Archive for the ‘Fire Fighting’ Category

Everyone likes the Fourth of July–fireworks, food, and fun. For some of us, it’s a time of hard work, thrills, and sometimes danger.

For the past seven years, I have been a professional pyrotechnican working in the fireworks display industry.

The BATF—Bureau of Alcohol, Tobacco, Firearms and Explosives, abbreviated to ATF has defined various classes of fireworks. Consumer fireworks are most often classified as Class 1.4G—stuff you can buy in stores and shoot in your back yard—state and local laws permitting.

Most display fireworks are classified as Class 1.3G. I have a federal license to posses and shoot Class 1.3G fireworks as long as I am working for the display company that sponsored my license.

Now that the legalities are out of the way, let’s get to the fun stuff!

Fireworks

The cone at the bottom of a typical shell is where the lift charge is located which is simply a bag of black powder enclosed in a protective cone of cardboard.

five inch shell

Tied into the bottom of the shell is quickmatch which is black match—cotton string covered or soaked in black powder that is enclosed in a paper tube or plastic tube all along the whole length. The tube forces the fire down at a very high speed (approximately 30 feet per second). This is what we light to “lift” the shell from the mortar, either electrically or by fire.

quickmatch

quickmatch closeup

You can see the blackmatch in the close up above.

The whole shell is wrapped in craft-type paper secured with glue.

On the top is a loop of string that is used to keep the quickmatch in the right place and in larger shells is used to lower the shell into the mortar.

To lift a shell, you need a mortar. They come in various sizes and are often held together to accomplish certain effects—the one below is called a finale rack—a series of mortars tied together that all lift shells at the end of a show.

finale rack

As you can see, there are several different sizes and the company I work for has a few of them.

mortar storage

Single mortars are what you see below and are often buried into the ground to stabilize them.

mortar

And, they come in a wide variety of sizes.

single mortar storage

big mortar

Our mortars are constructed of fiberglass which doesn’t cause the shrapnel problems if they blow out like the old steel mortars. They are also cheap to make and are lightweight.

mortar closeup

Shells blowing apart mortars happens more often than you would think and makes for an exciting experience when you are close to them.

This is why we wear protective clothing: it’s mandatory that you wear blue jeans, a cotton shirt, a helmet with a face shield and ear protection, gloves, and safety glasses.

safety gear

The most complex of shows to set up and shoot are electrically fired. Some shows are also required to be electrically fired—like those set to music and every barge shoot.

wired barge

The shells are ignited by an electric match which, when an electric current is applied to it, ignites a combustible compound. Think of a model rocket igniter but much more powerful.

e-match

The matches are wired into slats which are screwed to the top of the mortar racks.

slat

slat closeup

The slats plug into cables.

slat cables

As you can see, it takes more than a few cables to wire up the shows.

The cables are plugged into a firing panel.

firing panel back

Firing panels come in a wide variety of configurations and sizes, some small:

small firing panel

Note the battery cables—most shows are fired using a car battery.

And some large-bigger shows are fired with larger panels.

100 shot firing panel

You may only notice that there are fifty switches. There are two banks. When you’ve fired the first fifty-shells, you flip a switch and you can shoot the second bank of shells.

bank switch

The really difficult part is making sure that the shells will fire when you flip the switch. There is a test function on the firing board which you can see below.

test and firing switch

There is an LED over each switch and if it doesn’t glow when you hit the test switch, then you have to figure out what is wrong with the circuit which can be very tedious to track down.

firing switches

Once the shells are loaded, wired, tested and otherwise ready to go, you can sit back and enjoy the show.

Next time we get to my favorite way of shooting a fireworks show—hand fired.

 

Today, you are going to learn how to run a fire apparatus pump. It isn’t as hard as you think and the steps are almost universal among all apparatus pumps. Naturally, there sometimes are more steps involved, and details like priming the pump–if needed, and proper settings of the throttle, but this should give you a rough idea as to how it’s done.

Who runs the pump? That’s easy, the person that drove the apparatus. Often called the engineer, they are responsible for getting the crew safely to the fire, placing the apparatus where it is most effectively used, and all aspects of pump operations including charging hoses, water supply, and making sure that the crews have sufficient water at an appropriate pressure to effectively fight the fire.

drivers side

Yes, it looks like something from Star Trek, but most of the switches are for emergency lights and radios.

The first step is to provide power to the pump. Usually, this is done by a PTO—Power Take Off.

On our Engine One, you put the apparatus into neutral, put the parking brake on, flip this switch, and then put it into drive. Yes, that means where you stop is where you pump. Some apparatus can “pump and roll,” but that’s a subject for another day. When the green lights come on, you can move to the pump panel.

pto

Engine One’s pump panel is used in this example.

pump panel

Another part of the engine that looks like it’s from Star Trek, but it isn’t that hard to run.

The second step is to get water to the pump. There are several potential sources ranging from hydrants to drop tanks, and other apparatus and all are handled in different ways.

For illustration purposes, let’s use the internal water supply of 1500 gallons from Engine One. It’s one lever. Move it all the way forward, slowly.

Step three can be a bit tricky—provide water to the hose. To make it easier, our department has color coded tags everywhere. Say the crew wants to use the blue pre-connect, they grab the blue hose, and check the blue tag above the hose tray to make sure the color matches which line they want charged.

Up on Blue

blue pre-connect

And on the pump panel, you see a blue tag, and a name on the hose your attack crew should have in their hands. “Up on blue!” would be the command to charge this hose with water. Again, you want to do this slowly. Everyone, be it the engineer to the attack crews must open and close their nozzles or valves slowly to prevent something called, “water hammer” where the sudden change in pressure could rupture a hose or damage the pump.

Hint, make sure the hose is completely out of the tray before charging it with water as expands to the point where you can’t get the hose out. Generally, you have to cut the hose to pieces to get it out which is very embarrassing.

The final step is to build pressure to the hose you have selected. This is done by a hand throttle on the pump panel.

hand throttle

This controls the throttle to the pump and the pressure of the water to the hoses. The red button in the middle is an emergency shut down.

Almost every aspect of the pump is connected to a gauge, making it a bit easier to see what you are doing.

gauge

How much pressure you use is dependent on the size of the hose. Say you have an 1-3/4 hose, generally it will have 100 PSI or so of pressure. Yes, you can stuff 275 PSI down it, but the attack crews will be screaming at you as the line will be uncontrollable.

That’s it, four steps to pump water from a fire apparatus. It doesn’t matter if the pump panel looks like this:

t4 pump panel

Or is a completely computer controlled system like what is on our Squad 3:

S3 pump panel

The new systems can do almost everything short of ordering you pizza, but I still like the old way of doing things as that is what I learned on when I joined the fire service.

That’s roughly about all you need to know how to pump water from fire apparatus. It isn’t that hard, is it?

Joe Collins is a twelve-year veteran firefighter/paramedic in the busiest volunteer fire department in our county. He holds numerous fire and EMS certifications—many of the same as professional firefighters. During the day he works as a Critical Care Paramedic in the highest call volume EMS service in Iowa.

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Want to learn more about firefighters and firefighting equipment? The Writers’ Police Academy features an on-site, working fire station. You’ll have to opportunity to see, touch, and try on the gear!

http://www.writerspoliceacademy.com/

 

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