The Golden Gate: San Francisco's Iconic Bridge

just before we get started with the video today i do want to say that it's brought to you by lucy go to lucy.co and use the promo code megaprojects for 20 off your order today more about them in a bit the large majority of american mega projects that we've spoken about on this channel are on the east coast gambar state building the pentagon and twin towers for example however today we're discussing the most iconic structure in the western united states the golden gate bridge located on the edge of san francisco the massive bridge is famous for its unique orange color and decorative aspects but beyond its iconic image it was also immensely practical despite all that the world didn't actually know of the men responsible for designing it until a couple of decades ago and according to current estimates it may be just sheer luck that it's never collapsed during an earthquake but one thing is for sure it's a sight to behold so let's get started [Music] san francisco sits on the tip of a small peninsula creatively named the san francisco peninsula one mile across the water from san francisco on the california mainland is marin county this one mile wide strait is called the golden gate as it leads from the endless pacific ocean to a complex of bays the largest of which is called the san francisco bay again creative san francisco has been a population center for well over a century but there isn't a ton of habitable land in the city itself the mid-19th century ushered in the california gold rush and the bay area's population ballooned within san francisco the number of residents tripled in the 10 years from 1850 to 1860 from 49 to 150 000. while san francisco was and still is the economic center for the region many of the town's workers lived across the strait in marin county following the population boom the first consistent ferry service was established in 1867 by the sausalito land and ferry service the trip across the strait took about 30 minutes but the boat's limited capacity slowed workers flow into the city around this time the area's most ambitious thinkers proposed building a bridge across the golden gate but the idea was cast aside as impossible and preposterous after all the 2000 meter golden gate strait was known for its inhospitable conditions like 97 kilometer an hour winds thick fog and a sea floor over 100 meters deep by the 20th century though attitudes began to change san francisco was continuing to grow but the lack of easy access was stunting that growth it became the largest city in america to rely on a ferry for such a considerable portion of its workforce in 1916 the bustling town hosted a world spare marked by ambitious futuristic proposals on developing the city with this aura of creative ambition in full swing a man named james wilkins published an op-ed in the local paper calling for the city to finally take the plunge and build the bridge san francisco's city engineer looked into the scheme and estimated that the cost would exceed 100 million dollars which is 2.3 billion dollars in 2020 which is far far from a feasible budget but he also requested proposals from anyone who could conceive of a more cost efficient design the call for input caught the attention of a man named joseph strauss an ambitious engineer who wrote poetry in his free time strauss was no stranger to designing massive bridges as for his master's thesis he developed a plan for an 89 kilometer bridge to cross the bering strait while that design was obviously never built you would know about that he had successfully completed about 400 bridges through the u.s most of which were smaller scale drawbridges strauss's design would cut costs by more than half so he was selected as the project architect under the stipulation that he would work with a team of engineers who were more experienced with such large-scale projects but while the plan was now set in motion the battle for building the bridge was just beginning [Music] strauss would spend the next decade growing support for the bridge and facing opposition from all directions the u.s navy and the department of war worried that the bridge would affect ship traffic or even become a target of bombings which would cut off the navy's ships in the bay area from the pacific ocean the southern pacific railroad was perhaps the most influential opponent as they operated the local ferry service local environmentalists argued that the bridge would ruin the area's natural beauty and other locals feared the tax implications of such an expensive project working in tandem these foes almost succeeded in blocking the bridge's construction but strauss put up a bite and found support wherever he could he filled the newspapers with op-eds and traveled throughout northern california to speak to labor unions booster clubs and politicians one of strauss's most important allies was the growing automobile industry which saw the bridge as a critical step in convincing locals to splurge on cars by the late 1920s the project was officially approved and the land was granted for the structure but the fight still wasn't over the next step was financing the project and the timing couldn't have been worse with the stock market crash of october 1929 came the great depression and money for financing the project was suddenly lost california's government approved the issuance of 30 million worth of bonds the following year which would be almost half a billion dollars today but nobody was willing to put forward that amount of money after two years of traveling the country