Surface Ships Need More Offensive Punch, Outlook

[shin_getter]

I don’t think anyone has any idea what happens when two peer competitors send dozens of anti shipping missiles at a formation. Real life tests are always only a few targets at most. I for one doubt the ability of modern combat systems to track and engage say 50-100 targets while friendly forces are also volleying a hundred defensive missiles and producing more target tracks. Plus perhaps ECM. I don’t think anyone knows what happens in a WWIII level naval engagement.

In ww3, I don't think either side with push their fleet into mass salvo range of ground forces and there generally isn't a good reason to throw fleets at each other in a pitched battle either.

Surface ships are just extremely fragile and any imperfection in air defense spells disaster. This is unlike ground forces that is robust to attack, where the PGM arsenal of Russia can't shut down the ukrainian airforce, never mind hunting down all the mobile launchers. In combat between near peers, no surface navy can press against ground forces without very unequal losses.

The navy likes to show off exercises where they hid a carrier task force off the Soviet Union. That is neat, but a week of carrier sorties while running all the defenses and misdirection would do nothing against even lightly prepared ground forces, while one instance of mistake or bad luck would result in billions of losses on the other side.
----
I think the pacific campaign was very misleading. Japan was not a near peer, it was a much weaker power and significantly due to the defensive advantages of naval warfare and vast distances that the conflict lasted so long. Imagine if Japan had a land connection with the united states, how long does it take to drive armored division through the place if not neutralized with B-17s all over the place?

With the increase of weapon and vehicle ranges, more and more of the earth is covered by ground based forces. Personally I think in western pacific conflict, outside of successful surprise attack, would have the Chinese fleet hiding somewhere in south China sea (assuming surrounding nations are neutral) while the US fleet covering convoy runs to Japan. Surface ships within the central combat area would get spammed missiles from all over the place, as there is numerous land launchers while air forces can mass quickly with inflight refueling and no surface fleet want to be outside of the area of absolute air superiority near their own forces.
----
The reasonable point of battle with both sides having near equal combat would be, covering forces for resupply of land forces, where the vulnerability of ships is covered by closer proximity to friendly forces: aka malta convoy battles. I expect the surface navy to always plan to have mass advantage in any engagement, yet still suffer serious losses except in the most lopsided force ratio situations.

 

[Josh_TN]

I don’t think anyone has any idea what happens when two peer competitors send dozens of anti shipping missiles at a formation. Real life tests are always only a few targets at most. I for one doubt the ability of modern combat systems to track and engage say 50-100 targets while friendly forces are also volleying a hundred defensive missiles and producing more target tracks. Plus perhaps ECM. I don’t think anyone knows what happens in a WWIII level naval engagement.

In ww3, I don't think either side with push their fleet into mass salvo range of ground forces and there generally isn't a good reason to throw fleets at each other in a pitched battle either.

It seems likely both sides could send huge volleys of air launched missiles at each other, and the PRC could launch large numbers of ballistic missiles as well. So I think mass salvos will be occurring.

I agree the Pacific campaign of WWII is not a good comparison for a host of reasons.

 

[Firefinder]

I agree the Pacific campaign of WWII is not a good comparison for a host of reasons.

Honestly Navy Wise there ISNT a good comparison for similar reasons.

Any Proper Peer Naval fight is going to be fucking Historical cause things have change so REVOLUTIONARY since WW2.

 

[bobbymike]

Who says water and electricity don’t mix? For today’s navies, their radars, weapons, and propulsion depend on it - Breaking Defense

There's a huge commercial infrastructure for electric drive for vehicles and manufacturing plants, which represents billions of dollars in investment that navies can leverage.

breakingdefense.com

 

[aonestudio]

US Navy shipbuilding too little, too late to catch China - Asia Times

The US plans to catch up with China’s navy by building its first frigates since the early 2000s, a strategic scheme that may make up for dwindling fleet

asiatimes.com

 

[sferrin]

US Navy shipbuilding too little, too late to catch China - Asia Times

The US plans to catch up with China’s navy by building its first frigates since the early 2000s, a strategic scheme that may make up for dwindling fleet

asiatimes.com

Just a fig leaf anyway. The US is going to build frigates. China is churning out cruisers, carriers, and two types of amphibious assault carrier. And they're still putting their shoes on in the submarine category. When they decide to run. . .

