# Could we build a bridge across the Pacific Ocean? **URL:** \ **Category:** Factual Questions\ **Created:** [January 23, 2013, 9:12pm UTC](https://boards.straightdope.com/t/could-we-build-a-bridge-across-the-pacific-ocean/648152 "2013-01-23T21:12:07Z")\ **Posts on this page:** 20\ **Page:** 4
**Author:** ![robert\_columbia](https://avatars.discourse-cdn.com/v4/letter/r/e79b87/32.png) [@robert\_columbia](https://boards.straightdope.com/u/robert_columbia)\ **Post date:** [January 25, 2013, 2:14am UTC](https://boards.straightdope.com/t/could-we-build-a-bridge-across-the-pacific-ocean/648152/61 "2013-01-25T02:14:14Z")
> [@Darth\_Panda](#): > > I’ll be damned if I’m going to ride a witch across the ocean. What if she was made of wood? ---
**Author:** ![robert\_columbia](https://avatars.discourse-cdn.com/v4/letter/r/e79b87/32.png) [@robert\_columbia](https://boards.straightdope.com/u/robert_columbia)\ **Post date:** [January 25, 2013, 2:21am UTC](https://boards.straightdope.com/t/could-we-build-a-bridge-across-the-pacific-ocean/648152/62 "2013-01-25T02:21:12Z")
> [@For You](#): > > Hokkaido to Attu is only like 1400 miles, that would be the longest open-ocean stretch. It would be a sinusoidal-ish structure where half the bridge is sub-surface tunnels, linked to sections above the water, hence yielding the minimum of interference with sea traffic. Once at Attu, it becomes a series of ridiculously long island hops to Alaska. However, Attu is part of Alaska and you are already on US soil. You can’t travel from Attu to Alaska because you are already _in_ Alaska. You could hop to the mainland though. One thing is clear. Whatever islands get hopped across are going to have booming economies during the construction and probably later, more if it is a road bridge and large numbers of travelers pass through as some will want to stop and spend money for food or a room for the night. ---
**Author:** ![Civil\_Guy](https://avatars.discourse-cdn.com/v4/letter/c/d78d45/32.png) [@Civil\_Guy](https://boards.straightdope.com/u/Civil_Guy)\ **Post date:** [January 25, 2013, 2:26am UTC](https://boards.straightdope.com/t/could-we-build-a-bridge-across-the-pacific-ocean/648152/63 "2013-01-25T02:26:14Z")
> [@Siam\_Sam](#): > > How about an underwater tube? Down below the surface low enough that shipping could pass over it? Still have currents - I don’t know how they compare with surface conditions - probably a little more consistent, if not less severe. What’s missing underwater is air. And still missing any convenient anchorage sites. Go down very far and what there is is very substantial pressure. But hey, it does avoid interfering with maritime commerce, and might turn out to be a valid option after all. Still, if we’re doing this just so we can say that we did it, I vote for the bridge across the Bering Straits. ---
**Author:** ![robert\_columbia](https://avatars.discourse-cdn.com/v4/letter/r/e79b87/32.png) [@robert\_columbia](https://boards.straightdope.com/u/robert_columbia)\ **Post date:** [January 25, 2013, 2:41am UTC](https://boards.straightdope.com/t/could-we-build-a-bridge-across-the-pacific-ocean/648152/64 "2013-01-25T02:41:10Z")
> [@DJ\_Motorbike](#): > > Easy! Build a giant ferry where when you drive onto it from one shore you start driving toward the other end, by the time you get to the other end of the ferry it has arrived on the other shore and you drive off without ever having to stop. > > Perfectly practical and eliminates the need to have the bridge span the entire length. Interesting question. Let’s do some rough math. It’s about 5500 miles from LA to Tokyo. Let’s assume that we’re going to let cars on the ferry drive at 60 MPH while on the ferry. The total speed that the car will travel across the ocean is 60 MPH \* speed that the ferry travels. Let’s pick a ferry size. For our hypothetical, our huge