THE AXIS AND ALLIED MARITIME OPERATIONS AROUND SOUTHERN AFRICA 1939 1945 - WAR ON SOUTHERN AFRICA SEA

22)UBOAT OFFENSIVE OFF S AFR

.3 The German U-boat offensives off the South African coast

In February 1941, after the German sinking results in the North Atlantic diminished considerably, the Befehlshaber der U-Boote (BdU) decided that the time for sending a number of type IX U-boats to operate in the South Atlantic was opportune. These submarines were to operate predominantly off Freetown. At this stage of the war, Karl Dönitz argued that the BdU focus all of their energy on the prosecution of the U-boat war in the North Atlantic, and not on far-flung operations in the remote corners of the globe. In his memoirs, however, Dönitz categorically stated that Hitler and the political leadership of Germany failed to understand this strategy, and in essence, the basic fundamentals of U-boat warfare.^[1] The BdU also made use of secret replenishment points in the Central Atlantic, particularly ‘Andalusien’. These secret replenishment points allowed for surface supply ships to rendezvous with U-boats and replenish their ammunition and logistical stores. In a greater sense, the replenishments enabled the Uboats to undertake two successive patrols in an operational area without returning to their bases in the Bay of Biscay, which could be as distant as 2,800 miles.

The system of double patrols proved extremely effective with some seven Uboats sinking more than seventy-four ship in the first half of 1941. During this period U69 (Metzler) travelled south along the African coast and mined the ports of Lagos and Takoradi in the Gulf of Guinea, after which the mines claimed several victims. This prompted the British Admiralty to close these ports temporarily. During the months of May and June, a total of 119 ships (635,635 tons) were sunk in the North Atlantic and the operational area off Freetown. Between July and August, the sinking results off Freetown dropped considerably, as there were only eight to twelve U-boats operational in this area at that time. The heavy losses of merchant vessels off Freetown persuaded the British Admiralty to reduce Allied shipping activity in the area to a minimum. The Admiralty would also redirect traffic to the relative safety of the Pan-American safety zone, an area then still closed to U-boats for political reasons. The very dense American commercial shipping off Freetown further complicated U-boat operations in the area, as they were naturally not allowed to attack neutral shipping. Following the loss of a unidentified surface supply ship, Dönitz redeployed the mainstay of his U-boats to operations in the North and Eastern Atlantic. Here, the merchant sinking potential continued to be substantial.^[2]

Fig 3.2: Grand Admiral Karl Dönitz^[3]

By October, only two U-boats remained operational off Freetown with enough fuel left to continue operations until forced to resupply from the Atlantis and Python (Lüders). After first operating off the coast of Freetown, U-126 (Bauer) subsequently sailed to the coast of Guinea, while U-68 (Merten) proceeded to Walvis Bay via Ascension and St. Helena. On its way to South-West Africa, U-68 sank the British tanker Darkdale (8,145 tons) off St. Helena, as well as a further two British merchantmen, the Hazelside (5,279 tons) and Bradford City (4,925 tons). The U-boat arrived off Walvis Bay on 11 November and observed no sea traffic. On 13 November, it sailed northwards and rendezvoused with the Atlantis south of St. Helena Island for replenishment. The Atlantis thereafter travelled northwards to resupply U-126 to the north-west of Ascension Island. On 22 November, however, the Atlantis was surprised en route and subsequently sunk by the cruiser HMS Devonshire. The survivors from the Atlantis were rescued by U-126. The Python, along with U-124 (Mohr) and U-129 (Clausen) also received instructions to assist with transporting the survivors, despite all being initially earmarked for an operation in Cape Town waters. Two days previously, the Python had resupplied U-124 and U-129 near the Saint Peter and Saint Paul Archipelago in the central equatorial area of the Atlantic Ocean. On her way to the rendezvous, U-124 also sank the cruiser HMS Dunedin (4,850 tons).^[4]

Fig 3.3: German U-boat crew assisting the survivors of a sunken merchantman^[5]

The survivors of Atlantis were transferred to the Python during the rendezvous with U-126. The Python was then ordered to remain in the South Atlantic as she had enough fuel and provisions to support the remaining four operational U-boats in the area. The BdU decided that U-124, U-129, U-68 – all of the type IX class – and U-A (Eckermann) should launch a surprise operation in the waters off Cape Town, after replenishing their supplies from the Python. This operation, however, came to nothing. On the afternoon of 1 December, after having resupplied U-68, and while busy resupplying U-A, Python was surprised and successfully engaged by HMS Dorsetshire after Ultra intelligence had pinpointed her location. While U-68 and U-A managed to escape the attack from HMS Dorsetshire by diving, the crew of the Python opted to scuttle the ship. 

