Bismarck at DS with better radar

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Re: Bismarck at DS with better radar

Postby alecsandros » Mon Aug 24, 2015 6:05 am

JAG wrote:Thanks to both of you, it seems incredible to me that a CA could survive unscathed when a BB and a CA were, or at least should have been, waiting with guns loaded and trained on the radar contact, and once in visual range there was no reason to refrain from opening fire instantly.

... BIsmarck fired 4 or 5 semi-salvos at Norfolk, from the rear 380mm gun turrets. The cruiser was straddled repeatedly and splinters arived on board.
BUT the shock of the main guns firing took out the main (foretop) Fumo27 surface-search radar. I do not have info about this set beign repaired in the following days, and I do not know if the other 2 Fumo27 sets had the same range and/or integration into the ship's fire control systems.

Some hints that radar-firing was possible (either by a repaired foretop radar, or by one of the other 2 sets) come from the action vs Vian's 5 destroyers, and a similar case 3 days later against HMS Sheffield, which had casualties on board and radar knowcked out by splinter hits.

But nothing certain.

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Re: Bismarck at DS with better radar

Postby Dave Saxton » Mon Aug 24, 2015 2:27 pm

dunmunro wrote:
Dave Saxton wrote:
The reason the British Type 274 could not spot shell splashes was because of none of the above. It's transmitted beam (which was not scanned) was so narrow that the shells would almost always fall outside the beam. In 1947 Vanguard's Type 274 got an additional spotting set added on. It was 3cm.


These training films suggest that type 274 could spot for range and line:......


From Howse:

As mentioned on pg 224, a 1.25cm splash spotting set, type 931, had been developed in Canada for use as an adjunct to type 274. Though its range-spotting capabilities were an improvement to type 274 itself the important advance was that it provided quantitative spotting for line which Type 274 could not do. With type 931 errors in both range and line could be read off the display directly and spotting corrections made accordingly..


I might add that with type 274 an initial splash spot for range as well was only possible if the splash happened to be within the transmitted beam. 12 prototypes of type 931 were made ready by the Canadians for the BPF, but never deployed before the end of the war. The RN didn't want to pay for the Canada developed radar and a ASE developed version, type 932, was ordered instead. Meanwhile a spare type 930 cannibalized from a coastal artillery set was installed on Vanguard by 1947. This was not satisfactory and a type 932 was eventually installed on Vanguard.

Howse:

The Type 274/931(2) combination was the last specifically developed surface gunnery system to be developed by the Navy. It remained in service until Belfast, the last of the wartime cruisers, went into reserve in 1963.
Entering a night sea battle is an awesome business.The enveloping darkness, hiding the enemy's.. seems a living thing, malignant and oppressive.Swishing water at the bow and stern mark an inexorable advance toward an unknown destiny.

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Re: Bismarck at DS with better radar

Postby Dave Saxton » Mon Aug 24, 2015 2:41 pm

BUT the shock of the main guns firing took out the main (foretop) Fumo27 surface-search radar. I do not have info about this set beign repaired in the following days, and I do not know if the other 2 Fumo27 sets had the same range and/or integration into the ship's fire control systems.


Schmalenbach implied that it was the foretop set. However, Luetjens only said the "forward radar" in his radio message to Group. We don't know which forward set it was.

The other radars were intergrated into the fire control systems.

The conning tower and aft radars would have less range than the foretop set.
Entering a night sea battle is an awesome business.The enveloping darkness, hiding the enemy's.. seems a living thing, malignant and oppressive.Swishing water at the bow and stern mark an inexorable advance toward an unknown destiny.

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Re: Bismarck at DS with better radar

Postby Dave Saxton » Mon Aug 24, 2015 3:39 pm

JAG wrote:
Dave Saxton wrote:
JAG wrote:Thank you Dave, that about settles it doesnt it? Were any hits obtained?


Yes.

Did PE open fire?


No.


Thx, could you please provide more details on the engagement? Target? Sunk? It was a Calais B?


The target was a British coastal convoy. I don't recall how many if any targets were sunk, but hits were scored. It was a Calais B.

This was June 1941.

The Calais B started blind fire operations during the Fall of 1940.

L Brown wrote: The Germans had set up long -range guns shortly after occupying that part of the coast, and Nov 11, 1940, scientists of His Majesty's Signal School were informed that a convoy had been subjected to accurate fire at night.


