2018/02/25

How to Fix the Belgian Armed Forces

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Belgium as a NATO member

Belgium has a little more than 11 million people and a GDP a little over EUR 400 bn. Public debt is above 100% GDP. Yet the government appears to intend to buy 34 F-35 Lightning II. This would cost USD 6.53 bn, plus likely EUR 1.5...3 bn additional expenses to modernise airbase facilities and other related costs. That's the equivalent of Germany buying 250 (when looking at population size) or 270 F-35 - a very major fiscal effort (much bigger than the annual military budget). To abstain from this effort would reduce the public debt by 2...3 per cent of GDP.


My stance is that membership in a large alliance does NOT mean that you need to pay more to be a "good" ally and actually helper to some of the most aggressive alliance members. The purpose is to enable small powers to achieve deterrence and defence in the first place to maintain peace and sovereignty and secondarily it makes security and defence cheaper. 

A simple model shows this; two countries are border on each other and a third, larger and threatening country. Going alone they would need to maintain armed forces to deter an attack by the bigger neighbour on their own, and deter by being able to inflict punishing damage on both neighbours at once if they attack. An alliance between the two smaller countries enables them to not consider each other as a threat any more, and to spend roughly half as much as without the alliance, for they would stand together against aggression by their larger neighbour.

It's a simple, reasonable and rational principle - and utterly covered up by the nonsense that politicians spew about how smaller allies should spend much on their military (to be a useful auxiliary forces pool for stupid small wars) because they are in an alliance.

This idea of an alliance combined with Belgium's high public debt and a certain fragility of the nation* leads to my conclusion that the armed forces of Belgium should provide a relevant contribution to collective security at low cost.

The Belgian armed forces

The Belgian military (Dutch: Defensie; French: La Défense) has land, air, marine and medical components, notionally unified in to one armed service. Active personnel is around 30,000 and there's hardly any reserve personnel. The annual military budget is about € 4 bn, that's a little less than 1% GDP.

Belgium has a short coastline with some ports, and its navy has been very small for a long time. Its air force had its best time in the 80's when it was equipped with lots of then still new F-16s. Its army had forward-stationed elements in Germany during the Cold War, and everyone seemed to consider them a weak spot in the string of divisions that guarded NATO in Central Europe during the Cold War. Today it's essentially a cluster of infantry battalions with traditional names, lacking artillery and tanks. The entire land component is incapable of true combined arms warfare.

Belgium is special

There are two things special about Belgium:
  1. It's home to NATO administrative/political headquarters and NATO's strategic level HQ, SHAPE.
  2. It's fairly close to Lithuania and wheeled vehicles could self-deploy to it in two days (technically). The wide rivers Rhine, Oder and Vistula would need to be crossed.**
There are thus two fairly self-evident missions for Belgium's armed forces:
  • To provide security for NATO HQs
  • To provide some quick reaction forces for NATO's deterrence and defence in the Northeast.
I suppose the latter should rather be land forces than some gold-plated strike fighters, for the latter could just as easily be deployed from the UK or Spain. Half an hour or one hour of additional ferry flight time makes much less a difference than one or multiple additional days of road marches.

My recipe

About sea power; no navy, but a coast guard with paramilitary status and at least two mine hunting-capable boats. Those should be faster than the current minehunters (15 kts) to be useful for policing and better for SAR. The two active frigates are nearing the end of their lives anyway.

About air power; no miniature air force and certainly no gold plated planes. Instead, the federal police could operate two transcontinental range business jets for VIP transport and the land forces should feature impressive area air defences.

About land power; this should be split into two parts.

A territorial forces division tasked with training and with providing security for NATO HQs, Bruxelles airport and federal government. This component would have the ordinary malaise of personnel being on courses instead of at their home units, and some officers would be exchanged and replaced by allied exchange personnel. The hardware highlights of this components would be some old AFVs and some high quality area air defence and BMD batteries, both for SHAPE's security.

A field army division would be tasked with a super-quick deployment of a mechanised brigade to the Northeast of Warsaw, provided German, British, French and Polish forces ensure there are enough bridges and military pontoon bridges available across Rhine, Oder and Vistula. The second mission would be to deploy a follow-up mechanised brigade a little later.

This division would have two mechanised brigades (tanks, infantry, artillery, engineers, air defences) in two-year tours, phase-shifted by one year. So one brigade would be training up from platoon training to unit training to battalion battlegroup training while the other would focus on maintaining the peak competence for a year. The personnel would have the individual training completed (in the territorial forces) before joining a brigade for two years, would be deployable*** and would be frozen in for two years. No-one would be sent to a course, no-one would be sent to a liaison tour, no-one would be promoted to a new position. Duds that were identified would have to be replaced with territorial forces 'personnel for the rest of the two-year tour.
One high value brigade would arrive NE of Warsaw in 2...4 days, and the second with lesser capabilities but identical (and complete) equipment would arrive in 1...2 weeks, capable of less demanding missions only. Tank transporters used to deploy the first brigade would be the only divisional troops save for some MP and a tiny divisional administrative HQ.

The TO&E of these mechanised brigades could be designed with integration into some multinational army corps in mind. The bilingualism of Belgium means that cooperation with Dutch, French and Canadian forces could be done with little friction from language barriers, while cooperation with Germans would also be fairly easy given the proximity and thus many opportunities for efficient joint training.
The brigades could be kept affordable by abstaining from gold-plating except in regard to signalling, (mostly passive) electronic warfare, anti-tank firepower and air defence. The quantity of tracked vehicles could be kept to a minimum (MBT and recovery tanks) to limit the quantity of needed tank transporters, but this doesn't mean that many fashionable yet cost-inefficient 8x8 AFVs should be purchased, especially no gold-plated ones. Nor should any fancy buggies or ATVs be used; road march efficiency and long-range cruise speed are important. As a rule of thumb it's the better the less motor vehicles the brigade has, especially if Vistula and Oder brigades are busted and but a few pontoon bridges of limited capacity (~250 vehicles/hour)  are available.

advisable high cost weapon systems:
  • SPGs: Caesar 2 or Archer
  • MBTs: refurbished M1A1 or refurbished M1A2 (due to good availability)
  • air defence: Land Ceptor, AMRAAM-ER or SAMP-T
(I mention this hardware only to communicate the necessary level of quality.)

I have not much knowledge of how the Belgian military copes with the bilingualism, but I strongly suggest that one should avoid making one brigade Flemish and the other one Wallonian. As far as I know the current compromise is to have some battalions in one and some in the other language, but brigades mixed. Multi-ethnic armed forces wisely prefer to keep their forces mixed above battalion and regiment level. This may not be the best for military performance, but it's often a necessity for the country's integrity in the long term. 

I strongly suppose that Belgium could have armed forces that would be more useful to the collective deterrence & defence effort while spending less on them (after investments in three to five years of reform).

S O

P.S:: I will not continue the "How to Fix" series till all NATO countries are covered. I chose Belgium because it represents a somewhat different case than the previous ones. It's no great power, not Mediterranean, and is not Eastern European. The "How to Fix" blog posts may be considered templates; they are largely transferable to similar countries.

*: Belgium is half kind-of-French and half kind-of-Dutch, not a nation-state. This predetermined breaking point requires that the people be extra-satisfied with federal government in order to maintain the peace and country. Belgian federal-level politics have failed to positively impress the people for a long time, and huge military spending mostly serves to reduce what perceptible good policies the government can afford to its people. In short; Belgian's federal government should better spend money on quality of life than on arms, or else the country may break up sooner or later.
**: The Elbe river looks big on  maps, but it's a flimsy obstacle in many places unless it's swollen by much rainfall.
***: Plain English: No women who could get pregnant, period. This does not exclude all real women and does not exclude any fake women, of course.
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2018/02/23

Modern warships (VIII) - links to previous naval-themed blog posts at D&F

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Some of these explained tech, thoughts and conclusions that were not covered in detail in the previous parts. These are most, but not all, of the "navy" tagged blog posts at D&F.
 
https://defense-and-freedom.blogspot.de/2008/11/mission-atalanta-or-how-to-demonstrate.html
 
https://defense-and-freedom.blogspot.de/2009/01/anti-ship-ballistic-missiles.html

https://defense-and-freedom.blogspot.de/2009/02/warship-stealth.html

https://defense-and-freedom.blogspot.de/2009/03/european-naval-power-requirements.html

https://defense-and-freedom.blogspot.de/2009/03/arm-in-anti-ship-combat.html

https://defense-and-freedom.blogspot.de/2009/03/shipborne-ir-decoys.html

https://defense-and-freedom.blogspot.de/2009/04/sams-with-active-radar-homing.html

https://defense-and-freedom.blogspot.de/2009/05/modern-sonar-technology-and-possible.html

https://defense-and-freedom.blogspot.de/2009/05/asw-vs-ssk-struggle-will-go-on.html

https://defense-and-freedom.blogspot.de/2009/05/concept-for-future-naval-battle-fleet.html

https://defense-and-freedom.blogspot.de/2009/06/sub-vs-asw-ship-range-mystery.html

https://defense-and-freedom.blogspot.de/2010/03/naval-procurement.html

https://defense-and-freedom.blogspot.de/2011/06/cold-war-naval-strategies-in-nato.html

https://defense-and-freedom.blogspot.de/2011/09/lpds.html

https://defense-and-freedom.blogspot.de/2012/11/is-finding-hostile-surface-warships.html

