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Rolling Airframe Missile (navalgazing.net)
191 points by cwillu on Feb 4, 2024 | hide | past | favorite | 124 comments



So many great articles on this site. This rainy Sunday is in serious jeopardy of falling off the cliff and being sucked into the gravity well wormhole that is navalgazing.net.

https://www.navalgazing.net/Phalanx

I've always wondered how the Battleship guns with the white dome cylinder chamber above the gattling gun worked, but the background story is way more interesting than I expected. Apparently it's called a Phalanx, and no, a person doesn't sit in the white cylinder chamber*.

* Despite Battlefield 2 leading me to believe a person occupied the cylinder, anyone remember Wake Island with the USMC carrier, F-35B, and J-10? haha, good times.


It's a radar directed gun. The dome thing is the radar. Once, a sailor was on top of one and the radar turned on, and it cooked the sailor. That radar has some real power.

The Phalanx motto is "it flies, it dies". It has an autonomous function. Turn it on, and it kills anything in its airspace. However, that's never turned on. WAY too dangerous, there's always a man in the loop.

There's two primary challenges for the Phalanx, also known as the CIWS (though this often pronounced "see whiz").

The first is finding the target in the first place, notably a sea skimming missile, picking it out of the surface clutter. The second is that, once identified, determining that its actually destroyed the target in a timely fashion so as to not keep pumping bullets into a flying debris field.

The system uses the radar to track both the target and the stream of bullets. So, to the radar system, all of the bullets are "tracers" to help the system direct the fire into the target.

Another issue with the Phalanx is that it's not armored, and the possibility of it getting hit by the shrapnel of the missile it took out, is not zero. Unlikely, depending on trajectories, but not zero. The missile may not explode, but it's still a bunch of metal hurtling at several hundred miles per hour.

While designed for the naval environment, the machines have also been deployed, and used in combat, mounted on trailers to be used in forward land positions as point defense against missiles, low flying aircraft, and even artillery shells.

The CIWS was recently used to down a Houthi missile in the conflict currently happening in the Red Sea.


Would the Phalanx have stopped a barrage of Neptune missiles, which were reported to have sunk the Moskva?

Was the defensive weaponry on the Moskva unable to defend against the Neptune, or did the crew make mistakes in operating it?


So this category of weapon is called a Close In Weapon System.

Moskva had 6 of these, the main russian CIWS: https://en.wikipedia.org/wiki/AK-630 It also had 40 short range surface to air missiles.

No one knows the exact details of the strike, but it's been suggested that Ukraine used a drone as a diversion. Another speculation is that in photos of the ship after the attack, the main search radar is in the downward, stowed position. This may suggest it wasn't on at the time of the strike, or it may have been moved as part of damage control.

All that said, incompetence has been a consistent theme with the Russian military in this war, and in particular with their black sea fleet.

Ukraine has had repeated success attacking with small unmanned surface craft, basically Ski-Doo style boats they've modified for remote piloting using a thermal camera and Viasat, and with a bunch of explosives. There's video footage from these attacks on twitter and such, and while it's very unclear, in some of them it appears there's no watch standing on the ship being attacked, or they're shooting at it using small arms rather than the CIWS.

None of this is definitive, but it is all consistent with poor training, apathy, and incompetence on the part of the crews.


The last readiness inspection document of the Moskva was leaked. To put it short, none of the defensive weaponry was working properly, none of it had worked properly for a decade, and no-one was doing anything about it.


In short, Moskva no worky.

From the 10 February 2022 readiness report

– Four of six generators needed repair; two were emergency use only.

– S-300F Fort [SA-N-6] director illuminator nonfunctional

– Both Osa-MA [SA-N-4] directors nonfunctional

– One AK-630 Gatling guns nonfunctional; others unable to load without manual process.

– All (3) MR-123 directors for AK-630 limited function.

Before we get all cocksure of ourselves over here on the USN side, we should probably stop to consider how incredibly down readiness rates have been on our own surface fleet. Between the dysfunctional surface fleet culture, the GWoT madness, government shutdowns, and a complete inability to find sailors who know how to work a mouse, the manpower problem is also, now, beyond critical. Wasn't too long ago we were apparently ramming everything with a navigation light and a destination somewhere in SEA. It's not unrealistic to see a Moskva in our own future, if we're not careful (and maybe stop drinking our own Rah-Rah-USA-Always-Wins koolaid).


Rumor was CIWS wasn’t working on the Moskva. Also some of radars interfered with each other so they kept some of them off. That was inferred off of pictures from the sinking and the radar used to detect sea skimming threats was in the stow position.

There is also more countermeasures than ciws. Warships also can deploy decoys and chaff to confuse radar homing missiles.


If ciws was not operable, then why was the Moskva positioned within range of the Neptunes?


I think the answer to that question can probably be applied to most of the Russian war effort.


In American AEGIS systems, the main AN/SPY-* radar would detect the missiles at distance and surface-to-air missiles would be fired at them. If failed, CIWS systems such as this Phalanx, SeaRAM, Goalkeeper, AK-630... would be activated, and hopefully it autonomously notices incoming supersonic object and engages it.

These systems aren't designed to be left on all the time just in case, but has to be put into standby mode at the beginning of a combat and un-leashed as needed. Moskva wasn't paying attention to the situation and all these equipment were visibly in stored, powered down state in leaked photos. Among suspected reasons were that the sailors were lazy, the Neptune was technically out of engagement range but upper atmospheric phenomenon allowed acquisition by luck, therefore the ship wasn't expecting it, etc.


