Thread: Truck Opps w/ lightning
08-12-2002, 10:09 PM #1
- Join Date
- May 2002
Truck Opps w/ lightning
This may be a pretty stupid question but I am an explorer and I am not going to act like I know everything like how most other explorers act. Im still learning here. But anyway, what do you do when you have a fire during a lightning storm and the roof or and upper window needs to be vented? Do you still put the truckies to work and pray that they dont get struck? Or is there another way of venting that I dont know about that could be used?
08-13-2002, 09:10 PM #2
- Join Date
- Jul 2002
what do you do when you have a fire during a lightning storm and the roof or and upper window needs to be vented? Do you still put the truckies to work and pray that they dont get struck?
You learn by asking. Never be afraid to ask a question. I think some of the truckies that live in the midwest or the east are better suited to answer your question specifically regarding the lightning storms. We dont have much in the way of storms here in the desert.
But, depending on the circumstances, you do have a some options other than placing the stick up, or people on the roof. You could use positive pressure ventilation, horizontal ventilation, or if your on the interior, hydraulic ventilation. But like I said, everything depends on the senario your facing.
08-22-2002, 03:10 PM #3
- Join Date
- Aug 2002
Every once in a while we will look up and note the pretty lightning.
08-22-2002, 03:21 PM #4
- Join Date
- Oct 1999
- Why? It's not like you're going to visit me! But I'm near Waco, Texas
i've only run into the situation once and we didn't put anyone on the roof top. granted the metal roof had a lot to do with the situation.NREMT-P\ Reserve Volunteer Firefighter\Reserve Police Officer
Experts built the Titanic, amateurs built the Ark.
09-16-2002, 02:01 PM #5
- Join Date
- Nov 1999
In that instance you be very careful. Ha Ha. Seriously though, for the roof use your judgement. If there are trees or other structures nearby that are taller than the roof of the fire building then its a gamble. Determine if you must go up top or if there is another way. If you do op to go to the roof don't throw the aerial or ground ladder ANY higher than necessary to get roof access. Get up quickly, open it fast and get the hell off. As for the upper windows you can take them out from the inside, the fire escape, drop a ground ladder into them, tool on a rope from the ground or an above window, etc. Just some thoughts.Stay low and move it in.
09-27-2002, 04:57 PM #6
- Join Date
- Dec 2001
Questions from "explorers" that are kind enough to say that they are not the type of explorers that know everything!
In any event, I know of and know there must be more records of injuries and fatalities of both civilians and firefighters that were suffered and directly caused because there was no adequate vertical ventilation during an interior aggressive attack on a combustible building in which there was a fire while occupied. Either No Ventilation, Inadequate Ventilation, Improper Ventilation, Or in the case of vertical - incomplete ventilation (more on this one if you ask)
I don't know of one firefighter injury caused by lightening during his or her roof operations for vertical ventilation nor do I know of any civilians injured during a storm that were taking refuge from the fire on the roof area or escaping that way.
Aside of all that, during humid conditions (rain storms) ventilation effects are greatly reduced and we need all we can get.
10-10-2002, 10:32 PM #7
- Join Date
- Mar 2000
- PA, USA
say a little prayer and get you...butt...up on the roof.
10-11-2002, 08:44 AM #8
We had this situation year and half ago. We put 2 aerials up during the storm. Guys in the bucket did mention what a nice light show it was during the fire. It would be interesting to see what the manufacturers would say about this..."This thread is being closed as it is off-topic and not related to the fire industry." - Isn't that what the Off Duty forum was for?
10-11-2002, 09:09 AM #9
- Join Date
- Nov 2000
- Sitting on my Laa Laa waiting for my Yaa Yaa
Bones, I'm guessing that operations in lightning conditions are probably not recommended by the manufacturer. In theory, if you stayed in the bucket and the boom and apparatus are properly grounded, the charge should pass to ground if lightning strikes the boom. Of course, how many of you ground your aerial apparatus? Do they come equipped for this? And of course, once you step out of the bucket, all bets are off. We all do what we have to do, but as was mentioned above, get there, do the job, and get back down out of harm's way as quickly as possible.
When I worked for the State Highway Administration, we had an inspector working from a bucket truck next to some high tension wires. Apparently, due to the humidity in the air, the field around the wires extended out to an unusual degree and energized the boom of the truck. The operator failed to put the grounding stake down and when the inspector reached out with a metal hammer to sound the steel beam on the bridge, he was electrocuted. Fortunately he survived, but with severe burns. It's not just lightning storms that can get you, so you always have to be aware of what's around when you're working with ladders of any kind. Stay safe all!Chris Minick, P.E., Firefighter II
Structures Specialist, MD-TF 1
These statements are mine and mine alone
I.A.C.O.J. Building crust and proud of it
10-11-2002, 12:23 PM #10Of course, how many of you ground your aerial apparatus? Do they come equipped for this?"This thread is being closed as it is off-topic and not related to the fire industry." - Isn't that what the Off Duty forum was for?
10-11-2002, 12:48 PM #11
I actually have done a little research on this subject in regards to crew working aloft on tall ships.
To the question of weather or not you will be hit, there are so many factors which decide if lightning will hit a location, sufice to say if the lightning will hit, it will hit regardless of the location of ladders, aerials, or personel. It takes approx 10,000V to jump 1 inch of air. Lightning bolts are miles long, do the math. The difference of a few feet of air to the roof or to the ladder will not make much difference to the lightning.
