Domus Acipenseris

Next Generation Attack Fighter study.
 
https://apps.dtic.mil/dtic/tr/fulltext/u2/a314256.pdf

Advanced Technology Tactical Transport
 
A Case Study in US Air Force Air-to-Air Armament Post–World War II through Operation Rolling Thunder
 

And here is an article from International Defence Review on Bradley -
which was reprinted in 1982 in Volume 13 "Tracked armoured vehicles" (of The International Defence Review Special Series) - a compilation of articles which appeared in IDR in late 70s.
This time I wasn't so lucky, so an entire page 62 was obtained only in plain text without any formatting, which is a mess. So I've decided to exclude it from text version of article.
it repeats this page https://babel.hathitrust.org/cgi/pt?id=uiug.30112075689338;view=1up;seq=12 anyway




 

It's a solid energy fighter, and flown right it was hard to beat, but it was also fragile and it engine needed to be replaced around 500 hours. It was also facing a pretty broken Germany. It was late to the show, and the P-38 should have been doing a better job, but for some reason they couldn't figure it out in england. 
 
It has a rep for being a super duper, best at everything, saved the day, superplane that nothing could touch, and that's total BS.  So that's what it the over rated part. 
 
It was still much better than any of the German prop jobs. 

I'm going to have to defend the P-51 here.  Is the performance all that?  No; the P-47M/N and a number of other Allied fighters could out-fly it.
 
However, it could run down anything the Axis had in the skies save very rare opponents like ME-262s, KI-84s and TA-152s.
 
Also, it was much cheaper than any Allied design that was greatly superior.  Also, it had insanely long legs for a fighter of its cost.
 
A handful of fighters, Axis and Allied were better individually, but as a long-range implement of strategic air superiority, it was good enough and, more importantly, numerous enough to kill the last remaining Axis air power.

Fireflies were definitely overrated. Trading more gunpower for poorer accuracy doesn't really help very much.
 
Mustang is way overrated. There is a general idea that the P-51 was better as a fighter than the P-47, but in reality the later-model P-47s pretty much outperformed the Mustang in every way while the P-51 couldn't be anything more than a long-ranged light fighter. They were complementary systems.
 
The Pershing's pretty overrated; as its engine issues were still a problem in the Korean War.
 
I don't think the SU-152s were really considered for heavy anti-tank work except for the rush job at Kursk; and in any case the tank destroyer that was reknowned for cat-killing was the SU-100. Of course with Panzer General logic the Su-152 is the bestest TD you can upgrade to. 
 
On the reverse side of things, the Mosquito really needs more credit even though everyone already sings it praises - it was just that good and it demonstrates what really kept bomber pilots alive instead of the silly "self-defending" delusions. Armoured vehicle-wise the one everyone keeps forgetting is the T-70 / SU-76.

As much as I like it, I think the Thompson is pretty overrated.  That fucker is pretty heavy for a SMG.

Yeah, the Merlin, Iowas, Il-2 and whatever else weren't terrible, it's just that I feel peoples' opinions of them are a wee bit inflated at times.

Speaking of the P-51, I think the Merlin is pretty overrated. If it wasn't for the invasion panic, the Brits would have had it replaced in most applications by the Griffon in late 41 or early 42. Also, in my opinion, the Allison V-1710 (when properly supercharged) was a better engine; it was capable of making just as much power, and was also simpler to produce.

I'm tempted to say Swordfish. Built its reputation more from the incompetence of the Italians and Germans it faced earlier in the war and the skill of its pilots than its actual qualities as a warplane

The P-51 Mustang. 
 
By the time it came along the Germans were already on there knees. 

Allied bombers over Europe get a lot of attention that I don't think is that warranted plus "tank buster" planes.

I hope it's ok to revive an old thread?
 
How about the bouncing bomb, used famously in the "Dam Busters" raid. Although regarded as a local tactical success; the failure to achieve its wider strategic goals and high collateral damage cast a shadow over its overall effectiveness.
 
http://www.bombercommandmuseum.ca/s,dambustersstudy.html

USS Houston off US east coast, 1944.
 

Des Moines and Roanoke, Barcelona 1952.

