Board logo

Engineering Story Problem
mangogrooveworkshop - 15/6/06 at 05:18 PM

Engineering Story Problem
A Backhoe weighing 8 tons is on top of a flatbed trailer and 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 ½ inch steel rebar
spaced at 6 inch intervals in a criss-cross pattern layered at 1 foot vertical
spacing.
Solve: When the shovel arm hits the overpass, how fast do you have
to be going to slice the bridge in half? (Assume no effect for headwind
and no breaking by the driver...)
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.

Answers later tonight


cossey - 15/6/06 at 05:32 PM

it only went 20 feet through it out of 45 feet. the trailer hookup would fail long before the arm got through the bridge and it would slow down pretty quickly.

http://www.equipmentworld.com/apps/news/articleeqw.asp?id=52814


mangogrooveworkshop - 15/6/06 at 05:42 PM


theconrodkid - 15/6/06 at 05:42 PM

i had just worked that out on my trusty abacus and you went and spoilt it


Humbug - 15/6/06 at 06:22 PM

quote:
Originally posted by theconrodkid
i had just worked that out on my trusty abacus and you went and spoilt it


Abacus? pah! I counted on my fingers


Liam - 15/6/06 at 06:56 PM

Hey that aint a backhoe!! It's an excavator!! I gotta start again now - it's all wrong all wrong

Liam


indykid - 15/6/06 at 11:06 PM

134 grand cleanup? ouch

a spectacular fcuk up, one might say!

i had wondered how a backhoe could hit a bridge though,

cheers for that laugh mango!
tom


zilspeed - 15/6/06 at 11:16 PM

There used to be a footbridge in the centre of Hamilton where I work. One morning, yer man came round the one way system with the low loader. On the back was a monster excavator.

You can guess the rest....

Exactly the same as above, except he got jammed underneath.

I vividly remember seeing the lorry driver standing at the side of the road with his piece(1) bag slung over his shoulder. Didn't wait to get sacked.

In this case, the bridge was taken down and to this day has never been reinstated.


(1) For piece, read lunch. In this part of the world, it's a piece bag, because you keep your pieces in it.