ferry will be 90 miles from bow to stern. The total amount of time it would take for a car traveling at 60 MPH to travel all the way from one end of the ferry to the other would be 90 Miles / 60 MPH = 1.5 hours (i.e. an hour and a half). So, to prevent our hypothetical driver from making it to the end of the ferry and driving into the water before docking, the ferry would have to travel 5500 miles in an hour and a half, so it’s speed would need to be 5500 miles / 1.5 hours = 3666 MPH. That’s four times the speed of sound. Yes, you still need to factor in the time it takes the ferry to get up to speed and decelerate. So if it takes 15 minutes to get up to speed and 15 to decelerate before docking, make the boat 0.5 hour \* 60 MPH = 30 miles longer. So the boat length is now 120 miles. Good morning cap’n. Ain’t dimensional analysis wonderful? ---
**Author:** ![Mahaloth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mahaloth/32/1079_2.png) [@Mahaloth](https://boards.straightdope.com/u/Mahaloth)\ **Post date:** [January 25, 2013, 2:45am UTC](https://boards.straightdope.com/t/could-we-build-a-bridge-across-the-pacific-ocean/648152/65 "2013-01-25T02:45:06Z")
> [@Elendil\_s\_Heir](#): > > I think we could do it, but it would be stupid, unnecessary, stupid, grotesquely expensive and stupid. Elendil’s Heir has just convinced me we should do it. ---
**Author:** ![msmith537](https://avatars.discourse-cdn.com/v4/letter/m/d9b06d/32.png) [@msmith537](https://boards.straightdope.com/u/msmith537)\ **Post date:** [January 25, 2013, 2:47am UTC](https://boards.straightdope.com/t/could-we-build-a-bridge-across-the-pacific-ocean/648152/66 "2013-01-25T02:47:38Z")
> [@robert\_columbia](#): > > What if she was made of wood? Or very small rocks? ---
**Author:** ![robert\_columbia](https://avatars.discourse-cdn.com/v4/letter/r/e79b87/32.png) [@robert\_columbia](https://boards.straightdope.com/u/robert_columbia)\ **Post date:** [January 25, 2013, 2:49am UTC](https://boards.straightdope.com/t/could-we-build-a-bridge-across-the-pacific-ocean/648152/67 "2013-01-25T02:49:26Z")
> [@robert\_columbia](#): > > …The total speed that the car will travel across the ocean is 60 MPH \* speed that the ferry travels… Sorry, it’s additive, not multiplicative. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [January 25, 2013, 2:55am UTC](https://boards.straightdope.com/t/could-we-build-a-bridge-across-the-pacific-ocean/648152/68 "2013-01-25T02:55:25Z")
> [@robert\_columbia](#): > > Sorry, it’s additive, not multiplicative. \ ---
**Author:** ![eschereal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eschereal/32/18939_2.png) [@eschereal](https://boards.straightdope.com/u/eschereal)\ **Post date:** [January 25, 2013, 3:16am UTC](https://boards.straightdope.com/t/could-we-build-a-bridge-across-the-pacific-ocean/648152/69 "2013-01-25T03:16:48Z")
> [@robert\_columbia](#): > > What if she was made of wood? A duck! Well, four ducks. Big ones. ---
**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:** [January 25, 2013, 3:26am UTC](https://boards.straightdope.com/t/could-we-build-a-bridge-across-the-pacific-ocean/648152/70 "2013-01-25T03:26:16Z")
> [@iamthewalrus\_3](#): > > Not sure if this is serious, but we definitely can’t build an arch that big, for the same reason that we can’t build a 10-mile-high skyscraper. We don’t have any materials to build it out of that wouldn’t get crushed under their own weight. PBS’s _Nova_ had a show on supertall skyscrapers a few years ago, and several top engineers were quite adamant that the only practical limitations on building skyscrapers these days were money and political will. The engineering know-how is there. > [@Princhester](#): > > Well OK then but would it be stupid? I’m gonna go out on a limb and say… yes. > [@Colophon](#): > > Hey, are you looking for investors? I am! PM me with your credit card number, please. > [@Mahaloth](#): > > Elendil’s Heir has just convinced me we should do it. Excellent! You and **Colophon** can be on the board of directors of my Unnecessary, Stupid and Grotesquely Expensive Pacific Bridge Co. Ltd. ---