I'd have stopped here if the Mayans had been correct.

https://defense-and-freedom.blogspot.de/2013/01/naval-and-air-warfare-problem-with.html

https://defense-and-freedom.blogspot.de/2013/03/anti-ship-missile-ranges.html

https://defense-and-freedom.blogspot.de/2013/06/piracy-lesson.html

https://defense-and-freedom.blogspot.de/2013/08/extra-long-range-torpedoes.html

https://defense-and-freedom.blogspot.de/2013/11/securing-maritime-trade-in-faraway.html

https://defense-and-freedom.blogspot.de/2013/12/the-case-for-pickets.html

https://defense-and-freedom.blogspot.de/2013/12/how-to-interpret-chinese-navy-maybe.html

https://defense-and-freedom.blogspot.de/2014/01/an-anti-submarine-strategy-which-doesnt.html

https://defense-and-freedom.blogspot.de/2014/02/trucks-soft-soil-and-ice.html

https://defense-and-freedom.blogspot.de/2014/02/corvettes-and-air-defence.html

https://defense-and-freedom.blogspot.de/2014/04/an-opportunity-for-disciplinary-action.html

https://defense-and-freedom.blogspot.de/2014/05/global-shipbuilding-industries.html

https://defense-and-freedom.blogspot.de/2014/07/lethality-of-navies.html

https://defense-and-freedom.blogspot.de/2015/02/the-stupid-is-strong-in-german-navies.html

https://defense-and-freedom.blogspot.de/2015/08/flottenverein.html

https://defense-and-freedom.blogspot.de/2015/09/an-asw-concept-for-future-2020s.html

https://defense-and-freedom.blogspot.de/2015/09/naval-commerce-raiding-today.html

https://defense-and-freedom.blogspot.de/2015/10/the-baltic-sea-and-baltic-defence.html

https://defense-and-freedom.blogspot.de/2015/12/the-economic-case-against-opvs.html

https://defense-and-freedom.blogspot.de/2016/01/the-difficulty-with-naval-guns-larger.html

https://defense-and-freedom.blogspot.de/2016/01/naval-air-defence-of-2020s.html

https://defense-and-freedom.blogspot.de/2016/06/asw-and-defended-corridors.html

https://defense-and-freedom.blogspot.de/2016/08/summary-of-my-naval-ideas.html

https://defense-and-freedom.blogspot.de/2016/10/maritime-trade-and-security.html

https://defense-and-freedom.blogspot.de/2016/12/musings-about-naval-power-in-european.html

https://defense-and-freedom.blogspot.de/2017/01/the-utility-of-nuclear-attack-submarines.html

https://defense-and-freedom.blogspot.de/2017/01/human-sacrifice-and-military-spending.html

https://defense-and-freedom.blogspot.de/2017/02/how-to-fix-italian-armed-forces-forze.html

https://defense-and-freedom.blogspot.de/2017/02/cooperative-engagement-capability-and.html

http://defense-and-freedom.blogspot.de/2017/03/the-y-20-and-transport-bombers-in.html

S O
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2018/02/21

Modern warships (VII) - conclusion; the two paths

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After more than 24,000 words it's time to come to the conclusions on a higher level, the level of force planning in general. I will try to avoid "fantasy fleet" writing, and I am aware that warships of frigate or destroyer size tend to be kept in service of the original user for about three decades regardless of their military utility in many of the later years.

Any whole (active) force conversion to a whole new concept would thus take about 35...40 years during peacetime, including the development and construction time for the first new paradigm warships.

Well, here are my two solutions to the challenges and requirements from the previous parts of this series:

The dedicated warship,
rethought to exploit the naval technologies of today

The need for a strong helicopter component and the need for many standardised VLS cells have been obvious in the previous articles. Both needs are a continuation of conventional warship designs. A convoy with but two warships as escorts might need many more helicopters than any ASW frigate may hold,  and the addition of AShM and (more) anti-submarine missiles into the VLS battery might require much more VLS cells than usual (even though ESSM may be quadpacked). So even these two conventional attributes may require much more deck area, volume and mass than any existing frigate provides for them (and together more than any destroyer has).

The closest real-world analogy and near-predecessor in concept:
Italian helicopter cruiser Vittorio Veneto (7,500 t, 9 helicopters, area air defence,
ASROC missiles, extremely powerful short range air defences)

A requirement is in my opinion the operation of multiple surface drones in addition to at least two towed surface decoys. The surface drones need to be recovered, replenished and maintained and all of them should fit into or onto the warship during severe weather.
Provisions for two speedboats to be recovered over the stern would not suffice. A more radical approach - a well deck - might be required.

The face of the ideal dedicated GP warship for the 2020's and 2030's might thus be more similar to that of a LPD than a frigate's. The size could still be kept to about 6,000-8,000 tons (much smaller than actual LPDs). The hangars would suffice for four to eight AW101 while the well deck would suffice for at least two towed decoys and six lifeboats/decoys that might even be equipped as pickets for sea skimmer detection. The forecastle would look longer than a LPD's shape, providing deck area for a 60-90 cell VLS and a main gun. This dedicated GP warship would not need to be very fast; 17...20 kts transoceanic cruise speed and 24...27 kts top speed may suffice, and it should be able to quickly turn its stern to an incoming missile, for a hit (even repeated hits) there would be the least catastrophic. A 17...19 kts cruise speed would allow for near-continuous towed LFASS operation, while faster-moving convoys would require sprints followed by slower sonar operation times at 17...19 kts or less.

Chinese Yuzhao class LPD (seen from the most favourable angle)


San Antonio class LPD, showing the well deck
This is not quite a "mothership" idea because the word "mothership" suggests a certain imbalance: A mothership is the platform that provide endurance and range, while the smaller platforms that operate from it provide the real (and especially most offensive) combat power. An aircraft carrier is a mothership, an amphibious warfare ship would even fit - this concept is rather about towed and free-moving decoys (the latter possibly also serving as pickets) and the by now very conventional operation of helicopters. This is far from for example having a large docking ship as mothership (or rather fleet replenishment ship) to multiple coastal corvettes.

A pair of such dedicated warships should be capable of escorting a convoy on a transoceanic route out of range of hostile land-based strike fighters. Land-based air power and coastal forces would be required to assist in some areas due to the increased threat levels there (such as in range of Su-34, in difficult rather shallow waters where submarine detection is especially tricky and generally for protection against naval mines in lanes in front of ports).

 
The auxiliary warship,
the only realistic hope when it comes to quantity

The Americans stand no chance to win a naval arms race with the PRC  - the U.S. has almost no shipyard capacity left. There are three shipyards that build defective, overpriced ships for the government, some Great Lakes shipyards (maximum length of ships built there for oceanic use is 225.6 m) and some capacity for yacht building and Mexican Gulf oil industry specialist ships. The Chinese would win a naval arms race within a decade with their worldwide largest shipyard industry capacity if they meant to do so.
Most global shipbuilding stats have U.S. shipbuilding filed under "others".
Civilian U.S. shipbuilding even ranks behind multiple European countries.

The Japanese shipyards might help the U.S., but the South Korean ones would almost certainly not, as taking part in such an arms race would put South Korea into Chinese crosshairs, and the only sensible strategy for South Korea in a U.S.-PRC conflict is to be largely neutral. The PRC's land power is simply too large and can't be neutralised with nuclear firepower because the PRC is a nuclear power with intercontinental reach itself. The U.S. could grow a shipyard industry for a naval arms race, but this would take almost certainly take longer in peacetime than the PRC would take to win said naval arms race.

The Europeans don't need to be concerned by this; neither the North Atlantic Treaty nor anything else compels them to face the Chinese. The Western Europeans should rather look at Russia, which makes delightfully little progress in its quest for navy modernisation.
The Russian government might nevertheless decide and succeed to build (and import) 30-50 SSI (U.S. DOD acronym: "SSP") submarines in the 2020's, and this would require a dissimilar response for European (European NATO or EU) security. Such a sub fleet could and would better not be "countered" by 30-50 SSIs of our own. It would require a defence for European shipping in coastal waters and on the Atlantic routes.