 

[Firefinder]

US Navy shipbuilding too little, too late to catch China - Asia Times

The US plans to catch up with China’s navy by building its first frigates since the early 2000s, a strategic scheme that may make up for dwindling fleet

asiatimes.com

Just a fig leaf anyway. The US is going to build frigates. China is churning out cruisers, carriers, and two types of amphibious assault carrier. And they're still putting their shoes on in the submarine category. When they decide to run. . .

Needs to be pointed out that Capablity wise...

The Difference between a Cruiser and A Frigate is basically nil at this point.

The bigger hull gets you some more missiles and an aerial combat center. Maybe a better radar...

Like that its.

Until the CPS comes online, which is better on Submarines anyways, not that big of a difference between crusiers and Frigates.

Especailly when you have the Burke, which despite is age, is still one of the better designs out that is still extremely dangerous before they get the Radar Upgrades and is still in production.

 

[sferrin]

US Navy shipbuilding too little, too late to catch China - Asia Times

The US plans to catch up with China’s navy by building its first frigates since the early 2000s, a strategic scheme that may make up for dwindling fleet

asiatimes.com

Just a fig leaf anyway. The US is going to build frigates. China is churning out cruisers, carriers, and two types of amphibious assault carrier. And they're still putting their shoes on in the submarine category. When they decide to run. . .

Needs to be pointed out that Capablity wise...

The Difference between a Cruiser and A Frigate is basically nil at this point.

The bigger hull gets you some more missiles and an aerial combat center. Maybe a better radar...

Like that its.

Until the CPS comes online, which is better on Submarines anyways, not that big of a difference between crusiers and Frigates.

Especailly when you have the Burke, which despite is age, is still one of the better designs out that is still extremely dangerous before they get the Radar Upgrades and is still in production.

5" gun. More, much larger, cells which means more capability. Larger, more powerful radars, more CIWS, etc. etc.. The idea they're the same is laughable.

 

[bobbymike]

Winning High-End War at Sea: Insights into the PLA Navy’s New Strategic Concept | Center for International Maritime Security

cimsec.org

 

[Josh_TN]

The Connie class is a lot closer to a Type 52 in capability than a type 54.

 

[totoro]

Though, 054 is 20 year old design now. More apt comparison to Constellation will be 054B. (or whatever its name is going to be) with some being already under construction, it's plausible the first will enter service around the time or a bit before the first Constellation.

 

[Josh_TN]

Though, 054 is 20 year old design now. More apt comparison to Constellation will be 054B. (or whatever its name is going to be) with some being already under construction, it's plausible the first will enter service around the time or a bit before the first Constellation.

Fair enough, and 54B does look like it might be an entirely new and bigger design. But the Connie is 7000 tons with a full Aegis combat system; the main thing it is lacking compared to Type 52 is another 16-32 Mk41s.

 

[jsport]

In a rare move, House Oversight lawmakers to hear from Navy program executives on shipbuilding - Breaking Defense

Rear Adm. Thomas Anderson and Rear Adm. Casey Moton are expected to testify on May 11 for a hearing likely to examine how the US is doing compared to China in producing ships.

breakingdefense.com

 

[aonestudio]

Bath Iron Works, Mississippi shipyard can't produce destroyers fast enough, Navy says

Defense Department officials want to scale back their buying of Navy destroyers, it appears, saying the nation's shipyards — including Bath

americanmilitarynews.com

 

[Scott Kenny]

MITRE's future navy plan has a concept called the "Magazine Ship." The MGX would carry up to 4 railguns, 1,000 missile silos, or 96 Pershing-III intermediate range ballistic—or some mix.

Might want to look at conventionally powered SSGNs at that point instead of
putting several billion dollars of high-end munitions on a converted fleet oiler that's
got very limited self-defense capability (SeaRAM + Nulka).

MITRE study attached.

You mean SSG.

And no, you want a full SSGN, because a Diesel-electric or AIP cannot keep up with the fleet. You want a 20 knot speed of advance, you need a nuclear powered submarine.

SSK/SSP are for jobs that the nuke boats cannot do, like SOF support, operating out of very shallow water.

 

[Scott Kenny]

Commence production of vastly more cost-efficient AIP SSKs (SSIs) for $ 400 million per copy in place of $ 2.6 bn SSNs.

