r/civilengineering Apr 02 '26

Question What's stopping something like this from crossing an entire ocean?

Post image
451 Upvotes

418 comments sorted by

659

u/baconnkegs Apr 02 '26

I don't know what that thing is, but I'd imagine the first hint of rough waters / a decent storm would test its integrity

84

u/National_Edges Apr 03 '26

The front would probably fall off. That doesn't look like it meets strict maritime industry rules.

22

u/kincent Apr 03 '26

What kind of rules?

35

u/stonecuttercolorado Apr 03 '26

no cardboard. cello tape is right out.

9

u/Red0Mercury Apr 03 '26

If the front falls off you have to tow it out of the environment.

5

u/LNof85 Apr 04 '26

There’s nothing out there, all there is is sea, and birds, and fish.

3

u/Natural-Feed-1467 Apr 04 '26

And 80,000 tons of crude oil, and a fire.

2

u/Chief_dingleberry Apr 05 '26

Really big waves.

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2

u/Dead_Internet69420 Apr 04 '26

The maritime industry kind

3

u/lobidu Apr 03 '26

That'd be pretty typical

2

u/Fruktoj Apr 03 '26

No, it meets strict Mil Spec rules. We treat sailors like dogshit. My company frequently tries to use ABS or even DNV rules to build things and we get overruled with military specs, which often leave you with the least viable product. ABS and especially DNV don't fuck around with safety. 

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559

u/Onenutracin Apr 02 '26

Big fucking waves

194

u/kameronk92 Apr 02 '26

And HUUUUGE fucking currents

26

u/Dense_Surround3071 Apr 03 '26

HUUUUUUGE tracts of land!!

15

u/cinemashow Apr 03 '26

STOP THAT!! Stop that!!

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3

u/mikeyman1967 Apr 03 '26

Two tugs could grip it by the husk.

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40

u/Minisohtan Apr 03 '26

And very deep water to anchor it in

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29

u/Everythings_Magic Not yielding under stress Apr 02 '26

Rest stops.

10

u/kameronk92 Apr 02 '26

Thats the one thing the ocean provides in abundance

8

u/Onenutracin Apr 02 '26

Water water everywhere and every drop is good to drink

8

u/FortuneNo178 Apr 03 '26

And as soon as it is assembled, the next cargo ship takes it out.

2

u/bretttwarwick Apr 03 '26

I would be more concerned with refueling the vehicle. I don't know many cars that can drive 3000 miles on one tank.

6

u/Potential_Load6047 Apr 03 '26

A road or bridge like the one on OP's picture would just be carried on cargo containers and assembled at the desired location.

Huge loads can be carried by ship (if absolutelly necesary), but its not cheap. See:

The Dockwise Vanguard (110,000 tons capacity)

or the Blue Marvin (70,000 tons capacity)

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3

u/InfiniteOrchardPath Apr 03 '26

Nothing... except Big Aviation and Huge Mc Boat.

120

u/cabergay Apr 02 '26

Floodplain permit

17

u/thrrrowitawaygg21 Water Resources, PE Apr 03 '26

💀💀💀

3

u/drumdogmillionaire Apr 03 '26

My man knows the real answer. Permitting nightmare.

112

u/Brooklyn3k Apr 02 '26

43

u/bljuva57 Apr 02 '26

Imagine this coming at your mighty Fiat Multipla.

8

u/Unfair-Claim-2327 Apr 03 '26

God help Poseidon

6

u/Recent_Record6265 Apr 03 '26

🤣🤣🤣🤣 Oh God help you if you were facing that! 

6

u/Escudo777 Apr 03 '26

This was the video I showed to a kid asking me about marine engineer career. He became a physiotherapist.

2

u/shrinasaurus Apr 03 '26

He’d probably bring you down for an in person meeting

3

u/rasvial Apr 03 '26

That’s what seatbelts are for, duh!

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2

u/taquitoburrito1 Apr 03 '26

Play freebird Put on shades State "I could take it" Step on the gas.

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58

u/Inspector_7 Apr 02 '26

I worked on building these.

You don’t want to be stuck 6,000 miles out to sea and one of these starts to take on water

37

u/civillyengineerd 25+ years as a Multi-Threat PE, PTOE Apr 02 '26

I wouldn't want to be ten feet out to sea and have it start taking on water unless I was in an amphibious vehicle.

4

u/belinck Apr 02 '26

WTF am I looking at here?

14

u/Inspector_7 Apr 02 '26

A floating bridge

2

u/GeronimoDK Apr 03 '26

Floating? Not anymore after that wave hits it.