**Author:** ![robert\_columbia](https://avatars.discourse-cdn.com/v4/letter/r/e79b87/32.png) [@robert\_columbia](https://boards.straightdope.com/u/robert_columbia)\ **Post date:** [January 25, 2013, 3:28am UTC](https://boards.straightdope.com/t/could-we-build-a-bridge-across-the-pacific-ocean/648152/71 "2013-01-25T03:28:14Z")
> [@TriPolar](#): > > \ Even if we halve the speed that we allow cars to travel on the ferry at to 30 MPH and double the length of the ferry, the ferry still has to travel at over the speed of sound. And steering a 200 mile long boat is gonna be a challenge - that’s about as long as the distance between NYC and Boston! ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [January 25, 2013, 3:38am UTC](https://boards.straightdope.com/t/could-we-build-a-bridge-across-the-pacific-ocean/648152/72 "2013-01-25T03:38:48Z")
> [@robert\_columbia](#): > > Even if we halve the speed that we allow cars to travel on the ferry at to 30 MPH and double the length of the ferry, the ferry still has to travel at over the speed of sound. And steering a 200 mile long boat is gonna be a challenge - that’s about as long as the distance between NYC and Boston! \ ---
**Author:** ![Zebra](https://avatars.discourse-cdn.com/v4/letter/z/c0e974/32.png) [@Zebra](https://boards.straightdope.com/u/Zebra)\ **Post date:** [January 25, 2013, 8:12am UTC](https://boards.straightdope.com/t/could-we-build-a-bridge-across-the-pacific-ocean/648152/73 "2013-01-25T08:12:41Z")
Maybe we can call the bridge Mohamed and then the terrorists won’t blow it up? ---
**Author:** ![LinusK](https://avatars.discourse-cdn.com/v4/letter/l/258eb7/32.png) [@LinusK](https://boards.straightdope.com/u/LinusK)\ **Post date:** [January 25, 2013, 8:32am UTC](https://boards.straightdope.com/t/could-we-build-a-bridge-across-the-pacific-ocean/648152/74 "2013-01-25T08:32:21Z")
OK OK you’ve convinced me. How about an Atlantic bridge, then? ---
**Author:** ![Boyo\_Jim](https://avatars.discourse-cdn.com/v4/letter/b/87869e/32.png) [@Boyo\_Jim](https://boards.straightdope.com/u/Boyo_Jim)\ **Post date:** [January 25, 2013, 8:58am UTC](https://boards.straightdope.com/t/could-we-build-a-bridge-across-the-pacific-ocean/648152/75 "2013-01-25T08:58:34Z")
> [@robert\_columbia](#): > > Even if we halve the speed that we allow cars to travel on the ferry at to 30 MPH and double the length of the ferry, the ferry still has to travel at over the speed of sound. And steering a 200 mile long boat is gonna be a challenge … But at the speed of sound, it won’t be a challenge for very long, so you can stay focused! ---
**Author:** ![Gyrate](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gyrate/32/3588_2.png) [@Gyrate](https://boards.straightdope.com/u/Gyrate)\ **Post date:** [January 25, 2013, 9:40am UTC](https://boards.straightdope.com/t/could-we-build-a-bridge-across-the-pacific-ocean/648152/76 "2013-01-25T09:40:52Z")
I bet [Brunel](http://www.youtube.com/watch?v=21QqXumEWFU) could do it. ---
**Author:** ![eschereal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eschereal/32/18939_2.png) [@eschereal](https://boards.straightdope.com/u/eschereal)\ **Post date:** [January 25, 2013, 7:23pm UTC](https://boards.straightdope.com/t/could-we-build-a-bridge-across-the-pacific-ocean/648152/77 "2013-01-25T19:23:31Z")
> [@robert\_columbia](#): > > Even if we halve the speed that we allow cars to travel on the ferry at to 30 MPH and double the length of the ferry, the ferry still has to travel at over the speed of sound. And steering a 200 mile long boat is gonna be a challenge - that’s about as long as the distance