Portable master streams give firefighters more options, better access to fires

Master streams were one of the first tools firefighters used after graduating from the bucket brigades. Early hand pumpers and steam pumpers were often equipped with a mounted nozzle through which firefighters could direct water. In many cases, this was the only mechanism firefighters had for applying water, as hose was not available or practical. Many a fire was fought, and probably even extinguished, with these devices. Today, the master stream is more versatile than ever because we can move it beyond the apparatus with hoselines.

PHOTO GORDON NORD, JR. Portable master streams give firefighters more options, better access to fires When putting a portable master stream into position, make sure all legs are properly extended and the anchor is suitably placed.

THE PORTABLE DESIGN
Portable master streams are designed for transport so firefighters can charge and operate them where needed. Several inlet options are available, including dual 2 1⁄2" or 3" lines or a single 4" or 5" line, and typical flows can reach up to 1,250 gpm (4,750 lpm). The size of hose feeding the master stream depends on the gpm needed, the distance the device must deploy to and the amount of pressure the pump and hose can handle. (For more information on master streams, see Paul Shapiro's "Engine Pressures" columns, January – June 2004.)

There are a number of different portable unit models, including lighter-weight units that flow 500 gpm (1,900 lpm) and heavier, bulkier units that provide larger flows. Of course, there are tradeoffs; the smaller units are easier to handle, deploy and store in hosebeds, but they provide less flow.

DO YOU NEED A MASTER STREAM?
I previously discussed hoseline and nozzle selection based on existing fire conditions and the potential for fire spread. The bigger the fire, the more water you'll need to extinguish it. Heavy fire conditions generally require the "punch" that a master stream device can provide, because these conditions show little sign of abating when we apply smaller handlines to them.

Most experienced fire officers instinctively know when they need a master stream device. Fire officers with less experience must make more of a judgment call. Generally, a house or building with one floor involved or fire showing at more than three or four windows will necessitate a master-stream attack. Other situations that may be suitable for master-stream application include:

• Quick knockdown situations;
• Defensive/offensive ops — hit the fire for a minute from the outside while the crew is preparing to enter;
• People trapped — use the master stream to keep fire away from trapped victims while preparing for and/or performing a rescue;
• Minimum manning situations — you can quickly put a portable master stream into service with two or even one firefighter to hold a position while other tactics are being prepared;
• Exposure fire — apply a fog nozzle directly to exposed buildings/tanks/equipment, but do not put up a water curtain, as this is generally ineffective against radiant heat; and
• Hazmat vapor release — use a fog nozzle to break up the toxic cloud, and dike water runoff.
  Even if existing fire conditions do not call for application of a portable master stream, the incident commander should consider placing them in crucial positions in case the fire spreads quickly.

USES & APPLICATION
Uses for portable master streams are many. Firefighters can deploy them into a warehouse to support protective openings in a firewall, or into high-rise buildings to allow heavy attacks on well-involved floors. We can also use them to continually apply water in extended operations, such as salvage-yard or debris-pile fires. When using portable master streams, you are limited only by your imagination and the capabilities of your equipment.

Applying the stream in the right place is key to a successful fire attack. The portable device can move into positions that a fixed device on a piece of apparatus cannot; therefore, you must decide the size of the device and how many to carry. As mentioned, the newer, lighter-weight units can stow easily in a hosebed (but you must secure them to meet new NFPA safety requirements), while the larger-capacity units require a larger "footprint," such as on the back step or on a flat overhead surface, to mount them. Some departments mount them in compartments; the newer folding guns lend themselves to this type of storage.

PHOTO GORDON NORD, JR. Remember to place portable streams on a flat, level surface, such as asphalt or concrete, and position them close enough to effectively extinguish the fire, but far enough away from potential hazards.

SAFETY ISSUES
Although portable master streams are far more versatile than fixed devices, they also come with their own set of operational challenges. When deploying a portable master stream, keep the following safety points in mind:

• Backpressure: Portable master streams flow a large amount of water and can accumulate a great deal of backpressure; therefore, if they are not properly anchored, they can become deadly. Controlling the device and holding down the equipment should not be left to firefighters. Instead, manufacturers recommend that crews secure the units via a strap or chain to an immovable object located in front of the gun, which can be a bit of a challenge on the fireground. If you must move the gun to one side or the other, you might need additional tie-downs.
• The angle of water delivery: Many portable guns feature a stop pin that will not allow the nozzle to drop below a certain angle, thus keeping the back pressure a bit under control. But the higher the location of the gun, the more difficult it may be to lower the angle of attack.
• Location: The device must be located close enough to the fire to be effective, yet far away enough to be protected from potential collapse sites, explosions or hazmat hazards, unless it will remain unmanned. The device should also rest on a smooth, level surface; dirt, grass or ground is preferable to asphalt, and asphalt is preferable to concrete due to the friction factors involved in the ground surface.
• Water weight: Firefighters must also remember the weight of the water being applied. A 500-gpm device applies 1 ton of water per minute, while a 1,000-gpm device applies 2 tons of water per minute. This is a great deal of weight to add to a structure, so officers must be aware of the potential for a subsequent collapse.
• Operation: When the device is put into position, make sure all legs are properly secured and extended, and the anchor is suitably placed. If the device comes with a shut-off valve, leave it shut until the line is charged. Once charged, open the valve slowly to avoid a water surge, as well as to control the device from reacting to the nozzle force. Follow all manufacturer's instructions for operating the equipment.

A FINAL WORD
Master streams have served a vital function in the fire service for many years. The portable master stream allows for even more versatility and utility, and the wide selection of modern devices gives fire officers many different weapons to choose from. These devices will continue to provide options for us to effectively control incidents, as long as we understand their limitations and how to operate with them safely.

Greg Jakubowski is a fire protection engineer and a certified safety professional with 27 years of fire-service experience. He is a Pennsylvania State Fire Instructor and serves as a captain with the Lingohocken Fire Company in Bucks County, Pa. Greg is also a principal in Fire Planning Associates, Washington Crossing, Pa., a company dedicated to helping fire departments and businesses preplan for emergency situations.