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Comment by chiph | Hacker News Reader

I'd hate to have been the helmsman on the Fitzgerald and the McCain, knowing a collision was imminent. But unable to steer away because of a lack of orders to do so.

(If they had, they would have been brought up on charges, in which their saving the vessel would have been a consideration, but not an excuse for their action)

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I thought there was always an Officer of the Deck empowered to make decisions in these situations?

I would also like to know the answer to “a the hull of a billion dollar warship having much less intrinsic strength than a Korean built containership that was delivered for a fraction of the cost?” and the other construction questions asked in the article.

It's my understanding that the bow of the containership struck the side of the warship. The bow of a ship is typically much stronger than the side. I suspect that the damage report would be very different - if not a sinking, then catastrophic damage to the containership, and little damage to the warship if the situation was reversed.

> The bow of a ship is typically much stronger than the side

Especially if it travels through ice in northern nations like here in Canada, ice is like reinforced concrete. A certain amount of ice not icebreaker level but even an icebreaker rides up onto ice and breaks it with the ship's own weight.

Only a handful of ships are reinforced to travel over light ice. They're called "ice strengthened" or "ice class" (https://en.wikipedia.org/wiki/Ice_class). They're really not intended to charge head-long into ice, but are safer when in waters that may contain random and hard to spot chunks of ice.

I'm not aware of any American combat ships outfitted to that standard. In fact, when it comes to ice-hardened ships in general the US has shockingly few, perhaps only two depending on maintenance cycles: https://warontherocks.com/2016/10/icebreakers-and-u-s-power-...

An icebreaker (https://en.wikipedia.org/wiki/Icebreaker) is meant to go charging through and in some cases even over ice. They're tough as hell compared to most ships.

The reason the bow is stronger isn't because of ice, it's because of the pressure exerted on the bulbous bow. It's a spherical protrusion that will have to be tougher or it'll collapse.

> An icebreaker is meant to go charging through and in some cases even over ice.

There seems to be confusion in that sentence, an icebreaker "goes through ice" meaning it works in a region with ice not literally plowing through the ice. Although if the ice is loose and floating yes but an icebreaker is designed with a sloped bow that rides up onto ice and then the ship's weight pushes down breaking the ice. No ship pushes through ice it would be like trying to push on two ends of an egg.

My dad worked for the Canadian Coast Guard for 33 years. He said for really thick ice (several meters) they'd sometimes have to use the ship's crane with a large cement block and pound at the ice at the sides of the ship. The crane is normally used for buoys. Sea ice, pack ice is like concrete great in compression but fails when a multi 100 ton ship in sitting on top (to a limit).

This was the ship my dad served on https://en.wikipedia.org/wiki/CCGS_Earl_Grey

Both U.S. navy ships had damage consistent with being hit head-on by merchant vessels. We're talking about the navy ships' hulls and structure resisting forces necessary to slow down the container ship enough that the ships can disentangle. I would not underestimate the forces that applied.

My understanding is that the OOD can do it (obviously), or the officer in charge of CIC can command a turn (but had better have justification).

There's also this: https://en.wikipedia.org/wiki/International_Regulations_for_...

As I understand, the CIC Watch Officer reports to the OOD and ordinarily has no authority to order maneuvers (only the OOD or whoever either has been delegated the Conn by the OOD or assumed the Conn by authority—which the CO, XO, and Navigator can do—has that authority.)

   I would also like to know the answer to “a the hull of a
   billion dollar warship having much less intrinsic strength
   than a Korean built containership that was delivered for a 
   fraction of the cost?” and the other construction questions 
   asked in the article.

This question is what made me doubt the rest of the article, which is ostensibly written by somebody with some level of naval expertise. I have no naval expertise, and the rest of the article seemed quite logical, but it seems strange to me to insist that this collision shouldn't have seriously damaged the Fitzgerald.

1. The Arleigh Burke class destroyers aren't big ships; the cargo ship was over 3x the size. 9,000 tons for the USS Fitzgerald compared to 30,000 tons for the cargo ship: https://www.nytimes.com/interactive/2017/06/18/world/asia/pa...

2. I am not sure that any ship ever designed by humankind has been built to withstand a 20-knot broadside collision with a vessel of its own size without taking any damage, much less one with three times as much mass. As I said above I'm no naval expert; please take me to school if I'm spectacularly wrong here.

3. While it would certainly be possible to build such a ship, the weight of the ship would need to be increased by an incredible amount. It would be a very slow ship. Or it could be fitted with a much more powerful propulsion system, at a tremendous cost - more weight, more fuel consumption, more $$$.

3a. Modern (the last 100+ years or so) ship collision survivability design principles basically revolve around bulkheads. It's impractical to make the entire hull thick enough to survive any conceivable disaster (because the boat still needs to float - you can't just add ridiculous amounts of armor everywhere) so the general principle here is to contain hull breaches, not to make sure that no hull breach ever occurs.

4. Generally, modern naval battles are not fought by ships ramming each other.

5. So we can understand why the Navy didn't optimize for that possibility, and at some point decided on a "please try not to let other ships ram you broadside" doctrine. Which made a tremendous amount of sense for a very long time, until our ships' crews decided to start tossing themselves about into the paths of oncoming vessels.

6. Seriously though: building ships to withstand this kind of thing without a scratch is crazy for basically the same reasons why building planes to withstand midair collisions with bigger planes (or, really, anything bigger than a seagull) is crazy.

All things considered, hats off to the designers of the Arleigh Burke class and the Fitzgerald's and John McCain's damage control crews. Considering the amounts of force involved here and differences in mass it's actually quite admirable that the god damn ships didn't snap in half or sink instantly.

> This question is what made me doubt the rest of the article, which is ostensibly written by somebody with some level of naval expertise.

