Many firefighters are accustomed to using “wet” hydrants, or hydrants supplied by a pressurized water source. For some departments, it’s so routine to fight fires and handle other incidents using these types of hydrants, that they’ve become unconcerned about arriving at an incident where public water isn’t readily available. Some departments may become so complacent that they remove the hard sleeves (drafting hoses) from their apparatus, as the hard sleeves are rarely, if ever, needed.
Other firefighters, who serve in districts that are many miles from the nearest “real” hydrant, need to quickly and easily access water from ponds, creeks, rivers or other alternative water sources, and therefore carry a variety of tools and equipment to accomplish this task.
Sooner or later, almost all firefighters will face the need to pull water from something other than a standard “wet” hydrant. Even if most or all of your district is equipped with standard hydrants, the potential always exists for the water supply system to malfunction or provide a supply that simply can’t match the required fire flow for the given incident. In these cases, drafting may provide the only alternative to getting the water needed for the firefight.
Firefighters may also find it necessary to draft from floodwaters to move water elsewhere, or to prevent buildings from flooding. In these cases, firefighters and apparatus operators need to be prepared to conduct drafting operations–and not the kind of “drafting” seen in NASCAR races.
If you’re setting up a drafting operation, you likely need to flow a good amount of water for an extended amount of time, and you’re probably facing a serious fire that requires water in a hurry. At the same time, flowing a lot of water quickly might just make a good knock on the fire, preventing a campaign-style firefight.
Like many other things in this business, setting up a drafting operation requires both speed and effectiveness without sacrificing one for the other. The equipment you carry must facilitate this, and your personnel must be trained to achieve it.
Where’s the Water?
First off, knowing before the incident occurs where you can go to draft will have a great impact on how quickly you can deliver water to the incident scene. If you have to take the time to search for accessible drafting sites while the incident is developing, you’ll delay the delivery of a continuous water supply to the fireground.
Once you’ve located accessible drafting sites, clearly identify their locations on maps/preplans and share the information with mutual-aid departments. On major incidents, water supply may need to be a part of the planning section, but the planning section chief will need something to work from.
Also important: Consider how you would access the draft site under all weather conditions, such as drought, snow, ice, etc. Specifically, consider how to cut through ice to access the water, and how to protect your firefighters from falling into the frigid water.
If the site is accessible enough, can you drive your apparatus right up to it, or even partially into it, and get two suctions into the water? Doing this will maximize the gpm that you’re able to supply from the site.
If you don’t have a drafting site, but you do have an accessible creek, is it possible to build an impoundment on the creek for fire water supply? During an incident, you can build an emergency dam out of ladders and salvage tarps; however, for regular firewater impoundment, you’ll most likely need permits to build it, and you’ll still only be able to sustain a draft at the gpm that the creek flows.
Proximity Problems
One of the major challenges with drafting is getting close enough to the drafting site to use it effectively. Remember that mobile centrifugal fire pumps are designed to draft at 10 feet of lift maximum. Although these pumps may be able to produce a flow greater than this, you may also achieve a flow that’s less than the rated capacity of the pump.
That said, draft can be pulled at greater than 10 horizontal feet from the source, as long as the total vertical lift approximates 10 feet or less. If enough hard suction (or piping for a dry hydrant arrangement) is available, you can position pumping apparatus 60 feet (or more) away from the water source, but all of the hose connections must be extremely tight to avoid air leaks that can limit or prevent a successful draft–and hand-tightening the connections is usually not enough to avoid this. To properly tighten connections, apparatus that need to draft should carry a rubber mallet.
Using Dry Hydrants
As mentioned earlier, preplanning will make things much easier during an incident, particularly when it comes to dry hydrants, because they not only need to be installed properly, but they should also be capable of flowing at least 1,000 gpm. Usually, this means you’ll need at least 6″ piping for the dry hydrant.
Think carefully about the fittings on the dry hydrant. Quite often, a male fitting is provided, but you’ll then need a double female adapter to connect the apparatus to the dry hydrant, which takes up time and effort when making the draft. Installing a dry hydrant with a female outlet doesn’t require an adapter, which expedites and simplifies the set-up and operation. Eliminating adapters also reduces the potential for air/vacuum leaks that can disrupt the draft.
