What if Hood hadn't blown up?
Moderator: Bill Jurens
Re: What if Hood hadn't blown up?
But Bismarck didn't press the attack against PoW after Hood was sunk. So it doesn't take more than the raw and undergunned PoW to make Bismarck turn away.
Re: What if Hood hadn't blown up?
I thought the turn away was due to a torpedo attack reported by PG's sonar.
Re: What if Hood hadn't blown up?
Vic,
Your interpretation and belief may well be correct.
However if Bismarck was under such serious threat from two capital ships and in imminent danger of serious battle damage I think the reaction of Lindemann (and Lutjens, who had the final say in the matter) would have been more substantial than the moves you detail. I think the Germans would have laid an immediate smokescreen and reversed course under cover of that smoke. Lutjens orders were clear - avoid battle with equal or superior forces - and if Hood had not blown up when it did and was indeed targetting Bismarck then Lindemann and Brinckmann would have been ordered to break off the action.
Your interpretation and belief may well be correct.
However if Bismarck was under such serious threat from two capital ships and in imminent danger of serious battle damage I think the reaction of Lindemann (and Lutjens, who had the final say in the matter) would have been more substantial than the moves you detail. I think the Germans would have laid an immediate smokescreen and reversed course under cover of that smoke. Lutjens orders were clear - avoid battle with equal or superior forces - and if Hood had not blown up when it did and was indeed targetting Bismarck then Lindemann and Brinckmann would have been ordered to break off the action.
''Give me a Ping and one Ping only'' - Sean Connery.
Re: What if Hood hadn't blown up?
To RF.
I doubt they would have employed a smoke screen for three reasons.
1. The British ships were known to be carrying gunnery radar, so smoke might not mask Bismarck as a target. What was not known is how accurate the British sets were. The wave lengths were known and it would have been felt that the British 10cm sets would have the advantage over the 1m sets used in the KM enabling accurate target acquisition for azimuth, when the German sets would not.
2. If smoke was used, the Germans themselves would have had their own capacity to fight back reduced, because although Bismarck carried Gunnery Radar, it had been damaged during the action against Norfolk and Suffolk the previous evening. Bismarck had to rely heavily on optical range finders which would be blinded by smoke. I believe the Gunnery Radar in KM ships at that time was not effective at ranges above 8 miles.
3. Hood blew up at 0600 and although the threat was greatly reduced at this time Bismarck already commmitted to the turn would be seeking to continue the engagement but with a shift of target. She needed to be able to fight back, so a steady course would be adopted so as to put the second ship under fire quickly and considering that PoW was hit at 0602:30, it seems that soemthing of the sort had been put into effect. PoW had turned out towards the enemy to aviod the wreck and smoke from Hood and was probably also heading west at this time. The angle of entry of this hit was 48 degrees from the starboard bow, which seems to confirm a westerly heading. In that event it would be entirely correct for Lindemann to engage PoW on his quarter using a relatively steady gun-range and keeping his A-Arcs open. Despite the hit on the compass platform PoW maintained her rate of closure with the enemy until about 0605 and if Bismarck turned during this time it would throw out her own gunners and hand a tactical advantage to the enemy, witha potential 10 to 8 gun superiority.
In relation to "2" above, PG's foretop gunnery control position was blinded by funnel gas and gun discharge after the turn to starboard and gunnery control was handed over to the after position. This makes it fairly certain that PG was not relying on radar for this action, though it might have been used to secure gun ranges.
Vic Dale
I doubt they would have employed a smoke screen for three reasons.
1. The British ships were known to be carrying gunnery radar, so smoke might not mask Bismarck as a target. What was not known is how accurate the British sets were. The wave lengths were known and it would have been felt that the British 10cm sets would have the advantage over the 1m sets used in the KM enabling accurate target acquisition for azimuth, when the German sets would not.
2. If smoke was used, the Germans themselves would have had their own capacity to fight back reduced, because although Bismarck carried Gunnery Radar, it had been damaged during the action against Norfolk and Suffolk the previous evening. Bismarck had to rely heavily on optical range finders which would be blinded by smoke. I believe the Gunnery Radar in KM ships at that time was not effective at ranges above 8 miles.