It's possibly a naive statement. I think it's a trap.

Fundamentally, the ship isn't designed to be hit at all. it's supposed to be fast and nimble. The walls could be paper thin (aside from getting shot at), because it's not supposed to be rammed in the first place. It creates a nifty dilemma. Either the whole class is poorly constructed, or those in command were complete failures. An expert would have a hard time saying the whole class is poorly constructed.

Less important but still relevant, an inquiry maybe should explain the bow vs side issue in ship strength. It'll dissuade obvious misunderstandings from lawyers, legislators and the general public - non experts.

I posted part, which I guess is missing the whole context in the article. That line is attached to redundant power, communications, and other problems that happened after the collision.

The author of the article is not exactly inexperienced in these matters.

I don't think it was an out-of-context quote. The author questioned why the (theoretically redundant) power and communications systems were knocked totally offline, which seems like a very fair question, and one of great importance. But I read it as a separate question from the issue of why the cargo ship was able to damage the Fitzgerald.

Yeah that's my understanding. Destroyers (and really, any modern naval ship) are not designed to slug it out in ship-to-ship artillery duels like WWI battleships. They are there to launch missiles at targets from a safe distance.

As WWII taught us, any surface vessel is essentially a sitting duck when it comes to air power in the form of planes, missiles, or missiles launched from planes. That is even truer today, as surface-to-surface and air-to-surface munitions have become that much more powerful and accurate. Designing a ship to withstand that kind of punishment is just impractical. The Arleigh Burke class can deliver some real destructive power but as always, air superiority is a must.

(This is where I reiterate that I am not particularly knowledgable on this topic; please somebody correct me if needed)

Modern naval battles won't be fought by ships ramming each other, they will be fought by sending supersonic missiles carrying large explosive chargers. Do these incidents give you any confidence that a modern US Destroyer could withstand even one hit?

I don't know jack about designing armor, but it seems to me that the problems of supersonic missiles and collisions with massive objects present different challenges.

Perhaps it's similar to the way that football pads don't stop bullets and yet bulletproof kevlar vests don't protect you from 300-pound football players?

Regardless, I know that the Arleigh Burke class has a number of antimissile countermeasures.

But the bottom line is: I really don't know of any vehicle (air, surface, underwater, ground, space, whatever) designed to survive supersonic missiles.

I mean, even massive WWII-era battleships were helpless against smaller munitions like 500-pound bombs dropped from planes. Air superiority: either you have it, or your ships are screwed.

Which is precisely the point. The ship is equipped with defense in depth against barrages of supersonic missiles. Defense against large ships ramming them, not so much.

Most modern defenses are active intercept. More and more weapons are such that practical armor doesn't buy you much protection.

> The ship is equipped with defense in depth against barrages of supersonic missiles. Defense against large ships ramming them, not so much.

Its got defense against that, too. Though the first stage of that defense is detection by sensors ranging from the Mk I eyeball to fancy radar, etc.

> Do these incidents give you any confidence that a modern US Destroyer could withstand even one hit?

Destroyers are not designed to be hit by missiles, they are designed to intercept and destroy missiles with Aegis or CIWS before the missiles hit them or the carrier they're protecting.

There is no amount of armor in the world that can protect you from a missile, because they are very easy to scale, all the way up to nuclear warheads.

IIRC I read somewhere on the internet (so it must be true!) that modern US destroyers/cruisers have a limited amount of (carbon fiber, IIRC) armor around a few critical places such as the command center. Not enough to protect against a direct hit, more to prevent shrapnel or spalling from killing the personnel there.

Yes, absolutely. The "all or nothing" armoring philosophy has been the dominant trend in naval armor since WWI.

https://en.wikipedia.org/wiki/All_or_nothing_(armor)

(I don't know about the Arleigh Burke class in particular, but I'd be shocked if this wasn't the case)

Yes, it's also a reason the HMS Hood blew up and intently sank with nearly 2,000 sailors from a single shell hit. Our destroyers are likely to be in battle for just minutes in a real war.

> I thought there was always an Officer of the Deck empowered to make decisions in these situations?

As I understand there must be an OOD, and there may also be a Conning Officer (usually the Jr. OOD) delegated under him and a Command Duty Officer above him, all with authority over shiphandling.

> I would also like to know the answer to “a the hull of a billion dollar warship having much less intrinsic strength than a Korean built containership that was delivered for a fraction of the cost?” and the other construction questions asked in the article.

As I understand, that's expected; warships are lighter, designed for speed and agility, and never double hulled (because that compromises speed and agility.)

There isn't a command duty officer when underway - the operational chain when it comes to shiphandling is Captain->OOD->Conning officer. Even on smaller boats like minesweepers there'll still be a conning officer, though often it's a more senior enlisted.

The big question in all this is "what the hell was the OOD doing before the collision"? Whoever had the deck had primary responsibility for knowing the situation around the ship. Here's a comment by someone who's been the OOD in those waters.[1] The other ship should have been seen tens of miles away on radar, and miles away visually.

A destroyer has more than enough maneuverability to avoid almost any collision. Here's a Burke-class making a hard 180 degree turn.[2] Those ships have 108,000 horsepower gas turbines, huge dual props, and large dual rudders. If the OOD calls for an emergency maneuver, a direction change happens fast. This isn't some underpowered, heavily loaded freighter.

Why isn't the Navy disclosing more about this? Are they hiding something? Eventually it's going to come out.

[1] https://www.facebook.com/richard.nikoley/posts/4734883396502... [2] https://www.youtube.com/watch?v=5Vih4tGmqjs

> But unable to steer away because of a lack of orders to do so.

Is this actually the case? They saw the collision coming but were forbidden to do anything? Or are you just engaging in conjecture?

Because if that is actually the case then it reminds me of NASA and Challenger.

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