Battleship Top Ten

[Hartmann10]

Hello to all ¡

Hartmann10 wrote:
It corroborates that the alleged "far superior" Allied radar technology was "jammed" frequently by: clouds¡¡¡

Also, I would like to say that another surprise to the Allies was the use of Japanese wood built planes, which were nearly immune to VT shells.

Hope this can help

What "far superior" Allied radar technology?

I am sorry Bgile . I have not been very clear. I replied maybe too fast. I referred to the previous posts where It was said that the allied radar technology was better than German/Japanese equivalents. I was referring to the problems of the radars concerning "clutter" (in this case, the clouds, composed of water vapour, where a very effective system to hide a plane, especially when speak of centimetric sets, which are very sensitive to the energy of resonance of the oxygen and water molecules, blinding all the radar screen).

What jamming?

The clutter made by the water vapour and oxygen make an very effective jamming of the radar screens. They in fact were completely cluttered or "blurred" when directed to rain or clouds, altough it won´t be a "mechanical" or "electro-electronic" jamming system.

Wood aircraft were nearly immune to VT shells?

Yes, the VT shells used a continuous radiofrequency emitting-receiving system to detonate the explosive. That is the same principle of a radar. The main problem with the electromagnetic waves is that they dont reflect in wood. In fact , the wood tends to absorb the electromagnetica waves so the VT shells were incapable of detonate when fired against wood airplanes. The same way was discovered by the Gemans three years before when the De Havilland "Mosquito" appeared. The only way to detect this plane by radar, was thanks to the big reflecting electromagnetic waves´ signature of the propellers (made of steel). The body and wings, completelly covered by wood where "invisible" to the radars. this discovery was completelly fortuite, but It was used in the design of the Horten-Gotha flying wing fighter, among with primitive RAM paint.

The Japanese made some of their aircraft out of wood, as did the Germans, because they had trouble getting enough of the proper metals.

Yes, It is all true, but It doesn´t invalidate the proven fact that the wood doesn´t reflect electromagnetic waves. It absorbs them. So, by mere coincidence, the planes made of wood were very difficult to nearly impossible to detect by using radars. That was my point.

To you have a source?

Almost all the books and technical data referring to radar detection will give you this explanation. You can check in every book concerning radar.

I hope that It will have been more understandable (sorry for my english )

[Bgile]

Hi ... thanks for the clarification.

Modern stealth aircraft are not made of wood. I have personally seen wooden small craft on radar. Japanese wooden aircraft had large metal engines and they were not shaped to produce stealth.

I haven't seen the reports you are referring to, but I'm obviously skeptical.

Wooden aircraft wouldn't do as much damage when they hit ships, would they? Wouldn't they burn rather easily, and break up when hit? Obviously we don't choose to make modern aircraft out of wood so there must be a few disadvantages.

[Dave Saxton]

I think a better way to describe the question of wood's reflectability to radar pulses is that it is relatively attenuated, rather than totally radar absorbing. The question of a wood aircraft or watercraft having stealth properties will depended largely on the shapes and lengths of surfaces, as well as such things as even small reflective objects such as a mast or a handrail, a pylon, a metal trim tab, a window frame ect... that will give it away before the range becomes so short that the wood surface refelections can be reliably picked up anyway.

Modern air tracking radar is generally L band or around 27cm. (In our research into using synthetic aperture radar for mapping through jungles it has been found that L band or UHF works better than X band as well.) This is because longer wavelengths detect aircraft without props much better than centimetic wavelengths. The Germans found that Eulkid operating on the 27cm band was far better at detecting and tracking aircraft than on the 9cm band.

Centimetric wavelengths do indeed have trouble with weather. Weather radar first began when the USN began testing 10cm radar in Carribean during 1942. It sees rain and snow storms and extremely high humidity better than it sees through them. GEMA did a lot of research on the refeltivity of fresh water vs sea water and water surfaces vs water vapor, snowflakes ..ect...

[Dave Saxton]

Well, I thing that it is not a fair comparison.
This page speaks about US and RAF heavy bombers and so on. These warplanes were very sturdy and resilient. It is nothing comparable to the allmost non-armoured Japanese warplanes.
It would have been interesting to compare the Luftwaffe goals against the US Navy It the US Navy would have encountered warplanes heavily armoured and flying at very high ceiling (almost the reverse thing to the actual encounters, even in kamikaze attacks (They flew near zero altitude to evade Allied radars).
I thing also as Dave, It is a not very good percentage of goals If We consider the quality of the Japanese planes and the alleged efffectiveness of the RFC 127 mm DP guns. They were in fact poor until the VT fuse was introduced.

It is my honest opinion, although I can be mistaken.

That's an important point Hartmann. The difficulty in knocking down one plane as compared to another plane will make comparing stats and data sets extremely difficult (which we shoudn't be placing much weight into anyway as its not really sound scientific methodology). For example, The F6F proved about three times more capable of surviving combat damage (especially flak and ground fire) than the F4U. If one is shooting mostly at F6F's then your scores are going to be relatively poor compared to if your shooting mostly at F4U's.