3. Hood blew up at 0600 and although the threat was greatly reduced at this time Bismarck already commmitted to the turn would be seeking to continue the engagement but with a shift of target. She needed to be able to fight back, so a steady course would be adopted so as to put the second ship under fire quickly and considering that PoW was hit at 0602:30, it seems that soemthing of the sort had been put into effect. PoW had turned out towards the enemy to aviod the wreck and smoke from Hood and was probably also heading west at this time. The angle of entry of this hit was 48 degrees from the starboard bow, which seems to confirm a westerly heading. In that event it would be entirely correct for Lindemann to engage PoW on his quarter using a relatively steady gun-range and keeping his A-Arcs open. Despite the hit on the compass platform PoW maintained her rate of closure with the enemy until about 0605 and if Bismarck turned during this time it would throw out her own gunners and hand a tactical advantage to the enemy, witha potential 10 to 8 gun superiority.
In relation to "2" above, PG's foretop gunnery control position was blinded by funnel gas and gun discharge after the turn to starboard and gunnery control was handed over to the after position. This makes it fairly certain that PG was not relying on radar for this action, though it might have been used to secure gun ranges.
Vic Dale
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Dave Saxton
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Re: What if Hood hadn't blown up?
Vic,
The Germans did not know about the 50cm and 10cm radars at the time of the Bismarck. The 10cm radars were not known until the recovery of an almost intact H2S from a crashed bomber near Rotterdam in Feb 1943. The 10cm radar was given the codename Rotterdam and a committe known as the AGR(Arbeits Gemeinschaft Rotterdam) was set up to deal with it. The AGR records also tell us quite a bit about what the Germans knew and when they knew concerning Allied radar. In a time line presented at one of the AGR meeting it gives the chronology of Kriegsmarine passive detections of Allied radar from 1939 up to May 1944. The 50cm radar was first identified in March 1943.
Previous to the Bismarck operation the British had not possessed any sea surveilance radar capability at sea against the Germans.The Germans had logged detections of radar down to 1.3 meters wave length by the British mostly on land and on marine patrol bombers. The first logged detection of British shipborne radar was 1.4 meters in May 1941. Indeed the obvious use of radar came as a real surprize to Luetjens and had quite a psychological effect. The first 10cm sets had not reached operational status yet, and when that time came in late August it was deployed first on warships engaged in anti-U-boat duties. The first 10cm sets for large warships came in late 1941 and early 1942. These sets were general tactical sets. The first 10cm gunnery radars deployed in the Royal Navy came in mid 1944.
Gunnery radar at that time was mostly used for ranging and was used with visual bearing data. If the target was obsured such that it could not be seen well enough to obtain the exact bearing of the target then it could not be fired upon. Blind fire radar directed gunnery requires bearing accuracies of a fraction of a degree. Such accuracy isn't possible without lobe switching, no matter the wave length. The German radar originally had lobe switching but it had been decided to not use it on production sets in 1937, and at the time of the Bismarck a new more advanced method of lobing had not become fully deployed yet. The British gunnery radar did not have lobe switching at that time. Lobe switching versions began to be phased in during the course of 1942.
The German Seetakt radar in 1941 had a battleship to battleship range of 25km in the case of the Bismarck's sets (assuming sources are correct pertaining to the exact models installed), and the PG's more advanced models had 30km range to a battleship.
The Germans did not know about the 50cm and 10cm radars at the time of the Bismarck. The 10cm radars were not known until the recovery of an almost intact H2S from a crashed bomber near Rotterdam in Feb 1943. The 10cm radar was given the codename Rotterdam and a committe known as the AGR(Arbeits Gemeinschaft Rotterdam) was set up to deal with it. The AGR records also tell us quite a bit about what the Germans knew and when they knew concerning Allied radar. In a time line presented at one of the AGR meeting it gives the chronology of Kriegsmarine passive detections of Allied radar from 1939 up to May 1944. The 50cm radar was first identified in March 1943.
