WesWorld

A design based on the work HDW did for the Bulgarian minelayer competition, this design may be built to provide fast minelaying support in quantities impossible for non-optimized designs.

KM Liegnitz, Germany Fast Minelayer laid down 1940

Displacement:
2,845 t light; 2,998 t standard; 3,317 t normal; 3,572 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(475.86 ft / 459.32 ft) x 42.65 ft x (13.94 / 14.67 ft)
(145.04 m / 140.00 m) x 13.00 m x (4.25 / 4.47 m)

Armament:
6 - 5.91" / 150 mm 48.0 cal guns - 107.85lbs / 48.92kg shells, 150 per gun
Dual purpose guns in deck and hoist mounts, 1940 Model
3 x Twin mounts on centreline ends, majority forward
1 raised mount - superfiring
4 - 3.46" / 88.0 mm 72.0 cal guns - 23.39lbs / 10.61kg shells, 360 per gun
Dual purpose guns in deck mounts, 1940 Model
2 x Twin mounts on centreline, aft evenly spread
2 raised mounts
8 - 1.46" / 37.0 mm 83.0 cal guns - 1.77lbs / 0.80kg shells, 1,200 per gun
Anti-air guns in deck mounts, 1940 Model
4 x Twin mounts on sides, evenly spread
16 - 0.79" / 20.0 mm 89.0 cal guns - 0.28lbs / 0.13kg shells, 2,000 per gun
Machine guns in deck mounts, 1940 Model
4 x 2 row quad mounts on sides, evenly spread
4 raised mounts
Weight of broadside 759 lbs / 344 kg
Mines
160 - 2,094.39 lbs / 950.00 kg mines - 149.599 t total
in Above water - Stern racks/rails

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 2.76" / 70 mm 1.57" / 40 mm 2.76" / 70 mm
2nd: 1.18" / 30 mm 0.79" / 20 mm -
3rd: 0.79" / 20 mm - -
4th: 0.39" / 10 mm - -

- Conning towers: Forward 2.76" / 70 mm, Aft 2.76" / 70 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 58,063 shp / 43,315 Kw = 34.00 kts
Range 5,200nm at 15.00 kts
Bunker at max displacement = 573 tons

Complement:
218 - 284

Cost:
£2.279 million / $9.115 million

Distribution of weights at normal displacement:
Armament: 376 tons, 11.3 %
- Guns: 189 tons, 5.7 %
- Weapons: 187 tons, 5.6 %
Armour: 84 tons, 2.5 %
- Armament: 57 tons, 1.7 %
- Conning Towers: 26 tons, 0.8 %
Machinery: 1,462 tons, 44.1 %
Hull, fittings & equipment: 868 tons, 26.2 %
Fuel, ammunition & stores: 472 tons, 14.2 %
Miscellaneous weights: 55 tons, 1.7 %
- Hull below water: 15 tons
- Above deck: 40 tons

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
943 lbs / 428 Kg = 9.2 x 5.9 " / 150 mm shells or 0.4 torpedoes
Stability (Unstable if below 1.00): 1.12
Metacentric height 1.7 ft / 0.5 m
Roll period: 13.6 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.72
Seaboat quality (Average = 1.00): 1.04

Hull form characteristics:
Hull has a flush deck,
a normal bow and a round stern
Block coefficient (normal/deep): 0.425 / 0.435
Length to Beam Ratio: 10.77 : 1
'Natural speed' for length: 21.43 kts
Power going to wave formation at top speed: 61 %
Trim (Max stability = 0, Max steadiness = 100): 67
Bow angle (Positive = bow angles forward): 30.00 degrees
Stern overhang: 3.28 ft / 1.00 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 20.00 %, 22.97 ft / 7.00 m, 16.40 ft / 5.00 m
- Forward deck: 30.00 %, 16.40 ft / 5.00 m, 16.40 ft / 5.00 m
- Aft deck: 35.00 %, 16.40 ft / 5.00 m, 14.76 ft / 4.50 m
- Quarter deck: 15.00 %, 14.76 ft / 4.50 m, 14.76 ft / 4.50 m
- Average freeboard: 16.40 ft / 5.00 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 164.5 %
- Above water (accommodation/working, high = better): 170.6 %
Waterplane Area: 12,257 Square feet or 1,139 Square metres
Displacement factor (Displacement / loading): 84 %
Structure weight / hull surface area: 44 lbs/sq ft or 217 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 1.09
- Overall: 0.54
Cramped machinery, storage, compartmentation space
Excellent accommodation and workspace room
Ship has slow, easy roll, a good, steady gun platform

Note: the 15cm guns are rated as DP because they have sufficient elevation to be used in an AA role, not because they are particularly proficient at it.

