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US Navy set off a 40k-pound explosive to test its new supercarrier (businessinsider.com)
101 points by throwkeep 41 days ago | hide | past | favorite | 119 comments



Shock tests: dramatic to view from the outside but ESSENTIAL to make sure you know how a ship will respond to concussion. There are a couple of large-type nuclear reactors on that ship and if a sudden jolt would cause the cooling loop to rupture it's better to know that now than in battle. Granted, the reactors are (or at least WERE) massively over-engineered so these exercises are more about all of the rest of ship's systems coping with a close-aboard concussion without electrical or communications blackouts from ruptured systems and connections.


What happens to that reactor if it's damaged (or destroyed) in battle? I guess what I'm asking is: what are the failure modes we're talking about?


It depends on where exactly the ship is when the reactor is damaged, but in general water is actually pretty good at containing radiation so my guess is that some wildlife will die or get cancer but it won't have long term effects like Fukushima did because the ship will sink and kill the core before it melts down, if it even melts down in the first place.

Regardless, it won't really matter, since sinking a US aircraft carrier probably means nuclear war.


> since sinking a US aircraft carrier probably means nuclear war.

USSR/Russian strategy against air carrier groups are nuclear torpedoes (launched from subs) and swarming nuclear cruise missles diving underwater some last mile before impact (launched from ships/subs/coast/heavy bombers).

Also don’t need to hit precisely - miss by couple hundred meters will do too.


Right, if we've got nukes in the water, who cares about what the on-board reactor is going to do. Whatever happens is certainly not going to be pretty.


The reactor has a larger fission product and transuranic inventory. It is the more dangerous one over an intermediate timescale after the short lived induced radiation goes away.


> sinking a US aircraft carrier probably means nuclear war

Remind me again what the geopolitical consequences were of the bombing of the USS Cole in 2000?

https://en.wikipedia.org/wiki/USS_Cole_bombing

Sinking a US aircraft carrier (especially if by proxy rather than uniformed military) probably means some strong statements and some court cases.


Did you forget the part where we went to war for 20 years and tore the entire region to shreds? Do Iraq, Afghanistan, or Sudan remotely resemble functional sovereign states after US intervention? What about the thousands of drone strikes and hundreds of thousands dead?

I would not describe our intervention in the Middle East as "some strong statements and some court cases."


That wasn't in response to the USS Cole bombing. Don't conflate that with 9/11.


9/11 was not an isolated incident and was the culmination of nearly a decade of damaged ME relations. If you'll remember, Desert Storm had been 10 years before, and Al Qaeda had bombed the WTC 8 years before. It was 9/11 that forced the US's hand, but it was not only 9/11 that justified their choice.


Blowing a hole in the side of a destroyer in harbor is hardly comparable to sinking an aircraft carrier.


> since sinking a US aircraft carrier probably means nuclear war.

Nice to know the US mentality hasn't budged an inch in 75 years. Please don't nuke the rest of us because you lost a dick waiving contest.


An Nimitz class aircraft carrier has around 6,000 crew members on board. Sinking an aircraft carrier would be an attack worse than 9/11 and elicit a similar response. Maybe some crew members would escape or get rescued, but a bomb large enough to blow up an aircraft carrier is also going to be large enough to kill everyone on or below the deck.

The space race was a dick waving contest and nobody was intentionally killed for that. Bombing naval vessels is not a dick waving contest.


> and elicit a similar response

You mean your going to invade a totally unrelated country and fight another 20 year unwinnable war?

Sign me up, that'll do wonders for my options scheme.


Have you forgotten why a US military was necessary just 75 years ago to save the UK from destruction?

https://en.wikipedia.org/wiki/Operation_Sea_Lion


Check your timeline. The US wasn’t even in the war then. Though American help was instrumental later in the war, the UK actually saved itself from invasion (with help from fellow Commonwealth nations). https://en.wikipedia.org/wiki/Battle_of_Britain


My point was not about US involvement in a specific battle but that of Nazi Germany's clear intent to invade the UK, likely only eventually abated by US involvement.

