Need some advice on what thickness steel to use.

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Ok so I am building a prop for firefighter training. This prop will simulate ripping a window gate off so occupants/firefighters don't become trapped at an emergency. (sorry I know some of you work hard to build these things)Gates such as these Anyway, essentially 3/4" wooden planks will be used to simulate breaking a real window gate. So the metal of the structure needs to at a minimum withstand more than the wood. Which I doubt is a problem. The problem is I want to know for sure before I build this thing that the steel I use will hold up to the test of time. Firefighters have some pretty big tools and like to get a bit more reckless than they sometimes need to be. The prop I am building will essentially work like the one shown in this video. This should give you a general idea of the forces being placed on the frame.Below is a small cutout of the overall design. I'm not really looking to share the full design at this time but the picture shows the actual bracket assembly that will hold the wooden piece and the plate behind it that will need to support the force of the prying tool before the wood fails. The backing plate, is 1/4" by design currently but the upright tubing you see is all 1/8" wall tubing. The sub frame on the right side of the photo won't really have to sustain the forces of the main frame. Am I better off making the main frame out of 1/4" just to be safe? Obviously to some degree a 1/4" plate affixed to a 1/8" tube is only as strong as the 1/8" but at the same time the forces being applied aren't totally affecting the 1/8" and that backing plate is also connected via two separate points to the frame via that small gusset. Last thing to note, that piece that acts as the backing plate/gusset behind the wood is going to be widened 2" top and bottom I just haven't had a chance to redraw it yet, so it will extend a substantial amount above and below the wood.Attachment 810941Last edited by BrooklynBravest; 08-20-2014 at 03:37 PM.
Reply:at first i had no idea what you were talking about but i read it a few more times and now i have no idea what you are talking about..and why anyone would train someone on a prop  when there is no substitute for the real thing also eludes me...sorry i aint no help..
Reply:In the first part, are you substituting 1" square stock window grates with plywood? I would think they are different in pretty much every way....In the Second part, 1/8strap might deflect, or even bend when using a pry bar..... I think that's what your trying to avoid, from the drawing right? Like weldbead said I'm sorta confused about the question... So this might not help, hopefully it dose!Real welders know how to penetrate!(Equipment)Whatever can be used to beat my opponent into submission!
Reply:Originally Posted by weldbeadat first i had no idea what you were talking about but i read it a few more times and now i have no idea what you are talking about..and why anyone would train someone on a prop when there is no substitute for the real thing also eludes me...sorry i aint no help..
Reply:Originally Posted by GarLOL, brother, if you have no idea what he is talking about, why did you post?  As far as substitutes for the real thing, there are plenty of good reasons why we don't want firemen ripping the metal bars off of peoples homes that are not on fire. Almost all real world training uses some type prop, policemen/ firemen, and our armed forces all train with props.  Good props makes for good training, and good training makes the hits from Mr. Murphy a little easier to dodge (but not always).     1/8" should be plenty strong enough for the upright tubing.  I'd go with 3/16" for the rest (1/4" is over kill).  Keep it light, so when it falls on the demolition guy the chance of injury is less.     Gar
Reply:If its just the base that stays attached to the wall, 3/16" should be plenty strong enough, but if your desire is to over build it, use 1/4". GarLincoln Electric, Power MIG 256Hypertherm Powermax 45 Miller Dynasty 280DXSmith O/A torchGenesis of a welding table
Reply:The weakest point is how it is attached. The picture above appears it would be quicker just to use a battery impact on the bolts. OR a BF partner saw .  That would go through it pretty quick.
Reply:I don't think the impact or saw would work very quickly on some of these forted up building with  many apartments on each floor  and working from a ladder to boot.
Reply:A cat excavator like this would be quick enough for ya Backed my CATMA over your CARMA oops clusmy me  What would SATAN do ?? Miller Trailblazer 302 AirPakMiller Digital Elite  Optrel Welding HatArcair K4000Suitcase 12RC / 12 VSHypertherm PM-45Rage 3 sawRusty old Truck
Reply:I call that OVER KILL!!!!!!!!!!!
Reply:Yeah, that qualifies as a "forcible entry tool" .No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Originally Posted by DSWYeah, that qualifies as a "forcible entry tool"
Reply:We have a prop very similar to the one in the video and the entire frame is 1/4"  I would go on the heavy side just to keep knuckle heads from tearing it apart. But let's face it you could build it out of 1"  plate and someone would break it, lose the pieces and swear they don't know what happend