Re:  USS Roanoke.  It's too bad the Worcester class armament failed.  They were really cool ships.  I've read that the 6"/47 didn't work well for AA.  Supposedly they built it to reach German bombers dropping standoff munitions like Hs 293 and Fritz X but couldn't fire fast at high angles.
 
Des Moines class armament is cooler.  Evidently they had to decide between the destructiveness of 8" fire against cruisers and Kongo class BCs and the rate of fire needed to stop DD torpedo attacks.  Instead of one or the other they chose both, an 8" with 10rpm.

Re:  USS Roanoke.  It's too bad the Worcester class armament failed.  They were really cool ships.  I've read that the 6"/47 didn't work well for AA.  Supposedly they built it to reach German bombers dropping standoff munitions like Hs 293 and Fritz X but couldn't fire fast at high angles.
 
Des Moines class armament is cooler.  Evidently they had to decide between the destructiveness of 8" fire against cruisers and Kongo class BCs and the rate of fire needed to stop DD torpedo attacks.  Instead of one or the other they chose both, an 8" with 10rpm.

More on the wider story here:
 
https://www.counterpunch.org/2019/01/11/who-or-what-brought-down-dag-hammarskjold/

https://www.theguardian.com/world/2019/jan/12/former-raf-pilot-shot-down-un-chief-dag-hammarskjold-1961-plane
 
A Belgian mercenary claimed to have shot down UN Sec General Dag Hammarskjold's plane air to air.  I don't know what all of the "CIA bomb in the plane conspiracy" guys will do now.  Supposedly Harry Truman told an NYT reporter it was an assassination instead of a crash and there is also said to be NSA intercepts of the pilot reporting a successful intercept to GCI.

Chinese Dark Sword drone. Note the DSI.
 

https://ntrs.nasa.gov/search.jsp?R=19960000737
 
What does the board think of the document above?  It's a 200 page 1995 NASA study on technologies and their impact on fighter agility.  It seems to explain why the F-35 was not made more agile than the F-16.  TLDR:  Not cost effective.

F-22 Restart study.

There were improved armor arrays being developed during the 1970s, which improved protection against both KE and HEAT compared to previous prototypes. The canceled Chobham-armor upgrade for the Chieftain tank also would have met the US requirements in many areas (and it had better side armor as demanded).
 
The British tanks had a higher level of protection, because more weight was used for the armor. The Chieftain Mk 5/2 would have had a greater weight as the M1 Abrams, but was designed to feature a weight-efficient aluminium construction - that means a lot more weight could be used for armor. The MBT-80 was heavier than the Abrams, but was designed to use a hybrid construction (steel and aluminium), so again more weight could be used for armor. The Chieftain with similar construction technology as the Abrams weighed quite a few tons more - more weight was available for the armor.
 
 
I think you might be misreading the graph. It shows the protection level in relation to the percentage of the surface area that achieves such a protection level. If you take a look at a photograph of a Leopard 2 taken from the front or at a scale drawing from the front and then take a look at the armored surface area excluding the tracks, you'll get 100% of the protected area. At 50% of this area, the very first production model of the Leopard 2 achieves a protection level equivalent to 300 mm steel armor or more against KE penetrators. Now given that the we know the armor thickness of the Leopard 2 - it has been measured, we know that at certain areas physically cannot reach a protection level of 300 mm or more against KE. We also know where the armor is thicker and thus most likely reaches more than 300 mm protection against KE. @Laviduce has done a lot of work on this topic, you can find it here and in the Leopard 2 thread.
 
If you take a look at the turret front - where the Leopard 2 has the thickest armor - you'll see that it covers about 18% of the armored surface area. Reading the graph at 18% leads to a protection level of about ~430 mm steel-equivalent protection against KE rounds.
 
 
I am not a big fan of repeating myself multiple times; this topic has been discussed excessively and sources have been posted here and in the Leopard 2 topic.
 
The official reports from the Comptroller General and the congressional hearing on the Leopard 2AV testing pretty much say that the biggest reason for the Leopard 2AV being considered worse protected was the armor coverage: the late XM1 prototypes had 86% more surface area covered by special armor. The Leopard 2AV also had somewhat poor armor protection, because the hull was hastly redesigned to accept special armor and Germany never had designed a hull for this type of armor previously. Some officials from the United States suggested that it was a clever idea to incorporate fuel tanks into the frontal hull armor, thus the Leopard 2AV had reduced special armor volume in the hull and a rather inefficient frontal hull armor array (replacing the fuel tanks with composite armor allowed to reach an equal or higher level of protection at a much lower weight).
 