Like you said, the UK saved itself (for now), but "American help was instrumental later."


After the Battle of Britain ended, and Operation Barbarossa started, it was impossible for Germany to invade the UK. That was 6 months before the US entered the war.

I get the point you're making, but American military involvement had almost nothing to do with the UK repelling German invasion specifically.


Not specifically. Imagine the war without US involvement. No more Western and Eastern front. Germany still wouldn't have captured Moscow but they would have secured large swaths of eastern territory and thus economic might. They would've had stable control over most of Europe and been further bolstered economically and militarily to eventually take the UK.


>No more Western and Eastern front. Germany still wouldn't have captured Moscow but they would have secured large swaths of eastern territory

I don't understand, in your made-up hypothetical, is there an Eastern Front or not? Or, are you mis-using "Eastern Front" to refer to the war with Japan perhaps?

As soon as Germany lost the Battle of Britain and then failed to immediately take Russia, their fate was sealed. The war was lost, period.

The next question was - would Russia overrun all of Europe (including Western Europe)? Without US involvement, that may have actually happened. Thankfully, it did not.


Terrible choice of battle, One that the UK won handily of its own ingenuity and cunning as stated in the wikipedia.


My point was not about US involvement in a specific battle but that of Nazi Germany's clear intent to invade the UK, likely only eventually abated by US involvement.


I means that someone's destroyed a USN super carrier, so the world has bigger problems to worry about?


Another example of why this sort of testing is important - without pressing the "because nuclear" emotional button: In WWII, Germany's new "pride of the Third Reich" battleship, Bismark, had her main radar equipment disabled during her first major battle. The cause? Concussion from firing her own guns. You'd think they'd have designed for and tested that, but...

(Your friendly, local WWII naval warfare enthusiast - or a few well-chosen YouTube contributors - can cite many, many more cases where shock/concussion damage was a painful or fatal surprise for the crew of a ship. Especially in battle, damage to important ship systems or structures tends to cascade rapidly out of control.)


Oh, they finally got that done. That was supposed to be done back in 2019, before the next carrier in the Ford class (CVN-79, the Kennedy) was launched.

They're still having problems with the electromagnetic launch system. Not, apparently, in the catapult itself, but in the system that powers it. Which is a big flywheel/generator thing. Output is about a megawatt, comparable to the highest performance Tesla cars.

The thing was designed about 15 years ago, before high-power electric car technology was widely available, so it's all custom. The next generation of this will probably be built using off the shelf electric auto parts. Probably on the PLAN's Type 003 aircraft carrier, scheduled for launch next year.


Sounds like power output is more like 100Mw.

> Each three-second launch can consume as much as 100 million watts of electricity, about as much as a small town uses in the same amount of time. “A utility does that using an acre of equipment,” says lab engineer Mike Doyle, but due to shipboard space limitations, “we have to take that and fit it into a shoebox.” In shipboard generators developed for electromagnetic catapults, electrical power is stored kinetically in rotors spinning at 6,400 rpm. When a launch order is given, power is pulled from the generators in a two- to three-second pulse

https://www.airspacemag.com/military-aviation/how-things-wor...


You're closer than I was. A maximum-load launch consumes 121 megajoules, which is 121 megawatt-seconds. Catapult launches take about 2s, so they need 60MW or so.


Makes sense, F16 is about 5-10 times heavier than model S and it needs to go in 2s from 0 not to 100 but to 200km/h


By the way, going to 200km/h instead of 100km/h is a 4x change in energy required.


Carrier launch is mostly F-18 aircraft of various variants, which are about 2x heavier than an F-16. An F-35 can be over 3x.


You're right, F-35C MTOW is 31,800 kg


I wonder how many fish died? And do they do anything to try and minimize the death toll of the sea creatures?


I think the larger amount of damage is done to the marine mammals, sea turtles, and other animals that are sensitive to sound waves.