The Mediterranean Sea could be secured by sealing its three entry points (Strait of Gibraltar, Bosporus, Suez Canal) and by allowing hostile submarines in the Med to expend the one load of munitions that they have on decoys and actual civilian ships (there would be no replenishment for them). That's cheaper than a huge ASW effort for the whole Med, or for a sweep of it. The average civilian ship that's being sunk by a SSI would be worth less than € 100 million and the probability that such a naval war happens is so low that it makes no sense to spend dozens of billions every year to counter a scenario in which a dozen ships worth less than a total € 20 bn would be sunk. Those billions of Euros can be spent on saving lives for real, not just hypothetically. An ASW force for convoy security or sweeps in the Med would only begin to make sense if dozens hostile submarines were expected in the region in addition to the Atlantic Ocean.

The situation is very different regarding the transoceanic (transatlantic) routes, for these cannot be secured with land-based helicopters, drones, LFASS-towing boats, mining bottlenecks et cetera. One would need the AAW and ASW capabilities as well as some ASuW capability.

The defence of the maritime trade on these routes could not be area-focused as with secured coastal lanes/corridors. Some form of convoy system would be necessary. The existing navies talk as much about how they secure their nation's maritime trade as you let them time to talk, but they do in fact almost nothing about it for real. Not a single navy - including the large American, Chinese and Japanese ones - comes even close to being able to provide sufficient escorts for a general convoy system. The Chinese, Japanese and South Koreans are the only ones with enough shipyard capacity to even only justifiably dream of securing their transoceanic maritime trade against missile-armed submarines and helicopter-operating auxiliary cruisers. The European (and American) answer to the challenge - should it ever arise - has to make do without dozens if not hundreds of new dedicated warship hulls.

The needed electronics, helicopters and munitions could be produced in the needed quantities in two years if laws are being passed to prioritise such military orders over any civilian orders and the designs were already completed. A hundred or more fully self-defending convoys could be created per year using containerised modules that turn cargo ships (mostly medium-sized container ships) into auxiliary warships. The production bottleneck would likely be helicopters, which would compete with air force orders for production capacities in times of crisis. Such auxiliary warships would mostly use redundancy and dispersion of modules among the convoy for survivability of the convoy as a whole instead of trying to reduce the signatures and improve the ability to cope with hits of a much smaller dedicated warship hull. Neither a convoy with dedicated warships as escorts nor a self-defending convoy would be safe from losing ships, of course.

It's thus high time to create an ARAPAHO II program for AAW, ASW, VLS, CIWS, radar, towed decoys, towed sonar, decoy projection, command, crew quarters, supply storage, auxiliary power generation, helicopter hangar and helicopter landing pad modules based on standard 40 ft ISO containers. Sonar sets to be built into the already existing bulbous bows of container ships (with new cover, obviously) would be needed as well.

plenty area, volume and payload is available for military purpose modules

Sets for dozens of self-defending convoys and additionally CIWS and decoy sets for hundreds of coastal traffic cargo ships should be bought once there's a threat justifying such expense rising. Small quantities should be bought even without such a threat to test the concept and gain experience onboard small chartered container ships.


Navy bureaucracies have zero incentive to become storage administrators running inventory and function checks on thousands of containers. They want ship hulls to play with. They want to go cruise at sea. That's what a navy is all about in their opinion - regardless of whether this is a means to a reasonable end.

That's why the navies as we know them have to die.

We need military bureaucracies that offer the most cost-efficient approach to satisfy deterrence and defence needs, not clubs of men who want to play with ships or boats at the taxpayer's expense. The outcome of European naval bureaucracies pursuing their self-interest is a combination of very high expenses and a de facto absent ability to secure maritime trade. We need the civilian masters of the naval bureaucracies to rein in and bring them on course to pursue the national interest over their bureaucratic self-interest, for the navies would never be able to do so or even only admit that they don't serve the national interest first and foremost. Without such an intervention we will simply keep wasting money for next to no benefits in return.

- - - - -

My thanks go to those who were willing to help by previewing and criticising a part or multiple parts of the whole (none saw this conclusions part). I did not incorporate all their recommendations, so the blame would still be on me for any errors or poor conclusions. The following previewers were fine with being mentioned: TAS@verdigris_blog, Chuck Hill

S O
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2018/02/19

Modern warships (VI) - other topics


This part is about several smaller topics that are not as much driving the general design and idea of warships. Most of them are 'back office' kind of things that should be mentioned.

Ballistic missile defence

BMD is an exception on this page; it's not back office at all, but instead a hype - and has been a hype for a long time. The days of SDI are over, but conventional ballistic missiles had the West's attention since they were used as propaganda munitions in 1991.

There are several ways of mitigating the ballistic missile threat that are essentially preventive or soft kill defences; they seek to avoid that the missile aims at the (correct) ship and most of them are being used anyway in order to avoid being targeted by ordinary cruise missiles. It appears to be fairly easy to defeat the sensors of a ballistic missile even if it was aimed right at the convoy; it may have nothing but a radar that's looking down at the convoy, no sensor fusion - and it has mere seconds to choose what to attack for the one and only approach. There's no turning around after being fooled by some chaff or decoy.

The hard kill methods can be separated into two distinct categories;
  • missiles with dedicated seeker and warhead for exo- or upper-atmospheric employment. These missiles may potentially deal with really long range ballistic missiles that were aimed at targets a long way behind the warship. Such missiles are hardly suitable to defeat aircraft or cruise missiles because of their specialisation for the conditions of the upper atmosphere (hardly any air to heat up an infrared sensor's window even at thousands of kph speed, little use for rudders in the thin atmosphere). These missiles may play a role against the satellites in very low orbits (all satellites are very short-lived in such orbits and thus need to be cheap, but the relative proximity to the ground makes less sophisticated sensors viable than with most satellites).
  • And then there are also missiles that may deal with ballistic missiles in the lower atmosphere as if they were hypersonic missiles coming from above.
Lance short range ballistic missile as seen by imaging infrared sensor

I am not aware of any aircraft- or shipborne ballistic missile designed to engage ships at sea. The only ballistic missiles capable of hitting a moving ship at sea appear to be the Chinese DF-21D which got a lot of press a few years ago because the USN worries that it might not be able to bomb China at will with its carriers if the Chinese have effective land-based long range ship-killing capability in them. Another example was the Soviet R-27K which was cancelled decades ago.

The purpose of convoy defence at sea doesn't require exoatmospheric intercept missile, and the same type of missile (SM-6) as for long range area air defence could be used for other BMD purposes.

I should also mention that the terminal approach speed of a missile is mostly dependent on the range of the missile; the longer-ranged ones are moving faster on their descent. Hence there are sometimes descriptions such as "can intercept ballistic missiles of up to 500 km range" given for area air defence missiles. A "BMD-capable" missile isn't necessarily able to stop all kinds of ballistic missiles, even if it can stop the short-ranged ones.

You also need a proper radar for the fire control if not the early warning.

Security in ports

Many great powers suffered severe losses of warships in port during the Second World War. The Americans were hit hard in Pearl Harbour, the Germans were hit hard in Brest, Tromsø and various German ports, The Italians were hit hard particularly in Tarent, the British were hit hard in Alexandria and Scapa Flow, the Russians were hit hard at Leningrad. The Italian and Russian capital ship losses in port even exceeded their losses of capital ships at sea, while the German losses of capital ships were about 50/50 in port and at sea. The security and safety at port is thus an important issue as proven by military history.

Classic port security was mostly about defensive minefields, blocking ships, the port's own air defences, anti-torpedo nets, maybe some smoke against bombers and certainly also sailors standing guard. This was insufficient (even though anti-torpedo nets helped a lot), was impotent against the Italian frogmen attacks and would help nothing against incoming missiles. Modern port security & defence needs to be better, much better. A € 2 billion warship is not much less vulnerable to most attacks in port than a container barge.

The air defences and BMD capabilities of warships at port should be ready if not active in wartime (though one search radar in active mode would be enough per convoy, ready to react to incoming threats in time). AEW cover makes sense even in port. Air defences need to be capable of protecting against terrain-following missiles.

Sabotage by hijacked cargo ships intentionally ramming anchored warships is possible by using a (floating) ship as blocking ship. The tug crews in port should also be ready and motivated to intervene.

Small boat attacks in port are rather unlikely in a conventional war between nations.

There's a surprisingly comprehensive wiki article about security against sabotage by divers or attack by tiny submarines.
  
