May 23/24 night shadowing and interception approach CS1/BC1

[alecsandros]

Gentlemen,
Have you noticed how large did the Wikipedia page of "battle of Denmark Strait" became ?
Amongst others, the "nhight shadowing and interception approach" appears very interesting (if not necessarily perfect), and dubiously enough it confirms my feeling that the dettached destroyers passed 16km from Bismarck in the middle of the night (visiblity down to 5km)

Of course, it's just Wiki.... but it's nice to see other people interested on this subjects as well.

Best,

https://en.wikipedia.org/wiki/Battle_of ... ark_Strait

"Before contact was re-established, the two squadrons missed each other by a hairsbreadth. Had the German ships not altered course to the west at 01:41 to follow the line of the Greenland icepack, the British would have intercepted them much earlier than they did. The British destroyers were just 10 mi (8.7 nmi; 16 km) to the southeast when the Germans made this course change. If the visibility had not been reduced to 3–5 mi (2.6–4.3 nmi; 4.8–8.0 km), the German vessels would probably have been spotted (since generally on a calm, clear day ship lookouts can observe large objects and ships about 12 miles (19 km) distant on the horizon. And if the ship's lookouts are in a crow's nest, the observable distance is even further).[9]"

[Antonio Bonomi]

Hello everybody,

@ Alecsandros,

thank you for letting us know about this new Wikipedia page update.

https://en.wikipedia.org/wiki/Battle_of ... ark_Strait

It is funny that the " Plagiarist John Asmussen " has been listed being one reference with his website entirely copied version of that battle version from my 2003 version and this website map too.
Being listed as a reference when he never decided which version was correct and always supported also Robert Winklareth " Reversed photo theory " is really funny, but you are right ... this is Wikipedia ...

In any case they do provide the due credit to the Court Martial request ... it seems they follow us closely ...

Before making any assessment about the destroyers distance at 02.00 am I like to plot them precisely on the map, ... with precise geographical reference ... than we will see where they were.

Bye Antonio

[alecsandros]

Thank you for your time and work Antonio,

Hope to hear from you soon.

In the mean time, I took another look at the English versions of Bismarck and PRinz Eugen KTB's for the night of 23rd.

What seems interesting to me is that Bismarck's aft radar is reported as malfunctioning as well (in addition to the main one which was damaged by shock damage of own guns), thus requiring PRinz Eugen to cover the stern sector as well as the forward sector, thus sweeping the entire 360 deg of horizon with her main foretop Fumo 27 radar (or so I think, as it had the largest range of the 2 equipments mounted on board). Does anybody know how long it would normaly take to sweep the horizon with that radar system set ?

There are no suspicious contacts reported in the KTBs, except something at around 4:07 - probably not usefull for our endeavor.

That doesn't mean, of course, that the destoryers couldn't have passed very close to the Germans... simply without being detected... as it was a night and a day full of errors, and radars (EM-II instruments) weren't perfect in the very least...

[Dave Saxton]

thus requiring PRinz Eugen to cover the stern sector as well as the forward sector, thus sweeping the entire 360 deg of horizon with her main foretop Fumo 27 radar (or so I think, as it had the largest range of the 2 equipments mounted on board). Does anybody know how long it would normaly take to sweep the horizon with that radar system set ?

1 minute and 10 seconds for the full 360*. The range to destroyers would have been 20 -25km.

Problems with Bismarck's aft radar position were also encountered during the AKVS testing period and had not been satisfactory put right at the time that the tests were terminated.

[wadinga]

All,
Although I am not sure everything is accurately recorded HMS Electra by Commander T J Cain as told to A v Selwood is a useful source. It is very literary, like Busch with plenty of dialogue.
He says

Shortly after 02:15 am Commander May opened formation and Electra and her sister ships, in accordance with Holland's latest order, spread out at fifteen mile intervals to 'search towards the north'.

......

An hour passed

He records receiving

From Hood. Enemy in sight. Am engaging.

After Hood is sunk

"What's our course to her last position, Davies?" Harry, working like an automaton, gives the plot and adds "We have sixty miles to go."

