The Otra and the Rauma

HNoMS Rauma (1939)

As the threat of war in Europe became ever more clear the decision was made to improve the Royal Norwegian Navy's mine warfare capabilities. At first a number of 2. class gunboats were rebuilt into minelayers and minesweepers, but with war looming it soon became clear that more capable vessels were...

 were two purpose-built minesweepers constructed at Nylands Verksted in Oslo

Oslo

Oslo is a municipality, as well as the capital and most populous city in Norway. As a municipality , it was established on 1 January 1838. Founded around 1048 by King Harald III of Norway, the city was largely destroyed by fire in 1624. The city was moved under the reign of Denmark–Norway's King...

. Both ships were completed and commissioned only a short time before the German invasion of Norway

Operation Weserübung

Operation Weserübung was the code name for Germany's assault on Denmark and Norway during the Second World War and the opening operation of the Norwegian Campaign...

. The Otra class vessels used the Oropesa

Oropesa

An Oropesa is a streamlined towed body used in the process of minesweeping. The role of the Oropesa is to keep the towed sweep at a determined depth and position from the sweeping ship....

 system of mine sweeping. As the threat of war in Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

 became ever more clear the decision was made to improve the Royal Norwegian Navy

Royal Norwegian Navy

The Royal Norwegian Navy is the branch of the Norwegian Defence Force responsible for naval operations. , the RNoN consists of approximately 3,700 personnel and 70 vessels, including 5 heavy frigates, 6 submarines, 14 patrol boats, 4 minesweepers, 4 minehunters, 1 mine detection vessel, 4 support...

's mine warfare

Mine warfare

Mine warfare refers to the use of different types of explosive devices:*Land mine, a weight-triggered explosive device intended to maim or kill people or to destroy vehicles...

 capabilities. At first a number of 2. class gunboats were rebuilt into minelayer

Minelayer

Minelaying is the act of deploying explosive mines. Historically this has been carried out by ships, submarines and aircraft. Additionally, since World War I the term minelayer refers specifically to a naval ship used for deploying naval mines...

s and mine sweepers

Minesweeper (ship)

A minesweeper is a small naval warship designed to counter the threat posed by naval mines. Minesweepers generally detect then neutralize mines in advance of other naval operations.-History:...

, but with war looming it soon became clear that more capable vessels were required.

Prelude

Shortly before the German invasion the UK

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 announced that the Royal Navy

Royal Navy

The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

 had laid a number of minefields

Operation Wilfred

Operation Wilfred was a British naval operation during World War II that involved the mining of the channel between Norway and her offshore islands in order to prevent the transport of swedish iron ore through neutral Norwegian waters to be used to sustain the German war effort...

 along the coast of Norway to interfere with the German import of Swedish iron ore

Swedish iron ore during World War II

Swedish iron ore was an important economic factor in the European Theatre of World War II. Both the Allies and the Third Reich were keen on the control of the mining district in northernmost Sweden, surrounding the mining towns of Gällivare and Kiruna...

 through the North Norwegian port of Narvik

Narvik

is the third largest city and municipality in Nordland county, Norway by population. Narvik is located on the shores of the Narvik Fjord . The municipality is part of the Ofoten traditional region of North Norway, inside the arctic circle...

. The British government claimed to have mined three areas; off Stad

Stad (peninsula)

Stad or Stadlandet is a peninsula in the municipality of Selje in Sogn og Fjordane county, Norway.The name is sometimes also written as Stadt, Statt or Stadlandet–not to be confused with the similar German word Stadt. The d in Stad is pronounced in Norwegian as a t. The Stad peninsula has a...

, Hustadvika

Hustadvika

Hustadvika is a long section of coastline outside the municipality of Fræna in Romsdal, Møre og Romsdal county, Norway. It is located in the shipping route between Molde and Kristiansund. The area is shallow and is full of little islands and reefs...

, and Landegode north of Bodø

Bodø

is a city and a municipality in Nordland county, Norway. It is part of the Salten region.The city of Bodø was established as a municipality on 1 January 1838 . Bodin was merged with Bodø on 1 January 1968. Skjerstad was merged with Bodø on 1 January 2005...

. In response to this report, the Norwegian government ordered the minesweepers Otra and Rauma to sail north from their base in Horten

Horten

is a town and municipality in Vestfold county, Norway—located along the Oslofjord. The administrative centre of the municipality is the town of Horten. The municipality also includes the villages of Borre, Åsgårdstrand, Skoppum, and Nykirke....

 and sweep the minefields on 9 April 1940.

Otra spots the invasion force

Before the order to go north could be carried out, however, the German invasion of Norway took place in the early hours of 9 April. As reports of intruding warships started coming in the Otra was sent out to investigate, and at 0410hrs report that the intruders were Germans. The invasion flotilla blocked the Otras return to Horten.

Capture

While her sister ship, HNoMS Rauma, was fighting the German naval forces in Horten Otra was cut off and isolated from the action. The next morning, 10 April, she was captured while at anchor in Filtvet

Filtvet

Filtvet is a small village along the Oslofjord in Hurum, Buskerud County, Norway.-Location:Filtvet is a 45 minute journey to Oslo by car. It has become a popular tourist destination during summer. Accommodation consist principally of camping sites. Filtvet lighthouse is on the west side of...

.

German service as the Togo

After capture the Otra was renamed the Togo and put in service as a Vorpostenboot

Vorpostenboot

Vorpostenboots were German patrol boats which served during both World Wars...

 and minelayer for the rest of the war. First the Togo served in as part of Hafenschutzflotille Tromsø

Tromsø

Tromsø is a city and municipality in Troms county, Norway. The administrative centre of the municipality is the city of Tromsø.Tromsø city is the ninth largest urban area in Norway by population, and the seventh largest city in Norway by population...

 guarding that northern city's harbour. Later she was transferred to Hafenschutzflotille Oslo. In 1941 the Togo was part of 59 Vorpoostenflotille as V 5908, where she served until April 1944 when she transferred to Vorpoostenflotille 65 as V 6512. After the German surrender she was part of the German Mine Sweeping Administration

German Mine Sweeping Administration

The German Mine Sweeping Administration was formed from former crews and vessels of the Nazi German Kriegsmarine for the purpose of mine sweeping after the Second World War, predominantly in the North Sea and Baltic Sea, and existed from June 1945 to January 1948.-History:The GMSA was formed on 21...

 (GM-SA).

Post-war service

On 18 January 1946 the Togo was returned to the Royal Norwegian Navy at Bogen

Bogen, Evenes

Bogen is the administrative centre of Evenes municipality, Norway. Its population is 392.Historically, Bogen is most notable for small-scale iron ore mining in the early 20th century as well as being a temporary base for the German battleship Tirpitz and cruiser Admiral Hipper.-References:...

 and on 30 October 1946 was renamed the HNoMS Otra. In April 1949 she was rebuilt as a minelayer training ship. 21 August 1959 saw her decommissioning and she was laid up at Horten until put out of service and sold in April 1963.