It should’ve had a ciws system. Probably older kashtan—m (there’s a newer panstir-m system). My guess it was either inoperable or switched off


IIRC Moskva was partly broken.


Conceptually, yes, the CIWS could have been effective against the missile the struck the Moskva.

The US had a similar incident, back in '87, with the frigate USS Stark. It was struck by two Exocet missiles launched by an Iraqi fighter during the Iran-Iraq war. The Stark was in international waters, and the attack was unprovoked. Bluntly, the ship was not expecting the attack, and was unprepared for it. While it was equipped with the CIWS, it was in standby mode. Also, the Stark mounted a single unit in the center of the ship, facing aft. As I recall the missiles actually struck the forward quarter of the ship. Even if the CIWS was enabled, I believe they would have had to turn the ship for it to engage the missiles.

As for the Moskva, let me qualify I have no support whatsoever for what Russia is doing. That said, I do have a base level of respect for fighting forces, and the people who staff them and stand the line.

I was shocked to hear about the Moskva. There's no reason those missiles should have struck that ship. That ship is particularly designed, much like our cruisers, to defeat threats such as those missiles. For the US Navy, a prime role for our cruisers is to defend not just themselves, but a fleet role. In simple terms, the cruisers are there to protect the carriers, and are bristling with systems and sensors designed for that task from several threats.

The Moskva was similar to that role. The CIWS is the "last resort". The CIWS is for when missiles penetrate the other layers of defenses in place, including things like the combat air patrol, air-to-air missiles, etc. The CIWS is a "last mile" defense.

The Moskva had layers as well. It should have taken several missiles to penetrate what the Moskva could have utilized.

Obviously, being in the West, I do not hear flattering things about the Russian forces, their state of readiness, training, morale, etc., etc. Based on that knowledge, and the fact that the Moskva was lost, it's clear to me that that ship should not have been where it was. Here was a high level ship of war, in a war zone, not as a spectator, but as a participant, and it was not ready for that attack. That ship and her crew were not qualified to be there, not prepared to be there, and those service people deserved better.

The Russian navy failed that crew, and they should not have been in harms way like that. The Ukrainian attack should have failed utterly. It shouldn't have even been close.

The Stark was very embarrassing, and there are many critics of the modern US Navy. The Stark, however, was completely surprised, they weren't a combatant, they weren't posturing, the Stark was in the area.

The Moskva should not have been surprised. They clearly did not anticipate the attack (as I understand it, everyone was surprised the Ukrainians had this capability), but it's not really clear if the ship was prepared and capable even if they did. There's stories that even after it was struck, the crew did not perform well and contributed to the loss of the ship.


So in your opinion the sinking of the Moskva does not herald the end of surface sea power (within land-based defense range) in the missile age?


No, just like the aircraft or aircraft carrier did not end surface sea power. It certainly changed the game, however.

We've been "in the missile age" since the 60s. Well demonstrated during the Falklands campaign with the loss of the HMS Sheffield to an air launched Exocet missile in '82. Mind, what killed that ship was fire (started by the missile, the missile also took out the main fire fighting system) and, again, the ship was not as prepared as it should have been to defend against the attack. Two missiles were launched, one missed.

The Phalanx came out in '78. The Navy has been working the missile problem for a long, long time. In the 80's the nightmare scenario was several dozen Backfire bombers launching several hundred missiles at the fleet from long range. Later, it was missile patrol boats. Now its drones.

Warfare is ever evolving. Tanks aren't dead yet either, despite drone and Javelins. But the land (and water) scape is ever shifting.


I do enjoy the visuals from the TV series The Expanse, when they use their CIWS equivalent to intercept missiles. Albeit I've always wonders how fast those "bullets" fly, versus the (again I'd assume) hypersonic (is sonic meaningless as a benchmark when talking about space?) missiles.


Apparently "hypersonic missiles" translates to "maneuverable anti-ship ballistic missile" in plain English. It's different from conventional cruise missiles in the sense that pocket Windows computers aren't phones.


Yes, sonic is meaningless as a benchmark in space. The speed of sound varies with air pressure (altitude) but it is always an important barrier in a gas atmosphere. However, in space it means nothing. A bullet fired into a gravitational well could just keep accelerating until it struck something or went into an orbit.


Speed of sound is not affected by pressure, only by temperature. It’s still variably with altitude though because the temperature is dependent on altitude in the atmosphere.


TIL!


At those speeds, the two are probably the same anyway.


Story I heard about the Phalanx is that it detected and fired on a kite. Split it in two with a short burst. Then two more bursts as it cut the two pieces in half. An engineer commented on the radar tracking it's own bullets and that the 8th bullet has it's aim improved by the tracking of the first bullet.


>...only a handful of cases in which ships equipped with Phalanx have been the subject of missile fire, and none that have actually seen the system tested.

Worth noting that this line is now out of date. Allegedly they've been tested in Yemen recently [1].

1. https://www.businessinsider.com/houthi-missile-close-us-wars...


I had thought it had been used during the gulf war in a friendly fire event.


