HSwMS M 20

International Callsign: Sierra-Bravo-Zulu-Mike

M 20 history
1939-40 The M-boats are designed and drawn by Jac Iversen
1941 December 1, launching at Plyms Neglingevarv (Stockholms Båtbyggeri AB)
1941-45 Minesweeping and patrolling mainly in Öresund
1943 October, rescue of Danish Jews across Öresund
1945-46 Post-war minesweeping on the west coast
1946 -52 Exercises, minesweeping and navigation
1952-59 Stationary Nya Varvet, Gothenburg
1960 Minesweeping Varberg-Grenå
1961-64 Practices, minesweeping and navigation
1964-67 Stationary Nya Varvet, Gothenburg
1967-92 Trial vessel for FMV, Minbyrån under the name HMS Skuld
1993 Larger conversion to a training ship at the Island shipyard on Öckerö
1993-2004 School ship, training of cadets in navigation and seamanship
2005 The association M 20 is formed. The Maritime Museum takes over ownership
2005-present Maritime museum ship. Preserved, displayed and used by the Association M 20
2020-21 Major renovation and refurbishment at Beckholmen
2021 December 1, M 20 celebrates 80 years in Neglinge

During the 1st World War, the terrible effect of the mine was fully realized. Makeshift means were devised to sweep up these deadly weapons, such as older destroyers and torpedo boats as well as fishing vessels which were really unsuited to the task of towing minesweeps but there was nothing else. In 1915, the Germans developed a new type of ship designed solely for minesweeping - the minesweeper was born.

A minesweeper must, among other things, have the following characteristics: Seaworthy, wide stern to simplify the handling of the towed minesweepers, two propellers for good manoeuvrability, armament for self-defense and being ground-going to clear deeper anchored mines. Good seaworthiness is sometimes the opposite of low draft but the Germans managed quite well but all minesweepers are rank.

In Sweden, they were fully aware of the dangers of mines. Masses of mines were laid outside the country's borders and they had to be swept with the means at hand. The fleet got its first 3 "minesweepers" as a bonus of leftover money from the F-boat collection, the Sprängaren class. The 1918 blaster still exists today and is being fitted out as a museum ship. These first minesweepers were really nothing more than tugboats equipped for minesweeping.
During the interwar period, a minesweeper of the German type - the Arholma class, and also two so-called motorized minesweepers M 1 and M 2 - were developed. In addition to minesweeper capacity, the Arholma had relatively powerful artillery, sinker bombs and mines. Both types were very successful.

When the next world war seemed impossible to avoid, Sweden set about building warships for the Navy. Shipyard capacity hit the ceiling and it was not possible to build both types of minesweeper, so it was rightly chosen to build the larger, more powerful type, a total of 14 were built, they served until the mid-1960s. But the need for the smaller minesweeper remained for coastal and inland operations. Then someone in the Marine Administration had a bright idea! Why not build them in wood, there were plenty of wooden shipyards that were not fully occupied when the war started. The task of drawing such a project went to Jac Iversen, i.a. known for its beautiful sailing boats – the M-boat was born.

Length: 25 m, width: 5.1 m, draft 1.1 m, displacement: 51 tons, a bottom-going minesweeper with a wide stern deck, two propellers, a 20 mm anti-aircraft gun, a machine gun and sinker, of course also minesweeping equipment. The machinery initially consisted of various crude oil engines and semi-diesels, but was later equipped with two full diesel engines with a total of 400 hp. The propellers had adjustable KaMeWa-type blades which, among other things, enables propulsion out of the entire speed register. A first series of 12 ships, the so-called 39-type (projected in 1939) was built, followed by 12 ships of the 40-type (projected in 1940.) The 40-type was a little longer, got a stronger bow, modified wheelhouse, etc. They all had very good seaworthiness and maneuverability. The M 20 was built in 1941 at the Neglinge shipyard in Saltsjöbaden. As a bonus effect of the wooden construction, you got less ship magnetism which made it easier when sweeping magnetic mines. The presence of the magnetic mine was unknown in 1939. The crew consisted, for example, of 1 officer, 1 non-commissioned officer, 2 petty officers and 7 conscripted sailors. Many were skeptical about building warships out of wood, would they last? They expected a lifespan of 10-15 years and if there was a war, which was likely, they wouldn't be that long anyway. In fact, they became very long-lived, no one knows yet how old an M-boat can be.

The M-boats did good service during the 2nd World War and not least during the so-called post-war minesweeping when 10-thousands of mines laid around Sweden's coast were to be cleared. During the Second World War, when M 20 was stationed in Öresund for patrolling, mine clearance, etc., she saved hundreds of Danish Jews fleeing across the strait. By the mid-1960s the ships were becoming obsolete for minesweeping but they were very suitable training platforms for future naval officers to practice navigation and maneuver on and were used for this purpose. The 39 series was sold or rebuilt into sea surveying vessels, customs yachts, etc., the 40 series was modified to be used during war as patrol boats for clearing divers known as Bvröj. In peacetime they were used as training ships. M 20 was rebuilt, renamed Skuld and became a test vessel for the Norwegian Materiel Agency.

In the 1990s, the M-boats were no longer suitable even as Bvröj, but the need for training vessels remained. The M-boats in the best condition were rebuilt into pure training vessels, so also Skuld, which regained its old name M 20. They got a new aluminum wheelhouse, wider command bridge, modern navigation equipment, etc., the machinery was modernized with new Scania diesels with reversing instead of KaMeVa propellers , the exhaust pipes were pulled out through the floorboards instead of up through the chimney. Instead, a shower was built into the chimney, a concession to the female cadets who at that time began to be added to the defense, one may assume. The Mindurk was rebuilt into a student cabin with room for 3 cadets and the cannon was taken ashore. All this – cannon, ammunition, sweeper and sweeper equipment added up to considerable weight, so when it disappeared the M-boats became a bit "front-heavy" and quite wet in rough headwaters.

In 2005 after 64 years of service as minesweepers, training vessels and BV sweepers, the last M-boats were finally to be decommissioned, the Fleet had been supplied with new modern training vessels and the M-boats were to be sold. An association was formed with the aim of saving an M-boat. M 21 was looked at, but she was damaged by a grounding, so M 20 was chosen instead. After a number of "tours", the Statens Maritime Museums (SMM) took over the ownership of M 20. Today she is owned by SMM and operated as a living, seagoing museum ship by the M 20 Association, to the delight of the association's members and other people interested in naval history.

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