 
The Comptroller General mentions that both the FRG and the United States weighed the protection of the perceived threats differently - given that the US Army valued protection against shaped charge warheads very high, that pretty much leaves only the optioon that Germany was more focused on protection against KE rounds. This is supported by the official protection requirements for the Leopard 2K including no protection against shaped charges (at a time when the United States were experimenting with various armor arrays to protect against shaped charge warheads) and the requirements for the Leopard 2(AV) - the Leopard 2(AV) was designed with protection against a 96 mm shaped charge (MILAN warhead) instead of a 127 mm warhead, but also against a tungsten-cored APFSDS round apparently fired from a high-pressure 105 mm smoothbore gun as fitted to the earliest ten Leopard 2(K) prototypes.
 

 
The Leopard 2K already had more than 300 mm vs KE at the turret front when hit straight on. I.e. the turret front was formed by a 38 mm high-hardness steel and a 84 mm armor steel sloped at 25° - that's 280 mm steel along the line of sight, which due to the high-hardness frontplate and spaced configuration will provide a noteworthy boost in armor protection.
 

 
Why do you think that the XM1 with three metric tons less weight, a greater frontal surface area, more armor weight & volume distributed to the flanks and with an overall physically larger size would have a higher level of KE protection?
 
 
The UK chart is interessting, but reading too much in a single number alone doesn't make sense. The same document clearly states that the Leopard 2's armor protection was "imbalanced" and lists the effective hull armor thickness of the Leopard 1, T-62 and Centurion... "Imbalanced" could very well mean "imbalanced protection between hull and turret", which is something that can be found on the Leopard 2K and the Leopard 1 tanks with upgraded armor (Leopard 1A1A1, Leopard 1A2, Leopard 1A3). Going back to the graph leaked with the Swedish presentation and doing an analysis of the surface area of the Leopard 2 front - as done by Laviduce - leads to a hull armor protection of 280 - 340 mm vs KE on the hull; I'd call that reasonable close!
 
It is also noteworthy that the Leopard 2 hull was still being redesigned and might have included little to no special armor (as in case with the Leopard 2AV) at that time.
 
 
No, that is incorrect. The slide from Dipl.-Ing. Rolf Hilmes' presentation at the DPM does say Leopard 2A4, but it also lists the weight of the tank at 55.2 metric tons, which means that it refers to a Leopard 2A4 from the early production batches.
 
The Leopard 2A4 was produced with three different armor packages:
the original armor package was used on all Leopard 2A4 tanks produced between 1985 and 1988. This is identical to the armor package adopted on the first production variant ("Leopard 2A0") from 1979 (Germany did not pay attention to upgrading the armor until a 1986 program by the BWB). the second generation armor package (in C-technology) was adoped in the middle of the sixth production batch in 1988 and was kept for the seventh batch. the third generation armor package was adopted in 1991 and utilizes (D-technology). It was used on only a few tanks, all of which were later split-up, the hulls were used for the Leopard 2A5, while the turrets were mounted on some of the oldest hulls Why does this matter? Because beginning with the adoption of the second generation armor package the weight of the tank was raised from 55.2 metric tons to 56.5 metric tons. Hilmes' citing a weight of 55.2 metric tons hence means that he either mixed up data from different variants (which would be stupid) or that he refers to the original production batches of the Leopard 2A4.
 
 
I think you posted a wrong link, because that is refering to an article on Andrei's website about Rheinmetall's 105 mm gun. Maybe you meant this graph from Krapke's 1986 book?
 

 
This shows the KE protection of the turret armor of various German and Soviet tanks in relation to the armor penetration. As you can see, the Leopard 2 is meant to survive a 125 mm APFSDS at 1,500 m distance; the Brits estimated a penetration of 445 mm at 1,000 m distance for the Soviet tungsten-cored APFSDS in 1978 and 460 mm for the DU APFSDS round. That would fit nicely to a protection level of ~430 mm at the turret front. At this time the Soviets had adopted the 115 mm BM-28 APFSDS with a certified penetration of 380 mm at 2,000 m distance, which - if this or a similar estimation was used for the 115 mm APFSDS in the graphic - would again fit to a protection level of ~430 mm...
 
