Tacoma Narrows Bridge Collapse - 1940

we're traveling over the Tacoma Narrows Bridge the original collapsed in 1940 only six months after its completion Michael Sullivan will share that story with us the area were standing in right now is in the southern section of Puget Sound which is the sort of Washington State in the Pacific Northwest kind of great inland water and when the Transcontinental Railroad came there was talk about one day being able to span huge it sound but it really wasn't an undertaking anybody was prepared to do during the Depression federal programs like the building of the Grand Coulee Dam and stuff though there were big job-creating public works projects happening in the Pacific Northwest and in the in the mid 1930s there began to be talk about creating a bridge over Puget Sound to reach from Tacoma to the Kitsap Peninsula kommen Narrows Bridge was opened on the 1st of July in 1940 after two years of construction when I'm driving toward one my heart begins let's add the bridge to John fur that's worth allodynia stream I sent there shaking in an empty lot pull the rope master then bat me in the darkest red or wild dogs leaping over abandoned eyes kind to me in the end the Tacoma Narrows is also a bit of a wind tunnel and people working on the deck began to notice movement an almost like airplane wing lift in the bridge so unlike just kind of horizontal movement they began to feel a vertical lift in the bridge especially in the center span you know there was no suspension bridge anything like this anywhere in our part of the world anywhere in the Pacific Northwest so that was an unfamiliar arity with just how a big thing like this was supposed to behave so people excited about it there is a certain musical kind of gracefulness about a bridge like this so people I guess just wanted to think it wasn't anything wrong that it was normal and once they get all the concrete down on the deck and everything they just a weight was added that that would all go away and then as we went out of summer and began to get into fall and the winds picked up a little bit our prevailing wind out of the Southwest which blows almost directly on to across the bridge deck they began to notice that the that there was an undulation in the deck and by fall soldiers were coming out from the military base for the novelty of riding the bridge so they'd go out and they'd kick their feet over the railing and stand on the out side of the bridge and lean out as far as they could and the center deck of the bridge would be rising not just inches but feet to a point where the undulation was so severe that to bottom mobiles our truck on an automobile coming in opposite directions the headlights of the vehicle coming at you would disappear under the rolling kind of hill of this of the deck so for conservative people something was horribly wrong from the very beginning for a community that was proud of their new bridge for the many people that participated in building the bridge it was unthinkable that this was wrong but the engineers began to work on the idea of some stiffening of the bridge they thought that the the railings on the side could be converted into sort of deep eye beams and that that would add some rigidity to the bridge and so some of those minor structural additions modifications were implemented or were about to be implemented as we got through October of 1940 and by early November of 1940 really only four months four and a half months after the bridge had been completed the weather began to shift into its winter patterns and and that really was the bellwether of what was about to happen on the morning of November 7th the winds kicked up to about 40 miles an hour and they were fiercely directed right at the side of the bridge as if it the wave wind comes over the wing on an airplane and instead of the normal undulation of the bridge the deck began to twist begin the turn and everybody noticed immediately that had been watching the bridge that that was a behavior people had not noticed before and so early in the morning of the 7th there were hundreds if not thousands of people that had come out on both sides of the bridge to be able to start to watch what was happening start to watch this behavior that the bridge keepers it was a toll bridge so the bridge keepers had had decided that they would close the bridge this just was wrong it just was not safe anymore and indeed it was it was just not a not a action that should happen with an inanimate object of this size one last car was coming across the bridge even though the access to the bridge had been shut off there was one last car coming across the bridge a man with his coming from his summer home over on Kitsap Peninsula headed towards Tacoma had a cocker spaniel with him in the car and by the time he got to the most severely moving part of the bridge deck he couldn't control the automobile so the car swung just screeched around and sort of ended up kind of diagonally across both lanes on the bridge and he jumped out and ran and got off the bridge and then for the next 30 or 40 minutes the bridge went in to just a violent just movement that no one had seen before and all the crowds on both sides all sort of you know closed in to just watch so there was I think everyone started to suspect that the impossible was about to happen that the bridge was going to was going to give it up was going to fail [Music] predator [Music] hit me hit me someday I will once I loved girl named gender standstill just like fall one day she jumps off the road into a dead deal she laughed in his head that we passed along but I held on to the dashboard with those wounds are prepared and fell of falling and girls jumper across the projection in the air [Music] and someday I will live in the end and in the air [Music] with no one really on the bridge strangely enough a university professor who had worked on trying to solve the puzzle it was enough time for people to be able to get out there and here's a University of Washington professor farquharson actually ran out onto the bridge trying to get the dog out of the car and there are there's great footage of him it looks like a Steven Spielberg movie today you watch that footage and you cannot even imagine that somebody would would run out onto the bridge and you know with this tearing sort of deck he got out there the dog was just too terrified to get out of the car so he gave up and then kind of strolled back was knocked down a couple times by the movement of the bridge finally got off the bridge and then in a few moments that followed the deck tore away from the hangers and maybe witnesses talked about it being like listening to gunshots because the the jewels they're called these big bolts that are the cable comes down goes through the deck and then there's a big bolt on the bottom to keep it from pulling out those jewels begin to pop and the cables begin to snap under the force the light standards on the bridge are just cutting swirling across rapidly and catching on the cables and in just a moment the connection between two sections of the bridge deck fail and there's a violent twist and tear of the deck and in the moments that followed that huge sections all begin to fail and most of the center span of the bridge underneath the big suspension cables falls way drops away from the bridge and then just plunge into Puget Sound no one is killed in the incident no one's even hurt so they demolished as much as they can this in November of 1940 and then as they begin to think about really having to reengineer the whole thing the clouds of war closed in of the site of the Second World War and by that time they realize there's no way during the war effort that they're going to be able to get the bridge rebuilt and then Pearl Harbor happens the Bremerton shipyards become a critical strategic thing and the focus shifts away from public works projects and in fact the towers and the steel on the bridge is actually removed and brought into the war efforts recycled and turned into bullets and tanks and whatever actually sections of the bridge of the steel are actually used on the alaska highway to build a highway up to Alaska during the Second World War because of the lend-lease program and the ties with the Northwest in Alaska so so it really the the the remnants of galloping gertie set in the channel through war and then it's only after the war that they begin to reconstruct a another suspension bridge and then in 1950 the second Tacoma Narrows Bridge is complete and that's the bridge we see in the distance here the steel bridge that's standing the steel towers in the distance I doubt that there's a textbook or a reference book written about bridge engineering that doesn't include Tacoma and the index because of the coma Narrows Bridge and it's impossible for me to imagine that engineering students all over the world have seen the film of a galloping dirties collapse it is one of those absolutely spellbinding moments in engineering history one of those Aster's those other failures of design that is completely captured on film and it is amazing it still is jaw-dropping to see a huge endeavor like this a physical object move with this much just dance almost with this much movement that are out of the parameters of the original design

Channel: BoogieFinger

Views: 205,236

Rating: 4.6229625 out of 5

Keywords: Tacoma, Bridges, wind, civil engineering, design, bridge design, bridge collapse, galloping gertie, 1940

Id: 1lX0UHdaPpg

Length: 14min 43sec (883 seconds)

Published: Sun Aug 06 2017