....

"Make immediately our course and speed to the others and tell them to conform."

Good God, its only ten past six

We had estimated, originally, that we would be in position by eight-fifteen, but thanks to Chiefie and his men we were improving on this forecast...........

Actually they were not early because it was

the smoke of the dirty funnel of a solitary merchantman

Got that Alberto, not all smoke in the North Atlantic comes from battlecruisers, no matter how much you insist it MUST in order to back up unsupported assertions
So their actual arrival was at about 8:15 presumably and they seem to have HMS Echo in company because he mentions Icarus and Anthony arriving slightly later.

He talks of going north after 02:15 departure for an hour, and yet somehow Electra is only 60 miles from Hood's sinking. I think they picked up Suffolk's sighting at 02:47 and headed south then. Or Holland's message had further unrecorded details like "Search around a box then give up and head SW".

If Cain remembered 60 miles accurately then he was that far from Norfolk's TOO 06:37 position of 63 21N 31 47W, at maybe 06:45 allowing for delay before transmission. Mearns says the destroyers were 30 miles N of the sinking position at 07:00 and spotted the oil patch at 07:45 based on Pinhorn. This does not exactly match with Cain's account.

Any thoughts?

All the best
wadinga

[alecsandros]

thus requiring PRinz Eugen to cover the stern sector as well as the forward sector, thus sweeping the entire 360 deg of horizon with her main foretop Fumo 27 radar (or so I think, as it had the largest range of the 2 equipments mounted on board). Does anybody know how long it would normaly take to sweep the horizon with that radar system set ?

1 minute and 10 seconds for the full 360*. The range to destroyers would have been 20 -25km.

Problems with Bismarck's aft radar position were also encountered during the AKVS testing period and had not been satisfactory put right at the time that the tests were terminated.

Thank you very much,

[alecsandros]

He talks of going north after 02:15 departure for an hour, and yet somehow Electra is only 60 miles from Hood's sinking. I think they picked up Suffolk's sighting at 02:47 and headed south then. Or Holland's message had further unrecorded details like "Search around a box then give up and head SW".

Sean,
I would try the following explanation:
Holland gave the order to spread at 24km. Say, for simplicity, that the eastern-most destroyer was Anthony, then to the west - Icarus, Echo, Electra.
IF the 4 DDs actualy complied to the order (as the 24km distance was an approximation - they couldn't have been perfectly locked into positions) , that means that the distance between Electra and Anthony according to the order should have been 72km Electra being western-most, and Anthony eastern-most.

Furthermore, depending on the method of spreading of the destroyers (it would take time for them to arive at 24km intervals from each other, as when the order was given they were sailing in company of Hood, at a few kilometers from each other), and on the angles of movement of each one of them, and of course, their actual speeds, the 4 DDs could have arived in a multitude of positions (possibilities) between 2:15 and 6:10.

[Alberto Virtuani]

Wadinga wrote: "Got that Alberto, not all smoke in the North Atlantic comes from battlecruisers, no matter how much you insist it MUST in order to back up unsupported assertions "

Hi Sean,
therefore you are now forced to acknowledge that W-W was not very "smart" at all (to use nice words), not recognizing the enemy (and not reacting at all to the smoke sight) from the same distance (19 sm) from which Holland recognized the German ships as "enemy" and turned against, without misidentifying them as merchantmen, as we already discussed in another thread........

My excuses to everybody here, for speaking about things that are not relevant at all to the thread subject.

from Wiki: "Before contact was re-established, the two squadrons missed each other by a hairsbreadth"

I tend to agree with "Wiki", thanks to Alec for posting the update to the page.
Holland himself was very close to the enemy at 2:03, any further move to north of the destroyers (especially the one most to West), should have taken them very close to Lutjens force. However, I suspect that they possibly were a bit too much to East (due to the last wrong absolute position transmitted by Suffolk) to be able to intercept Germans anyway, while I think they could have spotted Norfolk at the same time, due to the same reason.....
Apparently "Lady Luck" was not with the British that night up to the moment (2:56) when Suffolk recontacted the Germans.


