Tirpitz and Graf Zeppelin 1941

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Paul L
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Re: Tirpitz and Graf Zeppelin 1941

Post by Paul L » Thu Sep 29, 2011 4:19 pm

lwd wrote:
Paul L wrote: ... From these and other sources I compiled the following list.

1939 ; 22 supply ships + 31 tankers [~ 6800 tons]
1940 ; 36 supply ships + 33 tankers [~ 8000 tons]
1941; 41 supply ships + 38 tankers [~ 8600 tons]
1942 ; 33 supply ships + 40 tankers [~ 8800 tons]
1943; 27 supply ships + 48 tankers [~ 8600 tons]
1944 ; 22 supply ships + 55 tankers [~ 8400 tons]
1945; 14 supply ships + 44 tankers [~ 8300 tons]
...
But this doesn't tell us how much time they were spending at sea or doing what. Certainly the round up of supply ships involved in the Bismarck sortie points to a problem if they are activly engaged in supporting a raider. It's also not clear just how many would have been available at any one time to support raiders. These also appear to be fairly small ships averaging a bit over 100 tons apiece unless the figure you gave was suppose to be an average rather than a total or some digits were slipped. The latter seems likely as the Ditmarches you mention were rated at ~20,000 tons

Yes the figures are the average cartage per tanker. Jak Mallmadd Showell reported that they considered setting up a second network in the Atlantic in 1942 but refocused the supply efforts elsewere. There was another network operating out of the Indian Ocean until early 1944. I will have to look up the source and see what else it reports.
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Re: Tirpitz and Graf Zeppelin 1941

Post by Paul L » Thu Sep 29, 2011 7:27 pm

How do you edit posts?

I found the reference to the Indian network. Its in Rossler’s "The Uboat" still considered the bible for Technical Uboat info.

pp 161 "In the Indian Ocean , on the other hand , supplying by surface vessel was possible until the beginning of 1944"

Jak Mallmann Showell also reported that Hitler forced Raeder to focus the surface fleet on Norway. He states that additional raiding missions were planed for late 1941 through late 1942 , but Hitler overruled Raeder and made him deploy all assets and missions to operate out of Norway to interdict traffic to Russia. Given his racial addenda this is perhaps not surprising. Showell also reports a large number of tankers and supply ships were located in neutral ports around the world and with some difficulty could be activated and fitted out in secret to fill in on supply missions. In some cases they could pay off local neutral ships to supply these raiders & Uboats.. pp126.

Showell also reports in chapter 4 that the Auxiliary Kreuzer [HSK] code was never cracked by the allies during the war and these were only located by interception and deciphering of the associated Uboat traffic.
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Re: Tirpitz and Graf Zeppelin 1941

Post by RF » Fri Sep 30, 2011 9:29 am

But the Indian Ocean network was only possible because of the unwilling assistance of the Japanese in providing port and base facilities.

A second supply chain in the Atlantic in 1942 would have been handicapped in being Biscay port based, with ships being passed down the English Channel. The main Atlantic entry routes from Germany around Iceland were blocked by radar carrying cruisers.
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Re: Tirpitz and Graf Zeppelin 1941

Post by Paul L » Fri Sep 30, 2011 12:48 pm

RF wrote:But the Indian Ocean network was only possible because of the unwilling assistance of the Japanese in providing port and base facilities.

A second supply chain in the Atlantic in 1942 would have been handicapped in being Biscay port based, with ships being passed down the English Channel. The main Atlantic entry routes from Germany around Iceland were blocked by radar carrying cruisers.


No they were neutral countries , not Axis countries. That much was stated in the text.

Germans were able to pass most traffic through the English channel until 1943. The RN survaillance was poor until that time. Radar was not very effective at this time in history, which is why I have great doubts that any raider put to sea would automatically get detected located and caught before it broke out. That usually only happened if good Ultra decrypts were involved and even then it was still hit /miss.
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Re: Tirpitz and Graf Zeppelin 1941

Post by RF » Fri Sep 30, 2011 5:21 pm

Well, Michel and Stier had a rough time getting through the English Channel in early 1942, as the RN sharpened up its act after the Channel Dash. Komet was sunk in the Channel later that year and Togo or Korenel, whichever name you use, was forced back by Whirlwind bombers.
I think any major supply operation going through the Channel in 1942 would be attacked by Allied forces, particulary if the supply included U-boats simply because of the enigma decrypts.
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Re: Tirpitz and Graf Zeppelin 1941

Post by Paul L » Fri Sep 30, 2011 5:43 pm

According to OHara 3/4 of the German traffic sent through 'the channel', went unchallenged through into 1943. After that only 1/4 went unchallenged.

