender is via the dump valve. Many dump valves are capable of unloading water tenders up to 3,500 gallons in less than 4 minutes. Pumping off the same amount of water requires additional time due to connecting hoselines and limitations on discharge or tank-to-pump lines. Square or rectangular dump valves have proven to unload faster than round valves. Also consider a larger dump valve. I’ve worked with a tender that had a small dump valve, which totally slowed down a shuttle operation because it reduced flow when placed in with other tenders that had square dump valves.
No matter how many pump operations or hydraulics courses I teach, I continue to encounter individuals who are afraid to draft. Drafting is a simple process that, when done in the proper context, works well for our needs. You should have no problems if you follow your department’s procedures step by step, based on the manufacturer’s recommendations, keep air leaks out and keep your portable tank filled. Many departments throw an inflatable beach ball into the portable tank to keep the venturi from drawing air into the hard suction. If your department works with portable tanks on a regular basis, consider buying low-flow strainers specifically for this type of evolution.
In addition to low-flow strainers and portable tanks, hose holders are used to hold supply hose onto rigid-frame portable tanks—an important safety device if you’re using apparatus without dump valves. This also offers additional flexibility if engines are used to shuttle water as a supplement to water tenders.
In addition, tank repair kits are necessary to repair portable tanks, and salvage covers can be spread out before tank deployment to reduce tank damage from sharp objects. Connector sleeves and tank shut-off clamps assist in joining rigid-frame tanks to increase your water storage capacity.
Practice makes perfect! Pull those tanks out quarterly and practice all of the steps to conduct a rural water shuttle. Be sure to document all training in a training report, as this will pay big dividends during an Insurance Services Office (ISO) evaluation.
Following the training, each member of the department should be able to successfully complete all of the tasks associated with a shuttle:
- Fill site set-up
- Dump site set-up
- Hard suction/strainer deployment
- Dump valve operation
Pump operators and water tender operators should be proficient in pump operation, drafting and apparatus maneuvering. Many departments specify dump valve controls in the cab so drivers don’t need to exit the vehicle to dump the load. This also saves valuable time that can be shaved off of our total fill/dump time.
Are you looking for additional information on improving water shuttles? Check your favorite fire equipment catalog for the latest information on portable tanks and tools. The National Fire Academy Learning Resource Center (NFA LRC) has multiple research projects on this subject and, of course, check your department’s standard operating procedures. Improving your fire flow can keep your personnel safe and reduce fire loss in your community. Why not learn how to do it effectively?
Until next time, stay safe!
The Water Supply Officer
Appointing a water supply officer (WSO) to manage your department’s water shuttle program will greatly enhance your ability to shuttle water. This individual will have responsibilities before, during and after a shuttle operation.
Prior to an incident, the WSO will pre-plan fill and dump sites, inspect portable tanks and other equipment, and train personnel in shuttle procedures. This position will fit into the Incident Command System, typically reporting directly to the operations section chief. The WSO can use the following resources to prepare for their responsibilities:
- NFPA 1231: Standard on Water Supplies for Suburban and Rural Fire Fighting
- FEMA FA 248: Safe Operation of Fire Tankers
- Insurance Services Office (ISO) Public Protection Classification (PPC) Program
Become familiar with how the ISO evaluates water shuttles and how they measure fire flow capabilities through shuttle. Contact your local ISO office for additional information.
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