The British then developed a Jammer for Seetakt called type 91. This jammer was first used in Feb 1941. As soon as the jammer was switched on, the firing of the German coastal guns ceased. The German counter was to give Seetakt the ability to change frequency. These jamming and anti- jamming developments correlate to experiences during the battle of North Cape years later.
Entering a night sea battle is an awesome business.The enveloping darkness, hiding the enemy's.. seems a living thing, malignant and oppressive.Swishing water at the bow and stern mark an inexorable advance toward an unknown destiny.

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Re: Bismarck at DS with better radar

Postby Dave Saxton » Mon Aug 24, 2015 3:52 pm

JAG wrote:
I still think the ships should have been ready to open fire in the direction of the radar contact and do so as soon as the CA came into sight, with better use of radar far more salvos could have been accurately fired and maybe allow the ships to escape.

Did PE open fire?


In the case of Norfolk 3 salvoes, including the first if I recall correctly, out of five total straddled. Grenfell's account states that the cruiser was straddled after it entered the fog. Schmalenbach reported that BS sent a warning to PG about the Norfolk contact several minutes before it opened fire on the Norfolk.
Entering a night sea battle is an awesome business.The enveloping darkness, hiding the enemy's.. seems a living thing, malignant and oppressive.Swishing water at the bow and stern mark an inexorable advance toward an unknown destiny.

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Re: Bismarck at DS with better radar

Postby Mostlyharmless » Mon Aug 24, 2015 4:34 pm

There was a general problem in the KM that radar was regarded as too secret for officers to be told about its capabilities. There is an amusing story in Louis Brown's “A Radar History of WW2” https://books.google.co.uk/books?id=uYg ... er&f=false describing how a torpedo officer on Hipper gave a convoy a Christmas present as he did not know about Hipper's radar.

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Re: Bismarck at DS with better radar

Postby JAG » Tue Aug 25, 2015 12:16 am

Dave Saxton wrote:Thx, could you please provide more details on the engagement? Target? Sunk? It was a Calais B?


The target was a British coastal convoy. I don't recall how many if any targets were sunk, but hits were scored. It was a Calais B.

This was June 1941.

The Calais B started blind fire operations during the Fall of 1940.

L Brown wrote: The Germans had set up long -range guns shortly after occupying that part of the coast, and Nov 11, 1940, scientists of His Majesty's Signal School were informed that a convoy had been subjected to accurate fire at night.


The British then developed a Jammer for Seetakt called type 91. This jammer was first used in Feb 1941. As soon as the jammer was switched on, the firing of the German coastal guns ceased. The German counter was to give Seetakt the ability to change frequency. These jamming and anti- jamming developments correlate to experiences during the battle of North Cape years later.[/quote]

Thx again, that certainly puts things under a very different light.

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Re: Bismarck at DS with better radar

Postby JAG » Tue Aug 25, 2015 12:27 am

alecsandros wrote:
JAG wrote:Thanks to both of you, it seems incredible to me that a CA could survive unscathed when a BB and a CA were, or at least should have been, waiting with guns loaded and trained on the radar contact, and once in visual range there was no reason to refrain from opening fire instantly.

... BIsmarck fired 4 or 5 semi-salvos at Norfolk, from the rear 380mm gun turrets. The cruiser was straddled repeatedly and splinters arived on board.
BUT the shock of the main guns firing took out the main (foretop) Fumo27 surface-search radar. I do not have info about this set beign repaired in the following days, and I do not know if the other 2 Fumo27 sets had the same range and/or integration into the ship's fire control systems.

Some hints that radar-firing was possible (either by a repaired foretop radar, or by one of the other 2 sets) come from the action vs Vian's 5 destroyers, and a similar case 3 days later against HMS Sheffield, which had casualties on board and radar knowcked out by splinter hits.

But nothing certain.


Dave Saxton wrote:
JAG wrote:
I still think the ships should have been ready to open fire in the direction of the radar contact and do so as soon as the CA came into sight, with better use of radar far more salvos could have been accurately fired and maybe allow the ships to escape.

Did PE open fire?


In the case of Norfolk 3 salvoes, including the first if I recall correctly, out of five total straddled. Grenfell's account states that the cruiser was straddled after it entered the fog. Schmalenbach reported that BS sent a warning to PG about the Norfolk contact several minutes before it opened fire on the Norfolk.


Thx to both of you, I was thinking more in the terms of the first radar contact, Suffolk, but it seems that firing just 5 half-salvos is just too few salvoes on Norfolk as well, what is that, a 2 mins engagement at that range? Nevertheless, lucky, very lucky ships...