Mine countermeasures

Dedicated MCM ships are not the subject of this article series. It does make sense to have limited MCM capabilities onboard an ordinary warship, though. A mine avoidance sonar capability makes sense on frigates and larger warships for self-protection and some divers are necessary to inspection , maintenance and potentially repairs underwater as well. A minehunting drone for object identification could be used, and might be of some use for battle damage assessment in ASW as well. A warship may thus have a limited capability against stationary naval mines, including clearing them with divers, with little extra equipment.
Mobile naval mines (such as self-deploying, torpedo-like mines) should be handled just as the heavyweight torpedo threat should be handled. 

Boarding

Warships need to be able to inspect ships to identify blockaderunners and auxiliary cruisers (cargo ships turned into raiders). This has to be done at a safe distance (see HMAS Sydney), and only a helicopter should thus be exposed to the great risk of closing in with a suspect ship in order to keep the warship itself safe. Some volume, some seats, and a winch capable of pulling up two grown men should help a lot. Additionally ropes for fast rapelling may be used during boarding. The extra training requirements affect but a few sailors and the extra equipment requirements (helmets, small arms, inspection tools) require but negligible expenses.
Boarding by boat / dinghy is unacceptable in wartime and the zenith of incompetence if done at wartime unless done close to port, period. The warship would need to come too close and be too much at risk to shorten the boat's cruise to and from the suspect ship to an acceptable level

Evacuation

Warships depend heavily on inflatable marine life rafts for survival of the crew of a sunk ship. The capacity of the boats carried by a warship is but a tiny fraction of the crew size. Navies mandate a certain excess evacuation capacity (as far as I know 110% capacity in the case of the USN), but the ability to actually make good use of this capacity after taking multiple hits, experiencing a fire and heavy seas is questionable. Frequent evacuation training is risky and may actually injure and even kill people, especially when done in cold weather and high sea states.
Everything that's inflatable is highly susceptible to damage by fragmentation, and the metal shells of inflatable marine life rafts are not protected against the fragmentation effect of missile hits.
Evacuation by helicopter is possible in principle, but has a very low throughput (personnel evacuated divided by time) and is thus of little help in case of a torpedo hit (which sinks a ship quickly). Severe fires onboard or stormy weather may impede evacuation by helicopter as well.

A simple way to improve the capacity for evacuation would be to mount many additional evacuation devices on vertical walls of the superstructure as was done during WW2 with Carley floats. This would go counter the polygonal radar stealth trend in warship construction, though.

enough orange +
reflexive tapes on a survival suit
Navy personnel often wears flash (fire) protection equipment when the ship is combat-ready or at war, but hardly ever do they wear survival suits. These are mostly reserved for those who are in boats or helicopters. Such suits might be a necessity for making good use of inflatable marine life rafts in cold weather, though. The transition from warship to inflated raft is the tricky part, and may easily go wrong regardless of technique used.

blue, black, white or grey uniforms are idiotic for shipboard use
The absolute minimum required for a sane approach for crew survival is to not give them uniforms that camouflage in no other environment than the sea. A rational uniform has to have a bright orange top part. It doesn't need to be exposed all the time, but the user has to be able to expose this easily detected colour with little force and one hand only. A bright orange hood might suffice. This isn't really about uniforms: Navies have to do their job and prepare for real battle - and this includes the nigh-certain events of ships being burned or sunk, and crews being forced to evacuate under difficult conditions. It's a mindset issue.

Firefighting for other ships

Water cannons can be used to assist with firefighting on another ship (at least cooling down the outside of a hull if nothing else). Some water cannons should be present in a convoy, albeit not necessarily on a warship.

Search and Rescue

SAR is a noble task and purpose for any ship or boat, and most warships would be particularly well-equipped for it. The combination of naval helicopter (FLIR used for identification of ships helps with searching and the boarding equipment helps with rescue), boats with outboard motor and ship-mounted infrared sensors (needed to improve the detection of sea skimmers) is a powerful one.
 
The problems with SAR are that it may divert helicopters from submarine search efforts and slowing a convoy down to care for survivors of one or multiple ships might endanger it. To detach a warship for the rescue effort would put the remaining convoy at increased risk and it might take a long time to catch up afterwards if the convoy's cruise speed is high. It may for this reason be impossible to just send small boats to pick up survivors without any ship staying behind for the effort. Even worse; those boats may be wanting for an evacuation effort if their ship gets hit in the meantime.
In the end it may be advisable to have a few commandeered civilian helicopters with the convoy, ready for rescue missions only (large cabin, equipped with winch).

Replenishment at sea

Warships can be replenished at sea, and this is done primarily with fuels and food. Replenishment of munitions at sea is possible as well, but the effort was widely judged to not be worth it. An exception to this rule was the rare torpedo resupply efforts for German submarines at sea in the Second World War. Missiles and torpedoes are so expensive that the national stocks don't exceed the inventories on board the ships by much (if at all) anyway.
 
Endurance

Warships can be resupplied at sea, but it would still be favourable to possess the endurance for a transatlantic (NY-Rotterdam) crossing at 17...19 kts with about 20% fuel reserve. This is more than just about fuel (including for helo operations) and cold storage capacity: It's also about crew quarters/morale, spare parts (especially for helos) and munition stocks (in particular lightweight torpedoes, and avoiding dependence on "expendable" sonobuoys).

Warships should have little trouble with such a requirement, but especially the fuel supply of and for drones may be an issue. Smaller craft are much less fuel-efficient than larger ones, and drones should be small. This is not an issue with towed decoys, but freely moving surface drones on picket duty for early detection of sea skimmers and such would have a fuel consumption on a 15...25 kts transoceanic cruise that's out of proportion to their size. Their systems would not be maintained by a crew since drones are by definition unmanned, and they would likely have little if any redundancies in order to keep them cheap and small. Drones would need to be recovered, maintained and refuelled by the warship's crew to achieve the endurance and appropriate cruise speed for a transoceanic convoy action. They would also be recovered ahead of high sea states, so the ship would need to be able to carry all its drones at the same time. To keep drones outside during a storm leads to high drone attrition and/or slows the convoy down as small surface craft become slow in high sea states (albeit wave-piercing hull shapes may help to maintain speed at medium sea states).
 
Speed and agility

Many convoy escorts used to be fast ships in order to catch submarines before they dove away, but many successful convoy escorts were slow designs (see Flower class ASW corvettes). To run away from torpedoes is impossible once they got close anyway, so there's little reason to emphasise the top speed much.

During the Cold War there was an argument that ASW frigates needed to be fast in severe weather to keep up with nuclear attack submarines trying to escape. That's now less of a concern since so much about ASW has become helicopter-centred. A submarine that's running away from a convoy before having done harm is a submarine that was protected against anyway.

The top speed of a warship doesn't look terribly important nowadays. The cruise speed on the other hand should keep the pace with the large cargo ships, which may cruise at 12...25 kts. A design for 17...19 kts cruise speed (with towed sonar array and towed decoys deployed) would thus make much sense. Towed sonars are still be usable at 17...19 kts at most, depending on type.
A higher cruise speed is very difficult to achieve with a small hull (relative to the much bigger container ships and tankers) and a given set of equipment requirements. Engines cannot be run on 100% output for days, so more power would be installed to achieve 20 kts of cruise speed than is actually necessary to reach 20 kts. Even more power may be installed for redundancy; marine engines may be shut down for maintenance during a cruise, and having more engines at hand means that a ship repairing one of its engines would not necessarily slow down a convoy or fall behind.
That extra power may help to quickly turn around the ship in response to an incoming missile if it's available within seconds. It's often preferable to be hit at the stern by a missile (above water!) than elsewhere. Warships of all sizes are pretty good at such emergency turns.




Medical support

A convoy at high seas should have the facilities for proper emergency surgeries. It's but one room that's required, and the two or three medical personnel (with more tasks than only medical affairs) that should be onboard any warship of 200+ crew anyway, so this is no extraordinary requirement. In worst case the helos may be able to shuttle additional medical personnel in from cargo ships or other warships.

NBC

Not all warships have a proper NBC filtration system, and it appears to be out of fashion due to the reduced threat of nuclear warfare. A washdown system that might clean a ship from fallout using seawater on the other hand may be most useful as camouflage against both infrared and radar sensors. Its spray helps to conceal and the water could also almost equalise the temperatures of the ships' surfaces and the sea.




A CV90120 light tank showing the use of mist as countermeasure to IR sensors (and likely laser ranging).

Naval intelligence

It's questionable how much the trick of guiding convoys around mobile threats still matters. Surface threats should be eliminated by air power easily, and subsurface threats would typically have unknown locations.
Naval intelligence is more relevant for identification of signals and echoes; noise profiles, radar and radio emission patterns and wavelengths et cetera. 
Missiles that may aim at particular parts of a target after identifying its shape with an imaging sensor would also need to know where to aim at for best effect.

