Battle of the Atlantic - Anniversary?

[MadScot]

According to this CBC News Report Canada marked the 60th anniversary of the Battle of the Atlantic today.

Obviously a specific date is hard to choose for a battle which lasted the length of the war; but surely March 1943, not May, would be a reasonable definition of "the turning point" of the battle. (The battles around convoys SC-121/HX-228 and SC-122/HX-229 being the critical ones).

Anyone have any suggestions as to why DND chose May. (Other than the fact the weather is nicer?)

 

[Richard III]

Generally, I agree with you on the HX-229 run as being the appropriate point, but those battles were widely regarded as disasters for the Allies more than anything, weren't they? A sign that the wolfpack was alive and well?

I read the same peice a few minutes ago, and they said quite clearly that they felt the date was the anniversary of the turning point. IIRC, March sucked, but May was the month that new radars and more aggressive use of Ultra meant there were almost no allied sinkings and a sudden clean wipeout of U-Boats.

As a result of the HX-229/etc. battle, April or May - again, working from memory - was if I'm not mistaken the month where Churchill and Roosevelt agreed that winning the battle was so important that subs would from then on be attacked by aircraft on the basis of Ultra intercepts alone if need be.

I will check this, but I think that was the reason.

R.III

 

[Grille]

In May 1943, Adm. Karl Dönitz (commander of fleet/sub fleet) was thinking about withdrawing all the subs from Atlantic because of the high casulties suffered recently. Because of a British plane w/ radar that came down in late February near Rotterdam, marine intelligence could picture the reason of casulties after inspecting the radar device. A major strat for the sub was a (multible) night surface attack, but now that was impossible (and in May '43 clear to the commander of subs). So if even Dönitz realized the situation (24.05.43), one could say for sure the Atlantic battle has come to a turning point.
Furthermore, the ratio "actual number of German subs/actual Allied tonnage of ships" changed (obviously) dramatically at this point of time. This came along w/ improved convoy protection tactics and a larger area being (radar-)observed. Plus, the *avarage* level of experience of sub crews dropped then, as the veteran sub commanders/officers were sunk.

 

[Richard III]

Yes, agreed, that matches my memory of the situation, only I'm also crystal clear that a large portion of the sub tonnage sunk had nothing to do with the radar but rather with Ultra intercepts that were then fed to planes that used the radar only for the closing approach.

I think the logic was that the Allies knew that the Germans knew about recent radar developments, and so Ultra decision makers could safely use the radar as a cover for the success of smashing so many U-boats so quickly.

 

[Grille]

Err, what is meant by "Ultra intercepts" ?
Not clear to me; I guess it's intelligence service's work, based on that captured scrambling machine "enigma". If so, of course, totally agree then, have just forgotten to mention above...

 

[Richard III]

Yes, "Ultra" was the UK's codename for any intelligence garnered from the breach of Enigma. Although it was more than the captured machine that did it.

Because it was so essential that the secret of the code breach be protected, the Allies had fought earlier phases of the Battle of the Atlantic with one hand tied behind their back, owing to allied unwillingness to attack a sub without some sort of secondary confirmation of its location from another source so that Kreigsmarine analysts wouldn't look to the codes as the problem.

Traditionally, if a U-Boat broadcast a position and the coded text was broken in time for the intelligence to be useful, without that secondary sighting, the allied response was to tell the convoy to adjust course to avoid "presumed u-boat concentrations" rather than to reveal specific positions.

The dangerous results in March got rid of any timidity on that score. As Churchill had famously noted, the worst months of the Battle of the Atlantic were the only moments when he was seriously worried about losing the war. Hence the willingness to risk the war's most priceless tool to win that particular battle.

R.III