I think it would be interesting to understand when exactly the destroyers abandoned their "run to North" and turned South to follow Holland. I don't remember this is recorded clearly on official papers, but I can be wrong.... Was it at Suffolk 2:56 - 2:57 enemy sighting report ? Thanks to Sean for posting Cain account that gives some good indications.


Bye, Alberto

[Antonio Bonomi]

Hello everybody,

@ all,

very good !

I think we are getting into it pretty well, since those are exactly the information and evaluations we need to keep into account.

The real geographical positions, the error margins on evaluating own positions by every warship involved, ... the orders and the reactions due to the information received, ... and last but not least the airplanes, ... that as far as I have read were also used to double check the warships correct positioning too, ... for Admiralty convenience ... and this tells the whole story about how important it was to have reliable information provided, ... with almost correct positioning, ... and the Admiralty War Room carefully following the situation knew it and wanted always double confirmations, ... especially from the airplanes.

In fact, we will see and realize that the error margins have been a very important factor on that night.

Once again, I confirm we will start from the Hood exact sinking position as a reference mark and than backwards, reconstructing the Hood and PoW tracks, ... and I already showed you above how it comes on the map, ... after we will apply the other warships.

Of course the Hood sinking position is a perfect indisputable geographical position, so we have a milestone to refer to, thanking David Mearns.

Bye Antonio :-)

[alecsandros]

I think it would be interesting to understand when exactly the destroyers abandoned their "run to North" and turned South to follow Holland. I don't remember this is recorded clearly on official papers, but I can be wrong.... Was it at Suffolk 2:56 - 2:57 enemy sighting report ? Thanks to Sean for posting Cain account that gives some good indications.


Bye, Alberto

I don't know if the DDs abandoned their northwards course. We will see what else we will find.

[Antonio Bonomi]

Hello everybody,

in order to continue this demonstration, ... I need anybody able to do it, ... to verify for me the Hood and PoW tracks by going backward from the " Enemy in Sight ! " radio report at 05.43 of May 24th, 1941, ... until the 22.30 of May 23rd, 1941.

Map_trial_Hood-PoW_109.jpg (115.51 KiB) Viewed 980 times

I give you the geographical coordinates of 8 key points so you can calculate known time, course and speed of Hood and PoW and verify my work on this map.

Point H : at 05.43 is 63° 20' N and 31° 50' W
Point G : at 05.38 is 63° 20' N and 31° 44' W
Point F : at 03.40 is 63° 47' N and 29° 54' W
Point E : at 03.20 is 63° 54' N and 29° 41' W
Point D : at 02.03 is 64° 28' N and 29° 13' W
Point C : at 00.17 is 63° 43' N and 29° 13' W
Point B : at 00.12 is 63° 41' N and 29° 11' W
Point A : at 22.30 is 63° 29' N and 27° 28' W

At latitude 63 the distance between each meridian is 27,23 sea miles, so from meridian 29 to 30 West for example.
At latitude 64 is 26,30 sea miles, so it decreases obviously going North from the equator toward the North pole.
The distance between each parallel is always 60 sea miles, for example between 63 and 64 North.

You can use those 2 works to check it :

http://hmshood.com/history/denmarkstrait/holland.htm

http://hmshood.com/history/denmarkstrait/woodward.htm

Bye Antonio

[wadinga]

Hello Antonio,

Your're not the only one on the road, I'm in Luxembourg so don't have access to resources, but could you put sources for the lettered positions?

David Mearns endorsed Commander Warrand's position having used it to find Hood's wreck and you have it from the Canadian radio intercept. http://jproc.ca/radiostor/hood.html By the way Mea Culpa this says the position was

not encoded

so reception lag on Norfolk and Suffolk's bridges would not include encode/decode time but still is not instantaneous from TOO 05:43. (Also why does this say 25/5/41?)

Presumably you have had to use PoW's logged positions and courses to backward-derive this course?