The Missouri got raked with it from its escort ship - not pleasant for anyone concerned I'd say.

http://billgx.com/2019/10/autonomous-friendly-fire/


tldr: the Missouri fired a chaff and the other ships CIWS was all “not in my airspace” and started shooting at it even though the Missouri was behind the target. Interesting, I wonder if the whole battlegroup has synced systems now to avoid such things, e.g. 1) I’m going to launch something, everyone else disregard it as a threat and 2) if a threat has a friendly behind it, don’t shoot it.

Maybe 2) is more of a judgement call since a few bullet holes is probably preferential to the alternative.


IFF in any capacity on Phalanx seems like a poor match.

At ranges that close... you really want a "deconstruct anything in the air" device, not a "consider what you're about to hit" device.

Which I'd imagine has been designer pushback on complicating it and going that route.

Safety through deciding what mode to set it in; not through leaving it alone and forgetting about it.


I don’t disagree, but I’m sure they had to come up with some mitigation after this. If each ship is shooting down the other ships primary/secondary/whatever countermeasure then in a worst case scenario you and your sister ships are only left with your CIWS. And they might still be busy shooting at your sister ships chaffs to deal with the real threat. I don’t know much about it, I just found it interesting.

Seems a bit like Star Trek - “Their shields go down for a split second when they fire”. Maybe the system goes dark for a second to avoid shooting down outgoing items? Syncing the shields might make this better (or expose other weaknesses?)


The issue is time.

Say it's a YJ-83 clone, so around mach 1.4 terminal velocity (476 m/s).

Phalanx tracks at 10km, engages at around 4km.

So it has ~8.4 seconds of engagement time to try to destroy the incoming missile.

... And that's a relatively slow modern target. A P-800 gets up to mach 2.4. BrahMos is mach 3?

I'd guess the Navy would generally rather keep CIWSs on a hair trigger, and just space their ships further apart in combat situations.

And afaik, most of the CIWSs have been removed in favor of RAM, since the gun-limited engagement ranges don't make much sense anymore.


Yep that's the one


And the system failed, requiring the last line of defense machine guns to engage.


Phalanx is the US CIWS based on the 20mm Vulcan gun. in other words, Phalanx is the “last line of defense machine guns” to which you are referring.

You may be thinking of Aegis, the integrated combat control system. We don’t yet know why the Gravely was unable to intercept the missile further out. Could have been human error, could have been a sea skimmer getting too close before being detected. To date, Aegis has been extremely effective against ballistic missiles and old cruise missiles. But given enough time an enemy can test your potential weak spots.


My grandfather invented / designed the bullets for the Phalanx. The dumbed-down idea is that smaller bullets with high kinetic energy can be more devastating to armored targets than larger, slower bullets releasing chemical energy. He used to take my mother out to the CA desert to help him test his latest designs on thick armored plates (they now decorate her front yard - metal!).

Reflecting on the Phalanx brings mixed emotion, given that the US Navy avoided paying patents on his designs and buried him in legal fees so that he never saw a dime (at least that's what I've been told). He was older at the time, and this absolutely took several years off his life. That said, I know he'd be proud to see his ideas still being relevant today, from implementation to video games.


I've wondered many times why a radar-directed machine gun isn't used to protect against drone attacks. The drones the terrorists used are rather slow moving, so the gun doesn't have to be that sophisticated. And it should be relatively cheap.


That space is currently littered with all kinds of new projects given the urgency. One that has stuck with me is the German Rheinmetall Skynex which works the way you are describing. It’s like a really high tech flak cannon. There are neat videos of it on youtube.


They are to some extent?

One issue of radar-directed machine guns in the context of the Red Sea is that machine gun range is limited, so they can only provide point defense. This means that a warship can only protect itself, and any commercial ships that are -very- nearby.

Yes, you could probably figure out a way to rig up a lot of these onto smaller ships to escort individual ships/convoys through, but hey you go to war with the navy you have.

Unironically, the LCS's might be useful in this role.

More generally, you see stuff like the army's new M-SHORAD having missiles (Stinger+Hellfire) and 30mm + 7.62mm guns.


I was thinking of the recent drone attack on a military base, where three soldiers were killed.


There is such a system, it's called C-RAM and is basically a Phallanx mounted on a trailer. You can find videos of them working at bases in Iraq recently. There's also smaller systems in development like M-SHORAD and MADIS (Army and Marines respectively if I remember right).

Whether stuff like that is deployed to a particular base is a question of them being available and the particular location being well supplied enough to use them. The M-SHORAD and MADIS systems are designed to mount on light vehicles so they can be deployed more readily and to smaller forward positions.


Oh. Yeah, I mean there's nothing preventing such a system - land based Phalanx is a thing. We also don't know what air defenses were even at the base (maybe they already had land based Phalanx...).

Sounds like the base was caught by surprise.


There was a friendly drone returning to base, so their defensive systems were turned off.


Isn't it the same problem - you need complete sensor and shooter coverage of the entire perimeter. Bases are pretty large - much larger than ships.

Also, as Hamas did, an attacker can try to overwhelm one point of defense, which means your sensors, targeting computers, and shooters need lots of extra availability (extra equipment and soldiers) everywhere.

I don't think you'd want the perimeter of a base covered with auto-targeting/firing guns. And also, on what does all that metal (bullets) land?


> on what does all that metal (bullets) land?

The Phalanx CIWS uses explosive incendiary tracer rounds on land. They self destruct after missing the target to avoid collateral damage


That's an interesting technology. Could it be used by everyone, in civilian guns? It might prevent a lot of bystander casualties from stray bullets, richochets, etc. OTOH, perhaps for bullets that hit, explosions occur on the target? That would not be good.

