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Repository for data pertaining to subject class of vessels

Arendsee class Minesweeper (Multi-purpose Minecraft Type 1940 Rev B) laid down 1940

Displacement: 496 t light; 526 t standard; 600 t normal; 660 t full load

Dimensions: Length overall / water x beam x draught

202.08 ft / 196.85 ft x 24.61 ft x 7.55 ft (normal load) [61.59 m / 60.00 m x 7.50 m x 2.30 m]

Armament:

2 - 4.13" / 105 mm guns in single mounts, 35.32lbs / 16.02kg shells, 1940 Model Dual purpose guns in deck mounts with hoists on centreline ends, evenly spread
2 - 1.46" / 37.0 mm guns (1x2 guns), 1.55lbs / 0.70kg shells, 1940 Model Anti-aircraft guns in deck mount on centreline amidships, all raised guns – superfiring
8 - 0.79" / 20.0 mm guns (4x2 guns), 0.24lbs / 0.11kg shells, 1940 Model Anti-aircraft guns in deck mounts on side, evenly spread, all raised mounts
Weight of broadside 76 lbs / 34 kg
Shells per gun, main battery: 400

Armour:

Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.18" / 30 mm 0.59" / 15 mm 1.18" / 30 mm
2nd: 0.59" / 15 mm 0.39" / 10 mm -
3rd: 0.59" / 15 mm - -

Machinery:

Coal fired boilers, complex reciprocating steam engines, Direct drive, 2 shafts, 1,524 ihp / 1,137 Kw = 16.00 kts
Range 3,000nm at 12.00 kts
Bunker at max displacement = 134 tons (100% coal)

Complement: 59 - 78

Cost: £0.229 million / $0.918 million

Distribution of weights at normal displacement:

Armament: 9 tons, 1.6 %
Armour: 6 tons, 1.1 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 6 tons, 1.1 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 92 tons, 15.4 %
Hull, fittings & equipment: 288 tons, 48.0 %
Fuel, ammunition & stores: 104 tons, 17.3 %
Miscellaneous weights: 100 tons, 16.7 %

Overall survivability and seakeeping ability:

Survivability (Non-critical penetrating hits needed to sink ship):1,302 lbs / 590 Kg = 36.8 x 4.1 " / 105 mm shells or 0.7 torpedoes
Stability (Unstable if below 1.00): 1.10
Metacentric height 0.7 ft / 0.2 m
Roll period: 12.1 seconds
Steadiness - As gun platform (Average = 50 %): 44 %
- Recoil effect (Restricted arc if above 1.00): 0.47
Seaboat quality (Average = 1.00): 1.76


Hull form characteristics:

Hull has raised forecastle, low quarterdeck
Block coefficient: 0.575
Length to Beam Ratio: 8.00 : 1
'Natural speed' for length: 14.03 kts
Power going to wave formation at top speed: 52 %
Trim (Max stability = 0, Max steadiness = 100): 22
Bow angle (Positive = bow angles forward): 12.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 24.61 ft / 7.50 m
- Forecastle (20 %): 22.97 ft / 7.00 m (14.76 ft / 4.50 m aft of break)
- Mid (35 %): 14.76 ft / 4.50 m
- Quarterdeck (35 %): 6.56 ft / 2.00 m (14.76 ft / 4.50 m before break)
- Stern: 6.56 ft / 2.00 m
- Average freeboard: 13.66 ft / 4.17 m

Ship space, strength and comments:

Space - Hull below water (magazines/engines, low = better): 82.8 %
- Above water (accommodation/working, high = better): 164.9 %
Waterplane Area: 3,461 Square feet or 322 Square metres
Displacement factor (Displacement / loading): 164 %
Structure weight / hull surface area: 36 lbs/sq ft or 178 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.78
- Longitudinal: 9.29
- Overall: 1.00
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Excellent seaboat, comfortable, can fire her guns in the heaviest weather

Miscellaneous weight - 100 tons reserved for minesweeping gear and up to 30 mines dependant upon employment

Vessels in class:

Arendsee – Laid down 1 Jul 1940; Launched 30 Aug 1940; Completed 16 Nov 1940
Kolpinsee – Laid down 1 Jul 1940; Launched 30 Aug 1940; Completed 16 Nov 1940
Blankensee – Laid down 1 Oct 1940; Launched 30 Nov 1940; Completed 16 Feb 1941
Muggelsee – Laid down 1 Oct 1940; Launched 30 Nov 1940; Completed 16 Feb 1941
Fleesensee – Laid down 1 Jan 1941; Launched 2 Mar 1941; Completed 19 May 1941
Rhinsee – Laid down 1 Jan 1941; Launched 2 Mar 1941; Completed 19 May 1941
Schwielowsee – Laid down 1 Apr 1941; Launched 31 May 1941; Completed 17 Aug 1941
Werbellinsee – Laid down 1 Apr 1941; Launched 31 May 1941; Completed 17 Aug 1941
Amersee – Laid down 1 Jul 1941; Launched 30 Aug 1941; Completed 16 Nov 1941
Wendsee – Laid down 1 Jul 1941; Launched 30 Aug 1941; Completed 16 Nov 1941
Dummersee – Laid down 1 Oct 1941; Launched 30 Nov 1941; Completed 16 Feb 1942
Edersee – Laid down 1 Oct 1941; Launched 30 Nov 1941; Completed 16 Feb 1942
Baalensee - Laid down 1 Jan 1942; Launched 2 Mar 1942; Completed 19 May 1942
Stolpsee - Laid down 1 Jan 1942; Launched 2 Mar 1942; Completed 19 May 1942
Gathensee - Laid down 1 Apr 1942; Launched 31 May 1942; Completed 17 Aug 1942
Kellersee - Laid down 1 Apr 1942; Launched 31 May 1942; Completed 17 Aug 1942

Räumboote Typ 1941



Tonnage – 150 tons (166 tons full load)
Dimensions – Length 41.1 metres; Beam 5.80 metres; Draft 1.60 metres
Machinery – Two shafts, Maschinenfabrik Augsburg-Nurnberg diesel motors, BHP 1,800 = 19 knots. Bunker capacity 11 tons, radius 1,000 nm at 15 knots
Armament –One single 20mm FlaK38 forward of the cockpit, one single 20mm FlaK38 amidships, one 37mm FlaK38 aft
Crew – 38

Construction:

R101 – R102: 3rd Quarter 1941
R103 – R104: 4th Quarter 1941
R105 – R106: 1st Quarter 1942
R107 – R108: 2nd Quarter 1942
R109 – R110: 3rd Quarter 1942
R111 – R112: 4th Quarter 1942
R113 – R114; 1st Quarter 1943
R115 – R116; 2nd Quarter 1943

Minesweeper Type 1942, German Multi-purpose Minecraft laid down 1942

Displacement: 447 t light; 475 t standard; 600 t normal; 701 t full load

Dimensions: Length overall / water x beam x draught

202.08 ft / 196.85 ft x 24.61 ft x 7.55 ft (normal load) [61.59 m / 60.00 m x 7.50 m x 2.30 m]

Armament:

2 - 4.13" / 105 mm guns in single mounts, 35.32lbs / 16.02kg shells, 1940 Model Dual purpose guns in deck mounts on centreline ends, evenly spread
2 - 1.46" / 37.0 mm guns (1x2 guns), 0.00lbs / 0.00kg shells, 1938 Model Anti-aircraft guns in deck mount on centreline amidships, all raised guns - superfiring
8 - 0.79" / 20.0 mm guns (4x2 guns), 0.24lbs / 0.11kg shells, 1938 Model Anti-aircraft guns in deck mounts on side, evenly spread, all raised mounts
Weight of broadside 73 lbs / 33 kg
Shells per gun, main battery: 400

Armour:

Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.79" / 20 mm 0.39" / 10 mm -
2nd: 0.59" / 15 mm 0.39" / 10 mm -
3rd: 0.59" / 15 mm - -

Machinery:

Diesel Internal combustion motors, Geared drive, 2 shafts, 2,447 shp / 1,825 Kw = 18.00 kts
Range 5,100nm at 15.00 kts
Bunker at max displacement = 225 tons

Complement: 59 - 78

Cost: £0.205 million / $0.820 million

Distribution of weights at normal displacement:

Armament: 9 tons, 1.5 %
Armour: 5 tons, 0.8 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 5 tons, 0.8 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 64 tons, 10.6 %
Hull, fittings & equipment: 269 tons, 44.8 %
Fuel, ammunition & stores: 154 tons, 25.6 %
Miscellaneous weights: 100 tons, 16.7 %