The real damage isn't from the actual explosion per se, but from the massive sound wave which propagates far from the site underwater[1]. That assessment is discussing explosions much smaller than the one the Navy just did (and is scheduled to do twice again).

I'd like to believe to do something to mitigate the damage, but I don't know what they could possibly do for something this violent.

[1] https://www.doi.gov/sites/doi.gov/files/migrated/deepwaterho...


Based on their lack of carefulness when doing hull cleaning I wouldn’t expect it


they drop pamphlets in the water, of course


Underrated comment.


Hopefully there's a way to scare the whales and other larger ones away prior too.


Yes, making loud noises. Dolphin savers do that by banging steel tubes in the water, so dolphins swim away from the Japanese kill squads.


Wondering how much of that is actual test and how much is posturing in context of South China Sea pass-throughs.. "this is the bomb we have to use just to test because, you know, our ships are that strong..."


For those worried about sea life, it looks like the Navy have SOPs in place for shock trials to prevent/minimize harm to marine mammals and sea turtles

https://www.whoi.edu/cms/files/Shock20Trials_46705.pdf


They have an array of underwater beacons. They don't care about animals or anything else that does not help them take whatever they want at any given moment


Not quite a full ship shock trial but there are lots of videos for MIL 901 shock testing online. The barge test is my favorite:

https://www.youtube.com/watch?v=swAWpmboN64


A funny thing about modern military theory is that drills and tests like these have helped ensure that another major world war will happen again, and why major world conflict abruptly dropped to 0 in the 1940s. So yes, these tests probably aren't great for the environment, but these things directly prevent thousands of bombs being dropped in World War 3.


I honestly think having several thousand nuclear warheads still pointed at various targets is what's really stopping WWIII. Aircraft carriers are sitting ducks in any major conflict and they know it. They're fine if your adversary is working a level or two above the stone age, which is the type of wars we've been fighting.


Sitting ducks? You have any idea how hard it is to find a carrier if you don't already know where to look? The ocean is a pretty big place, carriers move pretty quickly, and spy satellites only have a relatively narrow cone of view with enough resolution to detect one from orbit.

Even if you found one visually, guiding a missile to accurately strike a moving carrier is extremely difficult. It's one reason China's much touted "carrier killer" missiles are less of a threat than the Chinese would like. While they could theoretically sink a carrier they rely on a complex system of satellites and radar to guide a missile in, disruption of any one piece of that system (remember the US has successfully tested anti-satellite weapons) and you won't be scoring any hits. Never mind the multi-layered missile defense systems that all carrier battle groups run with, which wouldn't be a guarantee but would have a chance. The most those missiles would is force the carriers to stay further away from the Chinese coast, which given the range of modern aircraft isn't that much of a burden if we're talking sea control.

As for naval combat, there's no combination of ships in any country's Navy that can hope to stand up to the US Navy in a protracted conflict. US carriers have undisputed rule of the seas for at least the next three decades, even against the likes of China/Russia.


There have been multiple instances where submarines surfaced right inside a carrier group, some in active exercises where a threat was expected. Even the Chinese did it at least once and there is a high chance that the Chinese did not surface on their first few encounters.

https://www.dailymail.co.uk/news/article-492804/The-uninvite...


That was 2007, or 14 years ago. I imagine the Navy has long corrected whatever error allowed that to happen, particularly given that China is now seen as a geopolitical adversary by a majority of Americans across the political spectrum.

Even if China did get extremely lucky and took out a couple of carriers in the opening shots of any conflict, there'd be several more on their doorstep within weeks at a far higher state of readiness.


That’s inexplicable because spotting that submarine is completely trivial. They run on diesel if I’m not mistaken, even now. You could easily blanket the area below you with radar. They must have simply not been looking, probably because there wasn’t any threat at all of attack.


The Swedish sub that surprised a US carrier at a training exercise was indeed diesel-electric, which is a great advantage. When stealth is required, they can use only their electric engine, or even stop it all together if the enemy is very close and listening. With a nuclear sub, the reactor and its cooling are always there.