(Tracers would be useful for bystanders and law enforcement. Self-detonating or not, maybe all ammunition should be tracers?)


Careless recreational shooters[] regularly start fires when using tracer ammunition. There would definitely be downsides to mandating that all ammunition be tracer rounds.

[]Also routine training exercises on military ranges.


In that specific attack there was a problem where it coincidentally happened at the same time a US drone was landing, so there was some confusion over the threat.


I suspect it has to do with western military industry shifting towards premium low volume products since the end of the last war, perhaps because making weapons of war had been weird to some people lately. They don't make hand portable or vehicle mountable 7.62mm or .50cal or 14.5mm mini-CIWS, only the multi-trailer ship-sized versions that are total overkill for drones.


If a target is moving slow enough it can be difficult to track. Similar to how you can defend against radar missiles by 'notching' aka flying perpendicular so the relative velocity of the target is near zero. Radar typically relies on the dopplar shift caused by the target moving to eliminate clutter.


If they can't see the target, how do they shoot missiles at it?

I've wondered the same as the GP: Why not just send a wall of metal at the drone from one of these things?

If not that, why not traditional anti-aircraft fire, with projectiles that explode in shrapnel clouds?


> Why not just send a wall of metal at the drone from one of these things? If not that, why not traditional anti-aircraft fire, with projectiles that explode in shrapnel clouds?

If this had been the 1950s or early 60s, every advanced military on the planet would have been able to do exactly that.

However, both aircraft (MiG-19+) and missiles were speeding up.

At some speed, it becomes impractical to solve a high-speed aircraft or missile problem with a gun. [0]

Consequently, development from the 70s on turned to missiles capable of dealing with these threats.

Which left the only remaining systems mostly consequences of failure to upgrade (e.g. the German Gepard).

As the saying goes, history doesn't repeat itself, but it rhymes...

[0] See: M19 (1945) > M42 (1953) > MIM-46 (1960-63, cancelled) > M-163 (1965) > MIM-72 (1967) https://en.m.wikipedia.org/wiki/M19_Multiple_Gun_Motor_Carri... https://en.m.wikipedia.org/wiki/M42_Duster https://en.m.wikipedia.org/wiki/MIM-46_Mauler https://en.m.wikipedia.org/wiki/M163_VADS https://en.m.wikipedia.org/wiki/MIM-72_Chaparral


There were still helicopters and slower ground attack aircraft to do gun defense against, and self propelled anti aircraft guns (SPAAG) like Tunguska, Marksman, Pantsir.

New advanced anti-drone guns like Skynex seem to be expensive and have expensive shells. Yet the range is quite small. Could work for high value targets, not to defend a country against large amounts of inexpensive drones?


>There were still helicopters and slower ground attack aircraft to do gun defense against

The biggest reason why gun systems are avoided nowadays is simply range. You are mostly unable to fling slugs out beyond 10 miles, while a Patriot and friends can reach out and ruin a day at 100 miles. The helicopter itself likely has a weapon that will ruin YOUR day out to about 12 miles. That means the helicopter safely murders you, and you cannot defend against it.

Also MANPADS take up the 10 mile air defense slack nowadays, which is why nobody developed anything further into SPAAGs, right up until everyone had the same "oh god time to re-learn how to skeet shoot against small drones" idea


The drones used by terrorists are homemade and slow moving.


But those weren't the primary threat military defense of ~1965-2020 was designed against. (Higher then) Lower, faster, and/or stealthier were the worries.

And aside from the economically-mobilized war that Ukraine is fighting (and Russia is gradually shifting to), it's unclear if capability or cost need to be optimized. For every conflict economically less than that, capability wins.

I expect the FPV quadcopter grenade-on-a-drone solution will be looked back on like the Toyota Hilux tactical -- effective when introduced, but superceded and dominated by specialized systems produced by military industry.


The solution then would be to have two radars a distance apart, so they can triangulate.


Locating the target isn't the problem, you don't need a Doppler shift to calculate range by time of flight. The problem is detecting the target at all. Radar in these sorts of defense environments will pick up an enormous number of returns off of the carrying vessel and sea surf, which is actually a rather difficult problem for radar because it reflects in myriad directions, it moves, etc. By far the easiest way to select an "interesting" radar return is to use Doppler shift to find something that is moving very quickly. That can't be just a wave, it has to be a missile.

The problem is that rotary wing drones are very slow (compared to missiles) and so they don't present an obviously different shift from the background. A lot of R&D is going on right now into better ways to select slow-moving, low-cross-section objects like drones from the background.

This sort of thing is much more difficult for missile defense than the more conventional radar application of airspace surveillance, because for several reasons (including the fact that this makes radar detection hard) missiles tend to come at you from close to or below the horizon. This means you're getting a huge amount of clutter (radar returns from the environment) around them.


Not to minimize the challenges, but I think it's worth pointing out that a lot of the drones of topical interest are -not- quadcopters.

The Houthis (for example) have been using UAVs (Samad and Qasef) are prop driven fixed wing drones with total mass in the 50kg+ class (and warheads in the ~20kg class). They have max speeds of 200+ kph, wingspans in the 2-5m range. The Samad has ranges in the 1000km+ range. Obviously, they could slow down in terminal stages of attack, and I have no idea what their stall speed would be like.