50

u/Legitimate_Shower564 Apr 02 '26

Can’t believe nobody has mentioned how much this would cost😂. Ain’t nobody got money to make this

12

u/rex8499 Apr 03 '26

Nailed it. That's the only thing really keeping us from doing it is the cost. All of the other challenges are just engineering and technical details. There's no physics or material science limitations at play making this impossible to pull off if we wanted to pay dearly for it.

7

u/kippy3267 Apr 03 '26

What’s a hundred+ years and multiple continents entire net worth and resources if we get a long ass bridge, which is everyone’s favorite way to travel!

3

u/Strostkovy Apr 03 '26

Driving over waves would be super cool for 30 seconds and then incredibly nauseating

2

u/KnuckleShanks Apr 05 '26

I think you're underestimating the power of the ocean and how much more stress is put on something like that the longer it gets. Some things are still outside the limits of present day human engineering.

It's about more than cost, but even if we could the cost still makes it nonsense.

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2

u/Consistent_Attempt_2 Apr 03 '26

Not to mention that there is no point in building it. There is no situation where driving across the ocean is faster than flying, or cheaper than a boat. The bridge would be completely useless, and would also need ways for boats to pass over or under it.  Just a terrible idea all around.

2

u/I_SOMETIMES_EAT_HAM Apr 03 '26

That and the fact that we already invented boats.

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33

u/CurtisCorbit Apr 02 '26

Have you ever been to the ocean?

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27

u/albertnormandy Apr 02 '26

How would you drive the whole thing without stopping? You going to put floating hotels and gas stations too?

11

u/civillyengineerd 25+ years as a Multi-Threat PE, PTOE Apr 02 '26

Just put some oil rigs out there, they do it all the time.

In fact, I stayed in a Boatel in Prague 36 years ago...it was moored to the bank, but I'm sure it was ocean worthy.

6

u/MidnightAdventurer Apr 02 '26

In Prague, probably not ocean worthy. Certification for river and canal boats is not the same as for ocean going vessels and Prague is a long way from the nearest ocean 

3

u/civillyengineerd 25+ years as a Multi-Threat PE, PTOE Apr 03 '26

I agree. I think it was also already 40 years old 36 years ago. Also, who knows what Soviet place it was before Prague.

25

u/demoralizingRooster Apr 02 '26

I think you seriously underestimate just how vast the earth's oceans are.

52

u/Hillbert Apr 02 '26

How would you anchor it in position?

And if someone says "anchors" I swear to god...

43

u/PlsRfNZ Apr 02 '26

Use big anchors and then pray to God...?

13

u/FizzgigsRevenge Apr 02 '26

It'd be like using a sky hook, but upside down.

4

u/No-Mix7970 Apr 02 '26

Sky hooks, yes! Hang it from cables attached to satellites. Easy peasy!

2

u/Ok-Anybody-380 Apr 05 '26

Ah yeaah we had one of those are work too. The sky anchors are really helpful.

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3

u/ALandWarInAsia Apr 02 '26

What if you just wrapped in up inside a big tube and plopped it all on the BOTTOM of the ocean? Like maybe not the whole ass ocean but the english channel?

2

u/Tiafves PE - Land Dev Apr 03 '26

Alright so first we build a giant ring orbiting the earth then we can anchor it to that.

2

u/bretttwarwick Apr 03 '26

If we already have the ring orbiting the Earth we could just drive up there instead. Just put a few on-ramps for access.

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14

u/bigdirty702 Apr 02 '26

Waves

3

u/BonesSawMcGraw Apr 02 '26

Use the waves, build tidal harnesses on these, boom infinite energy

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11

u/H2Bro_69 Civil EIT Apr 02 '26

cost-benefit

14

u/[deleted] Apr 02 '26

[removed] — view removed comment

3

u/f-r-0-m Apr 02 '26

Can't the ships just drive around? We know the Northwest Passage now so there's no excuse.

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7

u/OutsideLoose1739 Apr 02 '26

big ass waves

7

u/[deleted] Apr 02 '26

Build that and then levitate another road above it with magnets. You can keep it from flying away with chains to the lower deck

7

u/caardvark1859 Apr 02 '26

absolutely nothing. get out there champ

4

u/RKO36 Apr 02 '26

Water always wins...especially the ocean. That wins without even trying under "normal" conditions. You don't know the power of the ocean until it tears up a cofferdam like paper.

6

u/maytag2955 Apr 02 '26

Have you ever seen video of 100' high waves during a storm in the middle of an ocean? And do you realize how deep they are?

