A tale of two engineers

[Don P]

I enjoy studying history and engineering and thought some of you might as well. There are two stories here, one of hubris the other humility. The scale of both projects was large but the moral of the stories applies to all of us who build.

The first is about Thomas Cooper and the Quebec City bridge collapse. Cooper was hired as lead engineer on the bridge project and saw that if he moved a set of piers a little wider than the original plans called for he would be able to seize claim to the longest spanning cantilever bridge. In order to make it work he juiced the allowable strength numbers of the iron, just a little. He then neglected to go back and factor in the increased dead load of the longer span. As construction proceeded he dismissed reports of things not fitting properly and in the end 75 workmen died as the span collapsed. When a Canadian engineer passes the boards he is handed an iron ring to wear as a reminder of his real obligation.
http://www.engr.usask.ca/classes/GE/449/notes/Quebec_Bridge_story.pdf

In the early '70's William LeMessurier designed a daring new kind of skyscraper for the Citicorp group in Manhattan. He thought he had covered all his bases in the design phase. Several years later a student writing a thesis on the building questioned his wind design assumptions. A student questioned an eminent engineer. He went back and checked his math, she was right. Then he checked the as built construction documents, they had substituted bolts for the designed welds. When he recalculated everything the stresses reached 1.6 times allowable in a 70 mph quartering wind. The factor of safety for steel is 1.6. This highly acclaimed building was in real danger, if he admitted to the error he might never work again, he would assuredly end up in court. He immediately owned up and everyone stepped up to help. Everyone lived happily ever after, Hero  8)
http://www.theaiatrust.com/whitepapers/ethics/study.php

[Grizzly]

So the moral remains. If your wrong.... admit it. Now and not later.

[LeeB]

Kinda along the lines that a lie becomes your future and the truth becomes your past. I don't remember where I came across this jewel, but it is so very true.

[kantuckid]

My tale of one engineer: During my apprenticeship as a UAW/URW mechanic millwright @ Goodyear Topeka Plant, we were constructing a steel platform for processing some material (I forget what it was) that required a forklift to place the stuff up on top, then it was dispensed below after mixing. We were mostly firewatching for the welders at the time, thus a lazy mans deal and in reading the blueprints the guy I was shadowing says, "which forklift is going to service this platform"? The young, in-plant, engineer who'd designed it came around later and we hit him up about the height and he says "oh, one of those with the high reach". "My guy" already knew that not one of the several hundred various forklifts in that plant could reach that high. It was built to completion as designed, then used only after a forklift was brought in that could make the lift. Duh...
I actually have full respect for engineers but in a similar fashion to medical doctors I place them 100% into human status. 

[Den-Den]

So the moral remains. If your wrong.... admit it. Now and not later.

Exactly right
There are additional lessons in those stories.
* Focus on cost savings can blind us to problems that we should have seen
* Pride can prevent us from seeing that we are wrong
* Connection between beams, braces & columns are very important

[dablack]

While in school to become an engineer, I taught SAT prep.  Before checking the kids work I would see that an answer was wrong right away.  It would be some tricky question about the cost of a candy bar or car or whatever.  If the answer was $.03 or $1,500,000 I would know it was wrong right away before actually checking that math or method.  I would make the kid go back and read the question again and then tell me their answer.  They would usually realize that their answer didn't work for the question and they would go back to work on it. 
Then I became an engineer and was working with fabrics for use on orbit.  I worked and worked on this new fastener technique to attach this fabric to that fabric.  I was going over my work and presenting the tensile strength that I had calculated for the newly attached material.  An older PHD pointed out that my new "knot" had a higher tensile strength than the base material that was being put together.  Basically, my answer didn't make sense. 
Point being, it is easy to get caught up in your numbers and forget out the big picture or if your numbers will stand up to the real world.  I think this is a good check for engineering work, building, or anything that requires logic. 

[Crusarius]

its funny. I am on the other side of all this. I am the test engineer. I get to test what the engineers design. Sometimes it is fun other times frustrating. Especially when you have tested it before and it has failed before.

I really don't like telling ppl they are wrong but when they say it was a bad test do it again then I like to show them how wrong they are

[Magicman]

Wonder whose failure the bridge collapse in Columbia was?

