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

[wadinga]

Hello Antonio,

You know, because you have the PoW tactical plot from Kew that the M/F D/F bearing on 068T on Norfolk's 02:29 transmission is represented exactly the same as all the others. It has no range therefore it is not a radar contact. PoW was specifically unable to search as ordered with 50cm Type 284 because the forward DCT could not scan for a sector over her stern. Holland probably incorrectly assumed the after DCT also had a 284. It did not. He forbade the use of the more easily detected Type 281 which did cover the stern sector. There is no indication PoW searched with any kind of radar across her stern.

Because it is an M/F D/F bearing on a Norfolk transmission there is no indication of range. It could be 8 miles or 20. Or 50. PoW did not see Norfolk on 068T because it was dark, and the visibility was poor and variable and maybe she was just too far away.

Norfolk's contact at 298T was not PoW because it is incompatible with the above. If Norfolk's gunnery officer actually thought it was Bismarck at the time why did W-W report it as unidentified? That was Johnson's subsequent speculation. The visibility was not 1 mile or 5 miles or 8 miles, it was logged as intensely variable, because there were dense snow and rain showers and fog. Norfolk evidently glimpsed something which was unidentifiable and may have been roughly 8 miles away. No course, speed or identity was possible. There is no indication it was any kind of Type 286 contact because on Norfolk's heading it could not give an indication from anything so far on the beam of the ship. It was so fleeting and uncertain a visual contact, it was obviously not worth diverting to investigate. Holland sent the destroyers back north at 02:15. Could the fleeting contact be one of them on a near-reciprocal course? With a relative speed change of close to 60 knots it would be fleeting.

Norfolk's Plan 8 only shows triangular "position" marks for Suffolk at 02:56, 05:41 and 08:00 on 24th. It doesn't even show a Suffolk track. All it shows is a speculative track for Bismarck . As has been made clear many times any M/F D/F bearings derived from Suffolk transmissions by Norfolk or PoW are bearings only. As such no position can be derived or plotted. Maybe Norfolk's missing tactical plot shows an M/F D/F bearing for every Suffolk transmission, through the early hours, but no bearing could say how far away Suffolk was from Norfolk.

All the best

wadinga

[Dave Saxton]

Hi all,

British radar scientist Brian Callick, who was intimately involved with the British WW2 effort, confirms that the 286 beam covered ~20* off both sides of the bow.

The 298* figure doesn't make sense for a radar derived bearing, either relative or true, at 0229 hours.

@Dave Saxton: Dave, is it possible that the contact got from Norfolk at 2:29 was a single, isolated, 286 radar one without any indication of the bearing ?
Do you know how the reading panel of the 286 was looking like ? Was it giving an (albeit approximate) bearing indication or should the ship been steered anyway to obtain such indication through the 2 side receiving antennas ?

It's possible but I think not likely. If 298* was relative it may be plausible, although unlikely, if the radar operator just a made a very rough estimate based on the larger pip. Quite a stretch I think.

@ Dave Saxton,

what do you think Dave about this occurrence from HMS Prince of Wales having the Type 284 switched ON at 02.29 for sure ?

Do you think it can be very likely a radar RD/F spot ?

POW's Type 284 could provide rather precise data. The bearing resolution was 3* using max signal, and the bearing accuracy using max signal was within 1 degree. Nonetheless, why no precise range data given?

However, Type 284 could not be simply turned on at a moments notice or switched on and off at will. Type 284 used anode modulation via a pulser device. This required considerable warm up time, sometimes of up to 45 minutes, before it could provide reliable range data. After about 20 minutes it may have been warmed up enough? The minimum warm up time before use for Hohentwiel, which also used anode modulation, is given as 10 minutes.

Dave, Having read up a little I believe M/F D/F bearings are less precise at shorter distances than at longer ones, because there is a less steep drop in signal strength as one approaches the null when changing azimuth. Do you have an opinion?

Makes sense. The precision of bearings derived by radio direction at sea circa 1941 was that of a few degrees margin of error if I recall correctly.

[Antonio Bonomi]

Helllo everybody,

@ Dave Saxton and Wadinga,

very clear and good inputs, ... many thanks.

So both the Norfolk as well as the PoW bearings were most likely NOT radar ones.