Previous to the Bismarck operation the British had not possessed any sea surveilance radar capability at sea against the Germans.The Germans had logged detections of radar down to 1.3 meters wave length by the British mostly on land and on marine patrol bombers. The first logged detection of British shipborne radar was 1.4 meters in May 1941. Indeed the obvious use of radar came as a real surprize to Luetjens and had quite a psychological effect. The first 10cm sets had not reached operational status yet, and when that time came in late August it was deployed first on warships engaged in anti-U-boat duties. The first 10cm sets for large warships came in late 1941 and early 1942. These sets were general tactical sets. The first 10cm gunnery radars deployed in the Royal Navy came in mid 1944.
Gunnery radar at that time was mostly used for ranging and was used with visual bearing data. If the target was obsured such that it could not be seen well enough to obtain the exact bearing of the target then it could not be fired upon. Blind fire radar directed gunnery requires bearing accuracies of a fraction of a degree. Such accuracy isn't possible without lobe switching, no matter the wave length. The German radar originally had lobe switching but it had been decided to not use it on production sets in 1937, and at the time of the Bismarck a new more advanced method of lobing had not become fully deployed yet. The British gunnery radar did not have lobe switching at that time. Lobe switching versions began to be phased in during the course of 1942.
The German Seetakt radar in 1941 had a battleship to battleship range of 25km in the case of the Bismarck's sets (assuming sources are correct pertaining to the exact models installed), and the PG's more advanced models had 30km range to a battleship.
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.
Re: What if Hood hadn't blown up?
To Dave
Thanks for your considered and well constructed reply.
I did mean 50 cm and not (as I wrote) 10cm as the wave length of the Type 284 fitted in Hood, PoW and Suffolk, which the Germans encountered at Denmark Strait.
I don't dispute what you are saying about what was "known" but there is a considerable element of lead and lag between technological development and production. The value of 50 cm radar over 1m sets will have been known to both sides in their respective technologies departments and once an advanced radar was sent to sea, extensive measures would be put into effect to prevent the enemy learning about it.
Apart from radars already installed, the ship's command and technical officers would be briefed as to the possible advances made by the enemy according to the latest technological discoveries made at home. For example; the RN did not have high-velocity weapons deployed as main battery in their Battleships, but it did not stop them correctly assuming that the Germans might have them. Also PG's War Diary shows that despite the advances made in passive sonar (GHG) in the KM, Captain Brinkmann was of the opinion that the British had a more advanced sonar fit in their ships, which they did not.
In Norfolk and Suffolk it was assumed that the German's own radar was limited to gunnery, yet PG was using her set very effectively for surface surveillance. Bismarck was tasked to discover the frequency of the new British sets with their extended range and it entirely possible that the German technological department considered it likely that sets of much higher frequency and greater accuracy for bearing had been already deployed. The fact that the Germans did not "know" what radars the British were using does not mean they did not "suspect" and where pertinent such suspicion would definitely condition tactics.
At the time of Exercise Rhine, the Germans learned that the British shadowing force had radar which outmatched their own and that the Type 284 set was fitted in Hood, PoW and Suffolk. This knowledge would indicate that the British might have a clear gunnery advantage from their radar. It might also be possible that the British shadowing force was supplying accurate radar-range data from the flank which could serve to correct azimuth smearing and enable very accurate concentration of fire.
Vic Dale
Thanks for your considered and well constructed reply.
I did mean 50 cm and not (as I wrote) 10cm as the wave length of the Type 284 fitted in Hood, PoW and Suffolk, which the Germans encountered at Denmark Strait.
I don't dispute what you are saying about what was "known" but there is a considerable element of lead and lag between technological development and production. The value of 50 cm radar over 1m sets will have been known to both sides in their respective technologies departments and once an advanced radar was sent to sea, extensive measures would be put into effect to prevent the enemy learning about it.
Apart from radars already installed, the ship's command and technical officers would be briefed as to the possible advances made by the enemy according to the latest technological discoveries made at home. For example; the RN did not have high-velocity weapons deployed as main battery in their Battleships, but it did not stop them correctly assuming that the Germans might have them. Also PG's War Diary shows that despite the advances made in passive sonar (GHG) in the KM, Captain Brinkmann was of the opinion that the British had a more advanced sonar fit in their ships, which they did not.