[JJ]

Nearby to me is the Portsmouth Naval Shipyard where nuclear-powered attack subs are built.
The Thresher was the first of a new class of attack sub, which sank during deep-dive trials due to some suspected mechanical failures:
https://en.wikipedia.org/wiki/USS_Thresher_(SSN-593)

I have a buddy who's father was a nuclear engineer at the shipyard.
Since the loss of the Thresher, the US Navy instituted a mandatory requirement before they will accept a new boat from the shipyard...  The engineers involved in design and overseeing the construction, must be on-board the boat as she dives to her maximum rated depth (hearsay to me, but from reliable source).   

You can bet there was a lot of double checking of assumptions, calculations, and testing requirements.

Anyway a quote from the link caught my eye:

    "I believe the loss of the Thresher should not be viewed solely as the result of failure of a specific braze, weld, system or component, but rather should be considered a consequence of the philosophy of design, construction and inspection that has been permitted in our naval shipbuilding programs. I think it is important that we re-evaluate our present practices where, in the desire to make advancements, we may have forsaken the fundamentals of good engineering."  Admiral Hyman Rickover during the 1963 inquiry

      JJ

[bdsmith]

There are many college freshmen who, when faced with the choice of majors, choose engineering based on job prospects but don't know which end of a hammer to hold.  Engineering is more than an education, it is a way of thinking and an innate talent.

Among my siblings, we have 3 engineers, 3 accountants and a forester.  The forester, who happened to be the youngest and following by example, attended college for 3.5 years in the mechanical engineering program with a future brother-in-law.  During a test in the senior year on vector addition, the BIL saw the (future) forester look carefully at his left hand with 3 fingers extended perpendicular.  The BIL caught his attention and waved his right hand, reminding the (future) forester that the right hand screw rule for vector addition only worked when you used your RIGHT hand.

The struggling engineer switched majors, put in another 2 years of college to pick up the necessary courses and became a very successful professional forester.

[submarinesailor]

Nearby to me is the Portsmouth Naval Shipyard where nuclear-powered attack subs are built.
The Thresher was the first of a new class of attack sub, which sank during deep-dive trials due to some suspected mechanical failures:
https://en.wikipedia.org/wiki/USS_Thresher_(SSN-593)

I have a buddy who's father was a nuclear engineer at the shipyard.
Since the loss of the Thresher, the US Navy instituted a mandatory requirement before they will accept a new boat from the shipyard...  The engineers involved in design and overseeing the construction, must be on-board the boat as she dives to her maximum rated depth (hearsay to me, but from reliable source).   

You can bet there was a lot of double checking of assumptions, calculations, and testing requirements.


      JJ

JJ - I know this to be fact.  Every sea trails (test dives) we did coming out of the shipyard, we always had a large bunch of managers, foremen and craft people on board during the trails. 

I remember the "Bravo" trails for the SSBN 624 boat had about 250 people on board.  The galley never closed because of the numbers.  The really bad part was that we could not dive until we reached the "safe" area off the coast of New London, CT.  Saft area equals a nice sandy bottom that was about 200 ft below test depth.  Have you ever had the opportunity to transit from Newport News to New London on the surface in December while riding in a round bottom boat.  Talk about of bunch of seasick sailors and shipyard works (Sand Crabs).

[DelawhereJoe]

This kinda reminds me of one of the local fire departments that saved up there money to buy a brand new ladder truck. They were so happy to have saved up the money and so excited to get it. Well no one bothered to check to see if it would even fit into the fire house, turns out that they need a door just over 1 ft taller to get it inside. Then it was time for another fundraiser to add onto the building.

[bdsmith]

I had an engineering buddy who bought himself a bright red, crew cab, long bed, dualy pickup.  Then he bought his "dream" house - a big "McMansion" on a small lot with all sort of special rooms and accessories.  The only problem was the garage was 12" too short for the truck and the driveway was even shorter!

[Crusarius]

This kinda reminds me of one of the local fire departments that saved up there money to buy a brand new ladder truck. They were so happy to have saved up the money and so excited to get it. Well no one bothered to check to see if it would even fit into the fire house, turns out that they need a door just over 1 ft taller to get it inside. Then it was time for another fundraiser to add onto the building.

we had to move the air lines to get it to fit in. everytime we put the truck in we need to make sure the platform is level or it takes out the door. If you hit the gas leaving the bay the truck stands up and takes out the main beam in the building.