These are more akin to the Shahed class drones that Russia has been deploying in Ukraine (though still much smaller), than the FPV drones we see attacking tanks/trenches.


The British used radar guided artillery to knock down wave after wave of V1s, which flew at around 400mph. Surely we could do better today.


The US Navy used radar guided artillery to knock down wave after wave of Japanese kamikazes, which flew at similar speeds. They were still sometimes overwhelmed by saturation attacks.

Modern US surface warships still have the same capability but most mount only a single large cannon (separate from the shorter ranged CIWS). There's no space for more. Research is underway to supplement those with lasers but those aren't operational yet and can only work with a clear line of sight.


Really? I had heard that sometimes pilots would nudge them off course or shoot them down but nothing about artillery, I thought radar came along a bit too late to use it for targeting with regard to the V1


> Automatic gunlaying (using, among others, the SCR-584 radar) and the proximity fuze played an important part in Operation Diver, (the British operation to counter the V1 flying bombs). Both of these had been requested by AA Command and arrived in numbers, starting in June 1944, just as the guns reached their free-firing positions on the south eastern coast of England. Seventeen per cent of all flying bombs entering the coastal 'gun belt' were destroyed by guns in the first week on the coast. This rose to 60 per cent by 23 August and 74 per cent in the last week of the month, when on one extraordinary day 82 per cent were shot down. The rate increased from one V-1 for every 2,500 shells fired to one for every hundred.

https://en.wikipedia.org/wiki/SCR-584_radar#Operational_use

> 90mm anti-aircraft guns were normally operated in groups of four, utilizing the SCR-584 microwave computer and being controlled by the M9 Director. The SCR-584 was accurate to about 0.06 degrees (1 mil) and also provided automatic tracking. Direction and range information was sent directly to the M3 Gun Data Computer, and M9 Director, which directed and laid the guns automatically. All the crews had to do was load the guns.

https://en.wikipedia.org/wiki/M9_Gun_Director


Wow. I honestly find it amazing what they accomplished back then. I spent like 6 hours reading the history of AEGIS when someone posted it here last year


"Impact" by Benjamin King and Timothy Hutton

"The answer to Pile's problems of directing the guns was the American S.C.R. 584 radar, the one used on the American 90mm anti aircraft gun, which had power elevation and traverse and an automatic fuse setter. The S.C.R. 584 was a gun-laying radar and "the most successful single application of the micro-wave ten-centimeter technique to ground fighting in World War IL It could automatically track an unseen target at night or in cloud or fog, supplying range, azimuth and elevation data to a gun director." The S.C.R. 684 had a range of 90,000 yards for early warning, and as a target got within 32,000 yards the set acted as a gun layer. It had no blind spots and could detect low-flying targets like the Fi 103. Unlike the British radar sets, it was also immune to Window. However, it was a complex piece of electronic equipment and required a number of scarce materials like tantalum, molybdenum and tungsten, as well as 140 vacuum tubes which were then in short supply in the United States. The fielded version weighed several tons and cost $100,000."

Impact, pg 174-175

"Aside from the redeployment, one of the reasons for the gunners' success was that new equipment had arrived. Anti-Aircraft Command received 135 of the long-awaited S.C.R. 584 radar sets and Pile was able to "borrow" an additional 165. Adapting these to the static British 3.7-inch gun required 200 modifications to the gun. Along with the radar sets came proximity fuses and 20 American batteries armed with the radar-controlled 90mm gun."

Impact, pg 207

"When controlled by the S.C.R. 584 radar set, the U.S. 90mm Ml Antiaircraft Gun was the finest antiaircraft gun of World War II. During the campaign they were operated 22 hours a day with two hours a day for maintenance."

Impact, pg 271


that's amazing. Thanks


Near the end of the blitz, the Brits claimed they were getting one kill per 100 rounds fired. That's an insane number, possible only with VT (proximity) fuses and radar directed gunnery.

The numbers from before those two advancements were closer to 100k rounds per kill


I've read opinions that radar was the single most effective innovation in WW2. It essentially doubled the effectiveness of anti-aircraft gunnery.

For example, the Bismarck battleship was loaded up with anti-aircraft guns. But it was unable to stop a handful of slow moving stringbags that attacked it, and one torpedo from one of them crippled the ship, leading to its destruction.

In contrast, radar directed anti-aircraft guns proved extremely effective against Kamikaze attacks.

The proximity fuse also used radar. Me, I would never have developed such a shell because I couldn't believe such a mechanism could survive being fired out of a cannon.


Pilots chasing down V-1s who shot at them from directly behind would risk immediately flying at high speed into the wall of shrapnel created by blowing up essentially a large powered bomb, often destroying or damaging their own aircraft in the process, which was very dangerous.

To avoid this, some pilots developed the tactic of flying along side the V1 then using their wingtip against the V-1 wingtip they would then flip it over and off course disrupting the primitive autopilot system so it would then spiral out of the control and hit the ground and explode hopefully in relatively harmless field.


yes, that's exactly what I had absorbed from somewhere


Ah yes, the safer alternative of nudging your plane against the flying bomb.


I thought so too, but lately I have heard and read accounts akin to a lot of what happened in late WW2 with regards to radar technology was highly classified and much didn't enter the history books.

Pilots shooting and nudging definitely happened but likely other, more advanced stuff happened too. The germans had fully automatic radar controlled flak guns.