In Norfolk and Suffolk it was assumed that the German's own radar was limited to gunnery, yet PG was using her set very effectively for surface surveillance. Bismarck was tasked to discover the frequency of the new British sets with their extended range and it entirely possible that the German technological department considered it likely that sets of much higher frequency and greater accuracy for bearing had been already deployed. The fact that the Germans did not "know" what radars the British were using does not mean they did not "suspect" and where pertinent such suspicion would definitely condition tactics.
At the time of Exercise Rhine, the Germans learned that the British shadowing force had radar which outmatched their own and that the Type 284 set was fitted in Hood, PoW and Suffolk. This knowledge would indicate that the British might have a clear gunnery advantage from their radar. It might also be possible that the British shadowing force was supplying accurate radar-range data from the flank which could serve to correct azimuth smearing and enable very accurate concentration of fire.
Vic Dale
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Dave Saxton
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Re: What if Hood hadn't blown up?
Hi Vic,
In my opinion the Germans probably didn't suspect that British possessed gunnery radar of significantly superior bearing resolution or radar of significantly shorter wave length in 1941. It is true that Luetjens reported that the British radar seemed to have a range of 35km. This was an over estimate by about 11,000 meters. Why and how he came up with this estimate is not known. Louis Brown believes that this error was the result of inaccuracies in the calulated positions of the ships at the time that B-Dienst intercepted Suffolk messages reporting Bismarck's posistion and course. Brown is sceptical that the Bismarck monitored the tracking with a radar detector. Although passive radar detectors can not measure range. Luetjens never reported that the British were using radar with a wave length of 50cm, although Group West asked him to try and find the frequency of the newly discovered British radar. Of course if Bismarck wasn't equipped with a detector why would authorities ashore ask him to try and find out the frequency?
This brings up the question of did Bismarck have a detector, and if so what detector? Many don't believe that Bismarck actually did and they have a case. I can't find any strong evidence of the antenna needed to serve the alledged receiver, although the Bali was so small it could be very difficult to locate in photos. Nonetheless, I have found evidence that a reciever could have been available in May 1941. The NVK had already developed snooping equipment by 1939 and the shipboard receivers later put into production were developed from this early equipment. The Metox was contracted for production with the firm of Metox because there was not enough NVK equipment on hand. The Samos was developed in parallel with the Metox but was designed to provide additional bearing data. The Tirpitz was already equipped with the needed directional antenna to go with the Samos receiver within months of the Bismarck operation. However, these equipment could not detect 50cm pulses. Although a detector could have detected one of the many British meters wave length radars in use. This is in my opinion the most likely reason Luetjens thought he was still being tracked. The minimum wave length they could detect was about 60cm. This calls into question the entire premise that the Germans suspected the British of possessing gunnery radar of wave lengths of 50cm or less during 41-42. If the KM knew or suspected that the British were using 50cm or less radar they would have developed and equipped their warships with detectors that could have detected such radar before 1943.
Why did the Germans not develop detectors capable of detecting wave lengths of 50cm or less until later? It was probably because their own experience indicated that 60cm was about the practical limit for radar using triodes. The Seetakt was originally 52cm using a magnetron. It was changed to 60cm when they switched to triodes. The early TS1 triode could operate down to 40cm but the power output was limited to 1kw and it would require intermittant use at that wave length. Later they changed the wave length to 80cm because it would naturally produce a slight boost in effective range and it increased the sensitivity of the receiver. It did not operate at 100cm. longer wave length does degrade bearing resolution if the antennas are the same. However, there was only a negligable difference in bearing resolution between less than 60cm and 80cm provided the use of a suffciently effectively large antenna array.
In my opinion the Germans probably didn't suspect that British possessed gunnery radar of significantly superior bearing resolution or radar of significantly shorter wave length in 1941. It is true that Luetjens reported that the British radar seemed to have a range of 35km. This was an over estimate by about 11,000 meters. Why and how he came up with this estimate is not known. Louis Brown believes that this error was the result of inaccuracies in the calulated positions of the ships at the time that B-Dienst intercepted Suffolk messages reporting Bismarck's posistion and course. Brown is sceptical that the Bismarck monitored the tracking with a radar detector. Although passive radar detectors can not measure range. Luetjens never reported that the British were using radar with a wave length of 50cm, although Group West asked him to try and find the frequency of the newly discovered British radar. Of course if Bismarck wasn't equipped with a detector why would authorities ashore ask him to try and find out the frequency?