The attacks on the Atlantis and Python, both while they were resupplying U-boats, were a matter of grave concern to the BdU and the SKL. They were convinced that direction-finding alone could not have guided the British warship to the exact location of the German supply vessels, though the raider code was never broken by the Allies. The crews of the Atlantis and Python were subsequently transferred to the four U-boats, whereafter they started their return journeys to the Bay of Biscay. During the return trip, U-124 managed to sink the American merchantman Sagadahoc (6,275 tons). The four U-boats then rendezvoused close to the Cape Verde Islands with four Italian submarines that had sailed from Bordeaux. These were the Pietro Calvi (Olivieri)^[6], Giuseppe Finzi (Giudice)^[7], Enrico Tazzoli (di Cossato)^[8] and Luigi Torelli (De Giacomo)^[9]. The Italian submarines helped to transport the crews of the Atlantis and Python to their bases in the Bay of Biscay. All eight submarines had arrived at their respective bases by the end of December. 

The destruction of the Atlantis and Python meant that surface vessels could no longer supply U-boats in the South Atlantic, which necessitated the temporary shelving of all plans for offensive operations in the waters off Cape Town. At this stage, it was also more economical to employ U-boats in operations off the American seaboard. The American entry into the war had incontrovertibly opened several new avenues of attack with the promise of rich merchant spoils and much shorter operational distances.^[10]

The sinking results of the U-boats operating in the North Atlantic off the American seaboard, as well as the Caribbean, had, however, decreased somewhat substantially. The BdU concluded in July 1942 that the reduction had occurred to such an extent that it was no longer worthwhile considering these areas as the main theatre for sustained Uboat operations. This was mainly due to the introduction of Allied convoys and effective A/S measures in these waters. The BdU hence adopted a policy of pursuing U-boat operations in distant waters, provided that the sinking results and prospects of success in these areas justified the economic use of force in such operations. They had the added advantage of coercing the Allies into spreading their A/S forces across the globe to engage the U-boats wherever they appeared. The main weight of the U-boat operations thereupon shifted to the mid-Atlantic. The renewed focus was on attacking convoys to and from Britain, as these areas were devoid of good air cover. 

At least thirty new U-boats were delivered per month during July, August and September 1942, mainly due to the clearing of arrears in U-boat construction from the previous year. The arrival of these new U-boats enabled the BdU to promptly resume operations against Allied convoys in the North Atlantic. The increase in forces furthermore allowed for U-boats to deliver surprise attacks in distant waters. The first three areas selected for the sporadic subsidiary operations were the waters off Trinidad in the Caribbean, Freetown, and a sudden onslaught in the waters off Cape Town. Dönitz had hoped to cause a diversionary effect with these distant interventions, pressurising the Allies into splitting their defensive forces between protecting the North Atlantic, the Eastern American seaboard, the Caribbean and the extensive African coast bordering the Indian and Atlantic oceans. The Japanese submarine offensive in the Mozambican Channel had naturally also contributed to this diversionary effect.^[11]

Fig 3.4: A German U-boat refuelling from a supply ship in the South Atlantic^[12]

By July 1942 the waters off Cape Town were still considered virgin waters by the BdU. The area had remained devoid of any noteworthy submarine activity, apart from U-68’s brief foray to the coast of South West Africa in November 1941. Prior to 1942, the BdU also did not favour sending single U-boats to operate off the southern African coast as their independent actions would alert the Allies and force them to adopt stringent A/S measures in these waters. Moreover, a single submarine operating in the Cape Town waters would not reach satisfactory sinking results needed to justify its deployment in such distant reaches. The BdU further realised that an operation off Cape Town could only materialise once sufficient numbers of U-boats were available to launch a concentrated attack and sustain it for an indefinite period to allow for satisfactory sinking results. Dönitz and the BdU, however, maintained that the primary focus of the U-boat war remained the sinking of Allied merchant shipping, and not merely the tying down of Allied forces through diversionary U-boat attacks.^[13]

Table 3.7: Statistical data on German U-boats operational in South African waters^[14]