Cargo ships would have to switch off AIS transponders in a convoy, and maintain radio discipline as ordered by the convoy leader. Many cargo ships are flying the flags of Panama and Liberia while being crewed by Filippinos. It's unclear how this would affect the availability and discipline of cargo ships in a future war. Most likely insurance schemes that compensate for the loss of cargo ships would be necessary, as previously during the world wars.

I may still underestimate the importance of naval intelligence. I do simply not believe that all important intelligence may be collected ahead of a war, so I expect a navy to focus more on being prepared to deal with the unknown than on trying to know as much as possible about threats.

Orbital satellites

Orbital satellites may be used to detect and even identify surface ships, but those would rarely be a threat anyway, as mentioned before. It's in theory possible to detect submerged submarines with orbital radar satellites, but this requires fairly fast movement at little depth, so it's not really relevant for all I know.
 
Hollow force syndrome

You may have read about low readiness of warships in one or another navy. This is sometimes due to teething problems, sometimes due to severe design flaws and sometimes due to modernisation programs.
There's one all-too common reason for low readiness that's easily avoidable: Insufficient funding for repairs at the industry and spare part stocks. These are either "hollow force" symptoms or symptoms of a ship being very old (and thus likely already of little military utility save for the training of inexperienced sailors).
A navy should simply not buy more ships than it can operate at a good level of readiness, and it should modernise or get rid of ships that have spare part supply problems because of obsolete parts that no-one still supplies or maybe even no factory of the world is still capable of producing (this happens a lot with electronics). The "hollow force" symptom is not a consequence of politicians insisting on budget cuts; it's a consequence of naval top brass and "defence" politicians insisting on keeping the quantity of active hulls high instead of adapting the force size to the cuts properly. It's better to mothball a ship or two than to have six ships in poor readiness.
 
Upgrading warships

The easiest ways to upgrade a warship is to give it better munitions (and to integrate them in fire control) or to improve the crew quarters. It's more demanding to upgrade the sensor equipment, and there's rarely a major hardware upgrade for radars or sonars despite the often 30 year-long career of most frigates and destroyers.

Upgrading of major weapons systems and even reconfiguring for different mission sets is made more easily if one makes use of standardised modules such as the Mk 41 VLS or modules from the MEKO system. One shouldn't fall for the "modularity" buzzword wholly, though: A navy that is in full marketing drive to sell to the nation the idea that it should get ten frigates and talks all the time about how easily it could reconfigure these for new mission needs thanks to "modules" would probably buy 12-15 modules for 10 ships, if it completes the module development at all. The naval bureaucracies are interested in having hulls, not in having all those peripheral things (save for the USN, which thinks it's an air force and spends more on aircraft than on ships these days).

Crew concept

The German navy is touting a 2-crew concept for the oversized, overpriced patrol ship that's the F125. The F125 is supposed to be more at sea per year by having one crew that recovers on land and one crew on duty. They did sell this idea by claiming that a single crew would be really small due to automation, so two crews would be affordable. They will predictably fail to recruit and train enough personnel for a 2-crew concept, and the crews are small because those ships have little sensor equipment and no more firepower than a 30 years old 300 ton fast attack craft. Moreover, the entire idea of having multiple crews is nonsense - even for embargo enforcement missions. NATO has well over a hundred warships. Let them rotate the next time some unfortunate small power faces the wrath and is embargoed by the United Nations. There's no need for one specific ship to stay on blockade duty for 60-80% of a year.
Transoceanic convoy operations would sure be exhausting to some degree, but a single crew with decent quarters and comfort onboard could still execute more such missions in a row than any naval bureaucracy would ever buy enough munitions for (remember the false contact problem). Bad leadership could change this for the worse, but a 2nd crew is no answer to that either.
To have a 2nd crew almost doubles the operating expenses of a warship for negligible gain in deterrence or defence value.

The average warship crew is composed of amateurs compared to the average cargo ship crew. There's more division of labour for tasks in navy ships (this is part of the reason for the way too many collisions at sea) and crewmembers are not very versatile because poor retention rates reduce the average time on sea in a lifetime of a navy sailor to a few years (if the sailor is member of a ship crew at all). Personnel policy and systems go beyond the scope of this article series, but really good policies would enable very different, vastly superior crew concepts with a bit smaller, but first and foremost much more versatile crews. A part of the reason for the current division between AAW and ASW ships is that to train for high proficiency at both takes too much time - the crews are not stable enough. Imagine a team that's 90% officers and sailors who have served on that one ship for the past five to ten years together, with 40% time at sea. Both their ASW and their AAW competence would be superior to anything known to any NATO navy.

Reserve displacement, volume and deck area

Reserve displacement is how much additional mass the ship can take in before being too heavy (to float). It used to be all-important to allow a ship to survive the leak caused by a torpedo hit, but nowadays it's especially of interest regarding upgrades. Good upgrades may add much weight, and an insufficient reserve displacement (or too much top heaviness) may prevent such an upgrade. Deck areas and volumes need to be reserved or used for low importance purposes or else one might not find places where to install the upgrade hardware and where to berth the additional crewmembers required to operate it.
There is an evil twin to such foresight; "equipped for, but not with" warship designs. These are yet another ugly way how naval bureaucracies try to get more and more toys (ship hulls) to play with; they buy hulls, but don't equip them fully. That's how underarmed ships like the La Fayette class (3,200 tons, but no more powerful than a 1,300 ton Sa'ar 5 class corvette) came into being. The bureaucracies then sometimes praise the "room for growth". One shouldn't fall for this. "room for growth" is a good idea exclusively if the basic equipment status is already fine.

Construction standards 

Much was written about how only shipyards specialised on warships can build proper warships, and I call B.S. on that. That's disinformation by shipyards that specialised on 'marketing' to naval bureaucracies (and politicians) and have lost competitiveness on the civilian market after decades of cushy contracts and having bureaucrats & politicians as their primary or only customers.

Warships have different construction standards that make a 4,000 ton warship much more likely to survive a hit than a 4,000 ton civilian ship, but much of this could be retrofitted, even an improved watertight compartmentation. In fact, a cargo ship with a cargo of secured hollow steel spheres could easily be rigged to stay afloat after hits that would sink any 10,000 ton warship.

The dilemma with firefighting at sea is that you want to cool down the area on fire to extinguish the fire for good, and the preferred way to do is is to inject water that evaporates (which converts a lot of thermal energy). The problem is that the more seawater you bring into the hull without it evaporating and escaping to the outside atmosphere the heavier the ship is going to be - until it sinks. To extinguish fires is often easy, but to cool down compartments that burned is much tougher. So as long as water is an important means to cool, a good reserve displacement and reliable control of ballast tanks are the way to go. An alternative way of cooling down burning compartments is to inject chemicals that react using the thermal energy as the activation energy. The fire's thermal energy gets converted into chemical energy. This can cool the compartment enough to extinguish the fire. Still, water is an important means to cool because it's plenty, it's free - and chemical agents are not necessarily procured and carried in the necessary quantities because the top brass has different priorities and peacetime isn't punishing such behaviour.

Fires can also be extinguished by covering the surfaces of flammable materials with less flammable materials (which may be super-quick, but is dangerous as the coating may coat lungs and suffocate people), by flushing out the atmosphere (and thus the approx. 21% oxygen - again not necessarily healthy for the crew) preferably with inert gases or by restricting the flow of oxygen to the fire (foam does this in addition to covering the flammable materials).
Automatic fire extinguishing equipment can be retrofitted into all compartments. De facto instant fire extinguishers are even installed on many yachts, at bus and truck engines, and there are even portable types that can be thrown into a fire to extinguish it.

There are mostly traditional ways of dealing with leaks (especially having many watertight compartments, plugging small leaks and protecting components against the electrical and chemical consequences of contact with saline water). You may also fill a compartment with a quick-hardening foam to limit how much additional weight a leak may add to the ship. This can be retrofitted as well.

Shock hardening (important for near misses of mines and torpedoes) is important as well, but it can be retrofitted to some degree.

Hull materials

Steel is relatively cheap and still the dominating material for the construction of ships, including warships. Aluminium got a really, really bad reputation after the USS Belknap fire where the superstructure lost its structural strength due to the heat of the fire and collapsed. An aluminium alloy structure does rather not melt in such fires; it becomes soft when hot and collapses under the weight of the superstructure elements it was meant to support.
USS Belknap after the fire, with collapsed superstructures
Plastic composites have been considered and used (especially for small craft) and fibreglass-reinforced thermoset matrix plastics may become the materials of choice for superstructures. They don't have the same corrosion issues and thermoset plastics don't melt. There are still issues at the interface with a steel hull because the steel and the plastic composite expand at different rates as they are warmed and accordingly contract differently as they are being cooled. The automotive sector despairs over this problem, that's why we don't drive many plastics-skinned cars.

