10 moments that changed the course of the war at sea

[pg55555]

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Dave,

You are using rose tinted glasses so strong that you really need to take them off.

The idea that German mid to late war radars were anywhere near on par with the western allies (except in VERY specialised areas) is laughable. The worsy of your claims is with regards to airborne radar for nightfighters where weight, drag and performance were all very poor.

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[Dave Saxton]

Well perhaps, but I receive no knowlegable counter argument of scientific or historical substance to force me to modify my position.

The idea that German mid to late war radars were anywhere near on par with the western allies (except in VERY specialised areas) is laughable.

Any specific comparisons and details?

[Hartmann10]

Hello to all and best regards ¡¡¡

The worsy of your claims is with regards to airborne radar for nightfighters where weight,

Rather the reverese was true. the German Night fighters were capable of carry two sets of radaras, both "Lichtenstein" B/c and "Lichtenstein" SN because these sets were very light, the weight of both sets was of more or less 130 kg (more or less 300 pounds). The only comparable Allied Set was the SCR 720 and it alone weighted not less than 412 pounds in the cropped version, with less power radiated, and less range attainable, if you like the full equipped set, you could go to near 830 pounds. The fact is that the SCR 720 was not able to be carried in a single engine plane, and you had to use the P-81 and P-61 (in the P-61 the initial sets were the lightweight sets because the engines were unable to cope with the needed power to use the full radar set, even using a pair of 2100 hp engines double row radial engines of 18 cylinders).

drag

The drag was initially more pronounced in the German sets, but that was solved at the end of the war with the "Morgenstern" aerial array, without penalty in drag.

and performance were all very poor.

In fact, the "Lichtenstein" SN-2 and the "SCR-720" had very similar performances if you read the primary source specifications.

Best regards

[pg55555]

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You are ignoring the antennae and ACTUAL performance showed a very different picture, or else why were Mosquitoes with half a generation earlier radars able to hunt the German Nightfighters ?

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[neil hilton]

Seetakt FuMO27 (1940)
Range to BB: 30km
Range to DD 16-20km
Range accuracy: 50meters
Bearing accuracy w/ Max Signal: 1-2*
Bearing accuracy w/ S-Rad: 0.10*
Resolution for range 50 meters
Resolution for bearing 6*

These stats are similar to mid 1950s era radars. And the Germans had it in 1940, yeah pull the other one. Something is wrong here.

Type 271 (1941)
Range to BB 23km
Range to DD 14km
Range Resolution 225 meters
Bearing Resolution 6*

These stats are unbelievable. This device with these stats is absolutely rubbish. Nobody in their right mind would pay for this crap and nobody would use it. My grandmother was more accurate than this and shes dead. An oujie board is more accurate than this. A set of convergence binoculars and a hand compass is more accurate than this. Something is definitely wrong.

Having looked through quite a few sources (books and internet) I can find a great deal of inconsistency in the radar stats.
This makes me think the primary data has been deliberately falsified for security reasons, at the time these radars were top secret it makes sense for their stats to be 'tweaked' before being 'released'. All nations do this. Why the real stats haven't been released more recently is a good question. Maybe it has but distinguishing it from the rubbish will be hard or maybe they just never bothered releasing the accurate stats.
Interesting.

[Dave Saxton]

The stats are not out of line for WWII era radars at all. The sources are not falsified. In extensive tests of the Seetakt radar installed on Graf Spee in early 1938 it was confirmed that it was effective to 25km depending on the size of the target ship. On April 9th 1940 Gneisenau’s Seetakt detected the Renown at 25km.

In 1940 the early model Seetakt was superseded by more advanced models. The stats I listed are for the 1940 model. What about similar British and American radar of 1941 and 1942?