This brings up the question of did Bismarck have a detector, and if so what detector? Many don't believe that Bismarck actually did and they have a case. I can't find any strong evidence of the antenna needed to serve the alledged receiver, although the Bali was so small it could be very difficult to locate in photos. Nonetheless, I have found evidence that a reciever could have been available in May 1941. The NVK had already developed snooping equipment by 1939 and the shipboard receivers later put into production were developed from this early equipment. The Metox was contracted for production with the firm of Metox because there was not enough NVK equipment on hand. The Samos was developed in parallel with the Metox but was designed to provide additional bearing data. The Tirpitz was already equipped with the needed directional antenna to go with the Samos receiver within months of the Bismarck operation. However, these equipment could not detect 50cm pulses. Although a detector could have detected one of the many British meters wave length radars in use. This is in my opinion the most likely reason Luetjens thought he was still being tracked. The minimum wave length they could detect was about 60cm. This calls into question the entire premise that the Germans suspected the British of possessing gunnery radar of wave lengths of 50cm or less during 41-42. If the KM knew or suspected that the British were using 50cm or less radar they would have developed and equipped their warships with detectors that could have detected such radar before 1943.
Why did the Germans not develop detectors capable of detecting wave lengths of 50cm or less until later? It was probably because their own experience indicated that 60cm was about the practical limit for radar using triodes. The Seetakt was originally 52cm using a magnetron. It was changed to 60cm when they switched to triodes. The early TS1 triode could operate down to 40cm but the power output was limited to 1kw and it would require intermittant use at that wave length. Later they changed the wave length to 80cm because it would naturally produce a slight boost in effective range and it increased the sensitivity of the receiver. It did not operate at 100cm. longer wave length does degrade bearing resolution if the antennas are the same. However, there was only a negligable difference in bearing resolution between less than 60cm and 80cm provided the use of a suffciently effectively large antenna array.
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.
Re: What if Hood hadn't blown up?
Having a radar detector doesn't necessarily mean you can determine it's frequency. We had a simple diode type detector in submarine periscopes that converted radar pulse envelopes into sound for use by the OOD just so he could have an auditory indication of a radar signal when the periscope was raised. With some experience you could even learn to tell what type of radar it (probably) was by the sound.
We could do more thorough analysis given a little time, but the simple detector gave a first impression of type and signal strength.
We could do more thorough analysis given a little time, but the simple detector gave a first impression of type and signal strength.
Re: What if Hood hadn't blown up?
I think this is attaching a far greater significance to what otherwise in operational terms is only a small matter. Maybe there are other means of locating the frequency, maybe the authorities ashore making the request were unaware there was no detector or had no idea of how to do the job.Dave Saxton wrote:
Luetjens never reported that the British were using radar with a wave length of 50cm, although Group West asked him to try and find the frequency of the newly discovered British radar. Of course if Bismarck wasn't equipped with a detector why would authorities ashore ask him to try and find out the frequency?
''Give me a Ping and one Ping only'' - Sean Connery.
Re: What if Hood hadn't blown up?
I haven''t come across any references to this equipment previously. If there was a detector why would it not be detailed with the other radio/radar/sonar equipment Bismarck was carrying?Dave Saxton wrote:
This brings up the question of did Bismarck have a detector, and if so what detector? Many don't believe that Bismarck actually did and they have a case.
''Give me a Ping and one Ping only'' - Sean Connery.
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Dave Saxton
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Re: What if Hood hadn't blown up?
