Luetjens chooses the Iceland-Faeroes Gap instead

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paulcadogan
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Luetjens chooses the Iceland-Faeroes Gap instead

Post by paulcadogan »

Hello all,

I'm not sure if this has been discussed before - certainly not recently to my knowledge....

Now it is understandable that after nearly running into the Home Fleet in February 1941 when he attempted to slip through the Iceland Faeroes gap with Gneisenau and Scharnhorst, Luetjens might have been unwilling to risk that again - but when you really look at it, that near encounter was extremely fortuitous (at least sort of for the British) given the extent of the sea way involved.

The Iceland-Faeroes passage is about 450 km wide. Though the Faeroe Islands had been occupied by the British in 1940, there was no airfield there in May 1941 (it was built in 1942-43). Three British light cruisers were on patrol - Manchester, Birmingham and Arethusa - NONE of which, at the time, had the radar tracking capability of Suffolk. All had the same Type 286 as Norfolk.

So 3 cruisers covering 400 km of ocean - what was the probability that, had Bismarck & PG come through their patrol area, ANY of them would have made contact, and even if they had, that they could maintain it. Of course, Luetjens could not have known this, but still - he didn't know of Suffolk's capabilities either, only finding that out after being unable to shake her off.

In using that passage, the Germans would have come through earlier - probably on the 22nd, so it would still have been Hood and PoW in a position to try to intercept if one of the cruisers was lucky enough to make contact. Even then, with wide ocean for maneuvering, and with German radar and GHG capabilities. the British cruisers could have been avoided or easily shaken off. No shadowing, little chance of interception by British heavy ships.

Another factor might have been the weather - but even in relatively clear conditions, it seems workable to me.
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Re: Luetjens chooses the Iceland-Faeroes Gap instead

Post by Dave Saxton »

paulcadogan wrote: So 3 cruisers covering 400 km of ocean - what was the probability that, had Bismarck & PG come through their patrol area, ANY of them would have made contact, and even if they had, that they could maintain it. ...........
Another factor might have been the weather - but even in relatively clear conditions, it seems workable to me.


I agree they likely would have broke out cleanly. Then would follow an operation much like Operation Berlin with the BS and PG arriving at France sometime in mid summer. The main difference would be Bismarck could/would attack any strong enemy escort up to and including old battleships rather than letting such a escorted convoy pass unmolested, unlike the Twins.

To give an idea to any readers who may not know about Type 286 radar: Type 286 was the 150 cm wavelength ASV (air to surface vessel) radar converted to a surface search model aboard warships. It was pressed into service to give British warships a radar- any radar. The antenna (286M) was fixed so that its warship had to be pointed at the target, although the beam width was on the order of 35*, so it did not need to be exactly pointed at the target. During the historical shadowing of Bismarck, it could not be used to track Bismarck because its range to a battleship proved to be about 10,000 yards. It was used to help Norfolk keep station with other British warships instead.

Nonetheless, Vian's destroyers used their Type 286s to locate the crippled Bismarck and to make torpedo attacks during its last night.

A liability of Type 286 for surveying of the passage by the British cruisers was that its transmissions could be detected by a radar detector over a great distance. Bismarck had a radar detector we now know, so it could more easily avoid the British cruiser patrols given such a wide space to manouver, making undetected breakout even more likely.
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Re: Luetjens chooses the Iceland-Faeroes Gap instead

Post by paulcadogan »

It would be interesting to find out how the three cruisers were deployed though. I recall Kenneth More in "Sink the Bismarck" commenting when he was updating the Air Vice Marshall that "our cruiser screen is spread much too thinly, now if your people could get into the air..."

Could the cruisers have used their aircraft - Walrsuses for Manchester & Birmingham, not sure if Arethusa had a Sea Fox or Walrus - to augment their surveillance? Of course, the weather would have had to be suitable for launching and retrieving.

But Dave, I doubt the cruisers would use that radar for enemy detection purposes given its limited range - it was probably switched off until there was some indication for it.
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Re: Luetjens chooses the Iceland-Faeroes Gap instead

Post by Dave Saxton »

Passing through these passages undetected was the norm rather than the exception. The Germans, with Hipper, Scheer, Deutschland, Scharnhorst and Gneisenau, and hilfkruezers, and supply ships, routinely did it; often encountering RN cruisers that remained unaware of the Germans or were unable to retain contact. The only exception was the historical Bismarck passage because of the Suffolk's Type 284 radar. So the odds are well in Luetjens favor that he will make an undetected break out, considering that the patrolling cruisers will not be operating a capable radar and they must cover such a wide expanse of ocean.

Patrol aircraft did not alter the outcomes of all these other passages. It is rare indeed that visibility will be good.
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: Luetjens chooses the Iceland-Faeroes Gap instead

Post by paulcadogan »

Dave Saxton wrote:The Germans, with Hipper, Scheer, Deutschland, Scharnhorst and Gneisenau,and hilfkruezers
No Dave!