Offboard electronic warfare

A few land forces have pioneered the use of helicopters as electronic warfare platforms, complete with jammers. Most VHF radio jamming is limited in its effectiveness because a line of sight is needed to the receiver that shall be jammed. Jamming vehicles are sometimes armoured, but their employment far forward or in prominent positions (hilltops, for example) is still dangerous and difficult. Raised masts may help with this, but helicopters have it much easier to get into line of sight; they simply climb to the necessary altitude.
Naval helo-based jamming would be possible as well, but the underlying reasoning would be different. Warships that outsourced air search to AEW helicopters would be largely silent; they wouldn't emit much themselves, and this should help their survival. Radio and radar jamming on the other hand requires an active emitter, so outsourcing this as well might make sense. The mobility and altitude of a helicopter could also help deal with the radio horizon issue.

There might be a reasonable case for an offboard radio/radar jammer to deal with attempts to identify ships by long-range SAR (synthetic aperture radar - more or less imaging radar) and for jamming radio datalinks to subsonic cruise missiles (at least jamming the link from missile to platform so the operator could not 'see though' the missile's seeker and help it with decisionmaking). The ASW helicopters would be an obvious platform of choice for this - maybe a jammer kit could be provided alongside an AEW kit? The AEW platform itself might help with jamming in its own radar band.

Propulsion

Propulsion is linked to speed, range, noise and seemingly unrelated things such as mast designs.
Modern cargo ships are motor ships; they have huge bore, low revolutions per minute diesel engines. They can burn some really low quality fuels, which allegedly they do outside of territorial waters where they don't get into trouble for the emissions. Such a propulsion is optimised for efficient cruise, reliability and repair during a cruise. It's also very loud.

Frigates and destroyers usually have separate engines for cruise and sprint, and typically these are coupled for sprint. The sprint engine is usually a gas turbine (and most advances in aircraft turbofans don't apply to such warship sprint engines because an increased bypass ratio doesn't matter in such an application) and very rarely a diesel engine unless the warship has a modest top speed. The cruise engines are usually either gas turbines or diesel engines. There's usually one cruise and one sprint engine per shaft in AAW warships, but ASW warships sometimes have the engines mechanically decoupled from the shaft to avoid that vibrations (noise) get transferred through the shaft to the sea. Two cruise diesel engines and a single vastly more powerful gas turbine is a common combination on small warships. Electric generators create electricity at and electric motors propel the shaft that drives the screw. This makes them extra silent, and I never quite understood why this wasn't considered just as necessary for AAW-specialised warships - they don't get to choose whether a hostile sub is nearby or not, after all.

Steam turbines had been favoured for about sixty or seventy years for warships, but have fallen out of use in new frigate and destroyer designs because of their inferior fuel efficiency compared to diesel engines and their inferior power density compared to gas turbines. Steam turbines were advantageous for the mast design, though; the absence of hot gasses allowed for a unified mast and funnel design (MACK), which is also possible with all-diesel propulsion, but caused some issues. Gas turbines have hot emissions that require large funnel designs.
Nuclear propulsion is a version of steam turbine propulsion in which a nuclear reactor instead of a heating oil-burning boiler creates the steam, but nuclear power has fallen out of use with destroyer designs and was never used in frigates (too expensive).

Most frigates and destroyers have two shafts and  two screws (sometimes as a controllable pitch propeller instead of a transmission or electric motor).
CODAG = combined diesel and gas (cruise without gas turbine power)
CODLAG = combined diesel electric and gas
CODOG = combined diesel or gas (sprint without diesel power)
COGAG = combined gas and gas
COGAS = combined diesel and steam
COGAG, COGOG, COSAG, CODAD, CODLOG, CODOD, ... - you get the pattern
a CODLAG setup
Integrated electric propulsion has no engine connected to screws by a shaft at all; both cruise and sprint engines (if separated at all) are entirely decoupled from the seawater. The result is the most electric power supply capacity for the ship, and the most silent propulsion. A single running cruise engine could this way drive multiple screws. An IEP could also increase power output at the screws quicker than conventional layouts if it can temporarily draw extra power from batteries. In the long term an IEP might use even more silent fuel cells, but those seem to fall short of their promise (though they are in use in German submarine types).

Auxiliary power units are low power output units for electrical power supply independent from the main propulsion engines and are built into many if not all warships. Such auxiliary power units may actually suffice to move a warship at very low speeds (~4 kts) in emergencies if they can be used to supply emergency propulsion systems (retractable screws with electric engine or Voith cycloidal rudder.

Designs have been pitched in which one or two huge steerable podded propellers with electric motors propel the ship, which is quite a departure from the classic engine-shaft-screw paradigm (civilian azipod example here).

As a rule of thumb, larger propellers can rotate slower for the same thrust and can achieve a higher speed without loud cavitation (this depends on them rotating slowly, and is limited by the low water pressure at few metres depth). Hence the single, huge screws on modern submarines.

Waterjets (ducted propellers) have a reputation for being very silent. The technically similar pumpjets were used on submarines and some torpedoes for this reason. Very few surface warships use waterjets so far, but they may become common.

S O
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2018/02/18

Modern warships (V) - land attack

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I don't care about naval land attack capabilities.

Land attack by sea is not about deterrence or defence. 

NATO powers could use naval cruise missiles, but hardly anything of interest should be farther than 500 km from friendly territories, and thus there's no reason why we couldn't use land-based missiles instead. If need be, we could use air-launched cruise missiles, even dropped from transport aircraft.

Cruise missile diplomacy is a violation of the Charter of the United Nations article 1,  the North Atlantic Treaty article 1, Briand-Kellogg Pact article 1 and Revised General Act for the Pacific Settlement of International Disputes that are in effect and thus have the force of law in all countries that ratified them (or had their legal predecessor ratify them).
Small wars are a waste of resources and almost all of them are also violations of the aforementioned international treaties.

Substantial naval cruise missile land attack capabilities are important only to despicable acts; cruise missile diplomacy, offensive small wars and strategic surprise attacks.

Naval cruise and (conventional) ballistic missiles of greater than 500 km range should be banned in my opinion. There's no legitimate justification for their existence. Nuclear-tipped ICBMs and SLBMs should be handled differently, as part of nuclear disarmament or move towards minimal deterrence regimes.

The only land attack mission of a navy that may be worthwhile and legitimate is to raid pirate havens, for that's how competent navies deal with pirates. See Pompey the Great. Pompey and his fleet wiped piracy off the Med in weeks (after months of preparations), primarily by going after their bases. The current crop of navies pretends that patrolling against pirates (=job creation scheme) is the way to go. No, it's not. You do intelligence, then you raid the pirate haven, blow up all boats, blow up the leader's villa and return home. This requires no more than some infantry (whether marines or regular infantry doesn't matter), some offboard motor-driven RIBHs (rigid hull "inflatable" boats)  and a small chartered cargo ship.

A reconquest of islands occupied by an aggressor should be avoidable by using embargos and blockades against the aggressor instead.

No warship needs to be set up for land attack.

A little land attack capability may be for free as AShM and guns may shoot at land targets as well, but that should have no priority.

S O
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2018/02/16

Modern warships (IV) - ASuW

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Land-based and carrier aircraft can attack naval surface targets much more easily, at much less risk and all this while being able to identify targets at a longer distance than surface warships themselves can do. Fast attack craft with missiles are thus an anachronism, and anti-surface warfare capabilities have become an afterthought for the design of warships.

Land-based strike fighters could reach a ship anywhere in the North Atlantic
with an anti-ship missile if supported by tanker aircraft.

The last naval warfare campaign in which surface craft were important was the naval blockade of the Sri Lankan government against the Tamil rebels. They used mere patrol boats to intercept blockade-running boats used by the rebels to import supplies from nearby India.

Other than this the unimportant Battle of Latakia in 1973 between Syrian and Israeli missile-armed fast attack crafts was the most recent relevant sea battle. Air power could easily have substituted for either party, but the air forces were busy apparently.

The first serious people understood in the First World War that air power could wipe navies from the surface of the sea within its effective range. Some bombs used and the first aircraft-dropped torpedoes had been developed, and even some guided weapons had been tested.

300 kg guided anti-ship glider, to be dropped from airships (1917)
Aircraft can synchronise attacks from multiple preferred angles with a well-timed application of anti-radar practically any anti-ship missile type (all of them are or could be adapted for air/sea use). They can do so while being a very fast and difficult-to-hit target, particularly at distances greater than about 40 nm. They can also provide standoff jamming and chase away or destroy AEW support.