I think the secret ingredient of "the Swedish submarine that sank an US aircraft carrier" is the Stirling engine:

https://en.wikipedia.org/wiki/Gotland-class_submarine


Ah indeed, forgot that tiny bit.


And that laissez-faire attitude towards operational security is what an adversary would count upon in a sneak-attack first strike scenario.

Remember the USS Cole?


Blanket the area below, as well as detect incoming very fast and small RCS objects, furtive aircrafts, small surface vessels, all on high sea clutter... I feel people have a very inflated idea of the actual performance and capabilities of on-ship multimission radars.


Can’t they just fire like 50 missiles in the carriers general area to airblast detonate?

Plus how hard is it to track the location of a huge ship like that… is it that hard?


> Can’t they just fire like 50 missiles in the carriers general area to airblast detonate?

A supercarrier would not sink from a nuclear airblast in the general vicinity.

In 1946, the US performed an experiment to see how such an airblast would destroy or damage ships, in the operation Crossroads, test Able. The bomb was a 23 kT one (so a bit higher yield than Hiroshima). It detonated at a hight of 158m. The light aircraft carrier USS Independence (10k tons) was only about 500m from the point of the detonation, and although severely damaged, it did not sink. The fleet carrier USS Saratoga (37k tons) was about 2 km from point zero. It suffered even less damage.

https://en.wikipedia.org/wiki/Operation_Crossroads#Able_targ...


Even if the ship survived, can the crew survive at less than 500m from ground zero?


Quite possibly. The classic nuclear weapons did their damage mostly through heat and pressure. They were relatively ineffective against troops in armoured vehicles, which is why alternatives like the neutron bomb were developed.

That said, the Hiroshima bomb was small by modern standards. A single Minuteman III missile can carry three W78 warheads, each with a yield of ~340 kT. China has similar nuclear capabilities.

It would be an unmitigated global catastrophe if those sorts of missiles started flying. Nobody would be safe.


China has approximately 300 nuclear warheads total. If they used 50 per carrier, they'ed still have half a dozen supercarriers to deal with, and now the American nuclear retaliation as well.

And 50 warheads might not even do it - naval ships are hardened structures, a carrier could likely survive a detonation within about 3 km for even the largest weapons in chinese inventories, and perhaps within hundreds of meters for a more realistic tactical weapon. 50 missiles each with 200 kt warheads would be able to clear an area roughly 30 km in radius, which a carrier could likely escape in about half an hour. Using 300 5Mt warheads, you'd need to know the position within 85 km, which it could travel in about 90 minutes, which is coincidentally about how long it takes for a spy satellite to complete an orbit.

Carriers are big, but oceans are really really big. Way too big for a brute force solution.


China has purpose-build non-nuclear anti-ship cruise missiles. There is a running game of chicken between the CCP and the US about whether they would dare use them against a US carrier group stationed in the SCS. The way the game theory works out, no they wouldn’t, but the sitting US president needs to have the stones to continue navigating the SCS.

Xi Jinping bluntly promised Obama he would not occupy the SCS, and then did exactly that, and Obama blinked and did nothing. All the other countries in the region, from Japan to Australia to India, are now crapping themselves as China extends further. For example, they are now regularly pushing military ships posing as fishing vessels into Indonesian waters as a repeat of the ‘cabbage leaf’ process they executed in the SCC. Indonesia is in a precarious position because it does not want to be muscled out, but they took on a lot of debt from Belt and Road for stupid initiatives. There are other countries in a worse situation. East Timor has taken on debt from b&r equivalent to a full year of its GDP, and sits on the edge of the Australian oil shelf. Australia is in a weaker situation than it should be due to not having enough coast guard style ships, and the difficulties sourcing world-class conventional attack subs.

This show may be the US signaling that it has learnt its mistake and won’t be had again.


I don't really see how non-nuclear cruise missiles affect the math of blanketing an area with nuclear weapons.