Hi RF,
von Muellenheim wrote:
" Besides her three radar sets, the Bismarck had a radar detector, a simple receiver designed to pick up incoming pulses of enemy radar"
and in a foot note the Baron provides this on Luetjens error in assuming his ship was still being tracked via British radar early on the 25th:
Hans-Henning von Schultz told the author in 1984: the Prinz Eugen was also equipped with radar detectors. These were passive radar sets with which the beams of a radio-location set (radar impusles) could be detected in a then still-inexact direction only. And since radar detectors would register radar impulses at great distances while the range of shipboard radar was still short, the great distance that existed between the Bismarck and her shadowers after contact had been lost excludes any chance that she was still being located by enemy radar. This was not technically possible at the time.
All radar equipment was shrouded in extreme secercy during that period. While the DeTe sets may have been listed (as communications electronics as a cover) as present, no details or specifics would be given, and it would not be surprising that nothing is said of detector gear. It was strictly forbidden to mention specific details pertaining to radar equipment.
Detection equipment was used by the Kriegsmarine during that time frame and previous ashore, and it could be quite possible that equipment of a different pattern compared to the later Metox/Samos type equipment was provided.
In my opinion it is a mistake to assume that they specifically detected and monitored the Suffolk's 50cm radar if they actually had detection gear. If Bismarck was still receiving radar pulses, misleading Luetjens, it was more likely one of the many meters wave length radar in use by the British that was being detected. This fits perfectly the properties of meters wave length radar.
Steve is right to point out that detection gear may have detected the pulse repitition frequency of radar of the wave lengths it could not pick up. There is evidence that the Samos could pickup PRF data later during the war. However, the PRF does not determine the operating wave length or differentiate between 50cm, 150cm, 330cm, 750cm, ....ect
The Baron does point out that two other possibilities exist for Luetjens to assume that the enemy still shadowed him besides radar. These were interceptions of enemy radio traffic that would indicate that they still maintained contact, and perhaps a misinterpetion of intercepts by B-dienst.
von Muellenheim wrote:
" Besides her three radar sets, the Bismarck had a radar detector, a simple receiver designed to pick up incoming pulses of enemy radar"
and in a foot note the Baron provides this on Luetjens error in assuming his ship was still being tracked via British radar early on the 25th:
Hans-Henning von Schultz told the author in 1984: the Prinz Eugen was also equipped with radar detectors. These were passive radar sets with which the beams of a radio-location set (radar impusles) could be detected in a then still-inexact direction only. And since radar detectors would register radar impulses at great distances while the range of shipboard radar was still short, the great distance that existed between the Bismarck and her shadowers after contact had been lost excludes any chance that she was still being located by enemy radar. This was not technically possible at the time.
All radar equipment was shrouded in extreme secercy during that period. While the DeTe sets may have been listed (as communications electronics as a cover) as present, no details or specifics would be given, and it would not be surprising that nothing is said of detector gear. It was strictly forbidden to mention specific details pertaining to radar equipment.
Detection equipment was used by the Kriegsmarine during that time frame and previous ashore, and it could be quite possible that equipment of a different pattern compared to the later Metox/Samos type equipment was provided.
In my opinion it is a mistake to assume that they specifically detected and monitored the Suffolk's 50cm radar if they actually had detection gear. If Bismarck was still receiving radar pulses, misleading Luetjens, it was more likely one of the many meters wave length radar in use by the British that was being detected. This fits perfectly the properties of meters wave length radar.
Steve is right to point out that detection gear may have detected the pulse repitition frequency of radar of the wave lengths it could not pick up. There is evidence that the Samos could pickup PRF data later during the war. However, the PRF does not determine the operating wave length or differentiate between 50cm, 150cm, 330cm, 750cm, ....ect
The Baron does point out that two other possibilities exist for Luetjens to assume that the enemy still shadowed him besides radar. These were interceptions of enemy radio traffic that would indicate that they still maintained contact, and perhaps a misinterpetion of intercepts by B-dienst.
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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Dave Saxton
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Re: What if Hood hadn't blown up?
The obvious presence and use of British radar did have a significant pschological effect upon Luetjens. This was the first time the British had demonstrated a capable sea surveilence radar aboard ship and was of great significance to the war at sea. In one of the messages to Group West Luetjens sent:RF wrote: I think this is attaching a far greater significance to what otherwise in operational terms is only a small matter. Maybe there are other means of locating the frequency, maybe the authorities ashore making the request were unaware there was no detector or had no idea of how to do the job.