Unfortunately I don't even think that this graph is very relevant, because it seems that the values are taken from the article "Panzerwaffen: Feuerkraft und Panzerung im Vergleich" published in the Swiss defence magazine "Allgemeine schweizerische Militärzeitschrift" in 1980. After finishing the Leopard 2 project, Paul-Werner Krapke retired and moved to Switzerland, where he worked on his book and published a number of articles in the very same magazine. While he did not publish this article, he might have fallen back to the values (or is it a coincidence that all of them match? I don't believe in this coincidence). The values are estimations according to the article.
 

 
According to the article, the 115 mm APFSDS used as example is made of WHA (not steel with tungsten-carbide slug), has a length of 545 mm and a diameter of 48 mm. It can penetrate a NATO tripple heavy target at 2,000 m. I don't think such an APFSDS was ever accepted in Soviet service.
 
 
I'm sorry, but that is just pure bollocks. Got any source for your impression? Because according to declassified documents available in the UK National Archives,  Germany was the first choice as partner on tank and armor development for the UK. The FRG got access to the full Chobham armor technology three years before the United States (from the British perspective, the US was too much focused on Vietnam and therefore an unreliable partner for defending Europe). The UK and Germany started developing a common tank for both countries in 1972 (to replace the Chieftain and the Leopard 1), which was protected with a Chobham armor variant specifically optimized to meet the German requirements. This armor was known as Buckhorse armor. The co-development ended in 1977, because of different opinions on the conception (Germany didn't want to design a second Leopard 2, when they already were making the Leopard 2; the UK wanted a conventional tank like the Leopard 2).
 

 
 
Based on the official data leaked by the Swedish trials, the Leopard 2-2A4 (1979-1987) had ~300 mm hull and ~430 mm turret armor protection against KE ammo, which matches with the other available sources and basic physics (more mass per area = better frontal armor protection). The Leopard 2 also made use of high-quality steel with ~380 BHN for the base sturcture, which lies above what is supposedly used on some other tanks (and specifically a lot better than the 270 BHN cast armor used on Soviet turrets). There is a Russian book which claims that according to a Soviet intelligence report from the 1970s, the "German Chobham" follows the same concept as the US variant, but uses a different sandwich structure: the illustrations of the Abrams' armor array show sandwich plates in a symmetrical configuration - front and rear plates of the sandwiches are rather thin. According to the Soviet report, "German Chobham" uses much thicker front plates (25 mm) made of high-hardness steel with very thin rear plates (3 mm). This would offer improved protection against APFSDS rounds (thinner steel plates like used on the Abrams are less efficient against APFSDS rods, while high-hardness steel improves protection), but would offer - at least per weight - less protection against shaped charges.
 
When it comes to the Leopard 2(A0) and the M1 Abrams, I think the easiest way to see why the Leopard 2 should have a higher level of frontal protection is to take the following things into account:
the Leopard 2 is physically smaller than the Abrams; it has a shorter hull, a shorter turret, a narrower turret and - if we exclude skirts - also a narrower hull. It has greater ground clearance, but is a bit taller. Overall the frontal profile is 10-15% smaller. the Leopard 2 focuses all its special armor on the frontal section; in case of the Abrams much more armor is used to protect the hull sides and turret bustle the physical armor thickness is greater on the Leopard 2 the armor of the Leopard 2 seems to be more focused on KE protection based on previous requirements and available sources  

 
 
The side skirts of both tanks manage to perfectly illustrate the design differences: the Leopard 2 has short but heavy ones, while the M1 Abrams has very thin ones, that cover a larger surface area.
 
Edit: Also Hans Rühle is a troll, who will say everything to reach his goal of Germany producing his own nuclear weapons. Accepting DU would be a first step in his opinion.