AIPs are not strategically mobile, they cannot keep up with the fleet.

For those few jobs that AIPs can do better than SSNs, they would have to be forward deployed where they will be used. So we'd be talking 4-6 AIPs based in England to work the Baltic and up around Norway to Arkhangelsk. Another 4-6 based out of La Maddelena to work in the Med. A final 6-8 based in Japan.

I'm basically talking about HISutton's Shallow Water Submarine, but I want it AIP with lithium batteries.

 

[Scott Kenny]

There's basically two options for the hull. Burke or Zumwalt. Zumwalt seems less likely until one considers it already has the excess power capacity, new gen propulsion already integrated with the hull. IF the cost issues with zumwalt stemmed from the radars, combat systems, stealth and so on - and not from the hull and propulsion itself, then it seems plausible zumwalt could be the best starting point.

Now, if 15 thousand tons is too much for USN future cruiser, then it's got to be Burke's hull. That'd basically mean flight IV, a ship with major changes, and sort-of an all-out burke fleet for the next 50 years for USN.

The Burke is too tight to provide excess power generation or rapid system swap capability. The Zumwalt is the obvious choice, possibly stretched back out to the original design length.

The other candidate is probably an LPD-17 hull. Question is whether that hullform be made significantly faster with more propulsion power.

Or use the Japanese mods to the Burkes? Kongo-class, Atago-class, or Maya-class.

Which are already fitted with flag quarters.

 

[Scott Kenny]

Wasn't the motivation for two reactors a federated design where one reactor was coupled to one propeller?

It may have been because they didn't have a single reactor available of sufficient power. That's why Enterprise had 8 reactors, two to a shaft.

No, it had 8 reactors because the conventional carriers had 8 boilers. And then each reactor had dual steam generators, so it effectively had 16 boilers and all that related pipework.

All following carriers had 2 reactors, each with 2 steam generators, for 4 sets of steam lines.

A dedicated ABM ship (or sub) would tailor the missile compartment to fit anything from a KEI to a full size GMD both equipped with high MKV count payloads. A sub based system would actually throw in uncertainty so nobody would know if you were sitting close enough for a boost phase intercept.

If you were positioned near the apogee of the ground track, you might still intercept in "bus phase" before warheads separate. Unless you go to space based interceptors this is the best alternative. Sticking to land sites mean you are essentially putting your assets at the target and the best you can hope is to intercept near the mid point of the trajectory after the warheads have separated.

The operational employment might be similar to an SSBN patrol. For a sub based system, you wouldn't need escorts (unless ASW technology has a breakthrough). For surface ships, you would be a very tempting target and would either need escorts or wind up looking like an LHD with a complement of F-35Bs. Until lasers and railguns develop to the point where they can reach up to ICBM warheads, a submarine would seem to be the better solution.

A BMD ship requires large radars that are a pretty good way above the water, constantly radiating and tracking everything that flies. Their radar can be detected at roughly 4x the tracking ranges, as a simple approximation. BMD is not a stealthy thing.

A submarine does not radiate anything, or else it is dead. BMD is not, cannot be, a submarine mission.

Yes, you might be able to operate a BMD ship like one of the boomers with two crew. You will also need all the hatches and watertight doors redesigned to allow larger openings for moving stuff on and off every 3 months. You will need spare parts built up and tracked, so that they're replaced before they fail. And I'm talking big items, like generators and radars being replaced regularly. This will also require shipyard support, because you're putting 9 months of man-hours of work (a full Selective Repair Availability) or more into a 35 day refit period. This is not cheap.

 

[Firefinder]

There's basically two options for the hull. Burke or Zumwalt. Zumwalt seems less likely until one considers it already has the excess power capacity, new gen propulsion already integrated with the hull. IF the cost issues with zumwalt stemmed from the radars, combat systems, stealth and so on - and not from the hull and propulsion itself, then it seems plausible zumwalt could be the best starting point.

Now, if 15 thousand tons is too much for USN future cruiser, then it's got to be Burke's hull. That'd basically mean flight IV, a ship with major changes, and sort-of an all-out burke fleet for the next 50 years for USN.

The Burke is too tight to provide excess power generation or rapid system swap capability. The Zumwalt is the obvious choice, possibly stretched back out to the original design length.