This brings up an interesting question about the PG performances in the Gulf of Danzig in 1945. The Soviets had a Naval Air Service very experienced by that time in attacks against shipping and warships. Apperantly they used lend lease A20's along with Sturmovik's and the twin engine IL4 torpedo bombers. They may have employed the rugged twin engine PE2 divebombers as well. The IL2 and IL4 were heavilly armoured and were relatively difficult to shoot down. Do you know if the Russian Navy employed the PE2?

[Bgile]

Why was the F6F more rugged than the F4U? THREE TIMES more rugged? That's huge. Why would they even bother to keep the F4U in service for the Korean War if it was that vulnerable? It must have been more vulnerable than the P-51, with it's glycol coolant. It must have had a serious Achilles heal? Any idea what that was, or where I can read about it? They were both radials, so this is really curious.

[Mostlyharmless]

I didn't think that there was such a huge difference in vulnerability but the analogy with the P-51s glycol is quite accurate. The F6F had a radiator for its oil close to the engine while the oil of the F4U was pumped to radiators in the wing roots for cooling. A hit on the oil piping and you are running your engine without oil.
ps. Another issue might have been that a F4U was relatively hard to land. A damaged F4U may have been very hard to land.

[Hartmann10]

Hello to all ¡

Hi ... thanks for the clarification.

It is nothing. Sometimes I don´t express myself correctly in English

Modern stealth aircraft are not made of wood

Yes, but the first "stealth" designed warplane, the Horten-Gotha 229, included, among a very advanced shape (for the time)design of the fuselage to evade radar, a mixed building in steel and wood, beeing the steel parts covered by prototypic "RAM" painting, as the Type XXI submarines with Schnorkel and radar masts covered by "Tarnmate".

Wooden aircraft wouldn't do as much damage when they hit ships, would they?

These warplanes ever carried bombs and fuel to make damage, as the Nakajima Ki-115 "Tsurugi", which only carried a bomb, and It didn´t carried guns. They were not as strong as the metal built warplanes.

I think a better way to describe the question of wood's reflectability to radar pulses is that it is relatively attenuated, rather than totally radar absorbing.

Ok, so It can reflect slightly.
Many thanks David ¡
I didn´t know about that. All what I have seen waas that It was allmost not reflecting properties.

aircraft or watercraft having stealth properties will depended largely on the shapes and lengths of surfaces

Yes, You are right. I think that I read sometime ago an scientifical study of geometrical shapes like diamant and truncated cones for aircraft, made in the sixties by American and Soviet scientists. I will check if i can find it.

Do you know if the Russian Navy employed the PE2?

Yes, It was frequently employed by the Russian Navy as reconnaisance and bomber attack plane.
Incidentally, one of the very last warplanes shot down by the Germans, the morning of the 8 of May of 1945 was a Reco-Bomber Pe-2 of the Baltic Fleet, looking for ships with civilian evacuees and convoyes of support to them. It was downed by the Fw 190 A-8 of Gerhard Thyben (He surrendered the Fw190 a few minutes later to British forces).
I will look for more data concerning the strenght and types of planes used by the Soviet Army.
Bests regards

[Hartmann10]

The F6F had a radiator for its oil close to the engine while the oil of the F4U was pumped to radiators in the wing roots for cooling. A hit on the oil piping and you are running your engine without oil.

I heard that the Corsair was more vulnerable sometime ago, but I didn´t know this detail. It can be the main cause.

ps. Another issue might have been that a F4U was relatively hard to land. A damaged F4U may have been very hard to land.

Yes. quite correct. Allegedly, only 189 "Corsairs" were downed in combat by other warplanes, but They had a much higher level of attrition when were used as fighter bombers.
Regards

[Bgile]

The F6F had a radiator for its oil close to the engine while the oil of the F4U was pumped to radiators in the wing roots for cooling. A hit on the oil piping and you are running your engine without oil.

I heard that the Corsair was more vulnerable sometime ago, but I didn´t know this detail. It can be the main cause.

ps. Another issue might have been that a F4U was relatively hard to land. A damaged F4U may have been very hard to land.

Yes. quite correct. Allegedly, only 189 "Corsairs" were downed in combat by other warplanes, but They had a much higher level of attrition when were used as fighter bombers.
Regards

Maybe what is going on here is not that the F4U was easy to shoot down with flak, but that the F6F was very hard to shoot down. I wonder how they compare with the P-47, which was known to be very tough and the P-51, which surely wasn't as rugged as the F4U, but served as a strafing aircraft in europe for a good part of the war because it was relatively hard to find German aircraft to fight.

I still think three times as vulnerable is very suspect, and I wonder where that comes from.

[Dave Saxton]

Why would they even bother to keep the F4U in service for the Korean War if it was that vulnerable?

Speed. The latest F4U4 model was nearly 50 knots faster than the F6F. With jets coming into service only the fastest available prop planes were wanted kept in service. In hindsight, once tasked with ground attack, the F6F may have been a better choice, just as the P47 may have been better for the AF.