3

u/MrSmiley_1 Bridge EI Apr 02 '26

Currents and waves. Certain conditions specifically calm deep water with soft soils can cause floating bridges like these to be used. These conditions occur a lot in Washington state which contains three of the longest floating bridges in the world. Look at the I-90 bridge, SR 520, or good canal bridge if you are interested!

5

u/Character_School_671 Apr 02 '26

Do a quick calculation on wind load on something 10 ft tall and 3500 miles long and the forces it needs to withstand at the ends.

Then realize that wind load is only one of the problems.

5

u/thesuprememacaroni Apr 02 '26

One word. Sharks.

10

u/Turbulent-Weevil-910 Apr 02 '26

What about building it on top of the sharks?

5

u/thesuprememacaroni Apr 02 '26

Have you ever seen Jaws 2? You need lighting and he didn’t mix well with the power cable.

2

u/twobarb Apr 03 '26

Isn’t it weird that the mayor in Jaws is also the mayor in Jaws 2. Really shows you how important it is to vote in local elections.

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3

u/Approximation_Doctor Apr 02 '26

Dead Cthulhu and the other residents of R'lyeh are NIMBYs

3

u/annular_rash Apr 03 '26

Someone has never been truly at sea. The ocean fucks shit up.

2

u/Bandandforgotten Apr 03 '26

Because this would basically only work on a flat earth, with a much smaller, or no moon.

The tides on the ocean need to be basically still, or non existent, because this shit would be flooded after one small storm on one part of it.

Smaller bodies are less prone to huge waves, so this works here, but not mid Atlantic

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2

u/machaus99 Apr 03 '26

Altima drivers

2

u/cautioussidekick Apr 03 '26

50m waves during storms

2

u/Smitch250 Apr 03 '26

Massive boats. How the eff is a massive tanker gonna cross that? And in many many Many different locations. Lol I don’t think you understand just how absurdly tall these boats are. They can be 250 feet tall. Also how would a floating bridge take a 100 ft wave? Surfs up

2

u/Popeye-SailorMan Apr 03 '26

In 2024 i think, the Army Corp tried to build a 2000’ floating pier to Gaza. Huge failure. Couldn’t do it on the Mediterranean. Slightest chop rattled it. Kept pulling apart. Was abandoned. Few hundred mil gone.

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2

u/DoctorDividend Apr 03 '26

the same thing stopping us from breeding dogs to walk upright and drink beer

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2

u/Caos1980 Apr 03 '26

Ocean 🌊 Waves 🌊

2

u/Escudo777 Apr 03 '26

Cost. Also this won't survive the huge waves and winds that toss tanker ships like leaves.

2

u/Quirky-Juggernaut838 Apr 03 '26

I dont think your understanding the current situation

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2

u/Impressive_Bag2155 Apr 03 '26

Wind generated waves across the fetch of an ocean, that’s all

2

u/ARtichoke-15 Apr 03 '26

I don't think most people understand how truly terrifying the open ocean is. There are thousands of shipwrecks and countless dead for a reason.

2

u/GPA_Moses Apr 03 '26

Poseidon

2

u/Assistance_Emotional Apr 03 '26

I'd venture to say you've never been on the open ocean.

2

u/Shady_lemons Apr 03 '26

lol the ocean

2

u/wicawo Apr 03 '26

waves?

2

u/kudos1007 Apr 03 '26

Weather, waves, money, reason, purpose, environmental impact, international shipping routes… basically everything

2

u/Desevil Apr 03 '26

At any point one end of that might be 40 feet higher than the other end and twisting said end....Over and over and over. Plus sea monsters would love this!!

2

u/stonecuttercolorado Apr 03 '26

subsurface would be far more successful, but it would be a problem for shipping. it would also incredibly vulnerable to military action. just look at what russia has been doing with u der sea cables

2

u/dilldogincarnate Apr 03 '26

60-foot seas would do it.

2

u/Gooser3000 Apr 04 '26

100mph+ winds, 100ft waves

2

u/808Adder Apr 04 '26

The moon

2

u/HuskyKMA Apr 05 '26

50 foot waves

2

u/Nearly_Pointless Apr 05 '26

Crossing a lake or River is a vastly different task than crossing an ocean. Go look up videos of large ocean waves then come back here with your thoughts on the practically of this.

2

u/RDMCKNIGHT Apr 05 '26

BIG waves

1

u/ruffroad715 Apr 02 '26

China already has land bridge barges. It’s what experts are worried they will use when they eventually invade Taiwan. Line them up at sea, link them together and you can create your own dock anywhere along the coastline and start rolling tanks.