On Norfolk a visual spot confirmed by Johnston ( thinking it was the enemy Bismarck ) ... probably incorrectly associated to the Suffolk known radio or assumed bearing ( 298°) they were carefully following to hang on to the enemy thru the Suffolk, ... just as confirmed by RearAdm Wake-Walker too on his own report, ... or ...
... another option as Wadinga is suggesting is that Norfolk spotted one of the destroyers sailing north on 298°, ... by the way, from where you took the 02.15 time Sean ? Since Capt Leach is telling us 02.05 for that order to north for the destroyers, ... and we have to realize precisely how many and in which way they were sailing north on that moment, ... because also the Germans reacted at 02.29 to something ... ref. PG war diary entry ...

On POW a radio RD/F of 68° to Norfolk transmitting on that moment to Suffolk, ... waiting for the radar Type 284 to warm up as you explained, ... but now the association of the 8 sea miles of Norfolk to this bearing only is doubtful ... so we have to rely on the other inputs ( like the various bearings at 03.20 and 03.36 from PoW to Suffolk and Suffolk to Norfolk ) we have for the Norfolk track to correctly position her on the map.

Still the 02.55 additional spotting of the " large vessel " makes the Norfolk very close to the PoW track on that moment, ... because at that point there were no more destroyers on bearing NW from Norfolk being spotted, ... but only the Hood and the PoW ahead of the Norfolk, ... and the visibility was still very bad ... just around 5 sea miles as for Capt Leach report.

Very interesting ... and now we have to obtain also the destroyers information ...

Does anybody have their log for May 1941 ? I mean the : Achates ; Electra; Antelope; Anthony; Echo, and Icarus.

Bye Antonio

[wadinga]

Hello Antonio,

Timing for the destroyers' turn: Cain in his book HMS Electra but even I have to admit his timings may be flakey.

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'.

Since the deployment signal was visual the timing may not be recorded. Mearns says all minor ships logs, including destroyers, were discarded. Whether they just kept going when Hood and PoW turned south or were detached some time after the turn, the four of them must surely pass the cruisers going in the opposite direction, without either side being aware in the dark and murky conditions.

PoW had no Type 284 which could bear usefully astern, the main DCT being constrained in its traversing arc and the 284 aerials pointed where it pointed. I think the same was true of Hood's installation. I think Holland hoped that PoW having the latest and most complete radar outfit might have 284 on the after DCT as well. I believe Holland, maybe via his staff, believed 284 could not be detected by Bismarck and 281 might be.

All the best

wadinga

[Antonio Bonomi]

Hello everybody,

@ Wadinga,

very clear Sean, ... many thanks ...

Now it is very likely that Norfolk bearing 298° could have been a destroyer or a previous Suffolk bearing information, ... but not the PoW.

Does anybody have an idea of how many destroyers ( 4 or 6 ? ) went north and in which formation, ... on which relative positions ? For how long ... etc etc ...

So, on that time, ... at 02.29 am, ... I will disregard the 298° bearing from Norfolk to PoW and only use the 68° from PoW to Norfolk, ... opening up the range on what it will result from the other information I have at 01.00, ... at 03.20, ... 05.41 ... etc etc ... in order to position the Norfolk track correctly, ... because 8 sea miles in not a confirmed distance from Norfolk to PoW due to the above possibilities.

Bye Antonio

[paulcadogan]

Hi all,

Now it is very likely that Norfolk bearing 298° could have been a destroyer or a previous Suffolk bearing information, ... but not the PoW.

Does anybody have an idea of how many destroyers ( 4 or 6 ? ) went north and in which formation, ... on which relative positions ? For how long ... etc etc ...

I think this is very likely the case - a merging of 2 almost simultaneous bits of info. Suffolk transmitted at 0225 and again at 0229, pretty much at the same time as the sighting of the unknown ship. Could Norfolk, under those conditions of erratic visibility, have mistaken a destroyer passing relatively closely as a "large vessel" much further away? And also, would Suffolk's 284 have picked up any of the the British destroyers if they had come within range?

It was only 4 destroyers remaining with BC1 at the time.

