# When will giant bridge and dams need replacing? **URL:** \ **Category:** Factual Questions\ **Created:** [July 27, 2017, 1:19pm UTC](https://boards.straightdope.com/t/when-will-giant-bridge-and-dams-need-replacing/792261 "2017-07-27T13:19:54Z")\ **Posts on this page:** 13\ **Page:** 3
**Author:** ![Alley\_Dweller](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alley_dweller/32/430_2.png) [@Alley\_Dweller](https://boards.straightdope.com/u/Alley_Dweller)\ **Post date:** [September 9, 2017, 1:36am UTC](https://boards.straightdope.com/t/when-will-giant-bridge-and-dams-need-replacing/792261/41 "2017-09-09T01:36:58Z")
> [@msmith537](#): > > I’m not sure I want to click all these links to Boners and erections.:eek: I agree. It would be much smarter to google “boners and erections.” ---
**Author:** ![Ignatz](https://avatars.discourse-cdn.com/v4/letter/i/3be4f8/32.png) [@Ignatz](https://boards.straightdope.com/u/Ignatz)\ **Post date:** [September 10, 2017, 10:14pm UTC](https://boards.straightdope.com/t/when-will-giant-bridge-and-dams-need-replacing/792261/42 "2017-09-10T22:14:59Z")
Definitely safe for work. They misspelled the name of the Bonner Bridge. It’s a time lapse view of some of the construction. ---
**Author:** ![filmstar-en](https://avatars.discourse-cdn.com/v4/letter/f/50afbb/32.png) [@filmstar-en](https://boards.straightdope.com/u/filmstar-en)\ **Post date:** [September 10, 2017, 11:59pm UTC](https://boards.straightdope.com/t/when-will-giant-bridge-and-dams-need-replacing/792261/43 "2017-09-10T23:59:49Z")
Galloping Gertie was a spectacular example of a design fault leading to the destruction of a suspension bridge. Design faults still arise from time to time that may catch design engineers by surprise. An example of this was the Millenium footbridge across the river Thames that had a disconcerting wobble when it first opened in 2000. This led to a vigorous exchange of views between the architect who wanted a particular style with no suspension towers, a spectacular ‘blade of the light’ and the bridge engineers who built it. While it was never going to fall apart, something had to be done to fix the wobble and it had to be fitted with dampers to absorb the tendency of walkers to subconsciously synchronise their steps. Here is a BBC science program that attempts to explain it all with models and demonstrations of the resonance problem that can affect bridge design. I experienced the wobble first hand when it opened and I found it quite acceptable. I did, however, notice a couple of old ladies with walking sticks having difficulty and being enthusiastically photographed by the press who were clearly onto something. I was not at all surprised when the scandal-hungry newspapers splashed a big story the next day that led to a lot of finger pointing by the professions involved regarding who was responsible for the bill. The bridge was duly fixed and has been pretty solid ever since. It shows that engineering projects can have unforeseen flaws that take designers by surprise no matter how diligent their work, especially when the design is new and uses innovative techniques. ---
**Author:** ![legion60](https://avatars.discourse-cdn.com/v4/letter/l/53a042/32.png) [@legion60](https://boards.straightdope.com/u/legion60)\ **Post date:** [September 11, 2017, 9:59pm UTC](https://boards.straightdope.com/t/when-will-giant-bridge-and-dams-need-replacing/792261/44 "2017-09-11T21:59:53Z")
> [@ssgenius](#): > > A better example is the Brooklyn Bridge (One of the first mega projects) > > [Brooklyn Bridge - Wikipedia](https://en.wikipedia.org/wiki/Brooklyn_Bridge) > > This is a bridge where sections of it are 150 years. It has gone through extensive renovation and refurbishment and is still in as good shape as it was when it was built originally > > However, as mentioned in many posts, it is not these landmark items that I would be concerned about, Moreso, the smaller local bridges and dams that were don’t get the attention of these mega projects. My mate Trigger, a road sweeper, has a broom like that. He has had the same broom for 15 years. It has had 8 new handles and 12 new heads but he swears it is the same broom of 15 years ago. ---