My post could be read as a correction to yours. Unintended. Perhaps I should have replied to randomopining. You made a significant point about the number of Chinese warheads. Once nuclear misses are discounted, I think it is significant that China has a type of non-nuclear missile that is designed for attacking carrier groups.


Yeah Obama was weak in this regard. Actually I've read that Biden had some of the most hawkish views on CCP in the admin. Obama was too naive, he believed in the good of countries etc. And I say this as an Obama support who voted for him.

Realistically though what could he have done? They should've been airtight on the CCP since the 80's 90's.


I agree with the thrust of your comment. The current situation is the result of decades of us (west) misreading the situation, rather than a single event of one US president. We saw what we wanted to see, rather than what was there.


Won't the nukes and EMP's fry the electronics which make them useless?


No, only high altitude detonations produce strong EMPs and carriers, like most high value military targets, are shielded even against those strong EMPs.


If we're talking nukes maybe (although if we're talking nukes carriers are largely irrelevant and nuclear missile subs become the primary threat), but once again the ocean is big. However huge the ship is, your search space is far larger. Even getting a siting from orbit could potentially be disrupted by weather. In the case of the pacific ocean you're literally looking for a moving football field in ~60 million square miles of ocean. Carriers in wartime wouldn't be sailing in straight lines over long distances either.

National interest had a good line about it: https://nationalinterest.org/blog/buzz/why-its-really-hard-s...

"And because carriers are constantly moving when deployed at up to 35 miles per hour -- fast enough to outrun submarines -- finding and tracking them is difficult. Within 30 minutes after a sighting by enemies, the area within which a carrier might be operating has grown to 700 square miles; after 90 minutes, it has expanded to 6,000 square miles."

Binkov on YouTube did a good analysis of the threats modern carriers face as of last year: https://www.youtube.com/watch?v=Ui8sBMA3VGM&t=205s

TLDR there are some technologies likely to show up in a decade or so that may make carriers harder to use, but would hardly render them obsolete.

As for conventional missiles, Binkov also did a good analysis on how many missiles it would theoretically take to take out a single AEGIS equipped destroyer. Carrier battle groups would have multiple such destroyers in addition to their own missile defense and those of other accompanying ships. https://www.youtube.com/watch?v=ZcwDfaY4OW4


> As for naval combat, there's no combination of ships in any country's Navy that can hope to stand up to the US Navy in a protracted conflict. US carriers have undisputed rule of the seas for at least the next three decades, even against the likes of China/Russia.

I don't know, hypersonic and/or nuclear warhead cruise missiles and nuclear torpedoes with significant range can do serious damage from a decent distance.


Not sure about the sitting ducks part. Carriers have mini iron domes to protect themselves from incoming ballistic missiles. Not to mention that they are moving targets, often themselves loaded with nuclear armed missiles (in case of an actual war).

They are a very very effective way to project power. It takes a lot to down one and in the process, the enemy will take a tremendous amount of damage.


Indeed, but it is far more complex than that. William Spanial (prof) has a full course on Nuclear Proliferation that's on-going on YT, I highly recommend academic and rigorious take on this topic than the random hoo haa on the internet: https://www.youtube.com/playlist?list=PLKI1h_nAkaQqivWh2_XEt...


80 million people died in WW2 so I dont think we can say there was reduced world conflict in the 40's

For the second half when it did reduce I'd say that is more because nations were exhausted from WW2, countries saw the horror of war more than ever before and started with increasing commitment to United Nations and nuclear weapons.

Maybe Ive misread what your were trying to say...


I meant that the 40s were the last major conflict. I could have just said “since WW2” but sometimes people don’t realize that it’s 2021 and 1945 was almost a century ago.


Aircraft carriers are a tool to plunder weak countries.

Carriers are offensive weapons, not defensive. That's why only USA has aircraft carriers: parasitizing on the world resources requires a huge offensive force that has to be regularly used to send a message: "Don't try to resist if we want your resources".