The German "alarm" at 0228 could potentially have been Suffolk, as she transmits an enemy report at 0229 of two at ranges of 20,900 and 25,500 yards and would have been astern of the Germans. But at that point, PG would have been ahead of Bismarck, so was the further contact. Could the contact also have been one of the destroyers?? Too bad the destroyers' records were discarded....

And BTW - a coincidental aside for us...... Hurricane Nicole, which scored a direct hit on Bermuda a few days ago, is churning towards the Denmark Strait, and though it will no longer be a true hurricane/tropical storm by that time, is projected to pass right through the area of the DS battle! (Sorry to digress, but wanted to share this - I'll do a post in the Off Topic section for those who might want to see more details!)

[Antonio Bonomi]

Hello everybody,

@ Paul Cadogan,

YES, I think we are getting very close now to the solution of those crucial moments ...

The destroyers being a very important factor to be considered on that area ... by the way, ... do you know which ones were detached and which one were still left sailing north out of those 6 destroyers ?

- Achates ; Electra; Antelope; Anthony; Echo ; Icarus.

Which ones were the 4 destroyers you are referring to that were still sailing to North at 02.15 until 02.56 ?

Does anybody have a record of those 6 destroyers movements ?

Bye Antonio

[wadinga]

Hello Antonio,

Anthony and Antelope had already been detached to refuel some time before.

Paul, Watch out with those Suffolk transmissions. Duncan's radio listing has Suffolk's (and Norfolk's) early morning 25th reports inserted incorrectly into the 24th sequence.

The narrative says:

Reports.- Made reports at 0028, 0101, 0131, 0231, 0247, 0256, 0319 and 0321 during the above phase.

In TOO 02:30 ie 02:31 Suffolk reports own course speed and position only. The TOO 02:47 is first re-acquisition on radar "surface craft"with TOO 02:56 expanded to two enemy ships. Note even with Type 284 the bearing changes from 180T 10 miles to 192T 9 miles.

Best regards
Sean

[Dave Saxton]

And also, would Suffolk's 284 have picked up any of the the British destroyers if they had come within range?

The KGV 284 trials indicated a typical range to destroyers of 13,000 yards.

[paulcadogan]

Paul, Watch out with those Suffolk transmissions. Duncan's radio listing has Suffolk's (and Norfolk's) early morning 25th reports inserted incorrectly into the 24th sequence.

Oops! Thanks for the correction Sean! I had indeed noticed that before - but didn't check it with this one! The signal I quoted was for the 25th... So scratch any related ideas..

And thanks Dave.

[Alberto Virtuani]

"Wadinga wrote: .....Holland sent the destroyers back north at 02:15. Could the fleeting contact be one of them on a near-reciprocal course? ......."

Hi Sean,
this is a very interesting theory, and realistic, I think (as Paul suggested too). However, in order to support it, we need to be sure about the exact timing when Holland ordered the destroyers to north (and possibly also about their actual deployment maneuver in the subsequent minutes....)

I have always thought that the destroyers were still going to north at the same time Hood and PoW turned 160° south, therefore at around 2:03. If this is the case, they should have crossed PG and BS latitude at around 2:15 (on German port beam), Norfolk latitude at 2:10 max, thus being quite too much to north by 2:29 to be possibly seen by Norfolk (that was in 68° bearing from PoW) on 298° even at 10+ sm.....
This is true especially if they started to spread at 2:15, as you posted from Cain......

If, as your sentence above suggested, the order to the destroyers was given after the turn to south, e.g. at 2:15 (thus when they had sailed together with Holland to South for 10+ minutes) , then it is well possible that the most eastward of them, after the counter-turn and her spread, could be occasionally spotted by Norfolk on almost opposite courses on 298°, approximately 5 to 10 sm distant.


Bye, Alberto

[Antonio Bonomi]

Hello everybody,

having now removed both the 298° and the 8 sea miles reference between the Norfolk and the PoW at 02.29, we are left with the PoW bearing to Norfolk of 68°.

Now, we know that Norfolk spotted also the PoW at 02.55, ... after having sailed 13 sea miles at 30 knots on 26 minutes, ... and this time it could not be a RN destroyer.

This occurrence happened while into a visibility area of around 5 sea miles ( ref. Capt Leach report ).