between NYC and Boston! Which means, of course, that the ferry must be completely enclosed, because otherwise the vehicles traveling on it would be facing a supersonic headwind – that would be pretty sucky for fuel economy. Theoretically, you might be able to overcome that issue by constructing the bridge out of a series of ferries cabled together, but even so, the cost of fuel to run the ferries at due speed plus the cost of fuel for the vehicles driving on them would be redundantly excessive, especially considering again the relative headwind issue. Not to mention the fact that for a car to be able to drive along a moving ferry at pace, that means most of the ferry’s capacity will be unused. ---
**Author:** ![steronz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/steronz/32/11765_2.png) [@steronz](https://boards.straightdope.com/u/steronz)\ **Post date:** [January 25, 2013, 8:05pm UTC](https://boards.straightdope.com/t/could-we-build-a-bridge-across-the-pacific-ocean/648152/78 "2013-01-25T20:05:16Z")
> [@Little\_Nemo](#): > > There are floating oil platforms. So presumably we could build a series of structures like those, moor them to the ocean floor, and stretch a roadway between them. Indeed, I’m picturing something [like this](http://steronz.com/random/bridge.jpg). A normal bridge built atop pylons, but the pylons are attached to some kind of a buoyant platform, maybe a low-density foam encased in a steel “bubble”. The anchor is submerged so that it’s unaffected by surface waves, and the bridge itself is built well above water level for the same reason. The platform is then anchored to massive concrete blocks on the ocean floor with long steel cables. The blocks are triangulated to keep the submerged platform in a precise location under the surface. If the bridge is overloaded then the platforms can sink a bit, which would be bad for the bridge surface, but I don’t see any reason this couldn’t be built with existing technology. My understanding is that this isn’t entirely unlike how floating wind turbines or oil rigs work, with the added engineering challenge of connecting multiple platforms together with a rigid structure. Oil rigs and wind turbines can float around a little bit without cracking asphalt. ---
**Author:** ![gnoitall](https://avatars.discourse-cdn.com/v4/letter/g/bb73d2/32.png) [@gnoitall](https://boards.straightdope.com/u/gnoitall)\ **Post date:** [January 25, 2013, 8:15pm UTC](https://boards.straightdope.com/t/could-we-build-a-bridge-across-the-pacific-ocean/648152/79 "2013-01-25T20:15:38Z")
> [@Tapioca\_Dextrin](#): > > Why not just build a floating road? [Pykrete](http://en.wikipedia.org/wiki/Project_Habbakuk) is the way to go. If you’re building far enough north to make Pykrete a viable material, you may as well just bridge the Bering Strait conventionally and be done with it. ---
**Author:** ![Johanna](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johanna/32/8318_2.png) [@Johanna](https://boards.straightdope.com/u/Johanna)\ **Post date:** [January 26, 2013, 5:06am UTC](https://boards.straightdope.com/t/could-we-build-a-bridge-across-the-pacific-ocean/648152/80 "2013-01-26T05:06:23Z")
> [@robert\_columbia](#): > > However, Attu is part of Alaska and you are already on US soil. You can’t travel from Attu to Alaska because you are already _in_ Alaska. You could hop to the mainland though. Not that his has any real bearing on your argument here, but it’s just interesting that the literal meaning of the name Alaska, from Aleut language _alaxsxaq_, is ‘the mainland’. Even more literally, ‘the object toward which the sea’s action is directed’. [Previous page](https://boards.straightdope.com/t/could-we-build-a-bridge-across-the-pacific-ocean/648152.md?page=3) [Next page](https://boards.straightdope.com/t/could-we-build-a-bridge-across-the-pacific-ocean/648152.md?page=5)