Overall survivability and seakeeping ability:

Survivability (Non-critical penetrating hits needed to sink ship): 1,614 lbs / 732 Kg = 45.7 x 4.1 " / 105 mm shells or 0.9 torpedoes
Stability (Unstable if below 1.00): 1.10
Metacentric height 0.7 ft / 0.2 m
Roll period: 12.0 seconds
Steadiness - As gun platform (Average = 50 %): 60 %
- Recoil effect (Restricted arc if above 1.00): 0.27
Seaboat quality (Average = 1.00): 2.00

Hull form characteristics:

Hull has raised forecastle, low quarterdeck
Block coefficient: 0.575
Length to Beam Ratio: 8.00: 1
'Natural speed' for length: 14.03 kts
Power going to wave formation at top speed: 58 %
Trim (Max stability = 0, Max steadiness = 100): 30
Bow angle (Positive = bow angles forward): 12.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 24.61 ft / 7.50 m
- Forecastle (20 %): 22.97 ft / 7.00 m (14.76 ft / 4.50 m aft of break)
- Mid (35 %): 14.76 ft / 4.50 m
- Quarterdeck (35 %): 6.56 ft / 2.00 m (14.76 ft / 4.50 m before break)
- Stern: 6.56 ft / 2.00 m
- Average freeboard: 13.66 ft / 4.17 m

Ship space, strength and comments:

Space - Hull below water (magazines/engines, low = better): 67.1 %
- Above water (accommodation/working, high = better): 164.9 %
Waterplane Area: 3,461 Square feet or 322 Square metres
Displacement factor (Displacement / loading): 197 %
Structure weight / hull surface area: 34 lbs/sq ft or 166 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.79
- Longitudinal: 9.02
- Overall: 1.00
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Excellent seaboat, comfortable, can fire her guns in the heaviest weather


Breakdown of miscellaneous weight

Reserved for minesweeping gear - 50 tons
Reserved for radar - 20 tons
Reserved for sonar - 20 tons
Reserved for future growth - 10 tons


Avensee: Laid down 15 Jun 1942; Launched 14 Aug 1942; Completed 28 Oct 1942
Kuchelsee: Laid down 15 Jun 1942; Launched 14 Aug 1942; Completed 28 Oct 1942
Barmsee: Laid down 1 Sep 1942; Launched 31 Oct 1942; Completed 14 Jan 1943
Leppinsee: Laid down 1 Sep 1942; Launched 31 Oct 1942; Completed 14 Jan 1943
Forggensee: Laid down 15 Nov 1942; Launched 14 Jan 1943; Completed 30 Mar 1943
Pomelsee: Laid down 15 Nov 1942; Launched 14 Jan 1943; Completed 30 Mar 1943
Jungfernsee: Laid down 1 Feb 1943; Launched 2 Apr 1943; Completed 16 Jun 1943
Seddensee: Laid down 1 Feb 1943; Launched 2 Apr 1943; Completed 16 Jun 1943

Spica class German Light Minelayer laid down 1931

(Converted from R-11 class Minesweepers)


Displacement: 546 t light; 568 t standard; 678 t normal; 766 t full load

Dimensions: Length overall / water x beam x draught

235.87 ft / 229.66 ft x 26.25 ft x 7.87 ft (normal load) [71.89 m / 70.00 m x 8.00 m x 2.40 m]

Armament:

2 - 4.13" / 105 mm guns (1x2 guns), 35.32lbs / 16.02kg shells, 1931 Model Dual purpose guns in deck mount on centreline forward
4 - 1.46" / 37.0 mm guns (2x2 guns), 1.55lbs / 0.70kg shells, 1938 Model Anti-aircraft guns in deck mounts on centreline ends, evenly spread, all raised mounts
4 - 0.79" / 20.0 mm guns (2x2 guns), 0.24lbs / 0.11kg shells, 1938 Model Anti-aircraft guns in deck mounts on centreline ends, evenly spread, all raised mounts
Weight of broadside 78 lbs / 35 kg
Shells per gun, main battery: 180

Armour:

Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.79" / 20 mm - -
2nd: 0.39" / 10 mm - -