I think the case has been made.
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Re: Tirpitz and Graf Zeppelin 1941

Post by RF » Sun Oct 02, 2011 5:07 pm

That statistic needs to be qualified. Due to enigma decrypts and photographic intelligence it was the case that the more significant ships, such as raiders, attracted Allied forces attention, while insignificant coastal shipping wasn't worth making a special effort. The fact is that in 1942 and 1943 100% of the raiders traversing the Channel outwards were intercepted. The first two raiders passed at increasing cost to the Germans, the third was sunk by an MTB within sight of coastal batteries and the last was hit by bombers twice before it could even get past the Straits of Dover.
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Re: Tirpitz and Graf Zeppelin 1941

Post by Paul L » Mon Oct 03, 2011 1:21 am

RF wrote:That statistic needs to be qualified. Due to enigma decrypts and photographic intelligence it was the case that the more significant ships, such as raiders, attracted Allied forces attention, while insignificant coastal shipping wasn't worth making a special effort. The fact is that in 1942 and 1943 100% of the raiders traversing the Channel outwards were intercepted. The first two raiders passed at increasing cost to the Germans, the third was sunk by an MTB within sight of coastal batteries and the last was hit by bombers twice before it could even get past the Straits of Dover.

Maybe your sources need to be updated.

O’Hara reports that 16 out of 21 HSK and blockade-runners [including 4 out of 5 HSK] transited the channel on their way through 1942. Montefiore reports the enigma black out period of 1942 meant that >90% of all decrypts were not being read for days on end leading to critical delays in any action. Just like the Tirpitz move on PQ17 in mid 1942 ,this meant breakouts were possible through out this period. O’Hara reports this situation had been reversed to about 4 out of 16 blockade-runners being intercepted and destroyed or captured by the end of 1943. Cracking the blockade-runners code was instrumental in achieving this at the end of 1943 as well. Through this period some networks naval traffic took 17 days to translate, which meant it was only of strategic value by then. Such outages continued through march 1943 and ensured enough wiggle room to allow for breakouts up until early 1943.

The case has been made.
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Re: Tirpitz and Graf Zeppelin 1941

Post by RF » Mon Oct 03, 2011 8:15 am

Paul L wrote: The case has been made.
This sentence was quite unnecessary and makes it look like a politician who thinks he can never be wrong.

There is no refutation of my observation that Michel and Stier passed the Channel with interception, the Komet was sunk anmd Koronel forced to return home.

This is proven fact. It is not part of a case.
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Re: Tirpitz and Graf Zeppelin 1941

Post by Paul L » Tue Oct 04, 2011 6:50 am

5 out of 5 is too small a number of samples to be anything other than anecdotal information. From what I’m told for human decisions you need dozens of samples to get any prediction of success or failure. The error bar would have to be substantial. For example the next 20 attempts could all succeed, so the final figure would be 5 out of 25 intercepted.

Besides Michael got through with minor damage due to large number of escorts , while Komet had poor escort. Looking at documented German convoys that were attacked by RN, it looks like in only 3 out of 10 cases did the RN succeed in attacking the convoy. But then we still need more cases to get better prediction figure.

I was reading a paper on predicting combat results based on hundreds and hundreds of WW-II battle . The results still only achieved 70% accuracy in their predictions.

Naval actions are mostly determined by command decision of one side over the other side, so this is critical.
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Re: Tirpitz and Graf Zeppelin 1941

Post by RF » Tue Oct 04, 2011 8:53 am

You have to be careful in applying statistical methodology and sampling to issues of naval actions, especially as no two actions are alike. They are, at the micro or tactical level, independent events. But at a more macro or strategic level these naval actions won't be independent events but part of a campaign within that geographical area. More significant or important targets are more likely to be attacked. Attacking forces are not a constant but would grow over time, defending forces become weaker. So one action cannot be directly equated with another. But there are indirect consequences going from one action to the next.
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Re: Tirpitz and Graf Zeppelin 1941

Post by srgt rock » Sun Nov 27, 2011 1:09 am

IMHO Germany with Graf Zeppelin commissioned in the spring 1941 is a massive game changer. IF Hitler would allow it to be! I will assume he agrees with what I propose.

First, a few beginning assumptions.