getting rejected by financiers strauss was on his last leg so he turned to amadeo giannini the president of bank of america and a long-time resident of san francisco strauss pleaded with giannini claiming that the state would scrap the project if they didn't have the funding soon his appeal worked with giannini and bank of america buying all of the bonds supposedly in an attempt to reinvigorate the local economy finally after 15 years of planning pleading and peddling the golden gate bridge had a clear path forward now just before we continue along that path let me put in a quick word for today's fantastic sponsor lucy so who is lucy well it's more like a what is lucy it's a nicotine gum and you might be thinking right now a nicotine gum it's not 1997 simon but well oh contraire my friends i mean it's not 1997 but nicotine gum let me tell you about it one of the smells of my childhood is actually nicotine gum as my dad smoked and he used nicotine gum to give up but it was a weird smell i can remember him saying that it didn't taste good at all but you know it did help him give up smoking so that's a good thing but that was back in the day that was mid 90s so lucy's on that same mission today they're providing a cleaner nicotine alternative through their revolutionary new gun lucy was started by two caltech scientists i felt the traditional products weren't speaking to their generation and they 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projected but it turned out that the city board wasn't actually a fan of his design his first mock-up included two double cantilever spans connected by a central suspension segment and this was rejected because it was apparently too ugly so despite strauss's title many modern historians and engineers claim that the bridge was mostly designed by three other men the first was an engineer named leon moy seth who was most notable for his work on the manhattan bridge in new york myself was the leading proponent of building a large suspension bridge an ambitious decision in and of itself as no suspension bridge had ever crossed such a large body of water moiseff was attached to the project early on as the city board felt his vision was much more visually pleasing another key contributor was irving morrow an architect who had spent most of his career planning residential spaces though moro was something of an unknown at the time he contributed most of the details that made the bridge such an icon personally designing the shape of the bridge's towers their art deco elements and the entire structure's lighting scheme more importantly he is the one who chose the bridge's color thankfully rejecting a proposal by the us navy to paint it black with yellow stripes finally moisef's right-hand man was an engineer named charles ellis though not credited with the title ellis is considered by most people to have been the project's principal engineer this meant that he was responsible for the bridge's overall structural design including dealing with the intense winds that flooded through the golden gate despite or perhaps because of assembling this dream team tensions between the men were often high straus's ego which had been so essential for getting the project approved made it difficult for him to give up so much control he suffered from bouts of paranoia often theorizing that three men were conspiring to get him removed from the project eventually strauss fired ellis when he uncovered that the man had communicated with moy seth who remember was alice's supervisor behind his back despite his firing alice continued to contribute 70 hours a week for the following years before transitioning to academia and becoming a global authority on structural design however one nasty part of strauss's attitude revealed itself in his ability to credit anyone else for their contributions following the bridge's completion strauss was celebrated as a local hero with the city erecting a large statue of the man the rest of the team received little to no credit whatsoever not until the late 20th century did historians reveal that strauss's contributions were mostly limited to getting the project approved now ellis moyes ever morrow are recognized as crucial contributors alongside strauss in designing and building the bay area icon construction finally began on the bridge on january the 5th 1933 altogether the bridge took just over four years to build eventually finishing on may the 27th 1937. the total cost was 35 million dollars 523 million dollars today placing it about one million dollars under the original budget it's unusual for a megaproject the builder's first task was to construct the anchorages for the two soaring towers that would bear most of the bridge's weight the anchorage near san francisco stood 305 meters from the coast while the other was on marin county shoreline the two anchorages required workers to blast excavations in the straight sea floor and pump out 9.7 million gallons of water before pouring concrete to support the structures each of the two towers stands 227 meters at 746 feet above the water the tallest of any suspension towers until the mezcala bridge was completed in mexico in 1993 at the top of each tower embedded in concrete are two main cables that run the bridge's entire length each of those two cables comprises exactly 27 572 strands of wire or over 130 000 kilometers of wire 250 pairs of vertical suspender ropes connect the wires to the bridge's roadway while construction went relatively smoothly for the duration there was one major accident in the final year of building a set of