**Author:** ![Scougs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/scougs/32/3158_2.png) [@Scougs](https://boards.straightdope.com/u/Scougs)\ **Post date:** [September 11, 2017, 10:34pm UTC](https://boards.straightdope.com/t/when-will-giant-bridge-and-dams-need-replacing/792261/45 "2017-09-11T22:34:38Z")
> [@Baron\_Greenback](#): > > Similarly the cantilever [Forth Rail Bridge](https://en.wikipedia.org/wiki/Forth_Bridge) in Scotland, in operation for 127 years, is still soldiering on. The thing looks indestructible, but of course it has needed regular maintenance over the years. > > The neighbouring [Forth Road Bridge](https://en.wikipedia.org/wiki/Forth_Road_Bridge), a suspension bridge opened in 1964, fairly quickly went over the capacity it was designed for, and indeed it had to temporarily close recently for emergency repairs, causing traffic havoc in central Scotland. > > Luckily the third Forth Bridge, the cable-stayed [Queensferry Crossing](https://en.wikipedia.org/wiki/Queensferry_Crossing), is just right next door and due to open in August 2017. > > One river, one neat example of infrastructure maintenance, and a [pretty impressive sight](https://pbs.twimg.com/media/CyXnM98XEAAD2KR.jpg) I came in to this thread to post just this example. The Forth Road Bridge is the same age as me. I also deal with more weight than I was expected to 🙂 The new Queensferry Crossing is now open, with a few teething troubles. They are hoping the tailbacks are caused by people just wanting to drive over the new bridge. It should calm down once people are used to the new approaches and the novelty wears off. > [@Darren\_Garrison](#): > > Yep. Which lead to a book called _Dam Busters._ Which led to a movie called _Dam Busters._ Which led to the Death Star trench run in _Star Wars_. Ding! That wasn’t the Dam busters, it was 633 Squadron. ---
**Author:** ![bump](https://avatars.discourse-cdn.com/v4/letter/b/7c8e57/32.png) [@bump](https://boards.straightdope.com/u/bump)\ **Post date:** [September 12, 2017, 2:48am UTC](https://boards.straightdope.com/t/when-will-giant-bridge-and-dams-need-replacing/792261/46 "2017-09-12T02:48:22Z")
> [@legion60](#): > > My mate Trigger, a road sweeper, has a broom like that. He has had the same broom for 15 years. It has had 8 new handles and 12 new heads but he swears it is the same broom of 15 years ago. > **[Ship of Theseus](https://en.wikipedia.org/wiki/Ship_of_Theseus)** > > The Ship of Theseus, also known as Theseus's Paradox, is a thought experiment and paradox about whether an object is the same object after having had all of its original components replaced over time, typically one after the other. > In Greek mythology, Theseus, mythical king and founder of the city Athens, rescued the children of Athens from King Minos after slaying the minotaur and then escaped onto a ship going to Delos. Each year, the Athenians would commemorate this by taking the ship on a ... I’m still using my computer from 1995 in some sense; I never replaced all of it at once- just swapped out various components from time to time. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [September 12, 2017, 11:32am UTC](https://boards.straightdope.com/t/when-will-giant-bridge-and-dams-need-replacing/792261/47 "2017-09-12T11:32:31Z")
I have replaced my computer a few times, but I assure you all I only use recycled or reused bits. Never new virgin ones. \ 😃 ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [September 12, 2017, 2:29pm UTC](https://boards.straightdope.com/t/when-will-giant-bridge-and-dams-need-replacing/792261/48 "2017-09-12T14:29:23Z")
> [@Scougs](#): > > Ding! That wasn’t the Dam busters, it was 633 Squadron. [Nope](http://www.google.com/search?q=dam+busters+star+wars&oq=dam+busters+star+wars). ---