They have almost zero contribution to the prevention of another major world war.


US carrier groups are the main defence against the ccp’s slow-push into its neighbour’s territory. This test may signal the CCP that their current generation of long-range anti-ship cruise missiles are less of a deterrant for US presence in the international waters called the South China Sea than expected. This should be encouraging to all ASEAN members, and the rest of the Quad. Good book just out on the dynamics in the region, /Red Zone/ by Peter Hartcher.


What has US to do with China neighboring territories that are located on the other half of the globe away from US?.. Same for Afghanistan or Iraq or Vietnam.


It is not equivalent. The US presence in the west pacific is welcomed by almost all the countries in the region, including Vietnam.

All of the countries supporting the US presence want to see the current rules-based order continue, and are alarmed by the CCP's illegal territory grabs.

There is no analogy with US engagement in the Middle East, Afghanistan, or the Vietnam War. That the US is a long way away is also not significant - several of its largest trading partners are in the region, and it has long-standing treaty obligations to many countries.

US security guarantees have served non-proliferation goals since the second world war, and everyone wins from this: lower investments in military, less risk of rogue nuclear weapons, simpler strategic calculations than if every small country had nuclear weapons.


Wow, so woke. Carriers certainly are offensive weapons, but by far their heaviest use was in the Pacific theater in WWII -- would you call imperial Japan a weak country that needed plundering?


Weapons used in WWII were different. There's no use for aircraft carriers now in a global conflict.

It is only an instrument to punish countries that are not willing to give up control of their natural resources (mostly oil-rich countries in the Middle East).


Historically somewhat related: The underwater shot Baker test of Operation Crossroads in 1946 which tested the effects of an underwater nuclear blast on obsolete warships some of which were captured Japanese and German ones from WWII: https://en.m.wikipedia.org/wiki/Operation_Crossroads


And if you want, you can go dive the wrecks of those ships at Bikini Atoll. It's on my bucket list: https://thedirtydozenexpeditions.com/bikini-atoll-wrecks (for one example) But it's about $10000


How much ocean life did that wipe out I wonder?


Prob a decent amount, but not because they were at the site of the explosion, but because an explosion will send a concussive sound wave through the ocean much farther than air. Found this assessment by DOI online and it has some equations and studies done on all sorts of turtles, fish, and marine mammals[1]. I think the largest explosions they are looking at are <1K lbs, this test was 40k lbs.

[1] https://www.doi.gov/sites/doi.gov/files/migrated/deepwaterho...


That's what I was thinking - it's grenade-fishing on a huge scale.

I hope at least some consideration and minimisation of this went into the plan.


Lots on the microscopic level, doubtful any fish or birds since they'd be scared away by the disturbances or not there in the first place. The ocean is massive and the Navy take efforts to minimize their impact on the environment, they wouldn't have done this over a reef.


To be honest, the answer is, "we don't know". And I mean it: this is a nuclear powered carrier, and if it's not clear, there's no permanent place where we store such waste. The Navy has a pretty dirty history of simply throwing such waste overboard before, "the knew any better".


Lots. But only 0.0000001% of the ocean was affected.


Life is not evenly distributed throughout the ocean, so it's possible it had little effect if the location was chosen wisely (away from structure, in wide open water). Not that I think they chose wisely, the US military tends to not care about stuff like that :/


You don’t exactly put aircraft carriers in shallow water, so this blast is unlikely to have done much to any appreciable amount of ocean life.


The Nimitz class carriers have a draft of 11.3m and can navigate the Suez Canal, the Gerald R. Ford class carriers have a draft of 12m so I assume they could too.

The Suez Canal has a minimum depth of 12m at low tide.

USS Nimitz navigating Suez: https://www.youtube.com/watch?v=W_HOjxu8nB8


The fact that carriers can navigate the Suez canal does not mean they can do anything else while they're doing it. A carrier in the Suez canal will be moving very slowly and all other operations besides navigating the ship and keeping its power and engines running will be shut down.