Conning tower: 1.97" / 50 mm

Machinery:

Diesel Internal combustion motors, Geared drive, 2 shafts, 9,152 shp / 6,827 Kw = 25.00 kts
Range 4,000nm at 15.00 kts
Bunker at max displacement = 197 tons

Complement: 66 - 86

Cost: £0.278 million / $1.110 million

Distribution of weights at normal displacement:

Armament: 10 tons, 1.4 %
Armour: 7 tons, 1.0 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 3 tons, 0.5 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 3 tons, 0.5 %
Machinery: 259 tons, 38.2 %
Hull, fittings & equipment: 181 tons, 26.7 %
Fuel, ammunition & stores: 132 tons, 19.4 %
Miscellaneous weights: 90 tons, 13.3 %

Overall survivability and seakeeping ability:

Survivability (Non-critical penetrating hits needed to sink ship): 282 lbs/128 Kg = 8.0 x 4.1"/105mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.24
Metacentric height 1.0 ft / 0.3 m
Roll period: 11.0 seconds
Steadiness - As gun platform (Average = 50 %): 67 %
- Recoil effect (Restricted arc if above 1.00): 0.15
Seaboat quality (Average = 1.00): 1.30

Hull form characteristics:

Hull has raised forecastle
Block coefficient: 0.500
Length to Beam Ratio: 8.75 : 1
'Natural speed' for length: 15.15 kts
Power going to wave formation at top speed: 67 %
Trim (Max stability = 0, Max steadiness = 100): 51
Bow angle (Positive = bow angles forward): 15.00 degrees
Stern overhang: 1.64 ft / 0.50 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 17.06 ft / 5.20 m
- Forecastle (33 %): 16.40 ft / 5.00 m (10.50 ft / 3.20 m aft of break)
- Mid (50 %): 10.50 ft / 3.20 m
- Quarterdeck (15 %): 10.50 ft / 3.20 m
- Stern: 10.50 ft / 3.20 m
- Average freeboard: 12.53 ft / 3.82 m

Ship space, strength and comments:

Space - Hull below water (magazines/engines, low = better): 149.4 %
- Above water (accommodation/working, high = better): 121.7 %
Waterplane Area: 4,016 Square feet or 373 Square metres
Displacement factor (Displacement / loading): 94 %
Structure weight / hull surface area: 22 lbs/sq ft or 108 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 2.86
- Overall: 0.60
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is excellent
Good seaboat, rides out heavy weather easily

Breakdown of Miscellaneous Weight

Air warning radar - 10 tons
Mine rails and mines - 80 tons

Refit/Conversion - Level III (cost 15% for vessels under 2,999 tons light)

Add radar
Modify armament
Modify superstructure to accommodate revised armament
Remove minesweeping equipment
Service life extension

Cost - 82 tons; Time - 43 days

Spica (ex-R21) – conversion commenced 1 April 1943; completed 14 May 1943
Altair (ex R22) – conversion commenced 1 April 1943; completed 14 May 1943
Regulus (ex R23) – conversion commenced 1 April 1943; completed 14 May 1943
Orion (ex R24) – conversion commenced 1 April 1943; completed 14 May 1943
Capella (ex R25) – conversion commenced 1 April 1943; completed 14 May 1943
Sirius (ex R26) – conversion commenced 1 April 1943; completed 14 May 1943
Rigel (ex R27) – conversion commenced 1 April 1943; completed 14 May 1943
Deneb (ex R28) – conversion commenced 1 April 1943; completed 14 May 1943

Minecraft Typ 1943 - Rev B, German Fleet Minesweeper laid down 1943

Displacement: 612 t light; 647 t standard; 916 t normal; 1,131 t full load

Dimensions: Length overall / water x beam x draught

227.05 ft / 219.82 ft x 28.87 ft x 9.02 ft (normal load) [69.21 m / 67.00 m x 8.80 m x 2.75 m]

Armament:

2 - 4.13" / 105 mm guns in single mounts, 35.32lbs / 16.02kg shells, 1943 Model Dual purpose guns in deck mounts with hoists on centreline ends, evenly spread
4 - 2.17" / 55.0 mm guns in single mounts, 5.08lbs / 2.30kg shells, 1943 Model Anti-aircraft guns in deck mounts on side, evenly spread
4 - 0.79" / 20.0 mm guns (2x2 guns), 0.24lbs / 0.11kg shells, 1938 Model Anti-aircraft guns in deck mounts on side, evenly spread, all raised mounts
Weight of broadside 92 lbs / 42 kg
Shells per gun, main battery: 300

