Title: Technical Thought required....................
Post by: Leftie on April 19, 2008, 05:20:04 pm
This is a bit of a brain teaser to say the least. The younger members will have to do the conversions.
I couldn't find my slide rule or abacus. But I have photographic evidence of the end result.
OK, I received this email from a pall stateside.
ENGINEERING PHYSICS CALCULATION
Problem:
A backhoe weighing 18 tons is on top of a flatbed trailer heading east on Interstate 70 near Hays, Kansas. (The boom and dipper stick is made of 80,000 psi high strength steel and the approaching overpass is made of 4,000 psi concrete, reinforced with 2 layers of 1 inch steel rebar spaced 6 inches each way in both the road deck and bottom of the box-beam bridge section.)
Solve:
When the boom and dipper 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 .
See pictures below.............................
(http://i197.photobucket.com/albums/aa64/jjkt15/truck1.jpg)
(http://i197.photobucket.com/albums/aa64/jjkt15/truck2.jpg)
(http://i197.photobucket.com/albums/aa64/jjkt15/truck3.jpg)
Answer - It doesn't really matter... The point is that the trucking company just bought themselves a bridge.
What would 'elf and safety' say?
I couldn't find my slide rule or abacus. But I have photographic evidence of the end result.
OK, I received this email from a pall stateside.
ENGINEERING PHYSICS CALCULATION
Problem:
A backhoe weighing 18 tons is on top of a flatbed trailer heading east on Interstate 70 near Hays, Kansas. (The boom and dipper stick is made of 80,000 psi high strength steel and the approaching overpass is made of 4,000 psi concrete, reinforced with 2 layers of 1 inch steel rebar spaced 6 inches each way in both the road deck and bottom of the box-beam bridge section.)
Solve:
When the boom and dipper 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 .
See pictures below.............................
(http://i197.photobucket.com/albums/aa64/jjkt15/truck1.jpg)
(http://i197.photobucket.com/albums/aa64/jjkt15/truck2.jpg)
(http://i197.photobucket.com/albums/aa64/jjkt15/truck3.jpg)
Answer - It doesn't really matter... The point is that the trucking company just bought themselves a bridge.
What would 'elf and safety' say?
Title: Re: Technical Thought required....................
Post by: Perdu on April 20, 2008, 12:23:15 am
oops
:-[
:-[
Title: Re: Technical Thought required....................
Post by: redstu on April 20, 2008, 08:21:27 am
Learning - don't take on a Hyundai - it seems to have survived pretty well
Title: Re: Technical Thought required....................
Post by: Lord Pig-Pen on April 22, 2008, 02:11:14 am
I will consult my old degree notes from Structural Eng.
First impresions are... faster than it was going and stronger chains holding the digger on the trailer.
Is it normal practice in the US to drive with the actor in the up position? ;D
First impresions are... faster than it was going and stronger chains holding the digger on the trailer.
Is it normal practice in the US to drive with the actor in the up position? ;D
Title: Re: Technical Thought required....................
Post by: Leftie on April 22, 2008, 02:32:08 am
I will consult my old degree notes from Structural Eng.
First impresions are... faster than it was going and stronger chains holding the digger on the trailer.
Is it normal practice in the US to drive with the actor in the up position? ;D
First impresions are... faster than it was going and stronger chains holding the digger on the trailer.
Is it normal practice in the US to drive with the actor in the up position? ;D
Normal practice is backacter down. But I think not low enough for this bridge.
On impact, the BA went up due to 'friction'. Pic 3 shows the hydraulics shot to pieces. Even pulled the ram out.
These are BIG f'ing machines so the haulage Co' should check heights etc.