I don't think there is a possible explanation, because people are beginning the argument from the wrong direction. People are making assumptions about the protection level, then try to find sources supporting it - i.e. first comes the thesis, then sources are searched to support it. That's the wrong way to start research - saying "the Challenger 1 needs to have 500 mm RHAe against KE" and then gathering all sources that say somewhat related. I can understand that Laviduce expects a high level of protection based on the thickness of the Chieftain's Stillbrew armor package and based on the greater weight of the Challenger 1 MBT - it could have a protection level of 500 mm vs KE. But we have no confirmation to these theories. With British documents showing that the estimated penetration of 125 mm tungsten-cored APFSDS ammunition was only 475 mm at point blank, I have serious doubts that a protection level of 500 mm or more against APFSDS  was required - that's simply not how tanks are designed.
 
The Challenger 1 development was pursued at a different timeframe than the Chieftain upgrade with Stillbrew armor, thus the requirements were different; in so far "just" 400-450 mm vs KE might be a lot more realistic based on the requirements for the MBT-80 project and the data of the Shir 2, assuming the armor package was improved over the latter tank. The Challenger 1 was approved in 1980, the Stillbrew upgrade in 1984. A lot can happen in four years of the Cold War. Even the Chieftain with Stillbrew doesn't reach protection comparable to 500 mm rolled armor steel vs APFSDS ammo, because cast steel provides up to 20% less protection than rolled armor steel.
 
Ceramic armor is not a magical solution to all problems. The T-64A used ceramic armor, yet it protection level was rather limited compared to later tanks.
 
 
This is wrong. The cited book - at least in its original German version - does not say what is claimed in the first paragraph of this screenshot of "Armor Basics". While the first quote can be found pretty much verbatim on page 76, the second part - i.e. "the ballistic effectiveness of the compouned armors against KE penetrators shows an improvement of only 1.2 to 1.4 over homogeneous rolled steel plate (incontrast to a factor of  2 against shaped charges." - cannot be found on page 76 or 77 of the original book. I have never read the translated version, but I am fairly certain that it doesn't say what is claimed previously.
 
On page 75, the claimed efficiency values (1.2 to 1.4 vs KE, 2 vs shaped charge) can be found: but that is in a paragraph on the armor protection of the T-72! The "factor 2 against shaped charges" is meant to be the mass-efficiency value and is based on a Swiss assessement from a 1982 issue of the Allgemeine Schweizerische Militärzeitschrift claiming that the T-72's hull armor is weight equivalent to a 120 mm steel plate sloped at 70° and provides twice as much protection against shaped charge ammunition as steel armor of the same weight. The same article also includes statements about the supposed performance of the T-72's armor against KE ammo: the article claims that the T-72, M1 Abrams and Leopard 2 use special armor and certain types of special reach a efficiency against KE ammunition of 1.2 to 1.4 per thickness (!). The T-72, which was believed by the Swiss authors to feature a 300 mm line-of-sight thick array of such armor (in reality it had a simple cast steel turret with a thickness of up to 500 mm, while the hull armor has an effective thickness of 547 mm), would then reach a protection level of 360 to 420 mm.
 

 
We know for fact that the T-72's armor neither reaches a mass efficiency of 2 against shaped charges nor that it provides a thickness efficiency of 1.2 to 1.4 agianst kinetic energy ammunition. It is a false assumption based on incorrect data from a time when the T-72 was still a mystery to NATO and non-aligned countries.
 
Everything else - regarding the effectiveness of ceramic armor - is not related to the Challenger 1. It is pure, unreferenced speculation that the tank would be fitted with such armor, even though it has been proven that Chobham is (mostly) based on spaced NERA sandwiches. Based on a number of declassified documents on the development of Chobham armor, there apparently were more than a dozen different Chobham armor arrays being tested in the early 1970s. Some of them were merely improved versions of earlier designs, others were created to experiment with new concepts (e.g. there was on Chobham armor array that incorporated high explosives similiar to integrated ERA). There might have been some Chobham arrays with ceramic component in them and this development might have lead to the array adopted on the Challenger 1  - but there is no proof for this; even if they are included, ceramics would only play a minor role. CeramTec ETEC, one of the market leaders in Europe for manufacturing ballistic ceramic materials, includes photographs of the Leopard 2 in its flyers, suggesting that some ceramic elements might be part of the armor array.
 