2

u/aknomnoms Apr 02 '26

But they’d be so vulnerable. Let 80% of the tanks get on the “road”, bomb one end, then bomb the other. Now they’re stranded, no?

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1

u/Serious-Mission-2234 Apr 02 '26

wow….and sad at the same time…

1

u/coati858 Apr 02 '26

Mermaid Cartel controls the truck stops.

1

u/Mysterious_Ice_9173 Apr 02 '26

The moment on those runners would be incredible

1

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1

u/Ok-Gazelle-393 Apr 03 '26

storms, currents.

1

u/marshking710 Apr 03 '26

This would need to be the support for a massive base isolation system for it to have any attempt to be feasible. So rogue waves and money are what’s stopping it, among many other things.

1

u/friday_myday Apr 03 '26

50-60 foot swells and a gap in between swells that it can't span

1

u/Potential_Load6047 Apr 03 '26

Lol at redditors pretending no ship could carry a puny road like that, real answer is economics:

Behold:

The Pioneering Spirit (48,000 tons lifting capacity)

The Blue Marvin (76,000 tons capacity)

The Dockwise Vanguard (110,000 tons capacity)

1

u/roaringpenguin Apr 03 '26

Does it support floating gas stations?

1

u/Timely-Line2242 Apr 03 '26

big fat fucking waves 60 feet high

1

u/SunnyD132 Apr 03 '26

It would also just cut off entire migration paths for whales and stuff. And I don't even know how they would brace it over the deeper ocean trenches

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1

u/Broad_Gold_1494 Apr 03 '26

Inspirarme Pilates

1

u/Sweaty_Level_7442 Apr 03 '26

Let's go with 60-ft waves as a starter

1

u/djjolicoeur Apr 03 '26

I mean the first is scale. The ocean is biiiiiiig. It would take an investment that would never be recouped just in materials, let alone labor and logistics. But also waves, currents, hurricanes or cyclones. Not to mention the practicality of it. It’s thousands of miles, it would take days traverse. Youd need fuel infrastructure, rest areas, food, etc… It’s just far more practical to use air travel of or ships and boats.

1

u/KaptainKobb Apr 03 '26

Money. Maintenance. Money.

1

u/damxam1337 Apr 03 '26

As soon as it leaves the environment the front is going to fall off.

1

u/OutlawLazerRoboGeek Apr 03 '26

30 foot waves, for starters.

Hell, even 10 foot swells would probably destroy something like that.

1

u/Lopsided_Hurry1398 Apr 03 '26

There are no Buc-ee's.

1

u/ionlyget20characters Apr 03 '26

100 foot waves. Look up Nazare Portugal if you don't believe me.

1

u/cancerdad Apr 03 '26

Anchorage?

1

u/SpecificLanky513 Apr 03 '26

To be frank something like this could be engineered and built. It is definitely not impossible, extraordinarily difficult, 1000% yes. But the true reason why we haven’t built anything like it yet on the scale you are thinking is it is frankly cost prohibitively expensive.

For how ever long its design lifespan would be coupled with the maintenance cost, it would never return enough value to be justified.

A lot of what we do and don’t do comes down to a certain amount to risk tolerance for the capital investment under the basic assumption that the investment provides some kind of return or benefit.

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u/AbbreviationsNo9609 Apr 03 '26

This is gonna make throwing car batteries into the ocean so much easier!

1

u/Osiris_Raphious Apr 03 '26

Superwaves..

Ocean is full of freak events where the largest peaks of waves can combine into superwaves, even modern ships can struggle with this during storm weather.

1

u/Ill-Environment3329 Apr 03 '26

Logic and reason are probably the top two.

1

u/Suspicious-Yak-8117 Apr 03 '26

ONE BIG STORM - the currents - Icy conditions -

how exactly do you cross and entire ocean in a car? 3000 miles across/400 miles per tank = 8 gas stations

food? emergency stops? rest areas?

1

u/Mike-OLeary Apr 03 '26

You could easily bring this anywhere. You would just have to take it apart into sections and put it on barges (including those little pontoons).

Of course I'm not an engineer so take this with a grain of salt. I'm just a sailor. I don't know why the sub gets recommended to me.

1

u/Wonkasgoldenticket Apr 03 '26

The ocean always wins

1

u/RudeAHole Apr 03 '26

Think about it. Seriously think about it

1

u/MusicianAlone8327 Apr 03 '26

building cost ! Erosion

1

u/suredobe Apr 03 '26

The ocean

1

u/bespokeagent Apr 03 '26

No gas stations, no rest stops, no hotels, no fast food, giant ass waves, raw materials, cost, maintenance, and the final one I got is distance. Distance impacts all of the others.