Carriers operate in deep water. The only times they are in shallow water are coming into or leaving port, or transiting a canal like the Suez in order to get somewhere.


I don’t know what you’re arguing against.

The parent comment made a verifiably false statement, I provided video evidence to the contrary.

It may not be carrying out battle manoeuvres in the canal, but it also isn’t immune to threat while it’s there.

I don’t see much reason why it couldn’t operate CWIS or launch missiles or aircraft while it’s there if necessary.

They could also serve at least some of their other, non-war, support functions while in shallow waters.


> It may not be carrying out battle manoeuvres in the canal, but it also isn’t immune to threat while it’s there.

The threat in such a place would not be an underwater explosion a couple of miles away, or a shock wave similar to that caused by such an explosion. It would be bombs or missiles targeted directly at the carrier. Which is not the kind of threat the test in the article under discussion was testing for.

> I don’t see much reason why it couldn’t operate CWIS or launch missiles or aircraft while it’s there if necessary.

Operate CWIS, yes, in the unlikely event that it had to.

I don't think carriers carry missile launchers of their own.

Launch aircraft, not unless they're helicopters or VTOL aircraft; see my response to Retric downthread. Even that kind of launch would be dicey while transiting a canal, since the carrier still needs some room to maneuver for such launches.


As to why you wouldn’t launch aircraft, surface winds while unable to reorient the ship are a problem. Now, they could probably launch an aircraft which is going to land somewhere else, again depending on wind conditions.

Also, shallow waters means something specific, the surface waves are affected by the sea floor. The US Navy actively avoids those conditions for a host of reasons.


> they could probably launch an aircraft which is going to land somewhere else

They couldn't launch anything that wasn't a helicopter or a VTOL aircraft. Carriers need upwards of 30 knots of wind over the deck, in the right direction (blowing from the front) to launch ordinary planes. You won't get that transiting a canal. Carriers do it by going to full speed in the open sea.


Any one plastic bottle affects a yet smaller fraction, and yet we have several ocean gyres filled with material that will last centuries. And they're growing.

I hadn't thought of this consideration before the grandparent of this post, but now that it's been mentioned, it does seem that the time we can blanket dismiss environmental effects in favor of national security are over.


I'm pretty sure no one is going to be setting off 40klb explosives at quite the same rate as plastics are being made and disposed of.


a bit related - typically the outer layer of the underwater part of the hull of large navy ships consists of a gun silencer/car muffler style structures several meters wide to dampen the direct hit explosion of a torpedo or similar scale munition.


Is this true for modern warships? WWII era capital ships had torpedo blisters to protect against hits, but AFAIK modern torpedoes don't work by blowing a hole in the side of the hull, but rather detonate under the keel. And the huge gas bubble formed by the detonation breaks the keel.


Aircraft carrier size baffles. That’s crazy!


> The ongoing shock trials, which the Navy was ordered to carrier out before the Ford could deploy

I wonder if that was intentional.


Here’s the video: https://youtu.be/ziVUumtxNuU

My biggest concern is how much marine life this affected. In Seattle marine construction projects (like piers) are required to implement various mitigation’s like bubble screens to limit shockwaves and sound from traveling, because they’ve found that even just a pile driver can kill fish half a mile away. This explosion is much, much bigger and I assume its shockwave and sound travel hundreds of miles, especially since it apparently set off seismometers and registered a 3.9 on the Richter scale.


This would be detectable a long ways away from the source. Acoustic energy like this attenuates slowly. In marine seismic exploration for oil and gas we use airgun source arrays that develop about 1000-2000 psi. You can watch your hydrophone array and see other crews operating tens of miles away and in the past, before source separation techniques allowed processing of data from surveys where simultaneous acquisition was occurring in close proximity, crews worked together to avoid having their data step on the other party's data so they operated withing time windows to minimize interference.

Nowadays with very precise clocks and event timing down to the gnat's ass fraction of a second it is less necessary since records can be correlated between source sensors and remote receivers with extreme accuracy.