Yes, a minelayer with that high a speed is an offensive weapon - and, I suppose, it could be a good one in certain situations. OTL Germany build several vessels of the type with the intent of offensive mining operations against the RN in the North Sea. The RN replied with the Abdiels.

Not a bad design for offensive missions; far too much invested for defensive mine warfare.

Seems to be a growing trend...

It seems to be a slightly re-jigged Lebrecht Maas to carry some mines all over the quarterdeck. Given that the Lebrecht Mass class are fitted for minelaying anyway I'm not sure of the point.

I'm not entirely sure of the point of an offensive minelayer for Germany anyway given the lack of enemies. I'd think that laying minefields along the Polish coast would be detrimental to any German naval efforts in the region.

The point, basically, is to carry a lot more mines than a Maas can carry. Offensive mining operations would take place wherever there was a need. Admittedly, the Admiralstab is not sure where that would be just yet, but it's better to be prepared than not.

Quoted

Originally posted by Hood
Seems to be a growing trend...

Looks like mines are the new torpedo in WW.

However I am sceptical of the delivery system.
Aircraft and submarines I see as better way of doing offensive mine warfare that a ship with lots of explosive on board.

Its the same with ships with heavy torpedo armament.
However Torpedo cruiser can fire its torps before engaging in ship too ship combat.
Fast Miner can also drop its mines when engaged but that is same as mission kill.

Frankly I'm not sold too this concept.

Aircraft were not regularly used to lay mines until 1943, if memory serves, and submarines lack capacity in comparison to a surface ship. Remember that minelaying surface ships, albeit not of Abdiel's speed, are still being made for Baltic countries like Finland and Sweden. They are also extremely useful for things like resupplying a besieged Malta under an aerial blockade.

Quoted

Originally posted by Brockpaine
Aircraft were not regularly used to lay mines until 1943, if memory serves, and submarines lack capacity in comparison to a surface ship. Remember that minelaying surface ships, albeit not of Abdiel's speed, are still being made for Baltic countries like Finland and Sweden. They are also extremely useful for things like resupplying a besieged Malta under an aerial blockade.

The OTL Heinkel He115 seaplane was equipped to do aerial minelaying - albeit with only a few mines at a time - but it was used to deploy the (then) new magnetic mine - and even a couple of them could cause havoc.

Now submarine minelayers have the advantage that if your enemy doesn't detect the sub, he won't have an idea the minefield is there until his ships start sinking. Admittedly, difficult in heavily patrolled waters, but potentially useful.

It's a case of horses for courses: aircraft can lay mines, but cannot lay dense fields of mines, submarines can lay mines but are usually limited in the number of mines they can lay, and ships can lay dense fields of mines in quantities most submarines can't match but are more vulnerable doing so.

Historically, Germany began air-dropping magnetically triggered mines in 1939.

Quoted

Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 58,063 shp / 43,315 Kw = 34.00 kts

In defensive mine warfare all that power will be waisted.

Although fast mine layers are useful, building a dedicated craft is expensive.
I myself did build a couple "fast" multi purpose platform however mine were 10kt slower. it was back in 1929, now If I decide to go that road again I'll go with 28kt tops.

Those are potent handy ships, but not what I see as needed.

As little nitpic isn't Liegnitz a not the best name?
Its not that big of a city and both the battle fought there were not all that great of a victory for Germany.

Quoted

Originally posted by Marek Gutkowski

Quoted

Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 58,063 shp / 43,315 Kw = 34.00 kts

In defensive mine warfare all that power will be waisted.

Although fast mine layers are useful, building a dedicated craft is expensive.
I myself did build a couple "fast" multi purpose platform however mine were 10kt slower. it was back in 1929, now If I decide to go that road again I'll go with 28kt tops.

Those are potent handy ships, but not what I see as needed.

They're not defensive minelayers, if I need those I'll build some Tannenbergs.

Quoted

As little nitpic isn't Liegnitz a not the best name?
Its not that big of a city and both the battle fought there were not all that great of a victory for Germany.

Well, it was fought facing 3-1 odds, and yet it was a victory., Though perhaps Rossbach would be a better name for the class.

Quoted

Originally posted by Hrolf Hakonson
They're not defensive minelayers, if I need those I'll build some Tannenbergs.

I still thing the whole idea of a dedicated Offensive Mine Layer for Germany is a waste of resources.
How many are You planing on building?

Quoted

Well, it was fought facing 3-1 odds, and yet it was a victory., Though perhaps Rossbach would be a better name for the class.

Hehehe.
I think I'll scratch ORP "Legnica" as a potential name for my Battleship.

Quoted

Originally posted by Marek Gutkowski

Quoted

Originally posted by Hrolf Hakonson
They're not defensive minelayers, if I need those I'll build some Tannenbergs.

