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The Energy of a Fire Truck in crash

  1. Sep 24, 2015 #1
    Hello all, I am in need of some help. I work for a fire department who had a significant fire truck crash last summer. Because of this, my department has set about making a training program for our drivers. Lucky me, I am in charge of said program.

    So I need some help.

    Here is the story. Last summer one of our Ladder Trucks ( fire truck with the big long ladder on the top of the truck that extends out, not a fire engine that has water) was traveling around 58 mph on a curved road then is lost traction, slide and rolled. No one was seriously hurt.

    Here is what we know. Said ladder truck was traveling around 58 MPH and weight 62,500 lbs. I know, using the formula for kinetic energy, ( KE= 1/2 Mass X Velocity squared) that this truck produced 7,016,409.78 ft lbs or 3,508 tons of energy.

    What I am looking for is a way so show the members of my department what that much energy looks like. As in, that kind of power in an explosion, or a wrecking ball destroying a building. I need a way to relay to my guys, the power that they are driving down the roads and highways every day.

    Luckily when this truck crash, it only hit a telephone pole a picket fence and a few cars. The extent of the damage was very little in comparison to what could have happened.

    I have searched the web for a way to show this and have come up with nothing. Someone suggested I try a Science blog, so I leave it up to you. What have you got ????

    And thanks for the help.
  2. jcsd
  3. Sep 24, 2015 #2


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    Wolfram Alpha is a handy tool for this.

    Chucking your numbers in,
    we get about 9.5 megajoules. (the same as your number in ft lbs, though I don't know what you mean by "3508 tonnes of energy")

    Which is about the amount of energy required to keep an iphone 5 going for 9 months...
    Or about 200 g worth of gasoline.

    So you know, not very much. I don't think comparing the dissipation of kinetic energy of the truck will make a very lasting impression on your drivers, sorry.
  4. Sep 25, 2015 #3
    Comparing disparate items is not a good picture in training. I would stay with something that is closer to the experience the people have. A fire truck is in an odd place as the rolling weight is heavier than many things but lighter than what is perceived as big. The truck that you are referencing could easily be compared to a tractor trailer. The Kinetic Energy in your truck would be roughly equivalent to a fully loaded Semi truck traveling at around 43ish mph. One could also compare it to a drag race car at close to 200 mph. The saving grace in the accident your evaluating is that the truck rolled ( dissipating energy), then it slid a distance ( further dissipation), and finally it took out some lesser objects to use the remaining energy. Lots of low impact stuff and a low damage would be the result.

    I would suggest that a better picture would be something that fits in with emergency responder concepts of life. In Seattle Wa. on 9/24 there was a tour bus and a Duck (old military amphibious craft now used for tours) that got wrapped up on a bridge. 40,000 lb bus vs 38,000 lb Duck. Impact speed was approximately 45 mph, end result was 64 people involved. 4 dead, 12 critical, 30 other injured. Major triage event and we just think those mass casualty drills are off the hook.

    Look at the numbers though. The forces are pretty close. The results easy to see. For you the Pictures are current and should be easy to find on the web. Most EVAP courses have some good other stuff for drivers to get a look at what can go wrong.
  5. Sep 25, 2015 #4

    Thank you for your response. I do have all the other info on from EVOC / EVAP / EVDC or what ever your want to call it. I just need a something that will catch there attention. In all actuality, I need to guys to just slow down. The are in the DC Metro area. It is a common thing (common in the fact that everyone) to drive 15 mph over the posted speed limits at all times. Lots of traffic in this area. Lots of migrant people from all over the world. Everyone drives and differing speeds but most are over the limit. So is the case with the emergency services because we go for our POV to the seat of the Emergency vehicle with the same driving habits. Its a hard pill to swallow to tell some one who responds fast to an emergency that they are going fast. Thank you you all your information. I like the idea of using Seattle as a reference.
  6. Sep 25, 2015 #5


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    How about a 4,000 lb car? Going at 230 mph?

    Get them to guess the speed required to achieve that energy before you tell them. I would bet they guess a lot lower.
  7. Sep 25, 2015 #6

    One thing to drive home with your guys. The Seattle incident or even a you tube search of emergency response accidents will serve you well. In actuality they need to understand two things:

    1) The old saying goes "One ahh Sh*t wipes out a thousand attaboys." Even the migrant drivers you are talking about are " good enough" They are not professional and they mostly get out of the way. Those of us in the emergency services are a big distraction. We are in fact the wild card that causes others to goof up. It is imperative for us starting at the driver (who should only be driving) to the right seat Capt or Engineer however your dept is configured ( right seat should deal with all the distractions) to drive not only for our vehicle but the others that do not know how to deal with the distraction that we bring along.

    2) Unless a person is a full time driver of a rig it will not work like you are used to. Drive time for them is the only answer to being able to drive. The size, acceleration, deceleration, and turning are all different then you are used to. Don't push it

    Appreciate your service.
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