I had recalled this approximate figure for ground fire vulnerability from conversations with pilots, but seeing the reaction here, I decided to check up on this. I asked one of the persons about it and he cited the Naval Aviation Combat Statistics-WWII documents. It doesn't give a firm number he said, but it was estimated that among carriers operating both types in similar combat missions, that the F4U was ~58% more likely to be lost in air combat scenarios. But the differential was estimated much greater (no hard number given) when both types enccountered flak and/or ground fire. He quoted the document:

" The F6F has a considerable advantage over the F4U when flown under the same conditions" (attributed generally to the F6F's considerably greater ruggedness.)

Looking at operations against the Germans by the the FAA of both types; I find that F4U's were lost at a ratio of about 5:2 to F6F's, despite the Hellcats flying the more dangerous missions of flak suppresion and pathfinders. Admittidly this is a finite sized sample but it is what it is. The numbers seem to mirror the general USN stats from a much larger sample, although this ratio may be high. Over greater time and a much larger sample the differential will probably be less pronounced. Perhaps the German flak once dependant on radar was more effective against the main strike forces, than against the flak suppression F6F's? One has to wonder why the British consistently assigned the more dangerous missions to the F6F's too.

[yellowtail3]

I wonder if maybe some of F4U losses had to do with operation losses/accidents... I understand the F6F was generally reckoned to be a better handling aircraft.

[Bgile]

I wonder if maybe some of F4U losses had to do with operation losses/accidents... I understand the F6F was generally reckoned to be a better handling aircraft.

The F6F was easier to handle on the ground and when landing because the pilot could see over the nose better. The F4U required more skill to land, which is why it wasn't carrier qualified for several months after it's initial introduction.

I don't see how 50 mph is going to make any difference against a Mig 15. The A1D Skyraider was an extremely successful close support aircraft and was much slower than the F4U.

[Dave Saxton]

I don't see how 50 mph is going to make any difference against a Mig 15. The A1D Skyraider was an extremely successful close support aircraft and was much slower than the F4U

Don't forget the chronology. At the time that the decision was made ( IIRC 1946) there was no thought of the Mig-15 or the Korean war. The difference in speed between the F4U4 and say the P-80 down on the deck wasn't that great, and the difference in speed between straight winged early Navy jets even less. Indeed the Navy remained skeptical of pure jets during this time frame. Early proposals for jets were rejected as too risky for carriers and this lead to hybrid proposals such as the Ryan Fireball. Marion Carl (originally a Navy test pilot but now in the Marines command) flew both the ME-262 and P-80 for the Navy in tests. Also the Navy now had the option of a faster Grumman fighter than the F6F in the form of the F8F, an exceptional dog fighter and fleet defense fighter by the standards of the time.

[lwd]

I did find this:
One Luftwaffe study estimated it took over 3,300 88 mm shells to sucessfully shoot down a bomber.
at http://histclo.com/essay/war/ww2/air/eu ... /flak.html

Well, I thing that it is not a fair comparison.
This page speaks about US and RAF heavy bombers and so on. These warplanes were very sturdy and resilient. It is nothing comparable to the allmost non-armoured Japanese warplanes.
....

It's a bench mark. Hard to draw too much from it. For instance the heavy bombers are bigger targets and flying in formations and not evading. Furthermore if you are looking at direct hits the armor on a B-17 isn't going to help much vs an 88 or larger. On the otherhand the ranges and especially the altitudes were greater for the heavy bombers. Doing any sort of serious comparison would require a considerable effort. It does point that the expenditure of several thousand rounds of heavy AA for a kill is about par for WWII.

[lwd]

...

Modern stealth aircraft are not made of wood

Yes, but the first "stealth" designed warplane, the Horten-Gotha 229, included, among a very advanced shape (for the time)design of the fuselage to evade radar, a mixed building in steel and wood, beeing the steel parts covered by prototypic "RAM" painting, as the Type XXI submarines with Schnorkel and radar masts covered by "Tarnmate".

There is considereable debate as to whether that aircraft really deserves the appelation of "stealth".

Wooden aircraft wouldn't do as much damage when they hit ships, would they?

These warplanes ever carried bombs and fuel to make damage, as the Nakajima Ki-115 "Tsurugi", which only carried a bomb, and It didn´t carried guns. They were not as strong as the metal built warplanes.

And there in lies part of the problem. They also have engines. No one ever claimed the Mosquito was a "stealth" aircraft in spite of it being made of wood. Or perhaps they have just not correctly.

I think a better way to describe the question of wood's reflectability to radar pulses is that it is relatively attenuated, rather than totally radar absorbing.

Ok, so It can reflect slightly.

Some of the signal can also pass through the wood and be reflected from metalic components inside the aircraft. Like the engine. Now a wood and canvas glider without any metallic ordinance is pretty stealthy. Not too leathal though.

aircraft or watercraft having stealth properties will depended largely on the shapes and lengths of surfaces

Yes, You are right. I think that I read sometime ago an scientifical study of geometrical shapes like diamant and truncated cones for aircraft, made in the sixties by American and Soviet scientists. I will check if i can find it.

As well as the compositoin.