Naval Detachment K

Naval Detachment K (Laivasto-osasto K) was a Finnish military detachment—specifically, a flotilla that operated on Lake Ladoga during World War II.

Background
The Continuation War began in the summer of 1941. The Finns, who had operated naval units on Lake Ladoga before World War II, began reestablishing a flotilla on the lake as soon as their troops reached its shores early on in the war. The headquarters was formed in Läskelä on 2 August 1941 and by 6 August, 150 motorboats, two tugs (used as minelayer s) and four steam ferries had been transferred there. The tugs and ferries were equipped with 47 mm guns and machine guns. The Finns also established a number of coastal batteries on the shores and islands of Lake Ladoga. The only "true" Finnish warship on Lake Ladoga at that time was the obsolete ex-motor torpedo boat Sisu. As the Finnish land forces advanced, new headquarters were established in the captured towns along the shores of Ladoga. The Ladoga flotilla's headquarters was eventually moved to Sortavala and the harbour at Lahdenpohja became its primary base of operations.

Naval Detachment K
Already during the spring Finnish Lieutenant General Paavo Talvela and Colonel Järvinen who was commanding the Laatokka Coastal Brigade came up with an idea that the boat traffic providing supplies to the Leningrad needed to be disrupted. Talvela then presented this idea to the Germans on his own behalf going past both Finnish Navy HQ and General HQ. Germans responded positively to the proposition and informed the slightly surprised Finns—who apart from Talvela had very little knowledge of the proposition—that transport of the equipment for the Ladoga operation was already arranged. Both the Germans and Italians sent naval units to Lake Ladoga to assist the Finns with coastal defence of the lake and to enforce the ongoing siege of Leningrad.

A combined Finnish-German-Italian unit, the Laivasto-osasto K (LOs.K., Naval Detachment K) was formed on 17 May 1942, consisting of the four Italian MAS boats, four German KM minelayers and the Finnish motor torpedo boat Sisu. The German and Italian vessels were grouped into two units under Finnish command. First to arrive was the Italian unit XII Squadriglia MAS on 22 June, consisting of four MAS torpedo boats (MAS 526, 527, 528, and 529). Five days later, four German KM-minelayers also arrived. However, the German minelayers suffered from inexperienced crews and unreliable engines and it took until 10 August before all German boats were repaired and deemed operational.

Einsatzstab Fähre Ost
Between 13 June and 15 August 1942 the Ladoga flotilla was strengthened by the arrival of two German naval contingents: Luftwaffen-Fährenflotillen II and III. These units had been formed in May 1942 at the Belgian port of Antwerp and redesignated Einsatzstab Fähre Ost (EFO) for duty on Lake Ladoga. The battlegroups acted independently but maintained close operational ties with Naval Detachment K. They were made up of twenty-three Siebel ferries (seven heavy artillery types mounting two to four 88 mm guns each; six light artillery types mounting smaller-caliber flak pieces; six transport, six repair, one hospital and one HQ) as well as nine I-Transporters or infantry boats (each capable of carrying 50 fully equipped soldiers). Four of the these boats were outfitted as minesweepers; three were kept as transports; one was rigged as a hospital ship and one as an HQ. In addition, one heavy Sturmboot acted as headquarters ship.

The Siebel ferries were originated by aircraft designer Fritz Siebel and intended for use in Germany's planned 1940 invasion of England, Operation Sea Lion. They consisted of two heavy Army bridging pontoons braced together with iron cross-beams and covered by a sturdy wooden deck. The ferries initially had a pair of Ford V-8 truck engines in each aft pontoon end, connected to standard water screws. Further power came from three 600 hp surplus aircraft engines mounted on an elevated scaffolding spanning the rear deck. The aircraft engines, however, were later dispensed with as they consumed considerable fuel and required excessive maintenance. Siebel ferries displaced approximately 140-170 tons, depending on type, and could travel up to 570 km at 8 kn. With their low freeboard and wide flat deck, they were easily configured for a variety of purposes.

In all, Oberstleutnant Siebel had a total of 30 vessels with 2400 personnel under his command.

Operations
Naval Detachment K's primary task was harassing Soviet supply lines to Leningrad on southern Ladoga, where British and American food and munitions were delivered to the besieged residents of Leningrad. The unit also staged attacks on enemy bases and conducted limited landing operations on the shores of Lake Ladoga. Some smaller Soviet patrol boats and several barges delivering food to besieged Leningrad were attacked and sunk during 1942 and 1943. The Finnish Ladoga Flotilla had clashes with the Soviet Ladoga Flotilla, which operated in Lake Ladoga from June 25, 1941, through November 4, 1944.

The EFO suffered losses during a raid to destroy Soviet radio station, lighthouse and coastal artillery emplacement on the strategically important island of Sukho (Suhosaari in Finnish) 37 km from the Southern coast of Ladoga, at the main supply route to Leningrad. The idea of the operation was presented to the Germans by the Finnish Lieutenant General Paavo Talvela. The German-run operation, codenamed Operation Brazil (Einsatz Brasil) began on 22 October 1942. Though the radio station and the lighthouse were torched and the coastal artillery on the island was destroyed, the landing was eventually repulsed and, in a running battle, the flotilla was harassed by Soviet aircraft, torpedo-boats, and gunboats all the way back to its base along the northern shore of Lake Ladoga. When approaching Sukho island, one light ferry (SF 12) run aground and several other ferries went to assist it. However one of the light ferries (SF 22) was hit by Soviet coastal artillery fire and one heavy (SF 13) and one light ferry (SF 26) that had gone to assist the grounded ferry (SF12) also became grounded despite of the efforts to get them loose. Ultimately, all three had to be abandoned. During the return voyage one heavy ferry (SF 21) had to be scuttled when it started to take in water so badly that they would not have made it back to the base. Infantry boat (I 6) assigned to the ferry was also lost. Losses suffered by the EFO during the raid were heavy artillery ferries SF 13 (grounded) and SF 21 (damaged, later scuttled), light artillery ferries SF 12 (grounded) and SF 26 (grounded) and infantry boat I 6—casualties for the naval and landing forces were 18 men dead, 57 wounded, and 4 missing. One of the lost ferries was taken over by the Russians.

Analysis
The operations of the international flotilla were a failure. Torpedoes proved useless in the shallow waters of southern Lake Ladoga, where they frequently struck the bottom. Nor did their magnetic detonators work well against the wooden hulls of Soviet barges and patrol boats. The secondary armament of the MTBs also proved too light to seriously threaten Soviet gunboats. German mineboats turned out to have extremely unreliable engines, keeping them docked in port far longer than they spent on actual operations nor were their influence mines especially useful against mainly wooden hulled Soviet vessels. The Siebel ferries of EFO had good armament but they were far too slow and had too short a range for effective operations. They were almost "sitting ducks" to the Soviet patrol boats, gunboats and bombers. As their personnel came from the Luftwaffe, with no sea-going experience, operations in the often harsh weather conditions were extremely difficult.

Dissolving the detachment
The Italian torpedo vessels were relocated from Lake Ladoga to Tallinn at the end of October 1942 and would eventually end up in the Finnish Navy. Likewise, the Germans withdrew most of their vessels, leaving two ferries and four infantry boats which Finns had bought. In January 1943, the Soviet Red Army launched Operation Spark, to open up a land connection to Leningrad and break the siege. Axis forces were pushed back 80 km and the Road of Life no longer had its previous significance. Neither German nor Italian units returned to Lake Ladoga, although smaller Finnish units continued to operate in the lake against the Soviets during 1943.