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#124395 - 09/27/06 11:58 AM Engineering Problem ...
Admin Offline

Registered: 10/07/00
Posts: 3417
Loc: NY, USA
forwarded by email today:
(original source unknown)
Problem: 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 bridge in half?? (Assume no headwind and no braking by the driver who is oblivious of the situation . . . )

Extra Credit: Solve for the time and distance required for the entire rig to come to a complete stop after hitting the overpass at the speed calculated above .
Answer: Scroll down..........

Answer -? ? It doesn't really matter... ? The point is that the trucking company just bought themselves a bridge...
Tools for Electricians:
#124396 - 09/27/06 02:32 PM Re: Engineering Problem ...
Rewired Offline
Registered: 01/01/06
Posts: 558
Loc: Hamilton, Ontario, Canada
THAT would have been something I would have LOVED to have seen! ( from a safe distance of course).
I would not believe it if I didn't see it!

#124397 - 09/27/06 02:47 PM Re: Engineering Problem ...
Dnkldorf Offline
Registered: 12/12/04
Posts: 1064
Loc: nowhere usa
Ah, a little duct tape and it'll be fine....

That is a funny post..
#124398 - 09/27/06 02:57 PM Re: Engineering Problem ...
Theelectrikid Offline
Registered: 04/30/04
Posts: 810
Loc: Levittown, PA
ROTFLMAO!! Must be an idiot to do that!

Ian A.
Is there anyone on board who knows how to fly a plane?
#124399 - 09/27/06 03:30 PM Re: Engineering Problem ...
walrus Offline
Registered: 07/25/02
Posts: 680
Loc: Bangor Me. USA
Can you say photoshop
#124400 - 09/27/06 03:33 PM Re: Engineering Problem ...
classicsat Offline
Registered: 11/23/02
Posts: 456
"I was delivering this overpass and ran out of gas"
#124401 - 09/27/06 04:17 PM Re: Engineering Problem ...
Gus99 Offline
Registered: 08/11/05
Posts: 24
Loc: Los Angeles, CA
They repaired the railing on both sides pretty quick didn't they!

#124402 - 09/27/06 04:21 PM Re: Engineering Problem ...
NJwirenut Offline
Registered: 09/15/01
Posts: 806
Loc: Bergen County, NJ
Not a fake:

Here's a news report:

[This message has been edited by NJwirenut (edited 09-27-2006).]
#124403 - 09/27/06 04:36 PM Re: Engineering Problem ...
steve ancient apprentice Offline
Registered: 03/04/05
Posts: 169
Loc: west springfield,mass
Even with my bi-focals I could see a sign as to how high the bridge is. Trueley Amazing.
#124404 - 09/27/06 04:54 PM Re: Engineering Problem ...
iwire Offline
Registered: 01/05/03
Posts: 4391
Loc: North Attleboro, MA USA
NJ thanks for providing the links.

I also thought I would point out that this is a type of hollow concrete box bridge.

It is not 3' or 4' of solid concrete, it is a couple of 10" to 14" decks.

Still amazing but much more believable that slicing a solid concrete bridge.

Zoom in on the first picture where you can see the bucket has punched a hole through the bottom deck in to the void.
Bob Badger
Construction & Maintenance Electrician
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