The other candidate is probably an LPD-17 hull. Question is whether that hullform be made significantly faster with more propulsion power.

Or use the Japanese mods to the Burkes? Kongo-class, Atago-class, or Maya-class.

Which are already fitted with flag quarters.

Honestly the Better Candite be the Korean Sejong the Great class.

It has the size and power reserves needed for the new toys coming out. The Korean put alot of effort in bring the hull up to 21 century needs, and upgrading everything unlike the US Did with the Flight 3s.

 

[Scott Kenny]

Honestly the Better Candite be the Korean Sejong the Great class.


It has the size and power reserves needed for the new toys coming out. The Korean put alot of effort in bring the hull up to 21 century needs, and upgrading everything unlike the US Did with the Flight 3s.

Hadn't thought about those, and you're right that they may have the installed electrical power to work with. Still seems to be a COGAG powertrain, though, not IEP.

 

[Scott Kenny]

Think of the submarine as an arsenal ship, cued by external sensors. There is no need for it to have any sensor apertures. It needs to be able to receive, "launch to x,y,z coordinates for TOT xx:xx:xxx" and send, "TOT xx:xx:xxx". Maybe not even that. Maybe the reply is simply, "done". External platforms deal with determining the initial coordinates as well as any coordination with the missile. Maybe a key gets sent to the sub for the flight as well for comm security. Have thought for years than having SM-3/6 on SSN/SSGNs in the South China Sea, or around Taiwan, would be a nasty surprise during a conflict. The other guy would effectively be grounded.

That is not easy to do for a submarine.

ELF is too low a data rate, at best it can send a message that translates to "(ship) has a message"

Then you come up to periscope depth, which takes 30 minutes to do safely and stealthily.

Been there, done that, got the Strategic Deterrent Patrol pins to prove it.

 

[Scott Kenny]

Vertical barrels were abandoned for no good reason but politics. Not a war winner.

Vertical barrels were abandoned because they were incapable of hitting anything close to the ship.

It turned out that the minimum range of a vertical gun was very close to the maximum range of a conventional turret.

 

[Scott Kenny]

Can you make up the lost capability of the Ticos by just building more Burkes? Say 3 Burkes to 2 Ticos? Can quantity make up for quality?

No, not really. The Ticos have command and control facilities that the Burkes don't have. The Japanese Aegis ships have been modified and enlarged to hold those facilities, but they're not the same as a Burke.

 

[jsport]

Vertical barrels were abandoned for no good reason but politics. Not a war winner.

Vertical barrels were abandoned because they were incapable of hitting anything close to the ship.

It turned out that the minimum range of a vertical gun was very close to the maximum range of a conventional turret.

Yes, that has been explained somewhere on this forum, but would argue a conventional horizonal 5" or even for a cruiser w/ a damn new lightweight 203mm. Previous USN trials on a guided and RAP or new ramjet 203mm rds could be the main horizontal gun for large combatants. The ideal would be a VLS+ VGS and some horizontal gun on combatants depending on the ship and suites which size.

The issue here seems that forgotten forgotten how much bombardment islands required in WWII..ie mnths. Precision will still only get one so far and msles are one shot wonders requiring reload at port. Open sea VLS loading appears to be problem as of late..

 

[Scott Kenny]

Their thinking seems rather muddled at best.

Yeah, it's a mess. The LAW seems like it's a pretty close cousin to the fast ferry logistics ships, just slower and with beaching capability. But then they're dabbling with also adding a small amphib back to ARGs (the return of the fast LST?) I can't decide if that's just appeasing the traditionalists or actually a more sensible approach.

I can't really believe that it makes sense to land a tiny Marine littoral detachment with just an antiship missile battery, for example, without also bringing some air defenses or a ground security force. At which point, yeah, you're approaching an LST in scale, way bigger than the LAW. And IMO it probably needs to be faster (at least ARG speed), or it's going to be stuck in transit when needed. But then the economics make it a much more expensive ship with a bigger Navy crew, which argues for competent defenses, not just a 30mm junk-basher. And the price spirals upward...

Or you need to send 3 of those ships, one with the arty/ASMs, one with a ground security team, and one with the AA coverage (then you get into troubles if you lose one of the ships, so they'd need to mix the units per ship). Though if the ship is closer to the 8000 tons, it may be possible to have all the parts in one ship.

