A possible offensive minelayer for the Kriegsmarine.
Brummer, Germany Minelayer laid down 1937
Displacement:
4,824 t light; 5,007 t standard; 5,521 t normal; 5,933 t full load
Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(513.48 ft / 498.69 ft) x 52.49 ft x (14.76 / 15.59 ft)
(156.51 m / 152.00 m) x 16.00 m x (4.50 / 4.75 m)
Armament:
8 - 4.13" / 105 mm 65.0 cal guns - 39.16lbs / 17.76kg shells, 360 per gun
Dual purpose guns in deck mounts, 1928 Model
4 x Twin mounts on centreline ends, evenly spread
2 raised mounts - superfiring
12 - 1.46" / 37.0 mm 83.0 cal guns - 1.77lbs / 0.80kg shells, 600 per gun
Anti-aircraft guns in deck mounts, 1929 Model
6 x Twin mounts on sides, evenly spread
6 raised mounts
16 - 0.79" / 20.0 mm 89.0 cal guns - 0.28lbs / 0.13kg shells, 900 per gun
Machine guns in deck mounts, 1928 Model
4 x Twin mounts on sides, evenly spread
4 raised mounts
4 x Twin mounts on side ends, evenly spread
4 double raised mounts
Weight of broadside 339 lbs / 154 kg
Mines
400 - 4,409.25 lbs / 2,000.00 kg mines - 787.365 t total
in Above water - Stern racks/rails
Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.18" / 30 mm 0.79" / 20 mm -
2nd: 0.79" / 20 mm - -
3rd: 0.39" / 10 mm - -
- Conning towers: Forward 1.97" / 50 mm, Aft 0.00" / 0 mm
Machinery:
Diesel Internal combustion motors, plus diesel motors,
Geared drive, 2 shafts, 37,021 shp / 27,617 Kw = 28.00 kts
Range 6,000nm at 15.00 kts
Bunker at max displacement = 926 tons
Complement:
319 - 416
Cost:
£1.844 million / $7.376 million
Distribution of weights at normal displacement:
Armament: 1,066 tons, 19.3 %
- Guns: 82 tons, 1.5 %
- Weapons: 984 tons, 17.8 %
Armour: 56 tons, 1.0 %
- Armament: 43 tons, 0.8 %
- Conning Tower: 13 tons, 0.2 %
Machinery: 1,026 tons, 18.6 %
Hull, fittings & equipment: 1,846 tons, 33.4 %
Fuel, ammunition & stores: 697 tons, 12.6 %
Miscellaneous weights: 830 tons, 15.0 %
- Hull above water: 800 tons
- Above deck: 30 tons
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
8,989 lbs / 4,078 Kg = 254.5 x 4.1 " / 105 mm shells or 1.6 torpedoes
Stability (Unstable if below 1.00): 1.30
Metacentric height 3.1 ft / 0.9 m
Roll period: 12.6 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.07
Seaboat quality (Average = 1.00): 1.21
Hull form characteristics:
Hull has rise forward of midbreak,
a normal bow and a round stern
Block coefficient (normal/deep): 0.500 / 0.509
Length to Beam Ratio: 9.50 : 1
'Natural speed' for length: 22.33 kts
Power going to wave formation at top speed: 53 %
Trim (Max stability = 0, Max steadiness = 100): 58
Bow angle (Positive = bow angles forward): 15.00 degrees
Stern overhang: 8.20 ft / 2.50 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 20.00 %, 24.61 ft / 7.50 m, 18.86 ft / 5.75 m
- Forward deck: 30.00 %, 18.86 ft / 5.75 m, 18.86 ft / 5.75 m
- Aft deck: 35.00 %, 11.48 ft / 3.50 m, 11.48 ft / 3.50 m
- Quarter deck: 15.00 %, 11.48 ft / 3.50 m, 11.48 ft / 3.50 m
- Average freeboard: 15.63 ft / 4.77 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 82.0 %
- Above water (accommodation/working, high = better): 155.1 %
Waterplane Area: 17,442 Square feet or 1,620 Square metres
Displacement factor (Displacement / loading): 174 %
Structure weight / hull surface area: 72 lbs/sq ft or 354 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.99
- Longitudinal: 1.08
- Overall: 1.00
Excellent machinery, storage, compartmentation space
Excellent accommodation and workspace room
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily
Carries up to 400 2,000 kg mines in above water, below deck mine rails.
Based on the historical Minenleger planned in1937, see
http://www.german-navy.de/kriegsmarine/s…ayer/index.html for historical details.
Note: NOT built to full warship standards.