The Battle for Lake Tanganyika was a series of naval engagements that took place between elements of the Royal Navy, Force Publique and the Kaiserliche Marine between December 1915 and July 1916, during the First World War. The intention was to secure control of the strategically important Lake Tanganyika, which had been dominated by German naval units since the beginning of the war. The British forces – consisting of two motor boats named HMS Mimi and Toutou – were under the command of the eccentric Lieutenant-Commander Geoffrey Spicer-Simson. The boats were transported to South Africa and from there by railway, by river, and by being dragged through the African jungle, to the lake.
In two short engagements, the small motor boats attacked and defeated two of their German opponents. In the first action, on 26 December 1915 Kingani was damaged and captured, becoming HMS Fifi. In the second, the small flotilla overwhelmed and sank Hedwig von Wissmann. The Germans maintained a third large and heavily armed craft on the lake, Graf von Götzen; this craft was attacked indecisively by Belgian aircraft and was subsequently scuttled. Developments in the land-based conflict caused the Germans to withdraw from the lake, and control of the surface of Lake Tanganyika passed to the British and Belgians.
Background
Strategic situation
Lake Tanganyika lies between what was then the Belgian Congo on the western side and German East Africa on the eastern side. By the start of the war, the Germans had two warships on Lake Tanganyika: the 60 t (59 long tons; 66 short tons) Hedwig von Wissmann, and the 45 t (44 long tons; 50 short tons) Kingani. Hedwig von Wissmann was quickly armed with four pom-pom guns taken from the scuttled survey ship Möwe and sailed out to the port of Lukuga on the Belgian side of the lake, where on 22 August she attacked the Belgian steamer Alexandre Del Commune, sinking her after two further raids.
This gave the Germans unchallenged superiority on the lake, with their position strengthened further with the sinking of the British African Lakes Corporation's steamer Cecil Rhodes in a raid in November 1914. The Germans used their control of the lake to launch an attack on northern Rhodesia, led by Major-General Kurt Wahle. This was beaten back, but further raids on Belgian territory and bombardments of Lukuga convinced the Belgians to support the British.
Despite this undertaking, there was little the Belgians or British could do to challenge the Germans. The Belgians had the components for a large steamer, Baron Dhanis, which if it could be assembled would be considerably larger than either Kingani or Hedwig von Wissmann, but did not dare to start construction on her while the Germans patrolled the lake for fear that she would be destroyed before she could be launched. The British had sent two 12-pounder guns to arm her with, but with little prospect of being able to launch her, the Belgians were instead using them as shore batteries to defend Lukuga.
German control of the lake was significant for the whole campaign in the central African theatre. While the British could muster troops to the south of the lake, and the Belgians had troops to the north, neither could push into German East Africa because of the risk that the Germans would use their boats to transport troops across the lake, and use them to cut their supply and communications lines.
Lee's plan
On 21 April 1915, John R. Lee—a big game hunter and veteran of the Second Boer War—arrived at the Admiralty to meet Admiral Sir Henry Jackson. Lee had been in Eastern Africa and had personally observed the German ships on Lake Tanganyika. He also brought the news that the Germans were preparing to launch a new ship from their fortified port of Kigoma.[a] Named Graf von Götzen, she had been constructed at the Meyer shipyard at Papenburg, disassembled and packed into 5,000 crates and transported to Dar-es-Salaam. From there, she had been brought by rail to Kigoma and assembled in secret. 220 ft (67 m) long and displacing 1,575 long tons (1,600 t), she would cement German control of the lake and allow 800–900 troops to be rapidly transported to any point on the lakeshore to raid into allied territory.
To counter this threat, Lee proposed that motor gunboats be sent to Africa and transported through the interior to the lake. They would be small and highly manoeuvrable, and—if armed with a gun with a range of 7,000 yd (6,400 m)—could both outrun and outgun the larger German ships. Using small vessels that could be transported intact meant that they could be launched immediately onto the lake, eliminating the risk of their discovery and destruction while being assembled. Sir Henry considered the plan and approved it with the words "It is both the duty and the tradition of the Royal Navy to engage the enemy wherever there is water to float a ship." Jackson passed the task of finalising the details of the operation to his junior, Admiral David Gamble. Gamble appointed Lee second in command of the expedition, and placed Lieutenant-Commander Geoffrey Spicer-Simson in charge.
Spicer-Simson was a man described by Giles Foden as "a man court-martialled for wrecking his own ships, an inveterate liar and a wearer of skirts." He had reached the rank of lieutenant-commander but had not progressed further owing to a number of mistakes and disasters, which left him in a small office in the Admiralty assigned to helping with the process of transferring merchant seamen into the navy. In 1905, he had come up with the idea of stringing a cable between two destroyers to sweep for periscopes and nearly sank a submarine. He ran another ship aground while testing the defences of Portsmouth Harbour, and later collided with and sank a small boat, killing a man. By the outbreak of war, he was in command of HMS Niger and a small flotilla at Ramsgate. He went ashore to entertain guests at a nearby hotel, from whose windows he watched Niger being torpedoed and sank. He had nevertheless commanded a survey vessel on the Gambia River and, due to a shortage of officers, was selected to take command. Lee went out to prepare the way through Africa, while Spicer-Simson assembled 27 men and two motor boats that had been built by John I. Thornycroft & Company to fulfil an order made by the Greek government before the war.