So it seems that now we should be evaluating a situation like this one between the Norfolk and the PoW :

Norfolk_PoW_0200_0340_009.jpg (48.43 KiB) Viewed 1108 times

I have traced 3 options : GREEN, RED and BLUE showing the 02.29 until 02.55 Norfolk positions .

GREEN : 14,5 sea miles at 02.29 from PoW and 11 sea miles at 02.55 from PoW
RED : 12 sea miles at 02.29 from PoW and 9 sea miles at 02.55 from PoW
BLUE : 10 sea miles at 02.29 from PoW and 7 sea miles at 02.55 from PoW

I have my personal opinion of course, ... ... but I like your one now ...

Bye Antonio

[Alberto Virtuani]

Hi Antonio,
I don't think option green can be a realistic one as an 11 sm distance at 2:55 (even if it was just a matter of an instant and accounting for asymmetrical visibility conditions in the area) is in contrast with PoW 5 sm visibility.....

Both option blue and (partially) option red are more probable (and not very dissimilar), BUT none of them can perfectly explain (the green one is perhaps slightly better in this sense) a destroyer seen by Norfolk on 298° bearing at 2:29 at a reasonable distance, as the most eastward destroyer would have been quite more northward, even accepting that they sailed to south together with Hollands until 2:15 (however,we are missing here key info about their initial position and their maneuvers to spread).....
So, we are still with the question regarding the contact at 2:29 on your proposed map: what was that one


Bye, Alberto

[Cag]

Hi All

I may be being quite stupid here and so apologise in advance but may I ask if someone can explain things to me?

We know that the crew of Norfolk sighted a vessel and later assumed it was Suffolk that they had sighted and communicated that at the time.

We know that at times visibility was very low.

We know that at 02.55 the visibility was 5nm.

Therefore if Norfolk was between 7nm and 14.5nm from PoW at 02.55 and the visibility was 5nm what conclusions can be reached from this?

I'm a bit at a loss as to where this is going? Are we trying to prove that at some point it might have been possible for Norfolk to have been close enough to may or may not see the PoW or Hood before the 05.37 signal?

As we know the ships logs were written 'at the time' as were the signals sent and no mention of any sighting of BC1 is seen in any signal or log.

It would be a very large jump to presume that prior to the Battle in which the Hood was lost Wake-Walker was already intentionally providing himself with an alibi for something prior to an incident to which as of yet he had no knowledge.

If someone could explain I would be grateful, if we are saying that in theory if Norfolk and BC 1 could have seen each other earlier and communicated then what difference would this have made, then I understand.

If it is anything else I'm open to enlightenment.
Best wishes
Cag

[Antonio Bonomi]

Hello everybody,

@ CAG,

I see your current difficulties, so let me try to explain what I am looking to realize too by providing those maps.

We know that soon after midnight the Suffolk lost touch with the enemy, while communicating an incorrect geographical position ( with course and speed ) by radio used by both RearAdm Wake-Walker to establish Norfolk course eastward of them based on that provided geographical position, course and speed ... as well as being used to ViceAdm Holland to drive the interception trial of its BC1 warships at 02.00 to the enemy, ... unsuccessfully.

Into this scenario, we have those 2 occurrences by Norfolk at 02.29 and 02.55 transmitted from her radio on messages, ... while exchanging radio messages with Suffolk too, ... and the BC1 warships U turn at 02.03 after the missed interception, ... until the 02.47 and 02.56 radio messages by Suffolk communicating that she was getting back in touch with the enemy 2 warships.

The destroyers being directed to north apparently at 02.15 ( and not at 02.03 when BC1 made the U turn to south ) becoming crucial now to realize what could have happened when a warship like Norfolk was transmitting that she saw a vessel ( either large or unknown ), ... simply because they were sailing north at 15 sea miles distance one to the other ( being 4 they covered 60 sea miles area ) just in the area where Norfolk was approaching too, ... but sailing south on course 220°.

All this happened into a visibility that was down to 1 sea mile, and became 5 sea miles after 02.45 ( at least from PoW according to Capt Leach ) and with the Norfolk having a radar that can see only ahead of her own bow until 8/9 sea miles at maximum if was a large vessel ( a cruiser or more ) according to her radar Type 286 M specifications.