Type 284 50cm (1941):
Range to BB: 26,000 yards (23.7km) (During Bismarck chase)
Range to destroyer: 14,000 yards (12.8km) (Tests on KGV)
Range to cruiser: 20,000 yards, (18,2km) (Tests on KGV)
Bearing resolution: 4.5* (this is the beam width, and bearing was determined by max signal; giving a accuracy 0.75-1.5*)

USN FC (Mk3) 40cm (1942):
Range to a BB: 28,000 yards (25.6km)
Range to a DD: 16,000 yards (14.6km)
Bearing resolution while lobe switching: 15*
Bearing resolution while using max signal: 7*
Bearing accuracy using lobe switching: 0.2*
Range accuracy: 0.1% of range +/- 45 yards.

RN Type 284M 50cm (1942) (This was the firecontrol radar used by DoY at North Cape)
Range to BB: 29,000 yards (26.5km)
Resolution for range: 150 meters
Range accuracy: 120 yards
Bearing Resolution: 4.5*
Bearing accuracy: 0.08*

These permormance are not significantly different from FuMO27. German radar was multi-role up to 1944.

The Type 271 (10cm) performance I listed is from British tests in 1941. This is not firecontrol radar, but a surface search set. A 6* beam width is desired for this purpose, and it was mainly designed to battle U-boats fighting on the surface at night. Note that SG (10cm) had a 5* bearing resolution. During the Battle of Barents Sea on the last day of 1942, the British found that the Type 271 on their destroyers had difficulty in acquiring the German cruisers and could not hold contact beyond 16,000 yards. Type 273 was Type 271 with much greater antenna gain used by cruisers and battleships. At Barents Sea, Sheffield’s Type 273 detected the Hipper at 21.5km (Luetzow's FuMo27 detected the British cruisers at 29km). The Belfast’s Type 273 at N Cape detected the Scharnhorst at 30km one time and at 23.7km the next time. (DoY used the brand new and more advanced Type 273Q during North Cape).

[cimmee]

The main outcome of the Doolittle raid was to prod the Japanese into attempting to extend their defensive perimeter further eastward. Thus they went for Midway, which allowed the Americans to set an ambush because they had broken the purple code. So it could be said it was the breaking of the code that was the more important thing not the Doolittle raid. Because they had broken the codes the USN could have set up an ambush no matter what direction the Japanese had gone in, even if the Doolittle raid had not occured.

While the code breaking arguably had a greater impact it was hardly a "moment" it was an extended effort that gradually netted more and better information. Furthermore the impact of the extension of the defensive perimeter was greater than just the battle of Midway. The Japanese were already stressed logistically. Pushing the perimiter out further not only stressed this system even further it weakended them all along the perimeter.

Having said that, the USN only actually knew the Japanese where heading for Midway because of the 'lack of fresh water on AF' radio deception trick. I would say that was the more important factor in the turning of the war in the Pacific.

Even without Midway or at least without the carrier battle there the turning point was coming soon. If the US hadn't known ahead of time about Midway there's still a very good chance that the Japanese would have failed to take the island and even if they had it would have become the proverbial "albatross around there necks".

shipping lanes to Britain. In reality the u-boats didn't at the beginning of the war, Donitz asked for 300 uboats, by the time he got them it was too late. But it was a close run thing for a while.
Another point regarding this was that Donitz never fully realised that the enigma had been broken, even though the uboats weren't sinking as much as expected, if he had he could have easily changed them and turned the tables again. That is a very interesting point. I believe he thought the reasons for the down turn in uboat results was the work of spies not codebreaking.

I've seen it suggested that Huff Duff played a bigger part in the defeat of the U-boats than Enigma.

That's correct. British code breakers (like all code breakers of the era) were imperfect @ best. Code breakers don't pinpoint U-boats, direction finding does.

[Thorsten Wahl]

I strongly believe that part of the believe in superiority of british radar came partly from the assessments of the Battle on the North Cape
from battle summary 24 sinking of the Scharnhorst
"

They were amazed at the small amount of damage in " Duke of York," and blamed the failure of
their Radar for their indifierent shooting. The superiority of British Radar equipment was generally
supposed to be the reason for the accuracy of " Duke of York's " fire, which was described as superb.
One survivor who had watched the fall of shot from the crow's nest described " Duke of York's " ability
to follow " Scharnhorst's " every movement as uncanny

."