scaffold collapsed killing 10 men however the project could have gone much worse if not for strauss's contribution of placing safety netting beneath the scaffolds to catch falling workers believe it or not this was considered a groundbreaking innovation at the time the movable safety netting saved lives throughout the rest of the project but in one circumstance it was unable to bear the weight of the collapsing scaffolding the bridge stands 67 meters 220 feet above the water and from abutment to abutment is over 2 700 meters long its main body is 1 300 meters which gave it the title of world's longest suspension bridge until it was surpassed in 1964. following the bridge's completion a week of opening ceremonies began marked by president franklin roosevelt sending a telegram to the world the massive structure was finally opened the celebration was raucous with more than 200 000 people walking across the bridge on the first day of opening and the people had much to celebrate though always a lovely and unique city san francisco had lacked a symbol of their stature with the brightly coloured golden gate bridge well they had their icon while the simple act of crossing the golden gate strait was impressive in and of itself the region's geography and climate forced the engineering team to overcome a few obstacles the bridge was designed to safely withstand winds of up to 109 kilometers an hour but in 1951 the area was hit with 111 kilometer an hour winds forcing the bridge to shut down for the day the windstorm revealed rolling instabilities and excessive swaying which could lead to a complete collapse in the worst of circumstances in fact a suspension bridge in tacoma washington designed by joseph strauss had collapsed from wind in 1940 less than six months after it had opened so after seeing the excessive swaying the bridge was reinforced with additional diagonal bracing on the trusses despite the additional reinforcement the bridge has still been subject to shutdown for winds exceeding 109 closing briefly in december of 1982 and 1983 during brief periods of winds around 115 kilometers an hour in 2019 though as part of a larger renovation project many slats on the bridge's sides were retrofitted with more flexible materials creating a more aerodynamic structure now the bridge can safely withstand winds up to 160 kilometers an hour 100 miles per hour which has never been recorded in that area strangely enough the only adverse effect of the new design is that the slats vibrate in strong winds creating a humming noise loud enough to be heard by residents in marin county across the bridge from san francisco the most significant complete renovation in the bridge's history came in the 1980s as we mentioned the bay area is notorious for its dense fog and mists which carry corrosive salt water into the air the golden gate bridge's original deck was made of rebar enforced concrete which can cause corrosion palling and eventually rusting of the metal rebar when mixed in with salt water over four years the entire bridge deck was replaced without ever shutting off traffic access instead of the rebar concrete the workers installed steel orthotropic deck panels which are 40 lighter stronger and more resistant to salt water the project cost an estimated 68 million dollars the final significant engineering challenge was the bridge's location near the san andreas fault this fault places the entire bay area in the middle of some of the world's hottest seismic zones in fact some seismologists predict that a long overdue super quake will hit the city in the coming decades while the bridge was initially viewed as indestructible by earthquakes it turned out this assumption was far from accurate in fact a 98 meter high support arch on the san francisco side of the bridge was vulnerable to collapse in the event of a large quake but the city has been lucky to avoid such catastrophes in the years following the bridge's completion a reinforcement project is underway currently and will soon surpass the surface upgrade as the most expensive project coming in at almost half a billion dollars though the project includes other components as well now despite its beauty and its magnificence the golden gate bridge is famous for one thing that can only be called a tragedy it is the most frequently used suicide spot in the world with most of the deck standing 75 meters above the water jumpers fall for four seconds often reaching alarming speeds of 120 kilometers an hour at such high rates most jumpers are killed on impact after decades of debate the addition of a suicide prevention net was finally approved the net extends six meters off the bridge and is supported by stainless steel effectively making it impossible for jumpers to reach the water though initially due for completion in 2019 the construction has been delayed by a shift in the contracting company's ownership the net is now expected for completion in 2023. altogether the golden gate bridge story is an odd one perhaps reminiscent of the idiosyncratic city that calls it home it remains a symbol of the distances that humankind can cross through creativity ingenuity and determination so i really hope you found that video interesting if you did please do hit that thumbs up button below don't forget to subscribe also please do check out our fantastic sponsor lucy who i'm linking to below and thank you for watching [Music] [Music] you

Channel: Megaprojects

Views: 141,169

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Id: xNG-a1gjxcI

Length: 16min 8sec (968 seconds)

Published: Tue Feb 02 2021