Armour:

Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.18" / 30 mm 0.59" / 15 mm 1.18" / 30 mm
2nd: 0.59" / 15 mm 0.39" / 10 mm -
3rd: 0.59" / 15 mm - -

Machinery:

Diesel Internal combustion motors, Geared drive, 2 shafts, 4,667 shp / 3,481 Kw = 20.00 kts
Range 8,900nm at 15.00 kts
Bunker at max displacement = 484 tons

Complement: 83 - 108

Cost: £0.314 million / $1.255 million

Distribution of weights at normal displacement:

Armament: 11 tons, 1.3 %
Armour: 8 tons, 0.9 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 8 tons, 0.9 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 121 tons, 13.2 %
Hull, fittings & equipment: 342 tons, 37.3 %
Fuel, ammunition & stores: 304 tons, 33.2 %
Miscellaneous weights: 130 tons, 14.2 %

Overall survivability and seakeeping ability:

Survivability (Non-critical penetrating hits needed to sink ship): 2,002 lbs / 908 Kg = 56.7 x 4.1 " / 105 mm shells or 0.9 torpedoes
Stability (Unstable if below 1.00): 1.20
Metacentric height 1.1 ft / 0.3 m
Roll period: 11.6 seconds
Steadiness - As gun platform (Average = 50 %): 62 %
- Recoil effect (Restricted arc if above 1.00): 0.25
Seaboat quality (Average = 1.00): 1.52

Hull form characteristics:

Hull has rise forward of midbreak
Block coefficient: 0.560
Length to Beam Ratio: 7.61: 1
'Natural speed' for length: 14.83 kts
Power going to wave formation at top speed: 61 %
Trim (Max stability = 0, Max steadiness = 100): 41
Bow angle (Positive = bow angles forward): 18.00 degrees
Stern overhang: 1.64 ft / 0.50 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 17.22 ft / 5.25 m
- Forecastle (20 %): 15.58 ft / 4.75 m
- Mid (50 %): 15.58 ft / 4.75 m (8.53 ft / 2.60 m aft of break)
- Quarterdeck (30 %): 8.53 ft / 2.60 m
- Stern: 8.53 ft / 2.60 m
- Average freeboard: 12.19 ft / 3.72 m

Ship space, strength and comments:

Space - Hull below water (magazines/engines, low = better): 69.7 %
- Above water (accommodation/working, high = better): 130.9 %
Waterplane Area: 4,471 Square feet or 415 Square metres
Displacement factor (Displacement / loading): 194 %
Structure weight / hull surface area: 42 lbs/sq ft or 206 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.86
- Longitudinal: 3.84
- Overall: 1.00
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Excellent seaboat, comfortable, can fire her guns in the heaviest weather

Breakdown of Miscellaneous Weight

Air and surface warning radar - 20 tons
Gunnery control radar - 10 tons
ASDIC/Sonar - 20 tons
Minesweeping equipment - 50 tons
Basic ASW outfit (DC and K-guns) - 20 tons
Reserved for future growth - 10 tons


Mondsee - Laid down 1 Jul 1943; Launched 25 Oct 1943; Completed 14 Apr 1944
Attersee - Laid down 1 Jul 1943; Launched 25 Oct 1943; Completed 14 Apr 1944
Eissee - Laid down 9 Nov 1943; Launched 4 Mar 1944; Completed 27 Aug 1944
Traunsee - Laid down 9 Nov 1943; Launched 4 Mar 1944; Completed 27 Aug 1944
Fuschlsee - Laid down 19 Mar 1944; Launched 13 Jul 1944; Completed 1 Jan 1945
Wolfgangsee - Laid down 19 Mar 1944; Launched 13 Jul 1944; Completed 1 Jan 1945
Hallstättersee - Laid down 28 Jul 1944; Launched 21 Nov 1944; Completed 12 May 1945
Wörthersee - Laid down 28 Jul 1944; Launched 21 Nov 1944; Completed 12 May 1945