Scheer, Hipper and G & S all entered the Atlantic via the Denmark Strait. The twins did so after their near encounter with the Home Fleet in the I-F gap. Deutchland and Graf Spee went into the Atlantic before war began with Britain and France, so could have used the Iceland Faeroes gap umolested - Graf Spee did. I suspect Deutchland did the same, but on her return to Germany she went via the DS!

Same for several of the hilfskreuzers. Altantis, Widder, Kormoran, Pinguin, Thor (and it seems Orion) ALL used the DS to break out. Michel, Stier and Thor (on her second cruise) used the English Channel. Komet, interestingly, went north of Russia to enter the Pacific via the Bering Strait.

Seems to me, the Germans felt the bad weather, overcast and fog in the DS afforded more protection and concealment than a wide area to maneuver, with less reliable weather instability.

Seems to me now that the DS was an area the British should have paid much more attention to - with tighter patrols and a more consistent heavy unit presence at Hvalfiord - a carrier even. :think:
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Re: Luetjens chooses the Iceland-Faeroes Gap instead

Post by alecsandros »

... As I understand it, Luetjens opted to stay beneath the thick weather front moving west, which I don't think covered the Faeroes Gap.
Visibility was remarkably bad in the Denmark Strait, and that's what Luetjens hoped for to escape detection.

The Admiralty was informed of the 2 ships leaving Bergen on May 20th, and air patrols from Coastal Command and RAF were intensified.

KGV/Victorious/Repulse with escorts set sail on May 22nd at midnight, and would have been at few hours hot steaming to an interesting interception, IF the 2 raiders were previously detected by one of the 3 cruisers...

---

OVerall, an interesting scenario, though I doubt the raiders would escape aircraft surveillance on the 22nd/23rd...
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Re: Luetjens chooses the Iceland-Faeroes Gap instead

Post by Dave Saxton »

paulcadogan wrote: No Dave!

Scheer, Hipper and G & S all entered the Atlantic via the Denmark Strait. The twins did so after their near encounter with the Home Fleet in the I-F gap..........
Same for several of the hilfskreuzers. Altantis, Widder, Kormoran, Pinguin, Thor (and it seems Orion) ALL used the DS to break out. ..
Yes I know. The tighter confines of the DS make it more likely that an encounter will happen and that contact can be retained for a longer period of time. If the British were unable to make contact and retain contact with in the DS in most cases, then I think it even more unlikely that they will be able to do either in the I-F gap.
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: Luetjens chooses the Iceland-Faeroes Gap instead

Post by paulcadogan »

alecsandros wrote:The Admiralty was informed of the 2 ships leaving Bergen on May 20th, and air patrols from Coastal Command and RAF were intensified.
Nope. The ships were detected near Bergen on the 21st (hence Hood & PoW being dispatched to Iceland leaving at about midnight on the 21st-22nd) - they were not discovered to have left until the evening of the 21st since the weather shut down air patrols in the intervening time, Tovey setting sail with Victorious and escorts at 10:15 PM - some 22 hours behind Holland in Hood.

But, I think you may indeed be onto something with regard to air patrols over the Iceland-Faeroes gap - after all Hood & PoW were observed AND photographed from the air when they were south of the Faeroes on May 22 - so air patrols were underway in the area.

Image

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Hypothetically, if BS & PG entered the I-F gap on the 22nd - they'd just have Hood & PoW to contend with as a first line interception. If it was early on the 23rd, then they might have had a pincer move with Holland coming from the south west and Tovey from the south east. Victorious could also have provided air search capability. But also - Tovey would have been further south, since he initially steamed westwards in order to rendezvous with the Repulse, before turning north west.
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Re: Luetjens chooses the Iceland-Faeroes Gap instead

Post by alecsandros »

... Let us consider a RAF Catalina discovering Bismarck and Prinz Eugen on May 22nd at 18:00, in transit through the northern part of the Iceland-Faeroes Gap, midway between Iceland and Faeroes, and out of sight for all 3 cruisers in patrol.

The Catalina approaches to confirm their identity, and is promptly taken under 105mm gunfire by the 2 ships. The Catalina escapes in the clouds and sends a coded message at 18:10. The message is deciphered and is read to Adm. Tovey at ~ 19:00

Now, what would be the likely course of action ? Could Victorious / KGV raise steam fast enough to make a sortie at ~ 22:00 and launch several air patrols starting ~ 6:00 in the likely direction of the enemy ?

Would those patrols likely be successful ?

Would Victorious be able to close the range enough to launch a strike against the 2 raiders ?