Between October and November, the Allies committed the majority of their escort fleets to the protection of the North African and Mediterranean waters. This action was the result of the unfolding campaign in North Africa, which further enticed Dönitz to strike towards the proverbial ‘soft underbelly’ of South Africa. The BdU, however, appreciated the logistical complications associated with operations in such distant waters, especially after the loss of the Atlantis and Python. As early as 1941, it experimented with the use of supply U-boats (milch cows^[15]) in provisioning submarines on remote operations. Furthermore, by August, the BdU had a large enough number of the type IXC U-boats at its disposal, which exponentially increased the duration of U-boat operations. Hence, when operating in conjunction with the milch cows, the offensive employment of U-boats now extended to areas previously devoid of any sustained U-boat operations. Dönitz furthermore hoped to extend U-boat operations to cover the African ports in the Indian Ocean, but accepted that this would only be possible by October when the new type IXD₂ U-boats came into service (see Table 3.7).^[16]

Fig 3.5: German U-boats operational in the Southern Oceans, circa 1941^[17]

By August, the BdU had earmarked four type IXC U-boats for the surprise onslaught in the Cape Town waters. The Eisbär group was ordered to strike a decisive blow at shipping in the waters off Cape Town during October. The wolf pack consisted of U-68 (Merten), U-172 (Emmermann), U-504 (Poske) and U-156 (Hartenstein), and was accompanied by the milch cow U-459 (Wilamowitz-Möllendorf). Dönitz argued that the U-boats were to remain in the operational area off Cape Town until approximately the end of October. The aim was to disrupt and destroy merchant shipping and achieve the necessary sinking results required to make such a far-flung operation a success. A fresh batch of U-boats would then relieve the Eisbär group and continue operations in this area. After the Eisbär boats had sailed for Cape Town from their base at Lorient in late August, they had to cover approximately 6 000 sea miles before they reached the operational waters off Cape Town.^[18]

To ensure maximum surprise, the SKL required the U-boats to remain undetected for their entire voyage to Cape Town. The SKL argued throughout September that the most important factor to consider was the strategic effect which the Eisbär group would achieve. This included throwing the traffic off the coast of South Africa into such a state of confusion that sea traffic around the Cape of Good Hope would halt. South African ports would then become clogged with ever-increasing numbers of merchant shipping seeking shelter. Be that as it may, only surprise could ensure this strategic effect. The BdU and Dönitz, however, argued that the most important factor to consider during the entire operation would be the actual sinking results achieved by the Eisbär pack. Dönitz thus argued that the Eisbär boats should attack shipping during their entire approach voyage to Cape Town. The ultimate goal of the operation, as Dönitz argued, was a short, sharp, U-boat offensive, which could yield the highest possible sinking results in the shortest possible time without incurring too many U-boat losses. The SKL and BdU eventually reached a compromise and decided that the U-boats could attack merchant shipping during their approach voyage to Cape Town, but only between the equator and 5° south.^[19] Dönitz’s reply to this debacle was that the strategists were once again out to “tickle” the enemy. To this he added, “Unfortunately I do not know of a single case, when an enemy had been tickled to death.”^[20]

During their voyage south, the Eisbär boats attempted – albeit unsuccessfully – to attack convoy SL 119 which was making its way to Freetown. While each U-boat continued its journey south independently, the wolf pack travelled in an extended harrow bone formation spread out across a vast distance. In this way, it was able to remain undetected and able to increase the chances for opportunistic attacks against Allied shipping. The U-boats were to replenish their supplies from U-459 on 20 September at a position approximately 20° south of the equator. While en route to rendezvous with U-459, U-156 sank the British troopship Laconia (19,965 tons) on 12 September. This chapter does not deal with the sinking of the Laconia, but it is of interest to note that Dönitz ordered the remainder of the Eisbär boats to assist in rescuing the survivors. Only once two Vichy French boats were despatched to help assist with the rescue of survivors, were the U-boats recalled from the rescue operation.^[21]

Fig 3.6: U-156 and U-507 assisting survivors from the Laconia, 15 Sept 1942^[22]

On 16 September, an indiscriminate Allied bombing attack damaged U-156 to such an extent that the BdU recalled it from the Eisbär group. The BdU rapidly replaced U-156 with U-159 (Witte) as the U-boat was then operational in the equatorial area off the mouth of the Congo River. The Eisbär boats rendezvoused with U-459 between 22 and 24 September to the south of St Helena, where each U-boat successfully replenished its supplies. This included 100-110 tons of fuel, four tons of lubricating oil and enough food stocks and other essential supplies for 30 days. The remainder of the U-boats’ journey south occurred without incident, and the Eisbär group arrived off the coast of Cape Town during the first week of October.^[23]