This is the way I see it, ... the Suffolk was on her duty of shadowing the enemy to get it back ( as she did successfully at 02.47 ) not knowing exactly where she really was ( understandable ) from a geographical stand point ( more than 25 sea miles west of her communicated geographical position ) and that is clear, ... just like the enemy track ahead of Suffolk too.

The BC1 warships Hood and PoW after the missed engagement at 02.00 with the enemy made an U turn south and started realizing that something was not right since before they were assuming everybody ( Suffolk, the enemy and the Norfolk ) being well to north east of them, ... while from their own radio RD/F now they started realizing that Suffolk and probably the enemy where now to north west of them, ... while the Norfolk was still to north east of them, ... and that did not match at all with their geographical radio communications. Question been now where the enemy is since Suffolk had lost it long time before and not yet got it back at 02.15. Into this situation ViceAdm Holland sent the destroyers to north searching for the enemy ( not being sure about where it really was ) while he was still assuming the enemy sailing ahead of Suffolk so to south while being to north west of his BC1 warships, ... and he was absolutely correct with this assumption, ... as we all know.

Into this evolving situation there was also the Norfolk, ... a good 10 sea miles west compared to her own geographical transmitted position, ... sailing south west on course 220° but still to north east of the BC1 warships that now were sending destroyers to the north. On board the Norfolk, just like for Capt Ellis and ViceAdm Holland, ... RearAdm Wake-Walker did not know where the enemy really was, ... and did not know yet how erroneous Suffolk position was, ... compared to his warship, ... he also did not know the BC1 warships presence, ... both Hood and PoW as well as the 4 ( were 6 ) Royal Navy destroyers ( this due to the radio silence of both BC1 as well as the destroyers ).

This made clear, it happened that at 02.29 the Norfolk saw a large vessel at 8 sea miles from her on true bearing 298°. What ship was this one ? On Norfolk they assumed it was the Suffolk and it was surely incorrect and impossible as we all know now.
It could have been the PoW, ... but PoW was getting Norfolk too on the same moment ( 02.29 ) with RD/F radio bearing but on a different position ( 68°), so we excluded this possibility too. It remain only a possibility it was one of the 4 destroyers sent north by Holland at 02.15, ... probably the one more to east just passing close to Norfolk at 02.29, ... and being spotted at 8 sea miles while on bearing 298° from Norfolk with very low visibility.

Different is the situation with the 02.55 vessel spotted by Norfolk, ... since still it cannot be the Suffolk ( as incorrectly assumed and transmitted by RearAdm Wake-Walker ) ... it cannot be anymore one of the 4 destroyers ... way to the north on that moment ... so it remain only the PoW possibility, due to the Norfolk and PoW relative course and speed.

Now on that poor visibility scenario, ... Norfolk could have spotted the PoW stern into the mist, night and fog, ... either by the radar ahead of her ( at the maximum of 8/9 sea miles distance of the Type 286 M radar ) or visual, ... while from PoW visibility was assumed being 5 sea miles on that moment ( Capt Leach report ).

I am only trying to realize which one was the most credible assumption scenario among the 3 ( GREEN, RED and BLUE ) I have presented, ... based on the above evidence we have.

Surely Wake-Walker was not assuming PoW being there ... he initially probably thought it was Suffolk since he transmitted that on his message, ... but after he realized it was not the Suffolk and he turned away the Norfolk to south east soon after, ... and this should confirm he assumed it was the enemy especially after the Suffolk 02.56 message, ... but he did not transmitted any more messages after the 02.55 one until 04.50, ... when he asked Suffolk if she was still in contact with the enemy.

From PoW they probably did not see the Norfolk on that moment, ... but they knew where she was north east of them because they were getting her on RD/F radio bearing while keeping their radio silence.

You are making a very good point about the Norfolk war diary missed entry for those 2 occurrences ( 02.29 and 02.55 ) that were not recorded, but only transmitted on their radio messages. Especially for the 02.55 one, ... an indication of the presumed distance and bearing would have helped a lot now, ... but unfortunately they did not record this fact in there.

Hope now all is more clear to you ... ... in case it is not, just ask me ...

Bye Antonio