Operation Regenbogen (U-boat)

Regenbogen ("Rainbow") was the code name for the planned mass scuttling of the German U-boat fleet, to avoid surrender, at the end of World War II.

Background

Axis-held territory at the end of the war in Europe shown in blue.

At the beginning of May 1945 Nazi Germany was collapsing under the Allied onslaught.

The Soviets had captured Berlin, and on 29 April Hitler had committed suicide. He had appointed Grand Admiral Karl Dönitz as Head of State and Supreme Commander of the Armed Forces. US Forces from the west and Soviet forces from the east had already met at Torgau, cutting the Reich in two, while in the north 21st Army Group was poised to capture Hamburg and the other German ports.

The state of the German navy, the Kriegsmarine (KM), was no better. Of its capital ships only Prinz Eugen survived, sheltering at Copenhagen; only the U-Boat Arm was capable of continuing the fight. The KM had approximately 470 U-boats remaining. Some 170 of these were operational U-boats (Front boats), based mainly in occupied Norway, and another 200 home-based boats in various stages of building, commissioning and working up; these were mainly in the north German ports and on the Baltic.

As head of the KM, and as commander of the U-boat Arm, Donitz was keen that his U-boat force should not be surrendered. However as the new German leader he was keen to extricate Germany from the war and, if possible, avoid Allied, particularly Soviet, retribution. To that end he had opened negotiations with the western Allies, through Field Marshal Montgomery commander of Allied 21 Army Group, in North Germany.

As the Allies closed in on the North German ports the KM started to destroy what was left to prevent its capture, while all servicable boats were ordered to bases in Norway. During May a final massacre of U-boats fleeing to Norway took place; 23 U-boats were destroyed or damaged beyond repair in transit in the first week of May.

Against this backdrop Donitz and the U-boat Arm made plans for a mass scuttle of his U-boats, to be carried out on receiving the code-word "Regenbogen".

The Operation

During May the Kriegsmarine started to scuttle its U-boats ahead of the advancing Allied armies.

On 1 May 1945 3 U-boats were wrecked at Warnemunde, outside Rostock on the Baltic coast, the first of a wave of scuttling boats and destroying facilities.

On 2 May a further 32 U-boats were scuttled at Travemünde, near Lübeck.

On 3 May Donitz sent is chief aide Friedeburg to Montgomery at Lüneburg to open negotiations for an armistice with the western allies. This was refused, as Freidberg was not empowered to agree to an unconditional surrender, upon which the Allies insisted. Also on 3 May another 39 boats were wrecked, 32 at Kiel and another 7 at Hamburg, on the North Sea coast.

On 4 May the Supreme Allied Commander, Eisenhower allowed the German forces in Northwest Europe, including naval forces, to surrender to Montgomery and 21 Group; for this, Montgomery insisted that German naval forces, including the U-Boat Arm, be surrendered intact. This would come into effect at 8 am on 5 May. Meanwhile on 4 May, four more boats, two in the Kiel Canal and two at Flensburg, were scuttled.

In the early hours of 5 May the Regenbogen order was given, only to be countermanded 8 minutes later,^[1] to avoid jeopardizing the surrender negotiations, and later that day all operational U-boats were ordered to cease hostilities. Despite this a further 87 boats were destroyed on 5 May; 64 on the Baltic (41 at Gelting Bay, 13 at Flensburg and 10 at various other points), while on the North Sea coast 23 boats were disposed of, 13 at Wilhelmshaven and 10 in the Weser estuary.

On 6 May there were no further sinkings, but on 7 May the two Walther boats were wrecked at Cuxhaven. Over the last week at least 195 U-boats had been scuttled.

On 8 May Germany surrendered unconditionally; the remaining naval units, including the surviving U-boats, surrendered to Allied forces. At least 150 U-boats were surrendered to the Allied navies, either at sea or at their operational bases. 52 boats were surrendered at sea, either on patrol or in transit, and 98 in port, mostly in Norway and at bases in Germany, Denmark and France. Four U-boats and their crews fled to neutral ports rather than do this; two (Argentina.

Conclusion

Various figures are given for the numbers of U-boats involved during this period; Kemp gives 218 scuttled, and 154 surrendered;^[2] Tarrant gives the same.^[3] Blair gives 222 scuttled and 174 surrendered.^[4] Neistle lists 195 scuttled ^[5] and 150 surrendered.^[6] A number of U-boats disposed of were not in commission; some had not yet been commissioned, some had been de-commissioned. The discrepancies are mainly accounted for depending on whether these are included or not.

Most sources ^[7] give a number of U–boats scuttled at the end of the war, and describe the Regenbogen order, conflating the two. Kemp describes the scuttle as an act of defiance, and quotes "Ali" Cremer's order to scuttle edit] Notes

1. ^ van der Vat p380
2. ^ Kemp p262
3. ^ Tarrant p228
4. ^ Blair p700
5. ^ Neistle p 198-99
6. ^ Neistle p 207-209
7. ^ Kemp, Roskill, Tarrant
8. ^ Kemp p 261
9. ^ Neistle p 160
10. ^ van der Vat p380
11. ^ Blair p700
12. ^ Blair p 700
13. ^ Neistle p 198-99
14. ^ Neistle p 202

References

• Clay Blair : Hitler's U-Boat War Vol II (1998) ISBN 0-304-35261-7
• Paul Kemp  : U-Boats Destroyed ( 1997) . ISBN 1 85409 515 3
• Axel Neistle  : German U-Boat Losses during World War II (1998). ISBN 1 85367 352 8
• Stephen Roskill : The War at Sea 1939-1945 Vol III, pt 2 (1960).ISBN (none)
• VE Tarrant : The Last Year of the Kriegsmarine (1994) ISBN 1 85409 176 X
• Dan van der Vat : The Atlantic Campaign (1988).ISBN 0 340 37751 8