Rappensee, German Minesweeper laid down 1947

Displacement: 497 t light; 512 t standard; 575 t normal; 626 t full load

Dimensions: Length overall / water x beam x draught

184.40 ft / 180.45 ft x 30.51 ft x 8.20 ft (normal load) [56.21 m / 55.00 m x 9.30 m x 2.50 m]

Armament:

1 - 4.13" / 105 mm guns in single mounts, 35.32lbs / 16.02kg shells, 1947 Model Anti-aircraft gun in deck mount on centreline forward
2 - 1.46" / 37.0 mm guns (1x2 guns), 1.55lbs / 0.70kg shells, 1947 Model Anti-aircraft guns in deck mount on centreline aft, all raised guns - superfiring
4 - 0.79" / 20.0 mm guns (2x2 guns), 0.24lbs / 0.11kg shells, 1947 Model Anti-aircraft guns in deck mounts on centreline, all amidships, all raised mounts - superfiring
Weight of broadside 39 lbs / 18 kg
Shells per gun, main battery: 150

Armour:

Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.59" / 15 mm 0.39" / 10 mm -
2nd: 0.39" / 10 mm 0.39" / 10 mm -

Conning tower: 0.98" / 25 mm

Machinery:

Diesel Internal combustion generators, Electric motors, 2 shafts, 1,502 shp / 1,120 Kw = 16.00 kts
Range 5,000nm at 12.00 kts
Bunker at max displacement = 114 tons

Complement: 58 - 76

Cost: £0.194 million / $0.777 million

Distribution of weights at normal displacement:

Armament: 5 tons, 0.9 %
Armour: 4 tons, 0.6 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 2 tons, 0.4 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 1 tons, 0.3 %
Machinery: 37 tons, 6.5 %
Hull, fittings & equipment: 351 tons, 61.1 %
Fuel, ammunition & stores: 78 tons, 13.6 %
Miscellaneous weights: 100 tons, 17.4 %

Overall survivability and seakeeping ability:

Survivability (Non-critical penetrating hits needed to sink ship): 1,668 lbs / 757 Kg = 47.2 x 4.1 " / 105 mm shells or 1.3 torpedoes
Stability (Unstable if below 1.00): 1.10
Metacentric height 1.0 ft / 0.3 m
Roll period: 12.7 seconds
Steadiness - As gun platform (Average = 50 %): 66 %
- Recoil effect (Restricted arc if above 1.00): 0.05
Seaboat quality (Average = 1.00): 1.46

Hull form characteristics:

Hull has a flush deck
Block coefficient: 0.446
Length to Beam Ratio: 5.91: 1
'Natural speed' for length: 13.43 kts
Power going to wave formation at top speed: 54 %
Trim (Max stability = 0, Max steadiness = 100): 45
Bow angle (Positive = bow angles forward): 15.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 14.76 ft / 4.50 m
- Forecastle (20 %): 9.42 ft / 2.87 m
- Mid (50 %): 9.42 ft / 2.87 m
- Quarterdeck (25 %): 9.42 ft / 2.87 m
- Stern: 9.42 ft / 2.87 m
- Average freeboard: 9.84 ft / 3.00 m
Ship tends to be wet forward

Ship space, strength and comments:

Space - Hull below water (magazines/engines, low = better): 47.7 %
- Above water (accommodation/working, high = better): 108.2 %
Waterplane Area: 3,500 Square feet or 325 Square metres
Displacement factor (Displacement / loading): 265 %
Structure weight / hull surface area: 65 lbs/sq ft or 319 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.59
- Longitudinal: 5.19
- Overall: 1.79
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is adequate
Good seaboat, rides out heavy weather easily

Breakdown of miscellaneous weight:

Radar and electronics suite: 15 tons
Degaussing equipment: 10 tons
Paravanes and other minesweeping equipment/gear: 75 tons


Rappensee – Laid down 1 January 1947, launched 10 March 1947; Completed 16 May 1947
Heidensee – Laid down 1 January 1947, launched 10 March 1947; Completed 16 May 1947
Boggensee - Laid down 1 April 1947; launched 8 June 1947; Completed 14 August 1947
Lautersee - Laid down 1 April 1947; launched 8 June 1947; Completed 14 August 1947
Hopfensee - Laid down 1 July 1947; launched 7 September 1947; Completed 13 November 1947
Ploggensee - Laid down 1 July 1947; launched 7 September 1947; Completed 13 November 1947
Tietzowsee - Laid down 1 October 1947; launched 8 December 1947; Completed 13 February 1948
Trenntsee - Laid down 1 October 1947; launched 8 December 1947; Completed 13 February 1948