 

[Scott Kenny]

Hudson Recommends 581 Ships, New Class of Corvette as Part of Input to Pentagon Fleet Plan - USNI News

The first of three inputs to the Pentagon’s Future Naval Force Study was released this week, the Hudson Institute is calling for a future U.S. Navy fleet of 581 battle force ships through the addition of 80 corvettes, 99 unmanned surface vessels, 40 unmanned submarines and 27 new small...

news.usni.org

581!!! Should be about 200 Virginia’s in the fleet

No, about 90 total attack subs, the dozen Columbia-class, and any Columbia SSGN derivatives built. I expect the Columbia-based GNs to have about half the missile sets of the BNs, with the leading missile quad identical to what's on the Ohio SSGNs. What would be wicked is if they had the forward compartment of the Virginia-successor, which is sounding like a Seawolf-sized torpedo room, with VLS. 62+ weapons up front. 6 VPM tubes amidships for 42 more.

Plus about a dozen of HISutton's Shallow Water Submarine (but fitted with AIP), to be used for supporting SOCOM. In fact, those SSIs should probably be ordered through SOCOM as "extra large SEAL Delivery Vehicles."

 

[Scott Kenny]

I am baffled by this subject. The USN has over 30 modern nuclear attack submarines at its disposal against a Chinese Navy with no operational ASW experience and a handful of noisy SSNs. You can then add the Japanese MSDF with its modern silent conventional subs.
Any large assembly of Chinese vessels can be sunk quickly and with no need to use surface assets or carrier airpower.
It took most of the best ASW assets in NATO to counter the Soviet Northern Fleet's noisy SSNs.

Because only 1/3 of them are at sea at any time. And another 1/3 could potentially be surged in an emergency, but you don't want to surge if you can avoid it because it completely messes up your shipyard schedules.

 

[Scott Kenny]

Austin mulling whether to send carrier Ike back to the Middle East

Defense Secretary Lloyd Austin visited the carrier Nimitz as they finished another record-breaking deployment.

www.militarytimes.com

We really need a facepalm smiley.

I never understood the point of having CVs operate in a bath tub next to several existing US air bases where they can't possibly avoid detection and draw too much draft to enter half of the body of water.

I've pondered on this as well. The Carriers can sustain an impressive op-tempo but is it needed to bomb terrorists? The Carriers have impressive C2 capabilities, but their orders come straight from CENTCOM. How much money and maintenance hours could be saved by using National Guard A-10s and F-16s?

100,000 tons of Haze Gray on the horizon sends a bit of a message.

Also, we did send National Guard to Iraq after Desert Storm for the no-fly zones.

 

[uk 75]

The RN blockaded Argentina with three second generation SSN armed only with torps.. I reckon five US SSNs with five more rotating with them should be able to cover key Chinese naval bases even without allied help.
Sink the carriers and the big landing ships and job done.

 

[Scott Kenny]

Lithium batteries probably can't compete with the energy density of Otto II, but I think there's advantages to having a second torpedo type with a more quiet launch/run and more variable speed for closer targets. I can't imagine the 20nm+ range of Mk48 is gong to get used much in a real shooting match, at least not against any kind of peer submarine.

Most submariners are trained to get close, to make sure the target can't outrun the torpedo. Very close.

 

[Scott Kenny]

Hypersonic Weapons at Sea to Premiere on Zumwalt-class Destroyers in 2025 - Naval News

The U.S. Navy is set to debut its first at-sea hypersonic missiles aboard one of the service’s three Zumwalt-class destroyers in four years, Chief of Naval Operations Adm. Mike Gilday said on 27 April 2021.

www.navalnews.com

It looks like the first USN deployment of hypersonics has shifted from either the Ohio SSGNs or their Virginia Block 5 successors to the Zumwalts, with the possibility that one of the 155mm turrets will be replaced with one or two Multiple All-up-round Canisters - which hold 7 Tomahawks on the Ohio SSGNs - modified to hold a TBD number of boosters for the Common Boost Glide Vehicle.

ETA the Navy Times version, which suggests three missiles per payload module.

What should become of the Zumwalt class? The US Navy has some big ideas.