**Author:** ![Scougs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/scougs/32/3158_2.png) [@Scougs](https://boards.straightdope.com/u/Scougs)\ **Post date:** [September 12, 2017, 2:46pm UTC](https://boards.straightdope.com/t/when-will-giant-bridge-and-dams-need-replacing/792261/49 "2017-09-12T14:46:34Z")
Hmmm. Arguments for both. I’d always heard 633 Squadron as the main influence, and this seems pretty compelling: [https://www.youtube.com/watch?v=4OZq-tlJTrU](https://www.youtube.com/watch?v=4OZq-tlJTrU) ---
**Author:** ![bardos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bardos/32/1069_2.png) [@bardos](https://boards.straightdope.com/u/bardos)\ **Post date:** [September 12, 2017, 5:46pm UTC](https://boards.straightdope.com/t/when-will-giant-bridge-and-dams-need-replacing/792261/50 "2017-09-12T17:46:06Z")
What about the Mosul dam built on gypsum rock? Seems to need constant upkeep/repair… ---
**Author:** ![Elendil\_s\_Heir](https://avatars.discourse-cdn.com/v4/letter/e/7cd45c/32.png) [@Elendil\_s\_Heir](https://boards.straightdope.com/u/Elendil_s_Heir)\ **Post date:** [September 12, 2017, 5:58pm UTC](https://boards.straightdope.com/t/when-will-giant-bridge-and-dams-need-replacing/792261/51 "2017-09-12T17:58:20Z")
> [@Ignatz](#): > > Definitely safe for work. They misspelled the name of the Bonner Bridge. It’s a time lapse view of some of the construction. No, it’s just someone driving along the current bridge, showing some construction equipment and rafts off to the side. ---
**Author:** ![ssgenius](https://avatars.discourse-cdn.com/v4/letter/s/b5ac83/32.png) [@ssgenius](https://boards.straightdope.com/u/ssgenius)\ **Post date:** [September 13, 2017, 2:03am UTC](https://boards.straightdope.com/t/when-will-giant-bridge-and-dams-need-replacing/792261/52 "2017-09-13T02:03:03Z")
> [@Isilder](#): > > Football stadiums are Berkerley university require rather dramatic repairs every few years… because they are built over an actual fault . (Baja ) California on one side, the USA on the other. > > However things like bridges and dams are built with movement in mind. > > with dams, they expect the substance of the hill beside it to also move, so as to not leave a significant gap. If a gap develops, they could caulk (or seal) the gap, or if required for structural strength, work on adding an extension that gives strength. Add a new wall downstream ? Basically when they add height to a dam, they have to make the buttresses bigger too … Vital to strengthen the buttresses downstream before adding the height. Not always.😃 > **[Collapse of the Peace River Bridge](https://www.thecanadianencyclopedia.ca/en/article/collapse-of-the-peace-river-bridge)** > > ​The spectacular suspension bridge across the Peace River south of Fort St. John, British Columbia, was opened in the summer of 1943, replacing a ferry crossi... This bridge (which was based on the design of the Brooklyn bridge) collapsed because the shale that is was built on, moved from a landslide causing it to partially collapse after 14 years of use. Interestingly enough, it was replaced by a conventional bridge ---
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [September 13, 2017, 9:04pm UTC](https://boards.straightdope.com/t/when-will-giant-bridge-and-dams-need-replacing/792261/53 "2017-09-13T21:04:39Z")
Little Rock’s main bridge connection to N Little Rock was replaced last year. The original Broadway bridge lasted 93 years. It’s a main traffic artery and gets a massive amount of vehicles. It’s was very solidly built and difficult to tear down. The replacement had been planned and scheduled several years earlier. > **[Broadway Bridge successfully implodes after hours of failed attempts](https://www.thv11.com/article/news/local/broadway-bridge-successfully-implodes-after-hours-of-failed-attempts/334026407)** > > LITTLE ROCK, Ark. (KTHV) -- Central Arkansans waited with bated breath Tuesday morning for the Arkansas Highway and Transportation Department to detonate the 93-year-old Broadway Bridge.   [Previous page](https://boards.straightdope.com/t/when-will-giant-bridge-and-dams-need-replacing/792261.md?page=2)