Ensuring that your dry hydrants are standardized is also important. Older dry hydrants may have 4½” or 5″ fittings, while newer ones may be equipped with 6″ fittings to complement the hard sleeves that fit today’s larger pumps.
Tip: Be aware of alternative water supplies, such as cisterns, and spend time preplanning how to use them. Some areas install cisterns or other water tank arrangements that may be connected to what looks like a standard hydrant, but it must be opened and requires drafting to operate. In other cases, dry hydrants may be located below the surface of an impoundment, which may require a valve or other arrangement that will need to be opened to access the water supply.
Suction & Strainers
If you have to draft, be sure that your apparatus is set up to do so. The newer, lightweight suction hose is not only very flexible (a huge improvement over the old, solid black hose), but it’s also transparent, which allows apparatus operators to observe water movement through the hose and watch for any air leaks.
The standard for hard suction is two 10′ lengths, but in many locations, more is needed. Engine companies that have many opportunities to draft often carry three 10′ lengths. This allows them to draft easily from at least two intakes to maximize the potential of larger pumps.
Some apparatus are set up with what is known as “squirrel-tail suction,” which is flexible suction hose that’s preconnected to suction on the apparatus. To draft using this type of hose, you simply drop the suction hose in a static water source; no connections are necessary. The Tokyo Fire Department (and other departments in Japan) uses cisterns extensively for water supply, so many of their engines are set up with squirrel-tail suctions to facilitate drafting from them. Engines with all-wheel-drive and front suctions can also usually access and use many static water sources.
Besides the suction hose, you’ll need a good strainer (or two). The standard barrel strainer is nice, but it needs to sit on a ladder or other piece of equipment while in the water to avoid picking up mud or silt from the bottom of certain water sources, such as a stream or pond.
The floating dock strainer is more effective, but it requires more storage space on the apparatus (newer models take up less space than the older ones). It sits on the water’s surface, which almost completely eliminates the potential to pick up mud or silt, but it can be pulled downstream and/or to the side when in a moving body of water, such as a stream or river. To avoid this, you may need to anchor the floating dock.
If your department uses tanker shuttles with dump tanks, you’ll need low-level strainers that can use the maximum capacity of the dump tanks. In some departments, the low-level strainers are carried on the tankers and left at the dump site, which allows any engine with the proper size suction hose to operate there. Remember: No matter which strainer you use, it must be fully submerged to be effective.
The temptation is great for departments with wet hydrants to eliminate hard suction and strainers from their apparatus; however, more than once I’ve seen an apparatus with no hard suction arrive at an incident where they unexpectedly needed to draft water. When resources are plentiful, apparatus can be shuffled so that those equipped for drafting can do so, but when resources are limited, any missing drafting equipment can prove costly.
Other Drafting Techniques
If a good water source is present, but it’s difficult to access via mobile apparatus, there are alternatives to dry hydrants. Portable pumps can pump up to 400 gpm, and some are designed to float on a body of water, much like floating dock strainers. However, they weigh more than 100 lbs. and take up a lot of storage space on the apparatus.
Smaller, all-wheel-drive apparatus with on-board pumps might be a better alternative. Turbodraft apparatus, which are essentially an eductor device that can access remote water supplies, can supply 280—670 gpm, from distances of 50—200 feet and with a lift of 10—20 feet, depending on the pressure pumped to it.
Conclusion
Any area where hydrants aren’t readily available or where hydrant water is limited necessitates drafting operations. There are a number of different ways to accomplish drafting operations, but each one of them requires planning, the right equipment and continuous training. Water is critical to most, if not all, firefights–make sure your department doesn’t become complacent. Make sure it’s fully equipped and ready to provide water where and when it’s needed.
Drafting Reminders
Here are a few things to keep in mind if your department must perform drafting operations:
- If you can access water supplies on private property, draw up a written agreement between the fire department and the property owner that outlines how often and under what conditions the fire department can use the water source.
- All draft sites should be checked at least once a year to ensure conditions are suitable for access, and that the depth of the water is still appropriate for drafting.
- Dry hydrants should be flushed and tested at least twice a year to not only ensure that they’re working, but also to get full ISO credit for them.
- If you’re interested in improving your rating, the ISO wants data on how quickly your apparatus can drive 200 feet to the draft point, set up a draft and establish full flow. This would also be a good exercise for your personnel to conduct to establish a benchmark and to determine if you have the proper equipment to make it happen.