1. Graf Zeppelin would most certainly use the Fi167 as it is such a great STOL aircraft, embarking a squadron would require only the flight deck space to store them. Throughout the sortie, unassisted Takeoffs.

2. The Battle Group WOULD NOT act as a unified task force. It would be made up of 1. a carrier task force, 2. a surface strike task force and a dedicated supply force. Operational doctrine would be close the similar formed IJN Ryujo battle group which operated successfully in the Indian Ocean in April 1942. (19 ships totalling 92,000 sunk tons and 3 ships damaged)

3. Since the air units that would have flown off GZ were being used in combat already, the pilots just need to learn to land on the carrier to be ready for the sortie.

4. Since unassisted TOs were planned, I would build a wooden cover to bridge the gap between the catapult launch rails and I would extend this wooden flight deck closer to the bow to increase total flight deck length.

5. Vectoring of fighter interceptors was something the LAND BASED Luftwaffe units were already doing in 1941. It would be as effective as either the Americans or the British were capable of at the time.

I see two major operations the Germans could have done in 1941 with Graf Zeppelin.

I. OPERATION ALBION 2

The KM launches an amphibious operation in July 1941 to capture the Baltic islands of Osel, Dago, Moon and Oldensholm.

Note: This would be a good combat workup for the carrier task force.

II. OPERATION RAPIER

The KM throws everything they have at the British before the United States officially enters the war.

TASK FORCES;

NORTHERN BATTLE GROUP

Carrier Task Force: Graf Zeppelin & 2 DDs
Surface Strike Group: Tirpitz, Scheer & Emden
Supply Group: Dithmarchen, Nordmarck, a S-boat Squadron and Hans Rolsholven(sea plane air support)

ATLANTIC BATTLE GROUP:
Surface Strike Group: Scharnhorst, Giensenau and Prinz Eugen. (If they can sortie, they are a go)

The battle plan would have the Northern Battle top off fuel in the Artic Ocean and then breaking through the ICELAND-FAROES gap in GOOD WEATHER. (In order to best utilize thier air assets)

The Atlantic Battle Group would sortie once the Northern Battle Group was in the Atlantic.

The orders would be for the forces to operate as long as thery were effective and then they would combine task forces and break back through the ICELAND-FAROES Gap returning to Trondheim.

Final note:I would conscider slapping a flight deck on the forcastle area of Dithmarshen or Nordmarck to be able to transfer replacement Fi 167s to GZ as needed.

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Re: Tirpitz and Graf Zeppelin 1941

Post by dunmunro » Tue Nov 29, 2011 4:44 am

RN counter forces:

Northern Group (Scapa Flow):

Victorious (20 Albacores, 15 Fulmars, + spares)
Furious (9 Albacores, 9 Swordfish, 6 Fulmars, 4 Sea Hurricanes + spares)
KGV
POW
Several Cruisers
DD flotilla

Atlantic Group (Gibraltar):
Ark Royal (36 Swordfish, 18 Fulmars)
Renown
Repulse
Several Cruisers
DD flotilla

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Re: Tirpitz and Graf Zeppelin 1941

Post by lwd » Tue Nov 29, 2011 3:25 pm

Paul L wrote:5 out of 5 is too small a number of samples to be anything other than anecdotal information. From what I’m told for human decisions you need dozens of samples to get any prediction of success or failure. The error bar would have to be substantial. For example the next 20 attempts could all succeed, so the final figure would be 5 out of 25 intercepted. ....
It depends on what you mean by "substantial" I guess. If we postulated for instance that there was a 50% chance of success then 5 failures would only occur ~3% of the time i.e. sufficient to reject the postulate in at the most common levels (typically 20%, 10%, or 5%). If we are content with a 10% chance of error that would correspond to a chance of success of just a bit over 1 in 3.

And of course these would not be completely independent. The RN has a fair amount more resources to put to the task if there is an embarassing success by the KM. The same cannot be said for the KM.

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Re: Tirpitz and Graf Zeppelin 1941

Post by lwd » Tue Nov 29, 2011 3:31 pm

srgt rock wrote:...The battle plan would have the Northern Battle top off fuel in the Artic Ocean and then breaking through the ICELAND-FAROES gap in GOOD WEATHER. (In order to best utilize thier air assets) ....
That virtually guarantees the British pick them up before they get far from Norway. Given how fragil carriers were and the number of planes in the area that doesn't sound good for the GS. Furthermore there's a good chance that cruisers can be vectored to intercept this forces as well. The battleships can be kept back to deal with the Tirpitz group.

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