Week 2: Quebec Bridge Flashcards
What was the mode of failure on the Quebec Bridge?
Failure of the bottom compression chords on the cantilever arm
What did the chief engineer of Phoenix Bridge Company say early on about Cooper that would indicate him breaching engineering ethics?
Cooper “happened” to find no issues with the Phoenix drawings/plans. When asked about this, he got frustrated and indicated that if anything further had to be done then the bid would be thrown out.
What three words became a touchstone for Cooper in his approach to the bridge?
“best and cheapest”
Apart from physical loads, what was the other “burden” that seemed to drive the project?
Financial Burden
What two reasons drove the lengthening of the bridge from its original design?
- Piers in deeper water more vulnerable to ice floes
- Lesser expense with piers closer to shore
What change did Cooper make to allow for a longer span?
Modified specifications that allowed for higher unit stresses
What step was skipped and assumption made due to financial burden early on in the project?
Testing was skipped since it was assumed Cooper’s experience was good enough
What critical step was skipped due to the rush to make steel fabrication drawings for the bridge?
There was no recomputation of assumed weights for the bridge under revised specifications
How many times did Cooper visit the bridge site in total?
3 times
When the high unit stresses used on the bridge were criticized by a consultant engineer, what was Cooper’s reaction?
He stated that the proposal would put him in the position of a subordinate, which he could not accept.
Since Cooper wasn’t coming to site, what did he do instead?
He delegated a young engineer to be his eyes and ears on the site
Which two engineers was the brunt of the blame placed on for the first bridge collapse?
Cooper and Szlapka
Although bridge design has greatly advanced and changed, what hasn’t changed?
The potential for human error