The Navy is looking at the possibility of designing a new hypersonic missile launcher to install as a payload module on its three stealth destroyers.

www.navytimes.com

I remember a LockMart ad from before they started the GN conversions, showed 3x ATACMS missiles in a Trident tube. Along with a quartet of Cormorant drones operating as recon planes and interdiction bombers. Scud hunting, basically. Cormorant went and found the TEL convoy, dropped bombs on it to stop it from moving, then some navalized ATACMS cluster bombed it to oblivion.

 

[Scott Kenny]

I think the Navy just doesn't want the weapon on its next surface combatant, and probably can't easily fit it on any of the current combatants.

Typically poor planning on the USN's part.

Not enough spare electrical generation on any existing ships.

 

[Scott Kenny]

*It should be pointed out that thanks to the Navy bright idea to have two crews per ship, one for port work and one for deployments, with the deployments crews being toss around different ships, each Spruance class hull age ten years in five. Reason for this was because the Crews just didnt care about taking care of them. They did not see the ships as theirs, so the mindset of let it be the NEXT guy issues was strong. This just lead to the ships being trashed like a five year old rental car, with all that implies. The fact that they lasted for most of their design life is telling that they built solidly. But by the time they were retired, they were scrapped, cracks in the hulls, gear permatelly inop, think of a issue a ship can have and they likely had it sadly. The Navy knew this so retired them when they did, basically didnt have a choice. For Refitting them to new was going to cost as much as the Zumwalts did, and we all know how THAT turns out.

Yeah, the way the Navy did the Sea Swap was incredibly stupid.

You want a ship at sea more? Give it two crews like the missile subs. Bring it to a port with a shipyard and IMF for each swap. Both crews own the ship, and work together combined during refit to work the boat.

 

[Scott Kenny]

About Navy being unable to fight a two-front war, it seems to be more the case that the Navy can't fight a one-front war beyond 30 days. If I recall correctly, there was a study saying that the shipyard shortage was such that any ship damaged in a conflict would be out-of-action for 1-2 years. Talk of two-front war is fantasy. How many naval bases have any form of air defense?

That was equally true in WW2. Any majorly damaged ship was out for 2 years.

 

[Scott Kenny]

The Case for a 600 Ship Navy: Now More than Ever with LT Joseph Sims, USN

templates are there, just look for them

cdrsalamander.substack.com

IMHO our best tech overmatch is submarines. We should have SSGNs and SSN(X)s coming off the assembly line like sausages.

Unfortunately, we do not have the industrial capacity to do that.

We could probably get up to 4x Virginia-class a year, with some warning. Long Lead Time Items suck. I'm not sure how much space EB has for the Columbia class, but if they can build 2 Columbia per year we could make one BN and one GN. Otherwise, the GNs will have to run at the end of the BN production.

 

[Scott Kenny]

The RN blockaded Argentina with three second generation SSN armed only with torps.. I reckon five US SSNs with five more rotating with them should be able to cover key Chinese naval bases even without allied help.
Sink the carriers and the big landing ships and job done.

China's got something like 3x the coastline of Argentina, and a LOT more green water boats to chase subs with.

I'm thinking about 15 subs out there hunting, plus a pair of Ohio SSGNs or another 8x VPM boats.

 

[TomS]

China's got something like 3x the coastline of Argentina, and a LOT more green water boats to chase subs with.

Also, Argentine ASW capacity was, politely, very poor.

 

[uk 75]

China has a lot of ships but they seem mainly optimised for surface warfare. There is no P3, Nimrod or P8 equivalent. And even if there were, US subs are a whole order quieter than Sov Cold War subs.
Chinese naval bases not its whole coastline are what you are choking off.

 

[Scott Kenny]

China has a lot of ships but they seem mainly optimised for surface warfare. There is no P3, Nimrod or P8 equivalent. And even if there were, US subs are a whole order quieter than Sov Cold War subs.

They recognize that, and are working on getting MPA in addition to AWACS.

Chinese naval bases not its whole coastline are what you are choking off.

IIRC, China actually depends on a lot of imports, the primary resource they have in-country is cheap labor.

Close off their economic output, just like the US did to Japan in WW2.

 

[Josh_TN]

China has a lot of ships but they seem mainly optimised for surface warfare. There is no P3, Nimrod or P8 equivalent. And even if there were, US subs are a whole order quieter than Sov Cold War subs.
Chinese naval bases not its whole coastline are what you are choking off.

There is a MPA version of the Y-8 that entered service a few years ago.