Scenarios

There are few legitimate scenarios in which frigates and destroyers might need to do ASuW in absence of any air support other than naval helicopters. Some of those are:
  • Passing through a strait and encountering Q ships or small boats / wing in ground effect craft
  • Engaging an auxiliary cruiser on an ocean after being attack with missiles, possibly from its helicopter(s)
  • Ship battle after failure of either side's air power to sink the warships
  • Surprise sea battle at the beginning of a conflict
  • A sea battle including at least one poorly equipped navy (imagine a Western navy would escort humanitarian transports to a Biafra-like conflict zones and getting engaged by a desperate Third World navy that wouldn't be destroyed before it opened fire itself)
  
Non-scenarios 

Still, I don't think the Taiwanese navy should for example equip warships to deter or sink a Chinese invasion fleet. It would be much more cost-efficient and thus much more effective to invest in land-based missile batteries instead. (Of course, their navy likes having toys at sea and thus they even have utterly pointless fast attack craft).

The extremely fashionable "Iranian speedboat threat" hype that appeared in 2002 during van Riper's use of simulated speedboats is ridiculous in my opinion. You won't have any trouble with Iranian speedboats if you don't attack Iran, and any powerful hostile country would be capable of much worse. The security of Kuwaiti and Saudi oil exports in the Persian Gulf is their problem. They can invest in a pipeline or two to the Red Sea for a few billion dollars. There's no reason why Western navies should prepare for war against Iran, and hardly any other scenario than another Gulf War/Blockade attempt for going that close to hostile shores in anything but a war of aggression. The last time the West escorted tankers against Iran was in support of Iraq waging its war of aggression against Iran - and Iranian oil exports were not protected, so it was at best a hypocritical Western campaign in support of an aggression.
As a rule of thumb NATO forces do not need to get close enough to hostile shores to fear speedboats in a defensive war. Such things might only happen in wars of aggression or stupid small wars.

Gap filler

ASuW by frigates and destroyers is thus nowadays a mere gap filler for when air power is not available. It was accordingly neglected by Western navies, which are still operating their 1970's generation of anti-ship missiles while the Russians kept innovating and refining their arsenal.
The typical armament of a Western warship for ASuW consists of 4 Exocets, 8 Harpoons or rarely 16 Harpoons and also a single or at most two guns of 57...127 mm calibre. There are a few other Western ship-launched missile types, especially Otomat (Italy) and RBS-15 (Sweden). The Otomat with its launcher is a bulky design similar to some Russian AShM launchers and to find or free up deck and roof areas for such launchers is difficult.
Guns of 57...127 mm calibres are not really ship killers, but they can disable and set afire ships with enough hits at the right places. The 57 and 76 mm calibres are rather boat killers than serious against ship targets, though.

The gap filler role of ASuW for frigates and destroyers means that relatively little money, volume, deck/roof area and weight should be allocated for ASuW. It's also quite important that weights mounted high on a ship are much more troublesome than weights located rather low - this is about top-heaviness (rolling) of ships and about metacentric height.




Some navies appear interested in joining the ASuW and land attack mission into one type of missile and one type of gun (the latter usually 127...155 mm), which would make some sense if land attack as a mission made sense. It doesn't make much or any sense in deterrence and defence, but it's a favourite child of great power gaming fans.

Basic tactics

There are formulas from operational research that are too far from realism to be of relevance - the Lanchester equations, for example. The insight that those who shoot first may hit before the others launch their missiles helped the Syrians very little in 1973. Their initial salvo was an utter failure, the Israeli return salvo a success.

To avoid being surprised seems to be the most important rule for naval combat if not combat in general.

Modern ship-to-ship combat may actually place a 100% emphasis on dealing with the naval helicopters. These can carry AShM, but more importantly they are the forward eye in the sky for their surface allies. To take out these helicopters could thus be the most important part of a modern sea/sea battle. Long-range area air defences would be expected to take them out if neither naval nor land-based fighters were available. That's a point in favour of carrying a few SM-6, for its effective range may be about 250 nm against helicopters according to published info.

A towed, tethered aerial sensor (project TALONS or a similar autogyro approach) could have a much farther horizon at altitude than mast-mounted sensors, but this would still not be a replacement for a helicopter. Moreover, I expect such tethered systems to be used at a much lower altitude for a simple reason; targets can be detected best on the horizon, when there's no sea in the background. Most sensors that could be lifted to 400+ m would have a much smaller effective range than the horizon distance at such  altitudes (almost 50 nm at 450 m altitude). Infrared sensors that do not betray the ship's location with radio emissions might have their effective range against missiles matched with the horizon at about 50 m altitude already, for example. 450 m towed altitude might be useful for ESM (passive direction finder for radio/radar emissions), though.
 

Another very important issue is to detect and identify early, and to make decisions without unduly long lags. This means especially that the tactical commander has to have sufficient confidence in a positive identification of a target. He couldn't simply unleash firepower of great destructiveness on what might be cruise ships or fishing boats. Even an utterly amoral commander wouldn't want to do so because wasting munitions on false targets might be the doom of friendly forces later. You got to get a positive identification of high confidence.
Anti-ship missiles with two-way HF datalink and imaging sensors might help with this if their radio connection wasn't cut, and relatively cheap drones with HF datalink could help a lot as well. They would either be shot down/jammed (confirming hostile presence) or report back.
No such drone is known to me as being in naval service. There were some projects, but none competed successfully with naval helicopters. Too bad killing those helicopters might be rule #1 in sea battles. In the end, sea battles are so unlikely that hardly any modern surface warship is really well-equipped for one. The Russians have some heavily armed (for ship killing) cruisers and destroyers, and that's about the most extreme there is.

Long range anti-ship fires offer a particular problem; the subsonic missiles may travel for 300 nm or even a thousand nm if built for it, but the targets would have moved by several nm and a convoy may have changed its formation. Targeting data input from before launch would often be obsolete, leaving the missile's computer all alone in its attempt to figure out which contact to engage. It might even hit some neutral ship that's in the wrong place at the wrong time. The answer to this is straightforward; a datalink by radio. The missile could at very least receive targeting updates, if not even send back processed sensor data. Datalinks aren't necessarily reliable even in peacetime and whatever eye in the sky was tasked to provide data for updates might be gone by the time the missile needs the updates. A higher average speed (supersonic missiles) and a limitation to shorter engagement distances can be used to make do without targeting updates by datalink. Alternatively, one might put neutral ships at risk and simply launch more missiles to make up for those that hit decoys and already wrecked or otherwise unimportant ships.

The supposed speedboat threat is similar to the heavyweight torpedo threat in that one might try to run away at 30+ kts even though the speedboats are faster. This buys more time for countermeasures, though mostly fast ships (running away wouldn't help 15...25 kts cargo ships as much). The installation of the gun on the forecastle of the LCS classes was thus plain stupid and regarding ASuW at best explainable with aesthetics. (The forecastle location makes a bit more sense for CIWS purposes). A ship that runs away from speedboats would want to be able to fire to the rear 30°, or else the last several knots of its top speed that were purchased at great expense of other ship characteristics would be wasted. The ship would not be able to move straight away from the threat and shoot at it with a forecastle gun at the same time.

What does it take to sink a ship?

Chuck covered this in several blog posts, so I'll simply link to him:
https://chuckhillscgblog.net/2011/03/14/what-does-it-take-to-sink-a-ship/
https://chuckhillscgblog.net/2012/04/06/what-does-it-take-to-sink-a-ship-illustrated/
https://chuckhillscgblog.net/2014/10/02/what-does-it-take-to-sink-a-ship-another-illustration/
https://chuckhillscgblog.net/2016/09/16/what-does-it-take-to-sink-a-ship-the-ex-uss-rentz-sinkex/

a heavyweight torpedo hit on a rather small warship
In the end, shells and missile warheads damage ships very much and often set them on fire, while torpedoes go to work opening the hull to seawater with often much more decisive effect regarding the question of whether a ship is floating or not.

ASuW with missiles

Area air defence missiles can be used to damage warships, and surface-to-air missiles have indeed damaged warships in accidents already. A firepower kill is feasible even with the small fragmentation warheads of such missiles, and a salvo of SM-6 (64 kg warhead, very long range against ships, up to Mach 3.5) missiles could weaken the defences of a targeted warship to such a degree that obsolete Harpoon follow-on missiles could score hits even without the element of surprise.
Some modern air defence missiles (with CIWS/short range and area air defence types) have demonstrated the ability to destroy tiny boats, even within well less than a nm distance. That's a nice to have backup, but warships shouldn't really come into contact with speedboat threats anyway.

Some AShM types are claimed to be able to fly evasive manoeuvres in the terminal approach to the target to improve survivability especially against gunfire, but it's unknown to me if any missile does so in response to actual targeting (or just as a matter of autopilot behaviour) and it's unclear just how effective this is. I suppose it would reduce the distance at which gunfire can intercept the missile, and thus increases the chance of missile wreckage or explosion fragments hitting the ship target.