Even they were not able to obtain accurate iunformation on german Radar "

the sets were of the mattress type

there wer also indications that german radar had similar performance


interrogation of Survivors

(ii) Gunnery Radar
No useful details of the particular gunnery radar arrangements of the Scharnhorst " were
obtained, but it appears that there were two sets, probably fitted with beam-splitting with a possible
accuracy of plus or minus one to two mils (3-6 minutes). (N.I.D. Note.---This bearing accuracy, if
true, would be of a high order comparable with that obtained with 274 and the later U.S. low angle
gunnery radars.)

(iv) First Contact with Force 2
...During this state of the action " Scharnhorst " was also engaging with her main and secondary
armament. Her firing, which was erratic to begin with, having started 2,500 yards short, improved in
speed and accuracy, until, between 17,000 and 20,000 yards, " Duke of York " was frequently straddled
and there were many near misses.

the wheather conditions made visual spotting challenging and Scharnhorsts shooting became more accurate, as the range increases, this seems a indication for a functioning firecontrol radar.
as german use of starshell was definately deficient and german personnel of optical equipment was blinded by the use of british starshell.

[Hartmann10]

Hello to all and best regards

You are ignoring the antennae and ACTUAL performance showed a very different picture, or else why were Mosquitoes with half a generation earlier radars able to hunt the German Nightfighters ?

The explanation is not only in the radar aerials, It is on the engines and power to weight ratio, and considering also the drag without aerials in both airplanes. The "Mosquito" was far more polished in aerodinamics.
The "Mosquito" MKXXX NF had two "Merlin" 76 developing 1760 hp and with two stage superchargers, so It could sustain higher power at higher ceiling than the Messerschmitt 110.
One comparison far more polite was the "Mosquito" against the FW TA154 both of them with similar in specifications and similar power in the engines, but the German Night fighter had the same aerials that the Messerschmitt 110, so It is secondary.
At any event, the main "Mosquito" variant with similar aerials was the MK II NF and the speed was only marginal against the Messerschmitt, so there´s no much of comparison.
Furthermore, the 75 Kw of power emitted (really a lot more was needed) from the SCR 720 were enough to reduce something like 20 miles per hour when switched on and were far more deletereous if We study the acceleration and rate of climb. A good amount of "Mosquitoes" of type "Pathfinder" equipped with the "Mickey Set" (the AN/APS-15), wich needed less power (something less than 24 Kw) were lost due to failiures of the engines caused by the need of power from the radar.

[pg55555]

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IGNORE the performance of the aircraft - the Mosquitoes had to hunt for German nightfighters (radar receivers did help here), whereas the German nightfighters had the option to be guided bt ground radar. German radar just wasn't up to the job.

( By the way re naval radars, the British found USN claims for range to be optimistic. It would seem that the USN used "best" ranges, whereas the RN (and UK in general) used service averages. )

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[paul.mercer]

I strongly believe that part of the believe in superiority of british radar came partly from the assessments of the Battle on the North Cape
from battle summary 24 sinking of the Scharnhorst
"

They were amazed at the small amount of damage in " Duke of York," and blamed the failure of
their Radar for their indifierent shooting. The superiority of British Radar equipment was generally
supposed to be the reason for the accuracy of " Duke of York's " fire, which was described as superb.
One survivor who had watched the fall of shot from the crow's nest described " Duke of York's " ability
to follow " Scharnhorst's " every movement as uncanny

."

Even they were not able to obtain accurate iunformation on german Radar "

the sets were of the mattress type

there wer also indications that german radar had similar performance


interrogation of Survivors

(ii) Gunnery Radar
No useful details of the particular gunnery radar arrangements of the Scharnhorst " were
obtained, but it appears that there were two sets, probably fitted with beam-splitting with a possible
accuracy of plus or minus one to two mils (3-6 minutes). (N.I.D. Note.---This bearing accuracy, if
true, would be of a high order comparable with that obtained with 274 and the later U.S. low angle
gunnery radars.)