Aichwaldsee, German Minesweeper laid down 1950

Displacement: 463 t light; 477 t standard; 535 t normal; 582 t full load

Dimensions: Length overall / water x beam x draught

184.40 ft / 180.45 ft x 30.51 ft x 8.20 ft (normal load) [56.21 m / 55.00 m x 9.30 m x 2.50 m]

Armament:

1 - 4.13" / 105 mm guns in single mounts, 35.32lbs / 16.02kg shells, 1950 Model Anti-aircraft gun in deck mount on centerline forward
2 - 1.46" / 37.0 mm guns (1x2 guns), 1.55lbs / 0.70kg shells, 1950 Model Anti-aircraft guns in deck mount on centerline aft, all raised guns - superfiring
4 - 0.79" / 20.0 mm guns (2x2 guns), 0.24lbs / 0.11kg shells, 1950 Model Anti-aircraft guns in deck mounts on centerline, all amidships, all raised mounts - superfiring
Weight of broadside 39 lbs / 18 kg
Shells per gun, main battery: 150

Armor:

Gun armor: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.59" / 15 mm 0.39" / 10 mm -
2nd: 0.39" / 10 mm 0.39" / 10 mm -

Conning tower: 0.98" / 25 mm

Machinery:

Diesel Internal combustion motors, Geared drive, 2 shafts, 1,414 shp / 1,054 Kw = 16.00 kts
Range 5,000nm at 12.00 kts
Bunker at max displacement = 105 tons

Complement: 55 - 72

Cost: £0.196 million / $0.784 million

Distribution of weights at normal displacement:

Armament: 5 tons, 0.9 %
Armor: 3 tons, 0.6 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 2 tons, 0.4 %
- Armor Deck: 0 tons, 0.0 %
- Conning Tower: 1 tons, 0.3 %
Machinery: 34 tons, 6.3 %
Hull, fittings & equipment: 320 tons, 59.9 %
Fuel, ammunition & stores: 73 tons, 13.6 %
Miscellaneous weights: 100 tons, 18.7 %

Overall survivability and seakeeping ability:

Survivability (Non-critical penetrating hits needed to sink ship): 1,551 lbs / 704 Kg = 43.9 x 4.1 " / 105 mm shells or 1.2 torpedoes
Stability (Unstable if below 1.00): 1.10
Metacentric height 1.0 ft / 0.3 m
Roll period: 12.8 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.06
Seaboat quality (Average = 1.00): 1.55

Hull form characteristics:

Hull has a flush deck
Block coefficient: 0.415
Length to Beam Ratio: 5.91: 1
'Natural speed' for length: 13.43 kts
Power going to wave formation at top speed: 53 %
Trim (Max stability = 0, Max steadiness = 100): 45
Bow angle (Positive = bow angles forward): 15.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 14.76 ft / 4.50 m
- Forecastle (20 %): 9.42 ft / 2.87 m
- Mid (50 %): 9.42 ft / 2.87 m
- Quarterdeck (25 %): 9.42 ft / 2.87 m
- Stern: 9.42 ft / 2.87 m
- Average freeboard: 9.84 ft / 3.00 m
Ship tends to be wet forward

Ship space, strength and comments:

Space - Hull below water (magazines/engines, low = better): 49.1 %
- Above water (accommodation/working, high = better): 111.6 %
Waterplane Area: 3,421 Square feet or 318 Square meters
Displacement factor (Displacement / loading): 254 %
Structure weight / hull surface area: 61 lbs/sq ft or 298 Kg/sq meter
Hull strength (Relative):
- Cross-sectional: 1.48
- Longitudinal: 5.09
- Overall: 1.67
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is adequate
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather

Breakdown of miscellaneous weight:

Radar and electronics suite: 15 tons
Degaussing equipment: 10 tons
Paravanes and other minesweeping equipment/gear: 75 tons


Aichwaldsee – Laid down 1 January 1950; Launched 9 March 1950