The journey of Mimi and Toutou
The British naval force consisted of two 40-foot-long (12 m) motor boats. Spicer-Simson suggested they be named Cat and Dog, but the names were rejected by the Admiralty. Spicer-Simson then suggested Mimi and Toutou as alternatives, which were accepted. As he later explained, these meant "Miaow" and "Bow-wow" in French. Their crews were assembled from acquaintances of Spicer-Simson, or from the ranks of the Royal Naval Reserve. Spicer-Simson proposed a number of improvements to the original design; they were cut down to improve their speed, Maxim guns and a 3-pounder Hotchkiss gun were fitted, though the Hotchkiss had to be fired from a kneeling position, and extra steel linings were added to the petrol tanks. The boats were tested on the Thames on 8 June, where arrangements had been made for Mimi to fire a practice shell from her 3-pounder. The shell hit the target, but both gun and gunner flew into the river, as the gun had not been properly bolted to the deck. The boats were loaded aboard SS Llanstephen Castle on 15 June, along with special trailers and cradles to allow them to be transported by rail or overland, and the expedition's equipment and supplies. Once they arrived in South Africa, they would have to be carried over 3,000 mi (4,800 km) inland, including the traversing of an 1,800-metre-high (5,900 ft) mountain range. Meanwhile, on 8 June Graf von Götzen was launched on Lake Tanganyika.
The first leg of Mimi and Toutou′s 10,000 mi (16,000 km) journey was completed after 17 days at sea and their arrival at the Cape. From Cape Town, they and the men of the expedition travelled north by railway through Bulawayo to Elisabethville, where they arrived on 26 July. After travelling to the railhead at Fungurume, they were detrained and dragged 146 mi (235 km) through the bush by teams of oxen and steam tractors to the beginnings of the railway from Sankisia to Bukama. At Bukama, the boats and stores were unloaded and prepared for a voyage down the Lualaba River, where despite running aground several times and being forced to take passage on a Belgian river steamer they completed their journey after sailing through Lake Kisale and arrived at Kabalo on 22 October. From there, a small railway took them to just short of the Belgian port of Lukuga, on the shore of Lake Tanganyika. Here Spicer-Simson met the Belgian army commander, Commandant Stinghlamber, and the naval commander, Commandant Goor, and preparations were made to launch Mimi and Toutou and to seek out the Germans.
Belgian and German preparations
The Germans had made use of the loss of the survey ship Möwe by taking some of her crew, and men from the merchant ships of the Deutsche Ost-Afrika Linie, and using them to man their ships. The German position on the lake had been further strengthened with the loss of the cruiser SMS Königsberg in the Rufiji River in July. Guns from Königsberg arrived at the German base at Kigoma, and the German naval commander on the lake, Captain Gustav Zimmer, had one of Königsberg′s 105 mm (4.1 in) SK L/40 Schnelladekanone (i.e. quick-firing gun) mounted on Götzen. Members of Königsberg′s crew also made their way to join his forces, and Zimmer placed former crewmember Lieutenant Job Rosenthal in command of Kingani. Job Odebrecht commanded Hedwig, while Zimmer himself commanded Götzen.
Against this formidable force, the Belgians could only muster a petrol-driven barge armed with two cannon named Dix-Tonne, a motor boat named Netta, and a whaler fitted with an outboard motor. Goor hoped to bring into commission the as-yet unassembled Baron Dhanis, and the hulk of Alexandre del Commune, which had been sunk early in the war by Hedwig von Wissmann. Zimmer may have been aware that the British were planning to launch ships on the lake, but he was also concerned that Baron Dhanis might be assembled and launched. The 1,500 long tons (1,500 t) Baron Dhanis was not necessarily a threat to Götzen in port, but he was determined to maintain his freedom of movement on the lake. Lacking concrete information he sent Rosenthal aboard Kingani to reconnoitre Lukuga.
The Belgians mounted floatplanes on the lake giving them the ability to observe the German positions and to bomb them.
Battle
Rosenthal investigates
Lieutenant Job Rosenthal, commanding Kingani, made several passes and observed work underway on a new harbour at Kalemie, south of Lukuga, where Spicer-Simson intended to make his base. Still lacking detailed information on the enemy's movements, Kingani returned early on the morning of 1 December and attempted to approach the harbour. Rosenthal's vessel was spotted by the shore batteries and driven away, but returned the following night and Rosenthal himself swam to Lukuga to examine the slipways under construction. He also discovered the camps, where the British flag revealed the presence of Spicer-Simson and his expedition. Rosenthal travelled down the railway line and discovered both Mimi and Toutou, and the disassembled parts of Baron Dhanis. Realising that the threat actually lay in the British vessels, he attempted to return to Kingani, but was unable to locate her in the dark. He attempted to conceal himself and hoped that Kingani would return at nightfall, but was discovered by a Belgian patrol and taken prisoner. While a captive he succeeded in sending a message, with a secret addendum written in urine to Zimmer warning him of what he had seen, but the message did not reach Kigoma for several months.
Mimi and Toutou are launched
The slipways at Kalemie were ready by mid-December, and on 22 December Toutou was launched onto Lake Tanganyika, with Mimi following the next day. Final preparations were made on 24 December, including the fuelling and the fitting of guns, after which brief trials were made. On 26 December, Kingani approached Kalemie. Rosenthal's successor – Sub-Lieutenant Junge – had orders to gather information on naval preparations, and at 06:00 in the morning – as Spicer-Simson was conducting morning prayers – she was sighted offshore.