On the night of 6/7 October 1942, Emmermann managed to infiltrate his U-boat successfully into Cape Town harbour’s roadstead. After conducting a reconnaissance, he found it to be empty of Allied merchant vessels. The BdU had initially ordered the Eisbär group to commence their attack on the shipping off Cape Town on the night of 8/9 October, but after receiving Emmermann’s report, it was decided to postpone the attack to the night of 10/11 October. In the meantime U-68 trailed several steamers while steadily approaching Cape Town harbour. During the evening of 7/8 October, Merten received Emmermann’s report stating that the roadstead was empty. Merten forthwith informed the BdU of the changing tactical situation in the waters off Cape Town. At that point, the U-boats were authorised to launch their attacks at midnight on 8 October. Local intelligence sources indicated that Cape Town harbour retained up to 50 ships anchored at any time, and the BdU believed that a surprise attack by two U-boats could achieve more than the desired results, after which the remaining U-boats were free to take offensive action. The U-boat commanders and the BdU were furthermore convinced that the South African defences would be caught totally unaware, for it seemed that neither their wireless transmissions nor their presence was detected.^[24]

Fig 3.7: A U-boat watching its target sink in the Southern Oceans^[25]

The resulting U-boat offensive succeeded in sinking 13 merchantmen within the first three days of operations. They were the Chikasaw City (6,196 tons), Firethorn (4,700 tons), Boringia (5,821 tons), City of Athens (6,558 tons), Clan Mactavish (7,631 tons), Sarthe (5,271 tons), Swiftsure (8,206 tons), Gaasterkerk (8,679 tons), Koumoundouros (3,598 tons), Examelia (4,981 tons), Coloradan (6,557 tons), Belgian Fighter (5,403 tons) and Orcades (23,456 tons).^[26] The U-boat pickings were initially child’s play. But as the surprise gained during the initial attack started to dwindle, and the South African and Allied counter-measures were activated, Dönitz ordered the Eisbär group to extend their operational area to as far afield as Port Elizabeth and Durban. 

The initial attacks on the merchant shipping off Cape Town were facilitated by the fact that the majority of South African lighthouses were still functioning at full capacity, while most merchantmen sailed independently around the South African coast. Because of this complacency present in South Africa, very few A/S vessels and aircraft were operational off the coast of South Africa by October. Bad weather, however, set in on 13 October, which forced the submarines further afield, with U-159 venturing as far as 40° south in search of merchant vessels.^[27] Shortly after the commencement of Operation Eisbär, U-68 and U-172 were forced to commence their return voyage. This occurred even before they had managed to fire all of their torpedoes.^[28] The BdU subsequently decided that U-504 and U-159 would move further south and south-east of Cape Town where they managed to sink several more vessels over the period of 13 October to 3 November.^[29] Its targets included the Empire Nomad (7,167 tons), Empire Chaucer (5,970 tons), City of Johannesburg (5,669 tons), Anne Hutchinson (7,176 tons), Ross (4,978 tons), Laplace (7,327 tons), La Salle (5,462 tons), Empire Guidon (7,041 tons), Reynolds (5,113 tons) and the Porto Alegre (5,187 tons). After these attacks, U-504 and U-159 also had to turn back to their bases in France. During their return voyages, the Eisbär boats succeeded in sinking a further three merchantmen: the Aldington Court (4,891 tons), Llandilo (4,966 tons) and the Star of Scotland (2,290 tons) (see Table 3.8).^[30]

Table 3.11: Merchantmen lost to Italian submarine operations, Mar-Apr 1943^[42]

Fig 3.8: The top U-boat aces in South African waters during the war – Karl-Friederich Merten, Wolfgang Lüth, Helmut Witte^[43]

By April, only U-182 remained operational off the South African coast. The BdU decided that a large number of IXD U-boats, which had become available during February and March, would be despatched to relieve the Seehund group, and collectively formed part of the second U-cruiser operation in the Southern Oceans. The extended fuel capacity of these U-boats allowed for greater operational freedom in distant waters. On 9 February, U-180 (Musenberg) – one of only two experimental type IXD₁ U-boats – left the Bay of Biscay destined for Madagascar. Musenberg was ordered to rendezvous with the Japanese submarine, I-29 (Kinashi) off Madagascar and deliver the Indian dissident Subhas Bose. During her voyage to the rendezvous, U-180 sank the Corbis (8,132 tons) on 18 April. After the successful delivery of Bose on 26 April, U-180 remained operational off the South African coast until 26 May without any further results.^[44]