(iv) First Contact with Force 2
...During this state of the action " Scharnhorst " was also engaging with her main and secondary
armament. Her firing, which was erratic to begin with, having started 2,500 yards short, improved in
speed and accuracy, until, between 17,000 and 20,000 yards, " Duke of York " was frequently straddled
and there were many near misses.

the wheather conditions made visual spotting challenging and Scharnhorsts shooting became more accurate, as the range increases, this seems a indication for a functioning firecontrol radar.
as german use of starshell was definately deficient and german personnel of optical equipment was blinded by the use of british starshell.

Gentlemen,
In the book 'Scharnhorst' by Alf R Jacobsen, he states that 'In the course of the next 27 minutes DoY pumped more than 200 heavy shells at Scharnhorst from distances as short as 4000 metres, strangely only seven or eight of them appear to have sored hits'
I am not a gunnery or radar expert, but this seems to me to be pretty rotten shooting, KGv & Rodney were shooting at this sort of range in the end and from the pictures taken by Ballard & Co they seem to have blown most of Bismarcks superstructure away, so what was wrong?

[Hartmann10]

Hello to all ¡¡¡
Let´s see:

IGNORE the performance of the aircraft -

You had been the one which mentioned first the "problem" of cropped performance in the German Night fighters only because of the drag caused by the aerials. i have shown you that It was not the case. I don´t see the need of ignoring the aircraft performance.

the Mosquitoes had to hunt for German nightfighters (radar receivers did help here)

Yes, but this is because they were defending Germany and the Mosquitoes were escorting and defending the bombers.
In the same way, the Germans used pasive radars to chase both bombers and night fighters, like the units of "Mosquito Jäger", which were single engined highly boosted fighters like Me 109 Gs and FW 190 As equiped with "Neptun" active radar and "Naxos" pasive receiver to hunt sweeping both Night fighter and pathfinder "Mosquitoes". The extremely light decimetric and metric German sets allowed for this.

whereas the German nightfighters had the option to be guided bt ground radar

Among with the US Navy night fighters and also the RAF night fighters. It was the only way to make an effective defence at night. I don´t see any different way to deal with the problem: The "SM", "SP" (both Navy radar sets) and "SCR-584" radar sets were used in this way, even when the main use of the "SCR-584" was the gunlaying. Also some British sets were used in this way in the "Baby Blitz" of 1944.

German radar just wasn't up to the job.

No, German radar was perfectly fitted for the job. The inferiority in numbers was the main problem against the waves of bombers and night fighters.
If you like I can post you the real performance of both sets the "SCR-720" and the "Lichtenstein SN-2 C", both the best sets for night figther job used in numbers. Both were almost identical in performance and the advantage of the german figters was that They always carried two different sets of active radars ("Lichtenstein" C and "Lichtenstein SN-2 B/C") plus some more sets of passive receiving sets like "Naxos". In fact, the German Night fighters, especially the Ju 88 G-6c were the best electronically fitted of all night fighters.

[Dave Saxton]

I strongly believe that part of the believe in superiority of british radar came partly from the assessments of the Battle on the North Cape
from battle summary 24 sinking of the Scharnhorst

I agree. It is interesting to compare the radar of Duke of York to Scharnhorst going into the battle and ignoring the fact that Scharnhorst lost its foretop set to battle damage at 0930 hours during the first skirmish.

Duke of York had separate radars for surface search, and main battery firecontrol. I have listed the performance of Type 284M above. Duke of York’s surface search set was Type 273Q. I believe this was the best surface search set available in late 1943. It was PPI equipped. There were two power outputs selectable: 70kw with a pulse width of 2us, and 100kw (IRRC) with a pulse width of 1us. So you could use the longer pulse width for maximizing range attainment (illumination energy being 140kw) or use a shorter pulse width for finer resolution for range. This set detected Scharnhorst at a range of 42km!