There are no publicly known dedicated anti-radar missiles in shipboard use nor any publicly known anti-ship missiles with ARMs as submunitions. ship-to-ship missile combat thus lacks the ARM element that air/sea combat may have.

Naval helicopters can launch anti-ship missiles, but they don't have much payload, so the heavy missile types are de facto unavailable. Two lightweight torpedoes is a typical payload for such a naval helicopter - that's twice about 250-300 kg. Almost all AShM weigh more than 400 kg, save for rare lightweights such as the Marte. NSM is rather light at 410 kg. The typical Western anti-ship missiles  such as Exocet and Harpoon are rather associated with medium and heavy helicopters, while the lighter end of medium helicopters tends to employ lightweight missiles such as Marte, Sea Skua, Penguin. The latter ones were still highly regarded as missiles against fast attack crafts (boats smaller than 400 tons), as those lack area air defences. To launch an anti-ship missile from the sensor platform itself is less of a technical challenge than a networked engagement (helicopter detecting, ship firing a missile).


Helicopters can switch between being in the radar horizon and being below it quicker than area air defence missiles with semi-active radar homing can exploit this for a kill. This allows for a quick radar scan and then hiding again, just as the Super Étendard pilot did who sank the HMS Sheffield with a single AM39 Exocet missile.

Anti-ship missiles of all categories mentioned in the AAW article may be launched by warships even though some missile types have no version for shipboard use (Sea Eagle, Kormoran and Kormoran 2 had none, for example).

ASuW with missiles is of course very much under influence of what was written in the part about AAW, as  a sea battle between capable warships would be about attack and defence.

ASuW with guns
 
Some post-WW2 warships were built without any guns. They didn't seem to need any, but this was later corrected and at least one gun (57 mm or bigger) is accepted as minimum backup to missiles today. The Falklands War and especially the air attack as San Carlos bay helped to dispel the reputation of in particular the British air defence missiles which were much less useful than their public reputation up to the Falklands War. Short range defences gained a lot of attention due to the Falklands War.

The 105 mm calibre was ridiculed as being of little value in ship-to-ship combat as early as the beginning of the 20th century, even as a deterrent or defence against the torpedo boats then in use. The explosive power of such a shell is too small. Modern 100 mm shells pack a better punch and proximity fusing makes it easier to achieve some effect on small targets (shell exploding above a boat and showering it with fragments), but the fundamental problem remains. Even 127 mm shells are of little sinking power unless they hit at the waterline. Submarines of the world wars sank scores of ships with 88 mm and bigger guns by getting very close and piercing the ship hull at the waterline. A blunt instead of rounded shell nose may actually help with penetrating the water on the final meter without ricochetting. Still, there's little ship-sinking potential in all naval gun in use world-wide unless the target is already utterly defenceless and needs nothing more than scuttling.

This fits to widespread opinions from the 20's to 40's which saw the lower limit for effective ship-to-ship combat guns at 150...155 mm, possibly 139 mm (the French view). 139 mm may thus be the lower limit of satisfactory ship-killing power with modern shell technology (better steel for thinner shell walls, more volume for better explosives). Attempts to install new guns heavier than 130 mm calibre in post-1960's warships were not really successful. Neither the navies nor the developers were able to resist automatic loading, which makes the whole thing much more expensive and heavy than necessary. One could employ a manually loaded 140 mm naval gun from the 1910's and mate it with a 100 or 127 mm turret's automated elevation and traverse control and would end up having the best if not only truly ship-killing (and naval gunfire fire support) naval gun system in service world-wide. Nobody seems to see a need for this, though. The last Western cruiser class with really good ship-killing gunfire capability was the Tiger class. The Zumwalt class "destroyers" have 155 mm guns, but those have munitions issues and are meant for land attack.

The typical guns on warships are thus of 76, 100, 127 and 130 mm calibre or smaller. A well-proportioned gun looks really good on a forecastle, but two 76 mm guns (mostly for AAW) or a single aft and low-mounted 127 mm gun seem to be the rather sensible choices. The latter would have little air defence capability (especially the American 127mm turrets that are lighter but halve a much lower rate of fire than Italian 127 mm turret designs), so a separate CIWS for the AAW role would be advisable.

76 mm L/62 Super Rapid turret (120 rpm) without munitions (and without optional STRALES): 7.9 t weight
127 mm L/54 Mk 45 Mod 2 turret (16-20 rpm) without munitions: 22.2 t weight 
127 mm L/64 turret (33 rpm) without munitions: 33 t weight

ASuW with torpedoes

Torpedoes used to be important in surface actions, but their short range and slowness eliminated them from being serious ASuW munitions for surface warships and boats. Their success depends too much on the element of surprise. Torpedoes could still be of use in scuttling crippled ships, but even lightweight torpedoes could do this. Only the latter can be carried in satisfactory quantities for ASW, so adding heavyweight torpedoes for ASuW and ASW in addition to ASuW missiles and ASW lightweight torpedoes is an unnecessary expense and adds unnecessary weight and manpower/training needs. The torpedo designs are available (the submarines' torpedo designs could be used), but it simply makes no sense to use them on surface warships.

Other remarks

ASuW missiles could be programmed to include an anti-helicopter mode, and be a little cheaper than long range area air defence missiles such as SM-6 in this role.

Helicopters have a theoretical ability to drop bombs and unguided PGMs, but I suppose that might at most be a niche with tiny PGMs or smoke munitions in support of boarding (fast rapelling/fast roping) actions. Doorgunners with machineguns are more relevant for this.

AShMs with two-way datalink could cooperate (fashionably: "as a swarm") and use their different perspectives to triangulate targets with IIR or passive radar, to report identified decoys as well as to synchronise their attacks to locally saturate defences.

Imaging infrared sensors (mounted on missiles) may be able to detect the muzzle flash of guns and the hot gases of air defence missiles. This could inform them about necessary evasive actions.

Imaging infrared sensors may also have the ability to tell already burning or sinking targets (pattern recognition showing the ship is already broken apart et cetera) from unscathed targets, informing the missile's decisionmaking in regard to target selection.

Supersonic missiles will likely not use IIR sensors because the friction at supersonic speed in the dense very low atmosphere would heat up the sensor's window. Good IIR sensor windows would also be aerodynamically inefficient.

Both the UV and the visible spectrum are dependent on daylight and even more weather-dependent than IR, and thus practically irrelevant for AShMs.

Conclusions

Again - as with AAW - an eye in the sky is most important and necessary for beyond/below the horizon fires (unless some other surface unit is more close to the target). Naval helicopters can detect, identify and even engage surface targets up to sea state 5 or 6. Long-range AAW missiles such as SM-6 might be useful in blinding the opposing force by taking out or suppressing their eye in the sky.

Area air defence missiles are relevant in ASuW even in an offensive role, especially to disable the air defence capability of the target. They may also be crucial keeping fixed and rotary wing aircraft from providing a positive target identification and targeting data for missile attacks.

Shipborne cruise missiles used to be installed in dedicated launchers on deck or on superstructures, but AShMs really should be loaded into vertical launch silos. This offers the advantage that opposing forces don't know the quantity of AShM that a warship has and that loadout can (in theory) be changed as estimates regarding ASuW threats and needs change. It also helps with radar echo reductions and generally frees areas and volume up for other purposes. Missiles in a silo are furthermore less of a secondary explosion hazard than relatively exposed missiles protected but by a tube. An effective  hit on an otherwise loaded VLS would be catastrophic even without the presence of AShMs anyway.

The long range of modern AShMs suffices and seems to make the armament of helicopters with AShMs unnecessary at least when a HF datalink to the AShM can be maintained by either the helicopter or the warship itself.

A combination of multiple anti-ship missiles seems unnecessary for a warship albeit it would be a nice to have for air power. A stealthy subsonic sea skimmer with great target identification abilities and the ability to aim at particularly important parts of a ship would be well-justified in moderate quantities. The total reliance on a IR-dependent missile may be inappropriate given the weather dependence of its sensor. A missile with both radar and IIR might be more reliable and adaptable. A mix of two different AShM missile concepts (stealthy IIR seeker sea skimmer and supersonic active+passive radar seeker sea skimmer) might make sense due to its desirable redundancy.

The range of AShMs does not need to be greater than 200 km and at least a datalink for the upload of new waypoints and target locations to the missile would be promising, while a two-way datalink to a helicopter and other AShMs would be even better.

The weight advantage clearly favours two 76 mm guns or even but one 76 mm gun as a warship's gun armament, and this should continue to be the standard for Western frigate designs and possibly warships in general (in my opinion). These guns do little ship-killing in ASuW, but they can cause a mission kill on a nearby warship or boat just as much as heavier calibre guns can do and they are lightweight and relevant as CIWS.

S O
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