Over the period of 9 April to 3 May, a further nine type IXD₂ U-boats made for the operational area in the South African waters. They included U-177 (Gysae), U-178 (Dommes) U-181 (Lüth), U-195 (Buchholz), U-196 (Kentrat), U-197 (Bartels), U-198 (Hartmann), U-402 (Freiherr von Forstner) and U-511 (Schneewind). The first of these U-boats arrived in the operational area towards the end of April, with U-177, U-181, U198 and U-402 sinking a number of merchant vessels between Cape Town and the Mozambique Channel. During May alone, seven merchantmen were sunk by these Uboats. They were the Nailsea Meadow (4,962 tons), Tinhow (5,232 tons), Northmoor (4,392 tons), Sicilia (1,633 tons), Storaas (7,886 tons), Agwimonte (6,697 tons) and the Hopetarn (5,231 tons). The main reason behind the sudden successes appears to have been the greater speed which could be reached by the type IXD₂ U-boats. In June, a further five merchantmen were sunk: the Salabangka (6,586), Dumra (2,304 tons), William King (7,176 tons), Harrier (193 tons), and the Sebastian Cermeno (7,194 tons). By the end of that month, the U-boats had replenished their stores from the German surface tanker, the Charlotte Schliemann, well to the south of the island of Mauritius.^[45]

After restocking, the U-boats relocated to new operational areas, which saw the submarines working towards the east coast of South Africa in a quadrant between Durban, Lourenço Marques, the Mozambique Channel, Mauritius and Madagascar. This new operational area at once proved more profitable, with the U-boats sinking a further 14 merchantmen.^[46] Included were the Michael Livanos (4,774 tons), Breiviken (2,669 tons), Hydraios (4,476 tons), Jasper Park (7,129 tons), Leana (4,743 tons), Alice F. Palmer (7,176 tons), Mary Livanos (4,771 tons), Robert Bacon (7,191 tons), City of Canton (6,692 tons), Pegasus (9,583 tons), Mangkalihat (8,457 tons), City of Oran (7,323), Efthalia Mari (4,195 tons) and the Empire Stanley (6,921 tons) (see Table 3.12).^[47]

Table 3.12: Merchantmen lost to the second U-cruiser operation, Apr-Aug 1943^[48]

Between 8 and 20 August, the U-boats used up most of their supplies and were obliged to return home. During this period, U-197 was lost after being bombed by Allied aircraft just south of Madagascar on 20 August. The remaining U-boats had arrived in Bordeaux by mid-October. Between 18 April and 17 August, the U-boats of the second U-cruiser operation accounted for 27 merchant ships sunk, totalling 153,718 tons of shipping lost. Despite more active South African and Allied counter-measures, Dönitz’s U-boats managed to sink 44 merchant ships off the coast of South Africa during the whole of 1943, amounting to a total of 256,243 tons of shipping lost. In October, the Faneromeni (3,404 tons) was sunk by the Japanese submarine I-37 in the Mozambique Channel. This was the last merchantman lost in South African waters for the year 1943. The Italian and Japanese submarines added six more merchantmen to this tally, amounting to a further 40,860 tons of shipping lost. Altogether the Axis submarine offensives accounted for 50 merchant vessels sunk in 1943, totalling 297,103 tons of shipping lost.^[49]

Map 3.4: Shipping lost to Axis submarines, 1943

For the remainder of the Second World War, more notably from September 1943, the BdU ceased to regard the region off the South African coast as a viable operational area. It argued that the submarines earmarked for offensive operations in the Far East would have to pass through South African waters before they could reach their fareastern bases at Penang and Surabaya. This would provide the U-boats with ample opportunity to attack Allied merchant shipping along the South African coastline during their journeys to and from the east. The A/S measures had become so efficient around the South African coast – especially the well-organised air patrol service by the SAAF and Royal Air Force – that the U-boats found it increasingly difficult to operate successfully against merchant shipping.

There were, however, exceptions to the rule.^[50] During the course of 1944, four U-boats, U-862 (Timm), U-852 (Eck), U-198 (Waldegg) and U-861 (Oesten), managed to sink eight Allied merchant ships, accounting for 42,267 tons of shipping lost. The merchant vessels that had been sunk comprised of the Dahomian (5,277 tons), Columbine (3,268 tons), Director (5,107 tons), Radbury (3,614), Empire Lancer (7,037 tons), Nairung (5,414 tons), Wayfarer (5,086 tons) and the Berwickshire (7,464 tons). The Point Pleasant Park (7,136 tons) was sunk by U-510 (Eick) on 23 February 1945. This was the last Allied merchantman sunk off the South African coast during the war (see Table 3.13).^[51]

Table 3.13: Merchantmen lost to German U-boats, 1944-1945^[52]

FOLLOWING PAGES ON THE SAME ARTICLE

21)THE JAPS OFF MOZAMBIQUE CHANNEL

23)CONCLUSION

24)THE MARITIME INTEL WAR IN S AFR

25)THE TROMPKE NETWORK