They used both (and barrage balloons as well). The space between the ~middle of the English channel and London was divided into "belts", with one type of defense operating in each belt to prevent interference (like flak shooting down your own fighters).

At first the flak guns were located near London (as that was the same flak guns that were protecting London against aircraft). It didn't work so well because it was very hard to hit a fast moving target like the V1, as crews not used to it tended to use too little lead. And even if the V1 was hit, chances were that the wreck would fall down on London anyway. So eventually the flak batteries were moved to the coast, and they got gun-laying radars and proximity fuses which dramatically improved the effectiveness of them.


The Shaheds fly much lower. You aren't likely to be able to shoot at them until they're close, unlike V1s where you could just send wave after wave of flak and destroy most of them.

Also, the drones are getting faster and faster, with the latest ones having turbojet engines.


Totally. I just guess the US didn't procure/deploy/use/turn-on the appropriate systems. Plenty of other posts in the comments identifying potential modern (and modern-ish) solutions that match your parameters.


I'm talking about a land based system to defend military bases from drone attack, not sea borne vessels.


They are.

In Ukraine German Gephard[1] systems have taken out a variety of drones. The older soviet systems can do some of this as well.

There's also a ton of newer smaller projects in development, aimed at something you can put on a truck to counter low cost consumer drones.

[1]: https://en.wikipedia.org/wiki/Flakpanzer_Gepard


Radar is essentially a searchlight shining up into the night sky. If you have a radar-directed machine gun pointing into the sky, it's relatively easy to triangulate where the emitter is and direct artillery to take it out.


If that radar is within range of enemy artillery it's already been destroyed.


Got it. Need one that can take out artillery rounds as well then.


They have been widely deployed for decades. But also, for decades (since WW2 ?) they seem to have been effectively useless (so far ??) : in all cases that I've been able to find (please correct me if I'm wrong), either the ship (and/or nearby friendlies) were on alert and the guided bomb never even made it into machine gun range, or the ship was caught unaware and that defense system was never even turned on.

(Not counting cases where radar would have been useless because the guided bomb moved under water.)


The US has Mk38 canon on lots of ships. The Mod3 added radar. Its primary focus is against small boats and could probably work against USV that Ukraine has been using against Russia. I hope the Navy is working in modifying to work against small and medium drones.

The other thing that might help against drones are the automated weapons stations hat are on lots of vehicles. I think I read about project to add radar and automated targeting of drones.


> I've wondered many times why a radar-directed machine gun isn't used to protect against drone attacks.

You mean something like Germany's Gepard?

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


I'd think the primary defense against drones on a naval vessel would be that the ship's made of metal, and doesn't have squishy humans wandering around (unless it's a carrier).

IOW a very small drone also means a very small payload.


The size of the payload is still a significant problem if your enemy is close with many drones. This video [0] shows a Russian missile cruiser being sunk by Ukrainian drones recently in the Black Sea. The problem these boats have with drones is that they are slow all around compared to a rather nimble drone which can react to its operations. As can be seen in the video multiple drones are used to sink the large ship.

Edit: A better article around the situation and effectiveness of the drones is at [1].

[0] Video Russian missile cruiser "Ivanovets" destroyed by sea drones at January 31/February 1 in Black Sea - https://v.redd.it/hevs3v05hyfc1

[1] https://www.theguardian.com/world/2024/feb/01/ukraine-sea-dr...


I think they were referring to aerial drones, which tend to have limited capacities for cheap ones.

Those were seaborne (naval) drones carrying about 1000 kg of explosives each if I remember correctly.


Maybe hard to sort out small drones from large birds?


The article on VLS is also quite nice

https://www.navalgazing.net/VLS


That adaptive deck launcher seems like you could almost drop that (well and some radar) on any ship and turn it into a warship…


> Battlefield 2

> anyone remember Wake Island with the USMC carrier, F-35B, and J-10?

I remember. The J-10s would eat the F-35s for lunch and immediately start attacking the carrier. They'd gun down the CIWS as they passed and bomb the crap out of players on the carrier's flight deck for good measure. Good pilots could time their passes so that their guns were lined up with the F-35 just as it respawned, destroying it before it could take off. Shame you couldn't sink the carrier like in BF1942.

Good times. Eternal shame on EA for C&Ding the community server effort.

> Despite Battlefield 2 leading me to believe a person occupied the cylinder

Haha I thought so too... BF2 required you to man it like a vehicle in order for it to do anything. It's only natural kids would think that.



Went for Phalanx article immediately too when I saw the link, I guess there is just something about that 20mm beast throwing massive tungsten slugs at even crazier speeds that no missile can compete with (for attracting readers).

These things require super quick reactions, operator is optional (and thats why no real usage in combat, USN ends up turning it off often in situations where they don't want to risk absolutely destructive friendly fire.

Now if everything will be eventually 'ai'-infused, well, fuck. Navy apparently doesn't trust automation with their lives much, and fancier neural network with unpredictable decision paths ain't gonna improve things.


You always want a human in the loop. FDS sometimes drives into trucks or disengages randomly. Automated defence systems shoot at stuff they consider to be a threat, and that can be anything from non-combatants to friendlies. Or just the enemy, but the particular attack might be a diversion, hence a human might hold the defence back. Also just for stealth, radar is a giant beacon leading right to back to you. As is a rapid fire 20 mm cannon.

Unless we have General AI, in which case, well, you'd still want a human in the loop, just at different level.


