By: Jim Sandas
VPS windows come in different styles depending on the anchoring system. The two most common types of these windows are the utility and perforated models, and can either be installed vertically or horizontally, depending on the on the size of the opening. The VPS perforated windows can be installed by a system of cables or rods secured to the face of the window and attached to a uni-strut, a metal bracing device attached to the inside of the building. A steel cable is strung through the top of the VPS, through the uni-strut and attached to a tightening mechanism. It is restrained by either a cable or threaded bolts.
Other VPS windows are installed using a crossbar attached to the window with a spring-loaded side pin. This crossbar is attached to the uni-strut, which is then attached to the inside of the building. It is also restrained by either a cable or threaded bolts. VPS windows are installed by using steel channels, which are fitted at the top and the bottom of the window opening. On both the top and bottom of the window, a steel bar is attached to the window covering with pins. The pins are attached to the bar and inserted into the slits on the side of the window covering.
There's a handful of basic firefighting tools required to gain entry in situations involving VPS windows, including a saw with a 14 inch metal-cutting blade, a Halligan tool, a flat-head axe and either ground ladders or a platform ladder/tower ladder to work from on upper floors. If you're first on the scene, inform the incident commander so the chief can gather the needed resources and develop an attack plan for buildings protected with VPS.
After that, there are a number of steps a firefighter must take before getting through a VPS window. Primarily, a firefighter must determine where the VPS unit is attached to the frame. These points are usually visible on the face of the VPS window. These attachment devices can either be metal tabs, metal rivet fasteners or threaded anchors. These attachment points will indicate the use of cables or rods which connect the VPS window to the uni-strut which is attached on the inside of the building. The number of attachment points will indicate the number of cables and rods used to secure the VPS window.
Usually there are 4 attachment points — two at the top and two at the bottom.
• METAL TAB
• METAL RIVET
• THREADED ANCHOR
If firefighters are operating at night or operating with poor visibility, determining the location of and type of attachments points can be difficult. The best thing for a firefighter to do is locate the spring-loaded pins, which can be found on the sides and bottom of the VPS window.
EXTERIOR REMOVAL OF WINDOW GATES:
After locating the pins, there's a number of ways a firefighter can gain entry through the VPS windows. The first method is locating the bars on the top and bottom of the window. They are usually located on the outside of the system. Starting with the bottom bar, use a metal-cutting saw with aluminum oxide blade to cut the bar approximately 6 inches from the edge of the window. Repeat the process on the top bar of the VPS window, using a ground ladder for stability if needed. A third cut may be required at the opposite side of the window bar. Don't attempt to cut the VPS down the middle; if a firefighter attempts to cut the crossbar in the center, it will cause the crossbar to bind on itself.
Remember, when using a metal-cutting saw, always take proper safety precautions. Wear proper protective equipment including eye protection, and if you're operating a powered saw from a ground ladder, make sure the ladder is angled properly and you do not over extend your reach. Never allow a firefighter to be positioned directly under the window system. With this three-cut method, the window gate will dangle rather than drop, but once the top cut is complete, the window system may fall with little warning. These window gates can weigh up to 75 lbs. and can easily hurt anyone below it.
Another way of entering through a VPS window involved using the metal-cutting aluminum oxide blade saw to cut the anchor points free. Starting with the lower anchor point, place the saw at a 90 degree cutting angle and cut completely through the fastener. Once the cut is complete it will free the VPS window. Remember, start at the bottom and work your way to the top, otherwise the window could fall.
Another method of removing a VPS window secured with springloaded side pins from the exterior is by using a rabbit tool (also known as a Hydra-Ram). Place the solid part of the tool against the building allowing its jaws to be positioned slightly above or below the springloaded pins on the side. If the VPS window has pins located on the top and bottom, place the device to either side of the pin. Pump the device until the VPS window is released from the crossbar. Once this is complete, proceed to the next crossbar and repeat. A Halligan tool may be needed as well.
Another method of gaining entrance through a VPS window deals with the perforated window gate, which has either metal rivets or threaded anchor. Using the pike end of a Halligan tool, punch a hole which is in close proximity to either the metal rivet or threaded anchor. Do not strike the pike end directly on the attachment point. Punch the pike end through the window gate, making a hole just large enough for the anchor head to pull through and release the VPS window. A firefighter can also strike the pike end of the Halligan tool directly on the side pin. Using either a flat head axe or maul against the Halligan tool, drive the side pin through the hole. If that doesn't work, try to drive the pin from the opposite side of the window gate.
Another way of gaining entrance involves wedging the adze end of the Halligan between the window gate and the building, either above or below the crossbar pin. Prying the window gate away from the building should free the crossbar pin. You can also repeat the same action to free the top crossbar pin. Once the top is complete, the window gate will open like a door using the two opposite crossbar pins as hinges. However, this method is very time consuming and tiring, so it shouldn't be a primary choice.
INTERIOR REMOVAL OF WINDOW GATES
Just like exterior removal of the VPS windows, there's a number of ways to take the window down from the inside. Either a Halligan tool or a flat head axe can be used to strike the metal hanger bars in the middle several times. That will cause them to move and release the windows. Once this is done, the entire channel can be turned sideways and the VPS cover removed. A firefighter must have a firm grasp of the window, and, if possible, more than one firefighter should help remove the cover by pulling it into the building instead of allowing it to fall outside which could cause possible injury to those on the exterior of the building. When removing this device, remember that the cables used to secure the VPS are under tension. It may be easier to pull the device as opposed to cutting the cables, which may cause them to snap and injure a firefighter.
Another method of removing the window system involves attacking the cable tension system. The cable tension system may be attached either by a threaded fastener or metal rivet. Always start with the lowest one first. Place the adze end of the Halligan behind the cable-tensioning device and pry it away from the bar. Next, take out the adjoining side the same way. Once that's complete, slide the crossbar up and out of the way.
There are several types of vacant property protection systems on the market, and there's various techniques of gaining entry into a building that works on one system, but may not work on another. Remember to take into consideration that these systems may prolong vent, entry and search operations during a working fire. When performing outside activities or performing building inspections, companies should take time to plan fire tactics pertaining to these buildings and unique problems they present. By having a planned strategy, firefighters can ensure that they will not be caught short.
If your fire department has a Critical Information Dispatching System (CIDS) or computerized pre-plans, make sure you mention the structure has VPS windows, and that will warn arriving units of the upcoming obstacles. It's also a good idea to hold drills to familiarize units that may not be familiar with these systems.
By being prepared, we can prevent and minimize injury to our firefighters and gain entry more effectively.