Vorpostenboot (plural Vorpostenboote), also referred to as VP-Boats, flakships or outpost boats,Campbell, p.93 were German patrol boats which served during both World Wars. They were used around coastal areas and in coastal operations, and were tasked with – among other things – coastal patrol, ship escort, and naval combat.
Characteristics
Armament
Vorpostenboote typically carried one or two medium-calibre guns (e.g., 88 mm), many light automatic anti-aircraft guns (20–40 mm), and a varying number of machine guns. For anti-submarine warfare they were also fitted with depth charges. They were crewed by sixty to seventy men, most of whom were weapons personnel taken from the naval reserve. While Vorpostenboote were able to engage and defeat light naval forces – such as small motor gun boats – they were not powerful enough to effectively combat destroyers or larger warships.
Some Vorpostenboote (and submarine chasers) were given heavier anti-aircraft guns and re-rated as Flakjaeger or Flakkorvetten.Gardiner & Brown, p.58
History
World War I
At the outset of World War I, the Imperial German Navy lacked sufficient numbers of warships to perform auxiliary tasks like coastal patrol and convoy escort. As such, the navy requisitioned a large portion of civilian fishing trawlers to perform these tasks, converting them into Vorpostenboote.Paterson, p.43
Interwar
After World War I, Germany's shipbuilding industry suffered because of the Great Depression, and many of the larger shipbuilders were unable to continue construction. As such, few trawlers were constructed during this period. However, with the rise of the Nazis, the few remaining companies experienced a major financial boost. Trawler production was revitalized, and new ships which would eventually become Vorpostenboote were built, such as the Carl Röver and R. Walther Darré.Paterson, p.44
Throughout the 1930s, these trawlers also grew in tonnage, and 400 GRT ships were the standard by the end of the decade. By 1937, the Kriegsmarine began actively commissioning trawlers for the express purpose of converting them into Vorpostenboote, hoping to standardize the design and minimize the time it would take to convert the civilian ships into warships.Paterson, p.45
World War II
Invasion of Poland The first operational Vorpostenboote flotilla (Vp-Flotilla) was formed in June 1939 in preparation for the naval operations of "Case White", the German invasion of Poland. Called the Reserve Patrol Flotilla, the flotilla consisted of eight commandeered vessels which were gathered together in just three days. By 18 August, orders were placed to increase the flotilla by ten vessels to a total of eighteen.Paterson, p.59
By the end of the Polish campaign in October, a significant number of new Vp-Flotillas had been raised. The 2nd, 3rd, 4th, 8th, and 11th flotillas consisted of eight trawlers each. Eight whalers made up the 13th flotilla, while coasters made up the 10th flotilla. The 12th and 15th flotillas consisted of a combination of whalers and trawlers, and the 1st flotilla was made up of eight steamers which would later be converted into Sperrbrecher mine clearance vessels.Paterson, pp.71-72
Winter of 1939
Several Vorpostenboote were lost in the harsh winter of 1939, in part due to mines (called "drifters") which had been broken free from their moorings by the foul weather. Ships sunk by these rogue mines included the Skolpenbank, Este, and Weser. The loss of the Skolpenbank led to the Seekriegsleitung (SKL, "Naval Warfare Command") clamping down on the amount of classified information carried on auxiliary vessels, since its wreck was never located and there was no way of knowing if information had fallen into enemy hands.Paterson, p.78 Also during the winter, British submarine presence in the Baltic Sea increased, leading to several encounters with Vorpostenboote. While several depth charge attacks on the submarines were recorded, they were unsuccessful; on the other hand, British submarines were able to successfully attack and sink multiple Vorpostenboote. One instance of this was when HMS Sturgeon sank V 209 Gauleiter Telschow in the Heligoland Bight on 20 November, escaping without detection.Paterson, p.86
Thick ice in the Baltic and rough sea conditions in the North Sea continued to hamper patrolling operations into 1940. In an attempt to combat these poor conditions, naval drifters in the North Sea were transferred to the Baltic, and trawlers from the Baltic were transferred to the North Sea. The drifters were better able to break up the ice, while the trawlers were still capable of holding up to rough sea conditions. However, this led to an overall reduction of ships patrolling the North Sea; only sixteen trawlers in two flotillas were operational at this time. The (Commander in Chief of Security West), under whose jurisdiction the North Sea patrols fell, repeatedly demanded a third flotilla be transferred to the North Sea, which was denied due to a lack of ships and manpower.Paterson, p.102
Invasions of Norway and Denmark During the invasions of Norway and Denmark in April 1940, Vorpostenboote continued their patrol duties and also escorted landing groups and tankers in ten convoys. In Denmark, few of these operations were contested, but in Norway there was resistance by submarines and surface ships. Submarines were particularly dangerous,Paterson, pp.128-131 The British submarine HMS Triton attacked the 2nd convoy, which consisted of the transport ships Friedenau and Wigbert and a heavy escort of Vorpostenboote and minesweepers.Kindell, Naval Events, April 1940 (Part 2 of 4) Monday 8th - Sunday 14th Triton spotted the convoy on the afternoon of 10 April and sank both transport ships and Vorpostenboot Rau VI, resulting in the drowning of more than 900 German soldiers. Despite launching more than 70 depth charges, the convoy was unable to sink the Triton which escaped with only minor damage.Paterson, p.131