And, the crucial aspect, would a strike of 9-Swordfish be able to score hits if the 2 ships were in close vicinity, and in relative good visibility and calm sea conditions ? (because the weather near the Faeroes was better than near the Denmark Strait)
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Re: Luetjens chooses the Iceland-Faeroes Gap instead

Post by paulcadogan »

Well in the actual situation, Tovey received the signal that "battleship and cruiser have left" about 1915 and waited for the patrol aircraft to land about half hour later so his chief of staff could speak directly to the pilot. So it was probably between 1945-2000 that the conversation took place and Tovey gave the order to weigh anchor for 2200 - so they needed about 2 hours to raise steam.

So your scenario is pretty close to what actually happened, but instead of a signal about an empty fiord, it would have been a report of enemy in sight at sea. Therefore the answer would be that, had the info been received at 1900 the fleet could have been underway at about 2100 at the earliest.

It would have been too far for immediate action by Victorious. Tovey would have had to send her scurrying north north west with the cruiser escort to get into position to launch aircraft for recon much less for attack. With only 9 Swordfish and 5 Fulmars she would have had to use the latter for recon.

I think it would have been "let me have an intercepting course for Hood and Prince of Wales!" which would have been perfectly positioned to the south at that time. KGV would then steam west to meet Repulse before turning north west to position themselves for interception should the enemy evade Holland's force.

The three cruisers would have converged on the area - maybe using their Walruses to locate the Germans (if the weather permitted launching).

I still think, particularly if the weather was not good, it would have been hard to maintain contact. In clear weather - if at least 2 cruisers could maintain visual on each quarter, then it might have been different. BUT on the other hand - once the Germans were aware of detection, they would have turned back as the Twins did, and headed for the DS....
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Re: Luetjens chooses the Iceland-Faeroes Gap instead

Post by A Raven »

There were more than three cruisers on that patrol line. There were also five trawlers, and one of the latter would have broadcast a warning. The line had gaps, but had a greater coverage given by just three cruisers. In addition, the mine barrier had been completed by March/ April of that year, making passage hazardous to German surface ships, deep and shallow fields having been laid.

It is difficult to definitely state what the odds would be in respect of Bismarck transitting the Denmark Strait undetected, but ... with the passage being only about twenty miles wide at the narrowest point at that time of year, because of the minefields/ice shelf, I would give much better than even chances, about ninety/ten in favour of detection. One cruiser maybe, but two, very doubtful, even allowing for inclement weather.

Supply ships: rolled up, thanks to Special Intelligence.* Bismarck would have encountered HM ships at every meeting point, and this would have included the tanker positioned in the Davis Strait, the one that was to have given Bismarck's first fuelling.

* Special Intelligence broke into the German high level naval codes on the 27th of May. Supply ship codes were being read by the 29th.

Dave Saxton wrote:Passing through these passages undetected was the norm rather than the exception. The Germans, with Hipper, Scheer, Deutschland, Scharnhorst and Gneisenau, and hilfkruezers, and supply ships, routinely did it; often encountering RN cruisers that remained unaware of the Germans or were unable to retain contact. The only exception was the historical Bismarck passage because of the Suffolk's Type 284 radar. So the odds are well in Luetjens favor that he will make an undetected break out, considering that the patrolling cruisers will not be operating a capable radar and they must cover such a wide expanse of ocean.

Patrol aircraft did not alter the outcomes of all these other passages. It is rare indeed that visibility will be good.
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Re: Luetjens chooses the Iceland-Faeroes Gap instead

Post by paulcadogan »

Thanks very much for that Mr. Raven!

I was checking back in Kennedy's "Pursuit" and saw mention of two Trawlers - Northern Isles and Northern Sky - but he wrote "trawlers like...." and did not state how many. I was about to ask if anyone knew, but you've pre-empted me!

Also, in Grenfell it is stated that Sunderlands of 201 Squadron patrolled the I-F gap from early morning until 9 PM on the 23rd - i.e. after Suffolk picked up the Germans in the DS. Weather had prevented the DS and Norwegian coast patrol flights completely while the Shetland-Faeroes gap patrols had to be stopped after 1 PM.

All in all, it's looking like a much more dicey situation from the Germans than I originally thought - although the lack of an effective radar apparatus on any of the three I-F stationed cruisers would have made shadowing more difficult in poor visibility, even if contact was made.

But I think I better understand why the Germans avoided using the I-F gap now - wide yes, but surveillance could still be heavy and it was a bit too close to Scapa!
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Re: Luetjens chooses the Iceland-Faeroes Gap instead

Post by alecsandros »

... A very important aspect for such a scenario would be the time of the day at which BS/PE attempt to transit the Iceland-Faeroes gap.

I understand sunset was around 00:30, and sunrise around 5:30.

If the Germans would manage to get by the British ships in the gap during that interval, they could be clear...

