Wednesday, March 10, 1943. The Peak of the Battle of the Atlantic. First combat mission of the P-47.

By Crew of PB4Y-1 107-B-12 of VB-107, November 1943.

March 1943 was the peak of the Battle of the Atlantic, with the largest convoy battle of the war, the battle over Convoys HX 229/SC 122 about to commence.  Commencing on this day was the two-day battle over Convoy HX 228 in which nine U-boots would sink five Allied vessels, one of which was a warship.  The battle over Convoy SC 121 ended on this day, in which 27 U-boots sunk 12 merchant ships.  During March German submarines sank 120 merchant ships while losing only 15 submarines.  A Royal Navy figure later observed: "The Germans never came so near to disrupting communications between the New World and the Old as in the first twenty days of March 1943."

After April, however, Germany naval fortunes were to decline rapidly.

On the same day, the U-633 was sunk by the British freighter Scorton, which rammed her.  In its career, it had been on a single patrol and sunk one vessel.  On the same day, Germany changed its Enigma Code, according to Sarah Sundin's blog, temporarily making the Allies blind in the Atlantic.

A couple of things to recall. At this stage of the war, the Germans were still doing very well in the Atlantic, and indeed their fortunes were increasing in that theater.  Crossing the Atlantic remained extraordinarily perilous.  Allied ships went down continually.  And it was exclusively a Western Allied affair, which they bore alone.

German commenced rationing nonessential goods, thereby prohibiting the manufacture of suits, costumes, bath salts, and firecrackers. It restricted telephone use and photography at the same time.

It's not surprising that they took this step, but rather it was taken this late.

Sarah Sundin reports.

Today in World War II History—March 10, 1943: Republic P-47 Thunderbolt fighter planes fly first mission with US Eighth Air Force based in Britain. US II Corps retakes Sbeïtla, Tunisia.

P-47C taking off, 1943.

P-47s did not have long enough range to escort bombers all the way to Germany and back, but they were nonetheless a game changer for the USAAF.  A new generation of fighters surpassing the capabilities of most Axis fighters was beginning to come online.

Here again, the Western Allies were waging a titanic war on the sea and in the air.  This benefitted all the Allies, but it was not borne by all of them.

The USSR established Laboratory No. 2 to research atomic energy.