However suggesting that the Shir 2's 325 mm steel-equivalent protection against APFSDS rounds could be increased to 500+ mm just by incorporating ceramic materials seems wrong. Burlington and Chobham are different names for the same thing - there are numerous files using both names to refer to the same armor arrays. According to the British DSTL, modern armor arrays designed to provide protection against KE and HEAT rounds follow a three-stage layout, i.e. they consist of:
a distrupting stage to break KE pentrators and shaped chage jets a distrubing stage, which makes sure that the particles and fragments of the broken penetrator change direction and yaw angle an absorbing stage, which stops the fragments from reaching the interior and absorbs the kinetic energy The options for designing the second stage are pretty much limited to different types of spaced multi-layer armor or other types of reactive armor; based on known armor arrays - such as the T-72B's armor and the M1 Abrams' armor, the distrubing stage usually takes up at least half the available armor volume. The first stage is often based on a reactive armor (see the wedge-shaped armor of the Leopard 2A5 or the Kontakt-5 ERA on late Soviet MBTs), although it could also be made using high-hardness steel, perforated armor or ceramic plates (the latter two variants being common on lighter vehicles, because this armor is more efficient against short, bullet-shaped penetrators). The absorbing stage also can include ceramic materials, but will always include a steel layer (which serves as strucutral support) and potentially kevlar, polymers or other materials.
 
In case of the M1 Abrams, the absorbing stage of the hull armor was a rather simple steel plate.
 

 
So simply adding ceramics to the armor won't drastically change the protection. The Challenger 1 would require a completely different armor array, which would suffer from the typical problems of ceramic armor against large calibre ammunition, such as a relatively low efficiency, low multi-hit capabilty and problems with cost and manufacturing. Armor consisting of layered aluminium oxide with polymer backing and steel enclosure provides the same protection against shaped charges as steel of the same thickness - thus a Challenger 1 with 700-800 mm frontal armor at most would be quite vulnerable to shaped charges.
 
 
The "Armor Basics" document from which these snipplets are taken is known to be outdated and incorrect in various aspects. The author speculated too much and used false premises to generate his values - armor thickness, armor weight and layout are often wrong. Here for example he ignored that the Challenger 1 turret is meant to provide protection along a 60° frontal arc (30° to each side of the turret centerline), but the Chieftain was designed with protection along a 45° arc only! Thus his whole idea of using the weight difference to scale the equivalent armor weight of the frontal armor is incorrect. He also claims that a 15% increase in steel mass would result in a steel mass equivalent to a thickness of 50 cm - this would mean that in his beliefs the Chieftain was having an armor thickness of 434 mm, which it does not have in reality - the thickness of the frontal turret armor of a Chieftain is about 240-280 mm according to sources posted earlier in this topic.
 
 
I don't know any "Ed Francis" and see no reason why his writing should be relevant to this discussion. Seeing that the origin of this quote is a post on the Warthunder forum, which wasn't even written by him, but somebody claiming to have spoken to him, I would be rather careful. This is a big pile of unreferenced claims, that in some cases is rather easy to disprove. It is all speculation with no sources.
 
If Burlington and Chobham were two different things, why would official US and UK documents use both names like synonyms?
 

 
There are dozens of documents on the development of Chobham/Burlington armor, which are using both names; they also use "Chobham spaced armour" and similar terms disproving the claims that supposedly were made by Ed Francis. And this is how the Chobham spaced armor is shown in the same document - no trace of ceramics!

 
Ceramics themselves do not bulge, but rather break; the elasitic backing behind the ceramic tiles will bulge. Ceramics are not suited for NERA sandwiches as long as multi-hit capability matters,
 
Even if this forum poster had asked Ed Francis on the topic and he let him type on the Warthunder forum with his account, I don't see why this name would result in the text being relevant to us. According to a quick google search Mr. Francis is a volunteer at Bovington, not an expert on AFV design and armor technology. Given that there seems to be no special credentials to his name and that Bovington still has a plaque citing incorrect armor values in front of the Chieftain tank, I do not consider this to be a source.
 
 
There are no exact figures, which is also related to the problem of "irrecoverably lost" being a philosophical question. However the Abrams supposedly did perform very well in ODS. There were 14 Abrams tanks with DU contamination after being struck by DU rounds or on-board fire, for which the US Army lacked procedures and equipment to deal with. If they recovered these later or not is unknown to me.