Naval Systems

Frauenlob class minesweeper

Also known as
  • Frauenlob class
  • Frauenlob-class minesweeper
  • Frauenlob-Klasse
  • Class 394
  • Klasse 394
  • Class 362
  • Klasse 362
  • Binnenminensuchboot Frauenlob
  • Type 394 coastal minesweeper
  • Frauenlobstrasse Type 394
  • M 2658 Frauenlob
  • M 2671 Frauenlob
  • W 31 Frauenlob

The Frauenlob class was a West German wooden-hulled inshore mine-warfare boat family built by Krögerwerft at Rendsburg. Bundesarchiv-linked records and specialist ship databases describe the boats as Class 362 coastal guard craft that became Class 394 inshore minesweepers, with ten Bundesmarine hulls entering service from 1966 to 1969 and three former German boats later forming part of Estonia's post-restoration mine-countermeasures force into the 2000s.

Frauenlob class minesweeper, Inshore minesweeper class, Naval Systems
Image source: Wikimedia Commons: FRAUENLOB 0014.jpg
Profile / Specs

Profile

Origin
Germany
Built by
Krögerwerft
Type
Inshore minesweeper class
Service note
1966-2002 German service, followed by Estonian transfer service into the 2000s
Produced
1964-1968 construction; 1966-1969 commissioning
Number built
10

Specifications

Length
43.80 m overall
Length between perpendiculars
38.01 m in the public class summary
Beam
8.20 m in SchiffsSpotter and class summaries; HMA lists 8.29 m for Frauenlob
Draft
2.10 m
Displacement
238 t in SchiffsSpotter/class summaries; HMA lists 249 t maximum for Frauenlob
Crew
24 in HMA; 28 in SchiffsSpotter/class summaries; some English-language summaries list 25
Propulsion
Two Mercedes-Maybach 12-cylinder diesel engines, each rated at 736 kW / 1,000 PS in SchiffsSpotter data
Propellers
Two four-bladed propellers, 1.18 m diameter in German class data
Speed
14.5 kn
Armament
One 40 mm L/70 Bofors gun and minesweeping gear
Mine-warfare fit
Minesweeping gear, with HMA listing 30 mines on rails for the minelayer configuration and English-language summaries describing magnetic/acoustic sweeping arrangements
Designation And Service Context

The Frauenlob class is best read as a small mine-countermeasures support class rather than as a combatant with documented conflict employment. German archival metadata identifies Class 394 as a former Class 362 coastal guard-boat/minesweeper program, while public ship lists show the boats moving through different W, M, and sometimes Y pennant-number conventions during service.

German service

Ten boats commissioned from 1966 to 1969 and served in Bundesmarine mine-warfare formations before withdrawals from the mid-1990s through 2002.

Sources: Historisches Marinearchiv Class 394 List; SchiffsSpotter: Binnenminensuchboot Frauenlob.

Estonian service

Estonia received former German Frauenlob-class boats as Olev, Kalev, and Vaindlo while rebuilding a mine-countermeasures force after independence; open sources differ on final retirement dates, so the page avoids a single exact end date.

Sources: Estonian Defence Forces Navy History; HMA records for Minerva/Kalev, Diana/Olev, and Undine/Vaindlo.

Mine-warfare role

The class combined a 40 mm Bofors gun with minesweeping equipment for inshore and coastal mine-countermeasures work, and HMA records also list a minelayer configuration carrying mines on rails.

Sources: M 2671 Frauenlob - Das Historische Marinearchiv; SchiffsSpotter: Binnenminensuchboot Frauenlob; GlobalSecurity: Type 394 Coastal Minesweeper.

Variants

Public records distinguish the original Class 362 coastal-guard designation from the Class 394A/394B inshore-minesweeper service designation; Estonian service reused three former German hulls under new names.

VariantConfigurationDesignation notes
Class 394AMain inshore-minesweeper subclass

German public class lists identify eight of the ten Frauenlob-class boats as Class 394A after their original Class 362 coastal-guard designation.

Sources: Frauenlob-Klasse - German Wikipedia, Historisches Marinearchiv Class 394 List

Class 394BTwo-boat subclass

Frauenlob and Minerva are listed as Class 394B boats in the public class record, while the wider family remained the Class 394 Frauenlob inshore-minesweeper class.

Sources: Frauenlob-Klasse - German Wikipedia, SchiffsSpotter: Binnenminensuchboot Frauenlob

Estonian Navy Olev, Kalev, and VaindloTransferred former German hulls

Estonian Defence Forces history lists Olev, Kalev, and Vaindlo as former West German Frauenlob-class minesweepers received from Germany during the rebuilt Estonian Navy's early mine-countermeasures period.

Sources: Estonian Defence Forces Navy History

Shipboard Gun

Frauenlob-class records identify the class armament as a single 40 mm L/70 Bofors gun alongside mine-warfare equipment.

Carried itemItem typeCarriage evidence
Bofors 40 mm L/70, 40 mm towed anti-aircraft autocannon, Air DefenseBofors 40 mm L/7040 mm naval and anti-aircraft gun

SchiffsSpotter lists Frauenlob with one 40 mm 40/L70 Bofors gun; the German class summary also lists a single 40 mm L/70 Bofors mount for the class.

Sources: SchiffsSpotter: Binnenminensuchboot Frauenlob, Frauenlob-Klasse - German Wikipedia

Timeline

Frauenlob class minesweeper Key Events

  1. Class 394 technical records begin

    A Bundesarchiv record surfaced through Deutsche Digitale Bibliothek places Frauenlob-class Class 394 technical-supervision files, including a 1964 general plan, in the BWB shipbuilding-technology archive series.