>crazier speeds that no missile can compete with

CIWS muzzle velocity is ~1000-1200 m/s, ~mach3, substantially slower than modern hypersonic threats at ~mach5+. Hence counters to hypersonic missiles are other advanced interceptors. There were papers in the 80s detailing physical limits from mechanical tracking to over horizon response times and TLDR IIRC was CIWS not suitable for fast, low flying and slightly maneuverable anti ship missiles.


Wow, you're right. Every link I follow on the posted article leads me into a fascinating wasteland of other articles from the site, each better than the last. This is some extremely high quality content.


Always important to look critically at the person speaking (I mean to imply nothing about them, just sharing what I found):

It [the blog] grew out of my time as a tour guide on the battleship Iowa (BB-61) in Los Angeles, and although I now live halfway across the country, Iowa is still one of the mainstays of this blog. It also came from my frustration with existing sources, which tended to be either way too high-level or too technical, with very little to bring an interested general audience up to speed. ...

I've been a military geek since I was in grade school, although my affections didn't settle on matters naval until after I graduated college with a degree in aerospace engineering. ... Unfortunately, I didn't like my actual job, and ended up getting another job in Oklahoma, doing work on military aircraft.

https://www.navalgazing.net/About

Certainly they should understand how flying machines work. I dunno about their history. :)


bean used to post long and in depth posts into the SlateStarCodex Open Threads, then someone helped him set up his own site, and here we are. He organizes meetups at Naval History sites too.


I'll just comment that that is the most clever website name I came across in a long time!


I had always wondered whether there was a missile that was spin stabilized with minimal control surfaces like this one. They mentioned it only had two control fins, but not whether they are independent. It seems possible to steer a spinning missile using a single actuator if the control pulses are precise enough.


From https://secwww.jhuapl.edu/techdigest/Content/techdigest/pdf/... it seems that the two control fins are driven off a single shaft/motor - so they are not independent.

The RAM uses single plane tracking - basically imaging that it's only ever steering in pitch. But because it's constantly rolling, "pitch" will sweep over both axes and control to zero.


Yeah (and apologies if I get this wrong after 30 years) with a rolling airframe, you can have two fins on the same axis that "wiggle" back and forth at the same frequency as the rotation of the missile. Direction control comes from the phase of the movement, so the fins are pushed in the direction you want to go when it rotates to that point.


Vikhr also does this, and Starstreak and M1156 both use a clutch to transfer force from a freely spinning fin assembly at the nose to the rest of the projectile when appropriate, achieving guidance without any movable control surfaces! Missile designers are very clever.


>spin stabilized with minimal control surfaces

The modern RAM Block 2 has four independently-actuated fins for agility[0], so nowadays the spin stabilization isn't being used to reduce the number of control surfaces.

Spin stabilization is still quite valuable. If an actuator fails (or worse, jams hard over) the missile won't veer off course, it just has reduced control authority.

[0] https://en.wikipedia.org/wiki/RIM-116_Rolling_Airframe_Missi...


BTW That's a pretty common control scheme for Soviet and Soviet-derived ATGMs. https://thesovietarmourblog.blogspot.com/2021/07/soviet-atgm...


newer versions have 4 fins... better read the actual article, pretty good stuff there


Just curious....what else have you always wondered about?


> The use of a gun limited effective range to no more than 1500 yards

Aren't sniper rifles effective at that distance (if they hit)? A weapon not constrained to human limits in dynamic movement, heat, sound, pressure, size, etc, isn't effective at a much greater distance?


The shell itself flies considerably longer, although 20mm shells start to slow down and drop much more quickly than even slightly bigger shells like 30mm (see e.g. the Goalkeeper CIWS for a similar concept using the same 30mm gun as the A-10 aircraft).

It's a question of hitting the target with a usefully high probability. At longer ranges dispersion is higher, so even if the aim is correct there's a chance it won't hit. And think of how it works; it shoots out a stream of shells, and tracks the target and the shells with radar. But what if the target is doing some evasive maneuvers, which AFAIU many anti-ship missiles do in their final phases? The shells fly out at about 900 m/s, and a subsonic missile flies at maybe 300 m/s. So by the time the shells whizz by the missile it has moved a quite considerable distance, and while the radar tracking can apply the correct amount of lead (with a Kalman filter or similar to take into account measurement noise), if the missile is doing some unpredictable maneuvers that might not help. With the missile closing at 300 m/s, you don't have very many cycles of shoot-see-where-the-shell-goes-adjust-aim before the missile slams into the ship.

And to make matters worse, there are also supersonic anti-ship missiles. Now evasive maneuvers in the high-density air at the surface isn't really a concept that works out for Mach 3 missiles, but, well, the missile compensates by flying as fast as the cannon shells.

Hence stuff like this RAM thingy is seen as a better system against high-end anti-ship missiles.


There's a third option, though I've very little knowledge of its capabilities: "smart" munitions.

These are ballistic, like bullets or shells, but have some capability for maneuver, as with a guided missile. A smart munition with longer range might make for a more effective countermeasure against high-speed (supersonic or hypersonic) missiles. Or possibly high-speed (supersonic) torpedoes, another emerging class of anti-ship weapons.