At maximum speed of 30kts, 5 hours of steaming would imply a distance traveled of ~ 270km, probably sufficient to break through (disregarding radar effects)...
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Re: Luetjens chooses the Iceland-Faeroes Gap instead

Post by Dave Saxton »

Retaining contact long enough to bring the Home Fleet battle groups in is the main problem for the British as I see it. Catching a glimpse of the enemy is one thing, but shadowing for hours on end is quite another. Unless there are prolonged periods of unlimited visibility- rather unlikely-it seems a difficult task without capable surface search radar. For example, when the Scharnhorst and Gneisenau tried the Gap previously they were spotted by a British cruiser briefly. The cruiser was unable to retain contact. It reported that it had seen the Hipper. The Germans will know by local radio intercepts if they were being shadowed or not as they did historically.

When the Scheer came back through the Denmark Strait in March of 41 its radar warned it of an approaching patrol in time to duct into a near by fog. This was a daylight encounter. They watched the British cruiser steam by. The British look outs never saw the Scheer. A second encounter came at night. In this case the Scheer's radar was not operating because the moisture resistant cases had been carelessly not closed up. The Scheer suddenly found it self in the wake of an enemy cruiser no more than 3,000 meters away on a bright star lit night. But once again the British look outs never saw the Scheer. This was in the Denmark Strait so the Germans really had no where to go. Such were the difficulties faced by the British patrols in any of the northern passages.

As Mr Raven points out, Enigma Intel will be available after the 29th due to the capture of Enigma keys from U-110 and the weather ships. The British could use Ultra Intel to help find Luetjens once out in the Atlantic by the arrangement of meeting of supply ships. The keys were not those used by surface warships in distant waters, but Prinz Eugen will need frequent re-fueling. The British will need to be careful in the use of this Intel so that the Germans don't become wise to it and change the keys.
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: Luetjens chooses the Iceland-Faeroes Gap instead

Post by A Raven »

Re you last paragraph,
The first reading of high level German naval codes (Special Intelligence) later known as Ultra produced the first sending of AIDAC (from Special Intelligence) messages to Tovey, (nobody else) on the 27th. These were from reading the NAVAL CODES, not the German airforce codes. Without looking it up and from memory, the first message gave details of the U boat patrol lines in the general area of Tovey's forces, followed by information on expected German air attacks. The material from reading the supply ship codes came two days later. The first use of the reading of the supply ships codes for surface warship raiders, brought about the sinking of the tanker Belchen on the 3rd of June by cruisers Aurora and Kenya. Belchen had been stationed in the Davis Strait.

All the OFFICIAL intelligence histories give much weight to the material taken from U110, but Erskine in his afterword to a later edition of Special Intelligence, dismisses this capture as being of no importance, and gives convincing reasons why.

The Bismarck sortie was the last by surface raiders, so that there were no codes to be read. The codes used for the Prinz Eugen and her supply ships were the same as those used for the Bismarck. ALL the supply ships that were rounded up by the use of Special Intelligence had a cover to fool the Germans, such as by the use of Dfing and traffic analysis. The Germans became suspicious several times during the war, but the German cryptographers refused to believe that their codes could be broken, and mathematically proved it several times.

Dave Saxton wrote:Retaining contact long enough to bring the Home Fleet battle groups in is the main problem for the British as I see it. Catching a glimpse of the enemy is one thing, but shadowing for hours on end is quite another. Unless there are prolonged periods of unlimited visibility- rather unlikely-it seems a difficult task without capable surface search radar. For example, when the Scharnhorst and Gneisenau tried the Gap previously they were spotted by a British cruiser briefly. The cruiser was unable to retain contact. It reported that it had seen the Hipper. The Germans will know by local radio intercepts if they were being shadowed or not as they did historically.

When the Scheer came back through the Denmark Strait in March of 41 its radar warned it of an approaching patrol in time to duct into a near by fog. This was a daylight encounter. They watched the British cruiser steam by. The British look outs never saw the Scheer. A second encounter came at night. In this case the Scheer's radar was not operating because the moisture resistant cases had been carelessly not closed up. The Scheer suddenly found it self in the wake of an enemy cruiser no more than 3,000 meters away on a bright star lit night. But once again the British look outs never saw the Scheer. This was in the Denmark Strait so the Germans really had no where to go. Such were the difficulties faced by the British patrols in any of the northern passages.

As Mr Raven points out, Enigma Intel will be available after the 29th due to the capture of Enigma keys from U-110 and the weather ships. The British could use Ultra Intel to help find Luetjens once out in the Atlantic by the arrangement of meeting of supply ships. The keys were not those used by surface warships in distant waters, but Prinz Eugen will need frequent re-fueling. The British will need to be careful in the use of this Intel so that the Germans don't become wise to it and change the keys.
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