" Presence of radar on enemy vessels with a range of at least 35,000 meters, has strong adverse effect on operations in the Atlantic. Ships were located in the Denmark Strait in thick fog and could never again break contact. Attempts to break contact unsuccessful despite most favorable weather conditions...."
Your correct that the actuall wave length was of little importance to Luetjens at the moment. Just the fact that the British warships had capable radar was a major development. I suspect that they did not know the wave length of the Suffolk's radar, and could not speculate that it was a gunnery or a tactical radar as its primary role. Nonetheless, GW did make the request to try and find out the wave length. Such information would be of great importance in determining the newly discovered British radar capabilities. I'm pretty certain that they deduced that the Suffolk was shadowing by radar from the radio intercepts in conjunction with the visibility conditions, rather than by specific monitoring of the Suffolk's 284.
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.
Re: What if Hood hadn't blown up?
I agree in essence with your last post Dave. The psychological impact on Lutjens I think was a significant factor in the loss of the Bismarck. And yes, it stopped any further break out runs by surface warships/hilfskreuzer through the northen passages. However:
1) Bismarck was first sighted by both Suffolk and Norfolk in the clear. That is how the British identified them; they were followed through the thick fog. Lutjens thus made an understandable but significant error in detail. A radar trace without sighting would only show a large unidentified ship.
2) When Gneisenau sighted and was seen by Naiad at the first breakthrough attempt to Operation Berlin, in the Iceland/Faeroes gap, Lutjens swung due north and moved to maximum speed in rough seas - Naiad, which only had a very brief glimpse, couldn't have kept pace even if she were equipped with radar.
3) Bismarck was sighted in the worst possible position in the most enclosed breakthrough route, with a friendly cruiser taking up part of Bismarck's field of fire astern. This ''boxed in'' situation enabled the Suffolk's radar to be at its most effective. Otherwise the risk would be that the shadowing ship was liable to be sunk, where the Bismarck had maximum room to manoevure.
1) Bismarck was first sighted by both Suffolk and Norfolk in the clear. That is how the British identified them; they were followed through the thick fog. Lutjens thus made an understandable but significant error in detail. A radar trace without sighting would only show a large unidentified ship.
2) When Gneisenau sighted and was seen by Naiad at the first breakthrough attempt to Operation Berlin, in the Iceland/Faeroes gap, Lutjens swung due north and moved to maximum speed in rough seas - Naiad, which only had a very brief glimpse, couldn't have kept pace even if she were equipped with radar.
3) Bismarck was sighted in the worst possible position in the most enclosed breakthrough route, with a friendly cruiser taking up part of Bismarck's field of fire astern. This ''boxed in'' situation enabled the Suffolk's radar to be at its most effective. Otherwise the risk would be that the shadowing ship was liable to be sunk, where the Bismarck had maximum room to manoevure.
''Give me a Ping and one Ping only'' - Sean Connery.
Re: What if Hood hadn't blown up?
Looking at the issue of the KM radar detectors, apart from the lack of directional indication there would obviously also be a lack of range indication, so the Germans, unless they had a measure of the original strength of signal, would at longer ranges be unable to determine whether the ship broadcasting the impulses was receiving the echo back. How would knowing the frequency help with this problem? Are we talking about jamming?
''Give me a Ping and one Ping only'' - Sean Connery.
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Dave Saxton
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Re: What if Hood hadn't blown up?
Hi Rf,
Your right that radar traces do not self identify. In the absense of IFF there is no way of knowing if they are freindly much less if they are a steamer, a cruiser, or a battleship...ect... During the aborted break out attemp during Operation Berlin the flagship's radar was temporarilly out of order, but the Scharnhorst's DeTe detected the cruisers and the operator was able to estimate that they were cruisers by the way they behaved, and their course and speed ..ect... so by the use of Scharnhorst's DeTe the were able to evade, were they had room to manuever.