Crew safety in the strike zone. If you are in the bucket and tower gets hit you may or may not get zapped, see my discourse on how lighting travels next parragraph. But even if you do not get eltrocuted, the crew will suffer sever hearing damage, possibly burns, and might have general concusive damage. If you are on the ground you are not by definition safe. Besides the damage from the lightning bolt there may be flying debris such as tree limbs and even parts of your ladder.
Lightning does very strange things. A friend of mine got hit on the schooner America a few years ago. He was on deck, feet on wet wood, about 15 feet from the shrouds (guy wires holding up the mast). The lightning hit the mast (the second time in less than 5 minutes), traveled down the cables holding up the mast to about 3 feet from the water. Now you would think lightning wanted to jump to the ocean, but no. It left the shrounds, jumped sidways through 30 feet of air to the rudder post (steering wheel), passing through my friend in the process. Why in the world did it go sidways? No way to be sure, but the rudder post must have somehow attracted the lighting (free electrons) to it. BTW, friend suffered minor burns, temp loss of hearing, and has never been quite right in the head since . I was stand on the boat next door and actually saw this happen (which is what prompted me to do this research).
There have been numerous cases of lightning strikes in marinas where the tallest boats are not hit, or even on the same boat with multiple masts, the tallest mast is not always the one hit.
The key to avoiding the hit appears to be a good ground. In the case of the two masted boat where the shorter mast is hit, often the taller mast has an antenna which is grounded through the radio. Lightning rods (contrary to popular belief) are not installed to provide a place for the lightning to go (which they do do when hit) but rather to provide a ground to the roof which equalizes the roof's potential (that free electron thing again) to prevent a strike. Modern lightning bonding systems use a device that looks like a wire bottle brush at the top rather than a spike, as the individual bristles are outlets for those free electrons, allowing more flow to provide a balance. By throwing a ladder you can upset the balance of free electrons on a spot which is priming to get hit and actually reduce the likelyhood of a strike by providing a ground to that point, not that I would recomend experimenting on you own (with due defference to that founding father of American fire fighting, Ben Franklin)
I was sailing in "lightning alley" off the coast of Fla in 98 and saw numerous strikes all around the boat I was on. The main mast was steel and 110' tall, grounded through the ship's steel hull. For hours squalls dropped bolts near us, some as close as a few hundred yards. Finally towards the end of the frontal passage we got tagged. No one was hurt, but $40,000 of electronics were fried (ironically the radio that was on was OK, the radio that was off was toasty). Why did we not get hit earlier, again there is no way to be sure, but the grounded mast probably made us "invisible" to the lightning. When we go hit it was probably just blind luck, that spot of the ocean was gonna get hit weather we were there or not, we just got in the way.
Last edited by Fire304; 10-11-2002 at 01:00 PM.
10-11-2002, 01:38 PM #12Originally posted by drkblram
hmmm, I think that blows the 35 degree rule-if
When my ship got hit off FLA we lost our GPS and the hull got magnatized so the compass was off by up to 35 degrees (depending on our heading). We did not have a gyro and were too far off shore for a good LORAN fix. Navigated to Bermuda with a bad compass and sextants.
10-12-2002, 11:12 AM #13Originally posted by drkblram
having done some sextant only work, OUCH!
I forgot the America had carbon fiber masts. must have been quite a show.
When my ship got hit the lightning actually hit a 30' SSB radio antenna on top of our 110' mast. The antenna was made of fiberglass and had 3 sections w/ metal couplers between. After the hit the top 10' were gone, the upper couple hit the teak deck and left burn marks in the wood. The next 10' looked like a giant fiber glass flower, like Elmer Fudd's shotgun when it blows up. Made a funny sound as it shimmered in the wind. We found shards of fiberglass embeded into other antennas from (what we guessed) when the top 10' exploded. The shards were 1-3" long and driven right through another 3' whip antenna that was about 5 feet from the SSB antenna. Also found shards embedded in a block of wood that another antenna was mounted to. We were lucky nobody got hit by the coupler when it came down, weighed about 5lbs and had fallen over 100'.
We used sextants quite a bit, teaching the students on board. The night before the hit the captain promised that "something would happen to our GPS in the night" and we were going to have to navigate our landfall at Bermuda using sextants only. The next morning quite a few of us were wondering what sort of connections he had .
10-14-2002, 02:09 PM #14
You made me doubt myself for a second so here it is...
Yes, we were lucky that no one got hurt. There were 6 people on deck at the time of the strike and the coupling dropped about 4 feet from one person. We were lucky that the glowing red coupling didn't drop into a fold of the furled up main sail. We were also lucky that none of the poured sockets in our rigging were damaged by heat, as most of them were epoxy. Would of sucked to have the backstay pull out while running before a 25knt squall.
The ship's crew was pretty proficient with sextants, and some of the students took to it like a fish in water, but some, well lets say we're lucky that there were a lot of us plotting locations. If we were off by 10 miles trying to find Bermuda, well a few weeks later we'd have found Africa instead. Its not a very big island.
You must have been on the new Maine, as last I knew the old one only had 3 cylinders and it was steam.
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