From the B-Dienst interceptions, albeit apparently logged against the wrong day is

0637B/25.5. Von 5dl = auf Norlfk an mta = Scapa. P
HMS Hood sunk in position 63º 21' north 31º 47' west, proceeding search survivor.

Mearns notes two Norfolk transmitted positions for Hood's sinking site, he liked the second IIRC.

All the best

wadinga

[Antonio Bonomi]

Hello everybody,

@ Wadinga,

now I am back home after Spain, Portugal and France, so I can spend some time on this thread ...

I have used as you suggested the PoW official information, for course changes and speed at each key ( from A to H ) turn from 22.30 of May 23rd until 05.43 of May 24th.

I think that both you and Tim Woodward got them pretty well too.

I have translated that Hood radio message you provided the link for :

http://jproc.ca/radiostor/hood.html

determining the exact position of Point H at 05.43 being 63° 20' N and 31° 50' W as I already explained on the page 5 of this thread on Thursday September 10th, 2015 at 7:13 pm :

Knowing that GFVA is the crossing point between 63N and 32W, it is written on David Mearns book on the map I have attached on page 3 of this thread, ... now we have to go 21 sea miles on geographical bearing 13 degrees ( as explained on the Hood radio message link above ) and we can mark the Hood position on our map.
That position is equal to 63°20' North and 31° 50' West.
This was Commander Warrand radio communicated Hood position at 05.43 that morning.

I know, just like David Mearns demonstrated on his book, that the Hood sinking positions ( both ) of HMS Norfolk are not correct and I know of course the precise geographical position of the Hood wreck, but I preffer not to disclose it even if it is not so difficult to realize it if one reads David Mearns book.

The 05.43 ( Commander Warrand ) Hood and PoW precise positions at this point is more than enough I think, because that is what David Mearns and I have used to determine the Hood wreck position precisely, ... and it was a perfect match, ... right on the spot.

I am sure that you, like I hope everybody else at this point, have realized that we are going from now onwards to use the precise real geographical positions to plot the warships, ... and we will be referring to the same information provided on various radio messages ... by the war diaries entry, ... and also the various D/F bearings ... and realize what happened and probably why.

But for the moment we need to create an agreed reference base, ... and that is the Hood and PoW track, ... because we do have all the data to make it right as I think I did already.

Bye Antonio

[Antonio Bonomi]

Hello everybody,

@ Wadinga

here the reference I have used for you and everybody to check.

SPEED of the track

From 22.00 ( Point A is 22.30 ) until 00.08 at 27 knots, than 25 knots until the 02.03 turn when the speed went back to 27 knots until 03.53 when the speed was increased to 28 knots until 05.43 and our Point H.

COURSE changes

From 22.00 ( point A is 22.30 ) until 00.12 ( Point B ) on course 285°, turn to starboard of 55° on course 340° for 5 minutes until 00.17 ( Point C ), other 20° to starboard on course 360° from 00.17 until 02.03 ( Point D ), ... than turn back 160° to port from 360° to 200° from 02.03 until 03.20 ( Point E ), ... than 20° to starboard from 200° to 220° for 20 minutes until 03.40 ( Point F ), ... than other 20° to starboard from 220° to 240° on course 240°from 03.40 until 05.38 ( Point G) ... other turn to starboard of 40° from 240° to 280° from 05.38 until the 05.43 and our Point H.

Bye Antonio

[paulcadogan]

Hi Antonio!

Quick question: How significant would be the effect of the sea current on what you're trying to work out? That would affect the actual distance covered, whatever the direction of the current relative to the ships' course.

Just asking....

While you guys are jet-setting around Europe, I am here bracing for our encounter with Super-Hurricane Matthew. It was looking pretty bad for us, but this evening it's looking like the center will pass between Jamaica and Haiti, sparing us a direct hit, but even if it does this both countries will experience heavy rains, flooding and tropical storm force winds. We are all waiting now, hoping for the best. It should start affecting us tomorrow (Sunday) evening, through Monday into Tuesday. If we lose power, you may not hear from me for a while.....

Paul