This is what happens when a tanker truck carrying 8600 gallons of gas overturns and goes up in flames:  :shock:



Linky

Some video of it happening  :eek:


http://mfile.akamai.com/12948/wmv/vod.ibsys.com/2007/0429/13218185.200k.asx

A backhoe weighing 8 tons is on top of a flatbed trailer heading
east on Interstate 70 near Hays, Kansas .  The extended shovel arm is made
of hardened refined steel and the approaching overpass is made of
commercial-grade concrete, reinforced with 1 1/2 inch steel rebar spaced at
6-inch intervals in a criss-
cross pattern, layered with 1-foot vertical spacing.

Solve:
When the shovel arm hits the overpass, how fast does the trailer
with the backhoe have to be going to slice the overpass in half?  (Assume
no headwind and no braking by the driver, who is oblivious of the
situation...)

Answer:It doesnt really matter.
The point is the trucking company just bought themselves an overpass







Jaimz

Holy crap - the arm of that digger is stronger than I thought it would be!  Apart from a few bends its pretty much in tact.

Quote from: Vini

Quote from: Jaimz

Answer:It doesnt really matter.
The point is the trucking company just bought themselves an overpass

Jaimz

I suspect BS, they did similar on Mythbusters about two weeks ago, though with a boat and a channel marker. The boat just deflected, as I presume the arm of the truck would have just crumpled.

mate, boats are pretty much made from air, you can kick one and put your foot through the front of a racing boat like that badger.

Well they -busters- rammed the boat three times into a solid non moving channel marker, and it did nothing. Nothing like in the picture.

I suspect similar for the truck/road. BS.

sok - I get it now..the arm penetrated from below..

true according to snopes..

http://www.snopes.com/photos/accident/hoecrash.asp

Is it me or do those pics not add up ? The ones taken from below do not show the arm having penetrated through the top rail from the side - eg this one..



yet the one from above shows the arm having sliced through the side..

Yeah it took me a few looks to get what happened.  The top view seems to show it slicing right through the brodge whereas the underside shows damage at both ends with a gap in the middle.

Now Ive looked at it it looks like the arm did just go halfway through.  The rest of the slice viewed from the top is just the debris spreading out in front of the arm.  The bottom shows how far the arm went through, then the gap which was untouched and the other damage is a blowout from the impact.



RE: the boat - mythbusters probably used a different hull.  Most modern boats theyd pick up round the San Francisco area would have plastic hulls.  The picture looks like a plywood race boat which would impact.  Its not really a myth - if you smash a plywood race boat into a metal pole it will get smashed - it happens a lot in racing.  A plastic or carbon fibre boat like most commercial ones are would defelct tho.

Well it clearly depends on what its made out of, what it displaces (or weighs for you landlubbers) and the keel area/draft.  Saying it will or wont break is like saying all car crashes are fatal.