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Re: Bismarck at DS with better radar

Postby alecsandros » Tue Aug 25, 2015 5:40 am

JAG wrote:
Thx to both of you, I was thinking more in the terms of the first radar contact, Suffolk, but it seems that firing just 5 half-salvos is just too few salvoes on Norfolk as well, what is that, a 2 mins engagement at that range? Nevertheless, lucky, very lucky ships...


Lucky indeed....
It appears Norfolk was taken under fire from 10km, Suffolk from 18km (about 6 salvos, I don't know if full or semi) and Sheffield from 12km (6 semi-salvos). They all reported close hits (splinters on board NOrfolk and damage and casualties from splinters on board Sehffield) or shock damage from enemy rounds (Suffolk reported leaks in her hull due to explosions of 380mm rounds).

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Re: Bismarck at DS with better radar

Postby Dave Saxton » Tue Aug 25, 2015 9:30 pm

A Raven wrote:By the time of the Bismarck affair, the RN were using blind fire by radar types 279 and 281 against unseen surface targets, and by types 284 and 285, also against unseen surface targets and against unseen low flying aircraft. The first writing that I can find (so far) date from around October/November 1940, and relate to actions in the Mediterranean.
When did the Germans begin to use radar directed blind fire against UNSEEN surface targets and against UNSEEN air targets? The word UNSEEN is key.
When did the Germans first fit radar receivers onto warships?
Thank you.


I had not seen this post before, so forgive me for the tardy reply.

They began using blind fire against surface targets by the fall of 1940 using the Calais B (coastal) Seetakt sets. May 1940 was when Radattel Peilung was introduced on the Series II models. Only with Radattel Peilung (a type of phased array scanning) or conventional lobe switching, could adequate bearing accuracy be obtained for blind fire. Previous Seetakt models aboard ship did not operate lobe switching. Some German destroyers were equipped with radar sets that had the capability by the autum of 1940, but I don't know when they actually used it. There is a battle report submitted by Erich Bey dated Nov 1940 that states that they used the radar sets for surface search and tracking but did not use it for fire control purposes (They withheld gun fire and tried a torpedo ambush of the enemy instead), so he could not report on the gun laying capabilities asked about.

Track charts within the documents reporting on the Scheer's attack on convoy HX84 on Nov 5 1940 show that the Scheer fired upon an unseen target for several minutes through a smoke screen and about 25 minutes after dark, from a range of ~20,000 meters.

Prinz Eugen was equipped with a radar set during 1942 that could locate aircraft accurately enough for range, bearing, and elevation, all necessary to fire accurately at unseen aircraft. So not before then by a German warship that I have read, although Luetjens entered remarks into the fleet KTB about using radar to target aircraft by warships during 1941.

Helmuth Giessler reports that a special radar warning receiver was constructed for Bismarck by Group West before the operation, but he could not confirm that it was actually embarked. When Luetjens reported that Suffolk was shadowing by means of radar, Group West asked him to determine what frequencies the enemy radars were using. It seems strange that Group should ask him to do this, if he did not have equipment to do so.

By Oct 1941, photos of the Tirpitz, Scheer, ..ect show the standard radar warning receiver antennas such as the Sumatra antennas (bow ties), and the Timor array. These antennas were used with the standard Metox and Samos receivers (60cm -350cm).
Entering a night sea battle is an awesome business.The enveloping darkness, hiding the enemy's.. seems a living thing, malignant and oppressive.Swishing water at the bow and stern mark an inexorable advance toward an unknown destiny.

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Re: Bismarck at DS with better radar

Postby Dave Saxton » Tue Aug 25, 2015 10:03 pm

Mostlyharmless wrote:There was a general problem in the KM that radar was regarded as too secret for officers to be told about its capabilities. There is an amusing story in Louis Brown's “A Radar History of WW2” https://books.google.co.uk/books?id=uYg ... er&f=false describing how a torpedo officer on Hipper gave a convoy a Christmas present as he did not know about Hipper's radar.


Poor education of officers, and especially gunnery officers, about the capabilities and limitations of radar, stifled by the extreme secrecy rules, was indeed a major stumbling block for the Kriegsmarine.
Entering a night sea battle is an awesome business.The enveloping darkness, hiding the enemy's.. seems a living thing, malignant and oppressive.Swishing water at the bow and stern mark an inexorable advance toward an unknown destiny.


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