I know for certain that Scharnhorst’s foretop FuMO27 was replaced by a brand new FuMO26 in the months prior to the operation. The main (but not only) feature of the new the radar was the huge 3x6 meter mattress. This antenna was very sophisticated and common mode. The amount of antenna gain was an order of magnitude greater than the previous Seetakt antenna. The main benefit of the greater antenna gain was a range increase of ~30% over that of FuMO27. This could have given Scharnhorst nearly competitive range attainment to Type 273Q. This radar probably would have been used for both surface search and for firecontrol, as I have found no conclusive evidence that SH was equipped with Hohentwiel radar.

there wer also indications that german radar had similar performance


interrogation of Survivors
(ii) Gunnery Radar
No useful details of the particular gunnery radar arrangements of the Scharnhorst " were
obtained, but it appears that there were two sets, probably fitted with beam-splitting with a possible
accuracy of plus or minus one to two mils (3-6 minutes). (N.I.D. Note.---This bearing accuracy, if
true, would be of a high order comparable with that obtained with 274 and the later U.S. low angle
gunnery radars.)

This is confirmed by German documentation. Calias B using Radattel Peilung lobe switching attained a bearing accuracy of 0.10*. The 1944 report: Erprobungserfarung fur dem Ortung Dienst reports that the bearing accuracy of FuMO26 was more than required for blind fire. (The same report also reports that the new and improved fine ranging system gave range accuracy of 25 meters.) The Ortunsgeraete overview documents (1944) describes that the GEMA anlage was now considered primarily firecontrol radar on large warships.

From this we may say that Duke of York held an advantage before the battle in terms of surface search radar, but SH would have possessed superior fire control radar had the new foretop FuMO26 set not been destroyed during the initial engagement with Burnett’s cruisers.

the wheather conditions made visual spotting challenging and Scharnhorsts shooting became more accurate, as the range increases, this seems a indication for a functioning firecontrol radar.
as german use of starshell was definately deficient and german personnel of optical equipment was blinded by the use of british starshell.

I agree with this analysis Thorsten. It could only be radar directed fire by the remaining aft FuMO27 set.

It is also worthy to note that official British descriptions of the second engagement with Burnett's cruisers state that Scharnhorst opened fire before the Norfolk did and quickly scored damaging hits on the Norfolk, then shifted fire to the Sheffield. Some German survivors stated that they already had the Norfolk targeted before opening fire based on "radar contacts". The initial angle of approach would have allowed the aft radar to bear.

[Dave Saxton]

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( By the way re naval radars, the British found USN claims for range to be optimistic. It would seem that the USN used "best" ranges, whereas the RN (and UK in general) used service averages. )

I also suspect this Phil. The British were quite severe about confirming the performance data under tight circumstances. For example, destroyer range attaiments were only to be with the destroyer end on and not broadside on. (Modern standard is to have the radar beam cut across the target ship diagonally at 45* angle to quantify radar cross section)

The ranges of various German radar listed by Fritz Trenkle do not state such details or the size of the target ship, or antenna height. I found that in many cases they are ranges to a 2,000 ton destroyer. But one case is the range listed for Calias B of only 15km!! ?? It is an actual recorded test range -but is the range attained to an MTB.

[Dave Saxton]

Among with the US Navy night fighters and also the RAF night fighters. It was the only way to make an effective defence at night. I don´t see any different way to deal with the problem: The "SM", "SP" (both Navy radar sets) and "SCR-584" radar sets were used in this way, even when the main use of the "SCR-584" was the gunlaying. Also some British sets were used in this way in the "Baby Blitz" of 1944.
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That's interesting about the USN use of GCI techniques, Javier. I don't see a better way to deal with the problem either. Luftwaffe practice was track the selected target initally with Freya and then to pass the baton to two Giant Wuerzburgs. One to guide the friendly fighter and the other to track the selected target. Young women guided the German pilots in. After the war the Allies had the Germans stage a war game of defending a mass bomber attack and they were very impressed how well the system the Germans had developed worked.