See: <https://en.wikipedia.org/wiki/Smart_bullet>


How long does it take for a bullet to reach 1500 yards? Around 2 seconds. How confident do you have to be in the movement of your target to hit them with a 2 second lead? Very. (Or you can follow the CIWS methodology and throw quite a few bullets at once)

The effective range isn't limited by the ballistics of the weapon (The 20 mm shells it fires will easily go 5+km), it's limited by actually hitting the damn thing you're aiming at.


Sniper rifles are firing a single shot, the bullet is smaller, and snipers can take significant time to prepare. I've heard of snipers firing a few hundred yards away from their target first to see exactly how their shot will be affected by drop and wind and only then aiming at their target. Sniper rifles have much less stress on them imposed by firing the cartridge than a Phalanx; a 12.7x99mm cartridge is nothing compared to 20x102mm. Finally, a sniper is firing a single carefully aimed shot; a Phalanx is firing 75 rounds a second from six rotating barrels.


How does that reduce effectiveness of a Phalanx against a drone? With all that metal flying, the pinpoint accuracy problem seems solved.


The M61 (the gun the Phalanx is built around) apparently has a 80% dispersion of ~5 milliradians (see this amazing reddit post complaining about DCS - note that the evidence points to a range of values - I think 5 milliradians is a fair summary https://old.reddit.com/r/hoggit/comments/eyddn3/m61_and_gau8... ). At 1500m that works out to a 75cm radius (I'm pretty sure its radius...) disc.

Assuming your firing at a missile flying right at you, and assuming a Cold War era threat (so say a Kh-22 fired from a Tu-22M), you're talking about a 92cm diameter target (46cm radius) that you're trying to hit.

In reality, things are worse because in addition to dispersion, your actual point of aim of your stream of bullets will be effected by external factors (like wind).

You can see how in the scenario layed out above, you do actually have what seems to be a reasonable chance of landing a few hits when you're spewing out hundreds of rounds within seconds. But you can also see how quickly the odds go to crap as you push the range further and further.

I think that gets to the reality of what the "effective range" value is. It is a rule of thumb designed to help weapons officers quickly determine how best to react in a scenario.

Remember that CIWS was envisioned to be deployed in a scenario where USN ships would be subject to saturation attacks by supersonic anti-ship missiles from multiple bearings and sources. Phalanx itself only has a magazine of ~1000 rounds, which is good for maybe only 10s of firing, so you really do need to conserve ammo.


I am no expert but I imagine one important tradeoff is between cartridge power (necessary for long range with sufficient energy) and cartridge size/mass, these systems have high rates of fire (because trying to hit very fast-moving targets) and that can't be easy with a giant cartridge.

What happened to "Metal storm"?


It didn't go anywhere that's for sure, found an /r/NCD post speculating reasons as to why[1]. Looks like they were bought and pivoted to explosive drones somehow[2].

1: https://old.reddit.com/r/NonCredibleDefense/comments/16xhmpv...

2: https://en.wikipedia.org/wiki/Metal_Storm


To shrink MIC budgets, using lasers to counter tactical missiles in clear weather will be significantly cheaper to operate than expending expensive missiles. Repeated drone and improvised rocket attacks shouldn't lead to an expensive war of attrition that only makes defense contractors rich while taking away budget from better uses.


I don’t think these systems will work against cheap, tiny drones or swarms of drones. eg. Russian ships vs Ukrainian boat drones.


Probably not. They were designed to take out multi-ton supersonic cruise missiles so they need a larger warhead than would be required against drone swarms. Of course, since they're so large and capable they certainly could take down _a_ drone, and then it becomes a question of how large the incoming swarm is.

Now, if the incoming swarm is large enough, then either each drone carries a tiny amount of explosives, or each drone is large and expensive. The US Navy has been building ships to protect against mass swarms of incoming cruise missiles since about the 60s or so, so if the incoming drones are large enough then you could also use larger missiles against them and rely on the RAM only for whatever leaks through.



In foggy weather lazers are not working well.


Is there a fundamental difference between a drone and an anti-ship missile?


In the sense that both are flying things loaded with explosives heading towards your ship, no there's no "fundamental" difference between them.

In practice, there's a world of difference. Drones are cheap and slow, but can be a big threat in a saturation attack style scenario. Do you want to spend a $1M+ missile to shoot down a $5000 drone?. Do you even have enough missiles to shoot down a swarm of 100 drones?

An anti-ship missile is much bigger and more expensive, but flies at around 300 m/s for a subsonic one, and up to 900 m/s for supersonic ones, giving much less time to shoot it down. And while the missile per se isn't armored, the warhead has a thick casing designed to penetrate deep into the ship before exploding, so hitting the missile with some shrapnel at short range isn't gonna help as the wreckage of the missile will still likely continue on a ballistic path and hit the ship. And the warhead is often big enough to cripple a warship with a single hit (well, maybe a carrier is big enough to keep on trucking).


The problem this brings up to me then is it's just a worse missile that we hope can be cheap while still being effective. But there's a lot of systems that this drone needs to still be at all effective. Miles of range, with a communication system, and guidance of some sort. Doesn't sound like $5000.

The real winner is the swarm of highly effective missiles.


There are only two types of ships:

Submarines and targets

http://www.johntreed.net/sittingducks.html


I wish you could control with arrows or `wasd`. Or if at least it showed a message explaining how controls work. Took me a bit to figure out controls on a laptop.


Did my adblocker block out a game on that page or did we read different articles?


I believe that was meant for https://news.ycombinator.com/item?id=39189285, "Missile Game".




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