  2. Lead boat enters Bundesmarine service

    Specialist ship records list Frauenlob entering Bundesmarine service in September 1966 as a Class 394 inshore minesweeper after launch and fitting-out at Krögerwerft.

  3. Ten-boat class enters service

    Historisches Marinearchiv's class list shows ten Frauenlob-class Class 394 boats commissioning between 1966 and 1969, from Frauenlob through Acheron.

  4. Former German boats join Estonia

    Estonian Defence Forces history records former German Frauenlob-class minesweepers entering Estonian service as Olev and Kalev in 1997, with Vaindlo following in 2003.

  5. Transferred boats leave Estonian service

    Estonian Defence Forces material places the last Frauenlob-class retirements in the same period that Estonia shifted to later mine-countermeasures ships, before Sandown-class minehunters became the navy's main mine-warfare vessels.

Media

Frauenlob class minesweeper Images

Frauenlob class minesweeper, Inshore minesweeper class, Naval Systems - view 1
Source: Wikimedia Commons: FRAUENLOB 0013.jpg
Frauenlob class minesweeper, Inshore minesweeper class, Naval Systems - view 2
Source: Wikimedia Commons: Minensuchboot Minerva M2663
Frauenlob class minesweeper, Inshore minesweeper class, Naval Systems - view 3
Source: Wikimedia Commons: UNDINE 0029.jpg
Frauenlob class minesweeper, Inshore minesweeper class, Naval Systems - view 4
Source: Wikimedia Commons: Minestryger til ophugning 1996
Frauenlob class minesweeper, Inshore minesweeper class, Naval Systems - view 5
Source: Wikimedia Commons: Binnenminensuchboot alberthafen.JPG
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Sources

M 2671 Frauenlob - Das Historische MarinearchivPublisher: Das Historische Marinearchiv | Note: Supports the Frauenlob Class 394/362 classification, Bundesmarine customer, Krögerwerft Rendsburg build yard, yard number, build start, launch, commissioning, and decommissioning dates for a Frauenlob-class boat. | Accessed: 2026-07-13SchiffsSpotter: Binnenminensuchboot FrauenlobPublisher: SchiffsSpotter.de | Note: Supports the class designation, Kröger-Werft Rendsburg build attribution, launch and service dates for M 2658, dimensions, propulsion, speed, crew, displacement, and armament. | Accessed: 2026-07-13Historisches Marinearchiv Class 394 ListPublisher: Das Historische Marinearchiv | Note: Supports the ten Class 394 ex-362 Bundesmarine boats, their names, class listing, and commissioning/decommissioning date range from Frauenlob through Acheron. | Accessed: 2026-07-13Deutsche Digitale Bibliothek: BArch BV 5/79180Publisher: Deutsche Digitale Bibliothek / Bundesarchiv | Note: Supports Bundesarchiv archival context for Class 394 Frauenlob technical-supervision records, the former Class 362 designation, the BWB provenance, and the 1964-1970 file period. | Accessed: 2026-07-13Estonian Defence Forces Navy HistoryPublisher: Estonian Defence Forces | Note: Supports Estonia receiving former West German Frauenlob-class minesweepers Olev, Kalev, and Vaindlo, and places them in the rebuilt Estonian Navy's mine-countermeasures development before later Sandown-class minehunters. | Accessed: 2026-07-13GlobalSecurity: Type 394 Coastal MinesweeperPublisher: GlobalSecurity.org | Note: Supports English-language summary data for Type 394 mine-countermeasures role, sweeping equipment description, armament, propulsion power, speed, crew, and unit listing; used cautiously because some text appears machine-translated. | Accessed: 2026-07-13Frauenlob-Klasse - German WikipediaPublisher: Wikipedia | Note: Baseline terminology source for the Class 362 to Class 394 designation, Class 394A/394B split, wooden construction, operators, dimensions, propulsion, armament, and hull list; retained as a secondary lead source rather than sole authority. | Accessed: 2026-07-13Wikimedia Commons: FRAUENLOB 0014.jpgPublisher: Wikimedia Commons | Note: Supports image provenance and CC BY-SA 4.0 licensing for a 1989 photograph of the Frauenlob-class lead boat at sea. | Accessed: 2026-07-13Wikimedia Commons: FRAUENLOB 0013.jpgPublisher: Wikimedia Commons | Note: Supports image provenance and CC BY-SA 4.0 licensing for a second 1989 photograph of the Frauenlob-class lead boat at sea. | Accessed: 2026-07-13Wikimedia Commons: Minensuchboot Minerva M2663Publisher: Wikimedia Commons | Note: Supports image provenance and CC BY-SA 4.0 licensing for a photograph of the Frauenlob-class Minerva at the Neustadt naval base in 1979. | Accessed: 2026-07-13Wikimedia Commons: UNDINE 0029.jpgPublisher: Wikimedia Commons | Note: Supports image provenance and CC BY-SA 4.0 licensing for a 1989 photograph of the Frauenlob-class Undine at anchor. | Accessed: 2026-07-13Wikimedia Commons: Minestryger til ophugning 1996Publisher: Wikimedia Commons | Note: Supports image provenance and CC BY-SA 3.0 licensing for a former Frauenlob-class minesweeper, identified as Nautilus, photographed at a Danish scrapyard. | Accessed: 2026-07-13Wikimedia Commons: Binnenminensuchboot alberthafen.JPGPublisher: Wikimedia Commons | Note: Supports image provenance and CC BY 3.0 / GFDL licensing for the Frauenlob-class Atlantis image. | Accessed: 2026-07-13