I still thing the whole idea of a dedicated Offensive Mine Layer for Germany is a waste of resources.
How many are You planing on building?

Haven't completely decided to build any. If I do, production will probably stop at 4 ships.


An alternate design:

KM Rossbach, German Minelayer laid down 1940

Displacement:
2,861 t light; 2,993 t standard; 3,299 t normal; 3,543 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(478.45 ft / 459.32 ft) x 45.60 ft x (13.12 / 13.78 ft)
(145.83 m / 140.00 m) x 13.90 m x (4.00 / 4.20 m)

Armament:
6 - 4.13" / 105 mm 65.0 cal guns - 39.16lbs / 17.76kg shells, 350 per gun
Dual purpose guns in deck and hoist mounts, 1940 Model
3 x Twin mounts on centreline ends, majority forward
2 raised mounts - superfiring
12 - 1.46" / 37.0 mm 89.0 cal guns - 1.79lbs / 0.81kg shells, 1,200 per gun
Anti-air guns in deck mounts, 1940 Model
6 x Twin mounts on sides, evenly spread
20 - 0.79" / 20.0 mm 89.0 cal guns - 0.28lbs / 0.13kg shells, 2,000 per gun
Machine guns in deck mounts, 1940 Model
3 x 2 row quad mounts on centreline, evenly spread
3 raised mounts
4 x Twin mounts on side ends, evenly spread
4 double raised mounts
Weight of broadside 262 lbs / 119 kg
Mines
200 - 2,094.39 lbs / 950.00 kg mines - 186.999 t total
in Above water - Stern racks/rails

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.97" / 50 mm 0.79" / 20 mm 1.97" / 50 mm
3rd: 0.79" / 20 mm - -
4th: 0.39" / 10 mm - -

- Conning towers: Forward 2.76" / 70 mm, Aft 1.97" / 50 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 61,987 shp / 46,242 Kw = 34.50 kts
Range 5,000nm at 15.00 kts
Bunker at max displacement = 550 tons

Complement:
216 - 282

Cost:
£2.154 million / $8.614 million

Distribution of weights at normal displacement:
Armament: 326 tons, 9.9 %
- Guns: 92 tons, 2.8 %
- Weapons: 234 tons, 7.1 %
Armour: 49 tons, 1.5 %
- Armament: 26 tons, 0.8 %
- Conning Towers: 23 tons, 0.7 %
Machinery: 1,584 tons, 48.0 %
Hull, fittings & equipment: 852 tons, 25.8 %
Fuel, ammunition & stores: 438 tons, 13.3 %
Miscellaneous weights: 50 tons, 1.5 %
- Hull below water: 10 tons
- Above deck: 40 tons

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
1,037 lbs / 470 Kg = 29.4 x 4.1 " / 105 mm shells or 0.5 torpedoes
Stability (Unstable if below 1.00): 1.29
Metacentric height 2.4 ft / 0.7 m
Roll period: 12.2 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.20
Seaboat quality (Average = 1.00): 1.04

Hull form characteristics:
Hull has a flush deck,
a normal bow and a round stern
Block coefficient (normal/deep): 0.420 / 0.430
Length to Beam Ratio: 10.07 : 1
'Natural speed' for length: 21.43 kts
Power going to wave formation at top speed: 62 %
Trim (Max stability = 0, Max steadiness = 100): 67
Bow angle (Positive = bow angles forward): 30.00 degrees
Stern overhang: 4.92 ft / 1.50 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 20.00 %, 24.61 ft / 7.50 m, 16.40 ft / 5.00 m
- Forward deck: 30.00 %, 16.40 ft / 5.00 m, 16.40 ft / 5.00 m
- Aft deck: 35.00 %, 16.40 ft / 5.00 m, 16.40 ft / 5.00 m
- Quarter deck: 15.00 %, 16.40 ft / 5.00 m, 16.40 ft / 5.00 m
- Average freeboard: 17.06 ft / 5.20 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 167.0 %
- Above water (accommodation/working, high = better): 188.6 %
Waterplane Area: 13,059 Square feet or 1,213 Square metres
Displacement factor (Displacement / loading): 88 %
Structure weight / hull surface area: 41 lbs/sq ft or 198 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 1.04
- Overall: 0.54
Cramped machinery, storage, compartmentation space
Excellent accommodation and workspace room
Ship has slow, easy roll, a good, steady gun platform

This one I actually like better 105mm are a better fit for this ship intended mission.

With may lead to a close range night fighting.
This ships guns are not too sink the enemy but too make them go away.
Rain of pain from 105mm will be more persuasive that a potential knock-out with a 150mm.l