During the Bismarck/Prinz Eugen passage they had detected the Suffolk by both GHG and radar quite a bit previously to the Suffolk sighting them, but since there were patches of heavy fog and rain/snow squalls, Luetjens had (based on previous expierences) every reason to believe that the Suffolk would be unable to maintain contact assuming it did sight them. It quickly became obvious after the fleeting sighting of Suffolk (by the way it behaved) that it had radar, which changed the whole ball game.
Concerning passive radar; passive radar can not measure range because range is measured by the elapsed time of the round trip of the radar pulse and there is no way of knowing the extact time that the pulse was sent. The only thing that can be done is to make a guess based upon signal strength. This is very imprecise and your correct that something about the typical signal strength, antenna gain, and receiver sensitivity, of the suspected radar would have to be known. British radar had to employ much greater signal strength than German radar of similar wave length to attain similar range, because the receivers were much less efficient. Thomas has in the past pointed out, that this may have been a possible reason that Luetjens (not knowing anything about the technical aspects of the newly discovered British radar) made the error of estimating the range of the British radar as at least 35km.
The propagation distance of the transmitted pulse of meters wave radar compared decimetric radar is significantly greater. Additionally, the ship to ship range that echoes can be recieved for meters wave length radar is generally less than 20km, but the range that it can detect high flying aircraft can be over a hundred miles at the same time. The reason for these properties is the vertical lobe structure of metric radar. This also means that the transmitted pulses of metric wave length radar ( via sky wave propagation) can also propagate for hundreds of kilometers in the right conditions. There is a good possibility that this was what occured during the early hours on the 25th after the British had lost contact.
Knowing the wave length allows some of the performance characteristics of the enemy radar to be better estimated, and it would allow the eventual development of counter measures. The Germans understood many of the physical properties of radar even at these early dates, and if the wave length of the Suffolk's radar could be known, then they could inform Luetjens of general performance estimates.
Your right that radar traces do not self identify. In the absense of IFF there is no way of knowing if they are freindly much less if they are a steamer, a cruiser, or a battleship...ect... During the aborted break out attemp during Operation Berlin the flagship's radar was temporarilly out of order, but the Scharnhorst's DeTe detected the cruisers and the operator was able to estimate that they were cruisers by the way they behaved, and their course and speed ..ect... so by the use of Scharnhorst's DeTe the were able to evade, were they had room to manuever.
During the Bismarck/Prinz Eugen passage they had detected the Suffolk by both GHG and radar quite a bit previously to the Suffolk sighting them, but since there were patches of heavy fog and rain/snow squalls, Luetjens had (based on previous expierences) every reason to believe that the Suffolk would be unable to maintain contact assuming it did sight them. It quickly became obvious after the fleeting sighting of Suffolk (by the way it behaved) that it had radar, which changed the whole ball game.
Concerning passive radar; passive radar can not measure range because range is measured by the elapsed time of the round trip of the radar pulse and there is no way of knowing the extact time that the pulse was sent. The only thing that can be done is to make a guess based upon signal strength. This is very imprecise and your correct that something about the typical signal strength, antenna gain, and receiver sensitivity, of the suspected radar would have to be known. British radar had to employ much greater signal strength than German radar of similar wave length to attain similar range, because the receivers were much less efficient. Thomas has in the past pointed out, that this may have been a possible reason that Luetjens (not knowing anything about the technical aspects of the newly discovered British radar) made the error of estimating the range of the British radar as at least 35km.
The propagation distance of the transmitted pulse of meters wave radar compared decimetric radar is significantly greater. Additionally, the ship to ship range that echoes can be recieved for meters wave length radar is generally less than 20km, but the range that it can detect high flying aircraft can be over a hundred miles at the same time. The reason for these properties is the vertical lobe structure of metric radar. This also means that the transmitted pulses of metric wave length radar ( via sky wave propagation) can also propagate for hundreds of kilometers in the right conditions. There is a good possibility that this was what occured during the early hours on the 25th after the British had lost contact.
Knowing the wave length allows some of the performance characteristics of the enemy radar to be better estimated, and it would allow the eventual development of counter measures. The Germans understood many of the physical properties of radar even at these early dates, and if the wave length of the Suffolk's radar could be known, then they could inform Luetjens of general performance estimates.
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.