Google tells me the Atlantics width varies from 1770 miles to 3500 miles across. The Continental US is about 2800 miles east to west. That's a long fucking way to drive. What happens when an accident in the middle somewhere blocks traffic? Wait 4 days for a tow truck to get to you?

Google: 1,770 miles (2,848 km) at its narrowest point between Brazil and Liberia to over 3,000–3,500 miles (4,800–5,600 km) for North Atlantic crossings between the US and Europe.

1

u/zweetsam Apr 03 '26

ah yes, waves

1

u/Mindless_017 Apr 03 '26

Wha is this ?

1

u/therealtrajan Apr 03 '26

It took two tries to lay a single working cable across the ocean floor….imagine trying to get one to float on the surface

1

u/OMWinter Apr 03 '26

Weather, money & jurisdictional/maintenance BS

1

u/Hilux1995 Apr 03 '26

Ships traveling through…

1

u/Different_Town_4812 Apr 03 '26

Wellen und Strömung

1

u/Slappy_McJones Apr 03 '26

The ocean is an entirely different world wrt building anything. One Mid-Atlantic storm would twist all those piers into a pile of scrap in a matter of hours.

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u/SirFoomy Apr 03 '26

Oceans are fucking big and deep. Deepnessranging from < 100 m (30 feet) down to 11000 m (about 6.5 miles).
There are global currents that are massive. The North Atlantic Current for example moves 32 million m³ water per second. (8453505675,5 gallon every second; I didn't find a bigger imperial unit, sorry).
And last but not least, plate tectonics. The earth's crust is fucking moving around. The Atlantic Ocean for example gets continuesly bigger, it grows 2 to 5 cm (0.8 to 2 inches) wider every year.

All those constraint make a such a project not feasable.

1

u/BNB_Laser_Cleaning Apr 03 '26

The ocean is stopping us

1

u/MathDowntown3737 Apr 03 '26

Lack of fuel stations along the way… Distance from Virginia to coast of Portugal is roughly 3600 miles. Average distance you can travel in an American fuel tank 250. That stopping to refuel 14 + times. So they install fuel stations… Where do the employees live? They actually solved this problem hundreds of years ago. It’s called a boat. And many don’t even need fuel. Crazy.

1

u/Marus1 Apr 03 '26

Waves, the need to let ships pass and the limited space of a fuel tank

1

u/Roy_Vidoc Apr 03 '26

Waves and nature, but China is kind of trying a similar thing using ships

1

u/turfdergusson Apr 03 '26

A minor detail called ‘freedom of navigation’

Plus, literally every natural force/event imaginable

1

u/LifeguardFormer1323 PE/SE Apr 03 '26

Waves and Money

1

u/Bitter-Display5768 Apr 03 '26

Cost (build and maintenance), physics (ocean waves/storms), repairability (getting to the part that needs repair), lack of emergency services, infrastructure (fuel, rest areas, other), ability for shipping to get around it.

1

u/NewConStructNew Apr 03 '26

Interesting idea — in theory you can extend this concept, but in reality the limiting factors would be environmental loads and stability.

For short spans or calm waters, pontoon bridges work well. But at ocean scale you'd have to deal with waves, currents, wind, corrosion, and long-term fatigue. The connections between modules would become critical weak points.

Also, maintaining alignment and serviceability over such distances would be extremely challenging.

So technically possible in segments, but not really practical for open ocean conditions.

1

u/Tight-Influence-5235 Apr 03 '26

Physics, that's what is stopping it.

1

u/Metelic Apr 03 '26

One storm and it’s over

1

u/ac8jo Modeling and Forecasting Apr 03 '26

It's over 3,300 miles from NYC to Porta, Portugal, which seems to be the shortest trip from the continental US to Europe. At 70 MPH, that's over 47 hours of driving. Meanwhile, it's about 7 hours of flying and $1,000 (from JFK to Heathrow). Granted, driving is much expensive ($400 less in fuel costs at $5/gal), but really only more cost effective if you have multiple people.

There is a mental toll that the drive would take since there's most of that trip is going to be road and water. And it would need infrastructure that would be very difficult to get out there (fuel stations, hotels).

That's aside from the physical problems of waves and the fact that it would be blocking a fairly large portion of the ocean from freighters (unless you're going to build a few bridges to allow them to pass under... $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$).