Two infamous railroad bridge tragedies are the Quebec Bridge and the Tay Bridge in Scotland. The bridge at Quebec collapsed when it was in the erection stage ; the Tay Bridge collasped when a passenger train was in the middle of the bridge. The Quebec bridge disaster was more tragic , more complex , and more dramatic then the Tay Bridge; more tragic because of the lives lost ; more complex because of the complex engineering in erecting a cantilever bridge; and more dramatic because ceasing erection of the bridge was being discussed.The design of the Tay was not complex; massive girders at a very high elevavationbearing on cast-iron “pipes” set on a base not much wider than the girders so a lateral force against the side of the girders could topple the bridge.
They were tragic all right.
Sadly, maybe unnecessarily, maybe not, engineering seems to be a science learned off blood-spattered pages.
Both were pretty tragic, especially to the victims’ families. Early days of civil engineering.
It has only been in the last 100 years or so that the science of engineering has replaced the art of engineering by developing measurment systems that are able to define the strength and other characteristics of the materials used in construction.
When engineering was an art, the engineers chose materials that they ‘thought’ were strong enough to perform the task they were asking to be done - engineering for longevity.
Now that engineering is a science, materials are chosen because of their price and specs that define them as being ‘just’ strong enough - engineering for price.
Yet dumb mistakes still occur such as the Florida pedestrian bridge collapse on the Tamiami Trail.
https://en.wikipedia.org/wiki/Florida_International_University_pedestrian_bridge_collapse
Push the envelope, don’t stop traffic, etc. Robling overbuilt his bridges (Cincinnati and Brooklyn) and they still stand.
Dumb is normally a function of cost cutting in engineering failures - Designers called for spec 1 that cost X, but the contractor substituted spec 2 that cost x - but spec 2 is also inferior to spec 1.
Sometimes the conversion from Imperial to Metric or vice versa will catch the engineers.
Add the Rocket Train bridge on the Meridian & Bigbee to your list (wasn’t the bridge’s fault, but rather the people maintaining it that failed)
Roebling followed the old medieval cathedral builders rule:
“Brethren, if thou art not sure, build hem stronger!”
Even they didn’t get it right all the time, but most of the time they did.
Sometimes the bridge collapse was only the very beginning of the horror, as at Ashtabula.
The design of the Tay was not complex; massive girders at a very high elevavationbearing on cast-iron “pipes” set on a base not much wider than the girders so a lateral force against the side of the girders could topple the bridge.
But it was not a coincidence that the bridge failed with a passenger train crossing it. The wind force had, indeed, not been considered by Sir Thomas Bouch in the design of the Tay Bridge, but the “High Girders” themselves were open enough in side view to not cause a problem. It was the passage of the train itself that increased the “sail area”. I understand that the locomotive and the passenger cars were blown off the track inside the girders and this precipitated the failure of the bridge.
It is possible that the train could have been blown over on the approach spans and might have fallen into the river without causing a bridge failure had the severe gust occurred a few minutes earlier. I think there was a system in place to suspend train services in high wind before the failure, but the limits hadn’t been reached before the train set out to cross the bridge.
The use of iron castings with excessive air bubbles causing a structural weakness contributed to the failure, these defects having been filled with glue and sawdust and painted over to avoid detection. I think inspection of these items was increased after the bridge failure.
Peter
The B&O constructed the Thomas Viaduct over the Patapsco River in two years from 1833 to 1835 to move their rolling tea kettles between Baltimore and Washington without in their wildest dreams visualizing the engines and trains and the loadings that would be operating over their creation in the ensuing 185 years. It still stands and supports everything that the B&O and CSX have thrown at it.
There was the bridge near Mobile that was hit by a barge, which caused the Amtrak train into the water with multiple fatalities.
The Bayou Canot Bridge was constructed as a drawbridge, at the time of the incident the bridge was not on a navigable section of the river system and had not be used as a drawbrige for 50 or more years. The tow and barge that knocked the bridge out of alignment was lost in fog and didn’t realize that they had hit anything.
https://www.ntsb.gov/safety/safety-recs/recletters/I94_3_6.pdf
The Quebec Bridge collapsed twice during construction.
The first collapse was due to the trusses in the south cantilever tower being improperly designed, it could not support its own weight.
The second collapse occurred when a hoist failed as the centre span was being raised.
75 workers were killed in the first collapse, 13 in the second. Many were Mohawks from a reserve near Montreal, who were renowned for their fearlessness when working at heights.
Thanks for mentioning this disaster…and the horror that lasted for hours.
At least the man more responsible than anyone else, because he insisted on an unproven and cheaper type of design, felt his responsibility so keenly that he later took his own life.
I wish a few more people who are responsible for parts of the public’s well-being would take the blame when things go disastrously wrong.
Question for the engineering pro’s among us: Sand-filled stone viaducts, whether for highways or railroads, must cost more than iron & steel bridges (by a factor of what?). But they last forever. Why don’t more highway departments & railroads see the long-term economic and safety benefits of viaducts?
More viaducts, please!
I’m not an engineer but stone or concrete viaducts have their own limitations. Cost is a major factor and they tend not to work too well over water or high level crossings.
I take your point, kinda. But isn’t the PRR viaduct over the Susquehanna River and the E-L’s Tunkhannock & Nicholson viaducts proof that they do?
Starucca Viaduct (Pennsylvania bluestone) is still in service after almost 150 years.
Tunkahannock (and little brother Martin’s Creek), Lackawanna concrete, still in service as well.
If they were built well, they’ll last forever.
Tunkahannock does show some spalling, but there’s a lot of concrete there.
OTOH, I know of a steel girder bridge built on stone piers, that has had one mid-river pier settle.
Remember - there was a time when manpower was cheap and machinery was expensive - and that was the time when many railroad landmarks were built.
Shocks Mills had a couple sections collapse in 72 during Hurricane Agnes, and Rockville had part of it fall apart - so I wouldn’t say they all last forever.
Scour of moving water has done in more than one bridge pier - highway or railroad makes no difference, Mother Nature doesn’t care whose engineering she defeats.