An event that registers as a 3.9 earthquake on a land seismometer far from the source tells you nothing about the energy near the source. That wave traveled thru the water column and into the sediments on the seafloor then into the crust beneath before being recorded at distant stations. It suffered attenuation at each interface due to Snell's Law. Some is transmitted, the rest is reflected across each impedance boundary. The true measure of the energy of this event comes from the near-field hydrophones. I bet they don't release that data. With that you could determine how loud it was at the source. Water doesn't attenuate acoustic signals very well though they do reflect at internal temperature and salinity interfaces. Navies take advantage of this lack of attenuation in their subsea communication strategies which allow communication over huge distances through subsurface water layers. Interesting stuff.

This event will show up on seismic records from hydrophones as a broadband signal with a large bubble pulse and multiple collapse peaks. The initial blast creates a huge bubble that collapses back in on itself and re-forms and collapses several times reverberating. It is huge and will affect marine life many miles from the test location. It would be interesting to see a decibel graph of the energy and power spectrum.

Even though modern seismic surveys are timed to avoid important seasons for known marine life there is no way to minimize the impact this will have on marine life that is currently nearby and "out of season" or out of the public eye.

I mentioned to a fellow geophysicist that submarine echo sounders were likely the cause of marine mammal beachings and this person, a PhD in Geophysics, told me that I was wrong because he had studied the issue for the industry and the energy from those tests was too low, the wrong bandwidth, etc. He said he would buy me lunch and show me the data to back that up.

I'm glad I have had the means to purchase my own lunch since that offer was made.


Judging by the picture of the explosion and doing my trigonometry calculations, it was 2.3 miles away from the explosion.


Cool - fuck the whales so we can test our war machine. This is stupid.


Well, this is short-term. Long-term, if they don't test their war machine, a new war can break up and kill waaaay more whales in the process, quite possibly all of them.


If any whales surface to the top upside down they collect them and cook them up. Cycle of life.


Err, I guess you'd be repulsed at what some society's did to make sure they had enough oil to light their lamps back in the day...


Great argument. You know what people also used to do in the past? Rape and pillage. Let's do that, too! Hey, there's also historical precedent for slavery. Let's reintroduce it!


Or the fact that Japan still hunts whales.


Canada hunts over twice as many whales as Japan. The US almost as much as Japan. Plenty of other countries putting up big numbers as well. Weird to single out Japan when the article isn't about Japan.


For context, whaling in Canada is entirely done by indigenous peoples using (more or less) traditional methods. Japanese whaling is industrial/commercial in nature (even though it’s performed under the guise of “research”).


Any idea of the budget for a test like this?


A carrier group costs around $7 million per day including upfront investment and operating costs [0]. Military high explosive costs around $100/kg, or $2m for a bomb this size. [1]

So, somewhat surprisingly to me, this operation was not just a rounding error in the daily budget.

[0] https://web.archive.org/web/20140813034340/http://www.cnas.o...

[1] https://newatlas.com/cl-20-high-power-military-explosive/240...


I think when you’re doing things on an aircraft-carrier scale the budget is usually, “yes.”


Misleading title.


> US Navy set off a 40k-pound explosive to test its new supercarrier

How is that misleading? Isn't that exactly what they did?


The title was previously "US Navy set off a 40k-pound explosive on its new supercarrier".

They did not, in fact, destroy a brand new supercarrier by setting off a 40k-pound explosive on it :-)


"On" is a flexible word:

> preposition, 1c. —used as a function word to indicate position in close proximity with: a village on the sea; stay on your opponent

* https://www.merriam-webster.com/dictionary/on


Most words are "flexible" and you have to take them in context to choose which of multiple possible meanings is most appropriate. In the case of explosive weapons, "on" usually means that the object of the preposition is the point of impact, as in "dropping bombs on target X".


TL:DR; The phrase "A bird dropped a large splat on my head" generally implies a much more upsetting prospect than simply "A bird dropped a large splat in my general vicinity."




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