engineering

Engineering

Why are you here?Do Engineering classes

matter?Or

Is a C good enough?

One day you are working at your desk and your boss walks in and says…..

“You know that tower you designed? The work site called and said they have a problem. Go down there and see if you can straighten it out for them!”

When you arrive you see……..

I knew I shouldn’t have slept in Mr. Sprague’s Engineering Class!

Source: http://ethics.tamu.edu/ethics/tvtower/tv3.htm#photographs

Seven people died in this incident!

Video

Going up

Video of the collapse

Pictures

The collapse of the tower during construction was the result of an incorrect engineering calculation.

Engineering gone wrong

How much force on each bolt?

FA = FB =T/2

FB=(L/d)T

FA=(L/d-1)T

How much force on each bolt?

Model used by riggers

T

FAFB

Free body diagram used by riggers

Model riggers should have used

Free body diagram riggers should have

used Note: L/d=6

What factor of safety would you use?

Engineering

Does it matter?

Or

Is a C good enough?


“You know that math floating point unit you designed on our last chip, there are some posts on the Web about it… Look into it.

You start reading the posts…Dr. Thomas Nicely, Professor of Mathematics at Lynchburg College independently discovered a bug and posted a message on the Internet. The bug only showed up in obscure math computations.

You tell your boss that the errata is a very small math error and unlikely that most users would even see it….

Intel's stated that it was minor and "not even an erratum“. This was not accepted by many computer users. The bug was easy to replicate by an average user (there was a sequence of numbers one could enter into the OS calculator to show the error),

During Thanksgiving 1994, The New York Times ran a piece spotlighting the error.

Intel changed its position and offered to replace every chip, quickly putting in place a large end-user support organization. This resulted in a $500 million charge against Intel's 1994 revenue.

No Big Deal…NOT!!!


“You know that electrical towers you designed? The NE US has lost power. They think something is wrong with your towers. Go see what the problem is!”

When you arrive you see……..

Oh, here is that missing negative sign!

Saturday, June 27, 1998

COLLAPSING ROOF AT MARKET INJURES 11, TRAPS 82-YEAR-OLD

The Associated P ress

Part o f a superm arket roof co llapsed Friday m orning, in juring 11 people - including an 82-year-o ld w om an w ho w as trapped under the rubble for about tw o hours.

http://www.stlnet.com/

St. Louis Post-DispatchTuesday, April 14, 1998

BALCONIES' COLLAPSE SPURS CITYW IDE INSPECTIONS

St. Louis offic ia ls are launching a cityw ide inspection of ba lconies like the tw o that co llapsed in a south St. Louis apartm ent bu ild ing over the w eekend, in juring six people - four seriously.


St. Louis Post-DispatchTuesday, July 15, 1997

COLLAPSE OF BRIDGE KILLS ONE48 HURT AT THE SITE OF MACCABIAH GAMES

Com piled From N ews Services TEL AVIV, ISRAEL

A tem porary bridge leading to an Israe li sports stadium collapsed M onday m inutes before the opening parade of an in ternational sporting event, k illing one w om an and in juring 48 other people , police sa id.


St. Louis Post-Dispatch

M onday, Ju ly 21, 1997

6 INDICTMENTS SET IN BRIDGE COLLAPSE AP JER U SALEM

Police have enough evidence to ind ict s ix people on crim inal negligence in the co llapse of a M accabiah G am es bridge that k illed tw o Austra lian ath letes and in jured dozens, a new spaper reported Sunday.

The daily Yediot Ahronot said that po lice w ould recom m end prosecuting the engineer w ho p lanned the bridge, the contractors w ho built it, the developer w ho h ired them and the gam es chairm an and cerem ony organizer.


St. Louis Post-Dispatch

Thursday, Septem ber 15, 1994

COLLAPSING GANGWAY KILLS SIX IN ENGLAND AP R AM SG ATE, EN G LAN D

A steel gangw ay to a Belg ian ferry snapped W ednesday m orning sending six passengers p lunging to the ir deaths and in juring seven others , includ ing four Am ericans


St. Louis Post-DispatchSaturday, July 18, 1981

Suspended Walkway in Hyatt Regency Hotel collapses; 113 dead, 186 injured.




What is the load held by the nut here?




http://m em bers.aol.com /R onG raham 1/fa ilure1.htm l#01Hyatt Regency skywalk, Kansas City MO. Two-level catwalk failed under live load, causing fatalities. Original design called for nuts where they could not actually be installed: original (impossible) design had each nut only helping to support the weight of one floor; the rod passing through the upper floor also passed the load of the lower floor through it, and not the nut holding up the upper floor. The installed design meant the nut under the upper floor not only had to support the weight of the upper floor but also the weight of the lower floor; the nut and rod were undersized to handle this load.. Upper catwalk supported itself and lower catwalk, by means of rods offset from one another. Live load may have caused harmonic oscillation by dancing. Even the static load of people exceeded design. Nuts tore through overloaded members. Blame

and liability for failure were "spread around," but some licenses were still lost.




W ednesday, January 27, 1988

LICENSE REVOCATIONS ARE UPHELD IN COLLAPSE OF HYATT SKY WALKS

The Missouri Court of Appeals at St. Louis ruled Tuesday that state authorities had been right to revoke the licenses of engineers found responsible for designing elevated walkways that collapsed and killed 114 people.

The elevated walkways, known as sky walks, collapsed July 17, 1981, at the Hyatt Regency Hotel in Kansas City. At least 186 people were injured in the accident, which was called by the National Bureau of Standards the most devastating structural collapse in the country.




W ednesday, July 17, 1991

10 YEARS LATER, EFFECTS OF HYATT COLLAPSE ARE STILL FELT SURVIVOR HOPES LESSONS HAVE BEEN

LEARNEDBy Tim Curran Of The Associated Press

KANSAS CITY (AP) - Sally Firestone isn't bitter about the hotel skywalk collapse that will keep her in a wheelchair the rest of her life.

She was left a quadriplegic with no feeling below her shoulders in the accident 10 years ago today at the Hyatt Regency Crown Center that killed 114 people and injured more than 200.

Engineering Classes

Does it matter?

Or

Is a C good enough?

Homework

Why Good Engineering is Important•Research an engineering failure.

• What happened?

• Why did it fail?

• What were the consequences?

•One page double spaced-typed.

•Due in class on Friday

engineering

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