Following the capture of Norwegian coastal areas and harbors, German auxiliary naval forces were spread extremely thin. Even at the beginning of the war, the Kriegsmarine had a barebones amount of patrol ships and minesweepers, and the defense and patrol of the Norwegian and Danish coasts would require a sharp increase in ships and manpower. The Kriegsmarine quickly began to press captured Norwegian vessels into service, but these were inadequate in number. Compounding the problem, the complex and tangled jurisdictions of the German naval commands meant that almost all drifters and trawlers requisitioned at this time were sent to the Baltic Sea rather than being used to guard the Norwegian coast.Paterson, pp.139-141 There were a few minor windfalls for the stretched auxiliary forces, however, such as on 5 May when three British armed trawlers and a Norwegian torpedo boat ran aground in a German-controlled area to escape Luftwaffe bombers. The ships were captured and the trawlers were pressed into service as Friese, Salier, and Franke.Paterson, p.148
Invasions of France and the Low Countries Even though the invasion and occupation of Norway and Denmark consumed the bulk of available Vorpostenboote, patrols in the North Sea had to continue in order to keep U-boat routes safe and clear of mines. With reduced numbers, the flotillas in the North Sea were susceptible to attack from British bombers and mines. The Hugo Homann fell victim to both these hazards: it was sunk by bombers on 15 April, salvaged and returned to service, and then promptly struck a mine and sunk on 6 May.Paterson, p.149
During the invasion of the Netherlands, Belgium and the Battle of France, Vorpostenboote mostly continued their usual duties without much interruption. During the entire period of the Battle of France, only a single Vorpostenboot was lost, when the Bayern struck a mine in the North Sea on 9 June.Paterson, p.152 Once the Dutch capitulated, the Kriegsmarine immediately began evaluating captured trawlers for their suitability to be converted into minesweepers and Vorpostenboote. More than 300 suitable vessels were identified, which would be necessary to clear mines from and defend the recently captured French, Dutch, and Belgian harbors.Paterson, p.153
Once the new front in the West was opened, pressure on Norway eased significantly. However, British submarines were still laying mines and harassing vessels off the coast. In May, Antares fell victim to a mine and in June HMS Snapper ambushed a merchant convoy and sank Vorpostenboot Portland.Kindell, June 1940 (Part 4)
Occupation and reorganization Following the capitulation of France, the Low Countries, and Norway, the Kriegsmarine had a coastline from the Arctic to Spain to protect. This entire stretch had to be cleared of existing mines, patrolled, and protected from submarines or re-mining. The demands of this task led to a major restructuring of the auxiliary navy, with new commands being established and new ships requisitioned and commissioned. Most of these were minesweepers and Sperrbrecher, but there were a handful of new formations which incorporated Vorpostenboote, such as the KSV norwegische Westküste in Bergen. Initially, the command consisted of just four fishing ships and two Vorpostenboote, but it would eventually expand to 45 vessels spread between three Vp-flotillas and a minesweeper flotilla.Paterson, pp.170-172
The Kriegsmarine were not the only ones who were unprepared for this new situation. Britain's RAF Coastal Command was initially ineffective in disrupting German convoys. Poorly equipped and coordinated, the British bombers were unable to deal significant damage to convoys between Norway and Germany, partially because of effective protection offered by Vorpostenboote and Sperrbrecher escorts.Paterson, p.190 However, these circumstances would shift in 1941 as Coastal Command received better aircraft, better intelligence, and the results of cracking German ciphers such as the Enigma codes. The greater threat posed by aircraft led to a gradual increase in anti-aircraft armaments carried on Vorpostenboote as the war went on, ultimately resulting in them being dubbed "flak ships" by Allied aviators.Paterson, p.191
Despite the growing capabilities of the British, total numbers of auxiliary warships in the Kriegsmarine continued to grow through 1941. The Security Forces underwent another reorganization, and by the end of the year four Sicherungsdivisions (Security Divisions) were established and steadily growing in size. Each of these consisted of five or six flotillas, of which one or two were Vp-flotillas.Paterson, p.198-201
Invasion of the Soviet Union
In June 1941, Germany turned east and invaded the Soviet Union in Operation Barbarossa. As this would primarily be a land war, the Kriegsmarine would play only a minor role in the invasion. Its main goal was to prevent any Soviet vessels from escaping the Baltic. However, there was a strong desire to avoid any major naval engagements, since once the port of Leningrad was taken, Soviet naval resistance would be made impossible.Paterson, pp. 219-220 At the outset of the invasion, the Kriegsmarine was mainly occupied with minelaying and minesweeping, and the 3rd Vp-flotilla was part of the large minesweeper contingent patrolling the Baltic Sea.Paterson, p. 220 There was resistance to this activity by Soviet surface ships, especially in the Gulf of Riga. One convoy escorted by Vorpostenboote was attacked by a large Soviet force of four MTBs, various aircraft, the cruiser Kirov and its supporting destroyers. The attack only managed to sink the landing ship Deutschland, inflicting minor damage on several other escort ships. Similar attempts to contest the Baltic were ultimately unsuccessful, but did serve to slow the German advance and prevent total control of the sea.Paterson, p. 226
Channel Dash