Bismarck Alternate Propulsion

Propulsion systems, machinery, turbines, boilers, propellers, fuel consumption, etc.
Paul L
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Posts: 268
Joined: Sat Jan 29, 2005 9:04 pm
Location: Vancouver Canada

Re: Bismarck Alternate Propulsion

Postby Paul L » Sat Sep 17, 2016 3:00 am

JAG wrote:Returning to the point in question, what could the KM have achieved had it decided to stick to Diesel and commerce warfare in 1934?

The powerplant would be heavier and occupy a larger volume while also needing a very long and thin ship (the P-class cruisers come to mind) in order to get the best posible speed out of the engines, everything else, weapons and armor would take a second seat to the powerplant needs in weight and volume....

So maybe a Bismarck-heavy ship, longer and thinner (30m maybe?), with 2x4x35/38cm in order to fit (and save weight) 16x12MZu42/58 large diesels on 4 shafts for 144.000hp? With triple 15cm superfiring over the main turrets achieving the same 6x15cm broadside as IRL.

Hopefully 30kts might be achieved with a huge range.

Feasible?



Hull has to carry fuel as well as motors armor etc. diesels use half as much fuel than turbine propulsion....so the heavier diesels are not a problem. Bismarck has 7000t fuel plus 3000t turbine/boilers. The same power with diesel might be 5000 t motors but it would have. ...5000t diesel fuel. The OPQ class was estimated @ 3nm/t diesel , while H class was estimated @ 2.2 nm/t diesel. Bismarck would be something in-between...may be 2.5nm/t diesel. This suggests an endurance of ~ 13,000nm @ 19knots or 5000nm @ 28 knots.
"Eine mal is kein mal"

Paul L
Senior Member
Posts: 268
Joined: Sat Jan 29, 2005 9:04 pm
Location: Vancouver Canada

Re: Bismarck Alternate Propulsion

Postby Paul L » Sat Sep 17, 2016 3:02 am

JAG wrote:Returning to the point in question, what could the KM have achieved had it decided to stick to Diesel and commerce warfare in 1934?

The powerplant would be heavier and occupy a larger volume while also needing a very long and thin ship (the P-class cruisers come to mind) in order to get the best posible speed out of the engines, everything else, weapons and armor would take a second seat to the powerplant needs in weight and volume....

So maybe a Bismarck-heavy ship, longer and thinner (30m maybe?), with 2x4x35/38cm in order to fit (and save weight) 16x12MZu42/58 large diesels on 4 shafts for 144.000hp? With triple 15cm superfiring over the main turrets achieving the same 6x15cm broadside as IRL.

Hopefully 30kts might be achieved with a huge range.

Feasible?



Hull has to carry fuel as well as motors armor etc. diesels use half as much fuel than turbine propulsion....so the heavier diesels are not a problem. Bismarck has 7000t-7700 fuel plus 3000t turbine/boilers. The same power with diesel might be 5000 t motors but it would have. ...5000- 5700t diesel fuel. The OPQ class was estimated @ 3nm/t diesel , while H class was estimated @ 2.2 nm/t diesel. Bismarck would be something in-between...may be 2.5nm/t diesel. This suggests an endurance of ~ 13,000-14,800nm @ 19knots or ~ 5800-6600nm @ 28 knots.... that's 50% more endurance for 3/4 of the bunkerage.
"Eine mal is kein mal"

JAG
Junior Member
Posts: 11
Joined: Fri Aug 21, 2015 6:38 pm

Re: Bismarck Alternate Propulsion

Postby JAG » Sat Sep 17, 2016 7:20 pm

Indeed, I was counting on the reduced fuel requirements in order to not end with a gargantuan ship but still achieve a long cruise range.

My doubt is whether that would actually fit, its a lot of engines and two very heavy turrets in the 30m beam necessary to achieve a high speed.

Paul L
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Posts: 268
Joined: Sat Jan 29, 2005 9:04 pm
Location: Vancouver Canada

Re: Bismarck Alternate Propulsion

Postby Paul L » Sun Sep 18, 2016 2:08 am

JAG wrote:Indeed, I was counting on the reduced fuel requirements in order to not end with a gargantuan ship but still achieve a long cruise range.

My doubt is whether that would actually fit, its a lot of engines and two very heavy turrets in the 30m beam necessary to achieve a high speed.




best I got with spring sharp was....

Bismarck light, Deutschland Battleship laid down 1936

Displacement:
42,044 t light; 44,150 t standard; 45,934 t normal; 47,361 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(860.87 ft / 831.69 ft) x 98.43 ft (Bulges 104.99 ft) x (30.18 / 30.98 ft)
(262.39 m / 253.50 m) x 30.00 m (Bulges 32.00 m) x (9.20 / 9.44 m)

Armament:
8 - 15.08" / 383 mm 48.9 cal guns - 1,764.00lbs / 800.14kg shells, 120 per gun
Breech loading guns in turret on barbette mounts, 1936 Model
4 x 2-gun mounts on centreline ends, evenly spread
2 raised mounts - superfiring
8 - 4.13" / 105 mm 65.0 cal guns - 39.16lbs / 17.76kg shells, 400 per gun
Breech loading guns in deck and hoist mounts, 1928 Model
4 x 2-gun mounts on side ends, evenly spread
4 raised mounts
16 - 4.13" / 105 mm 65.0 cal guns - 39.16lbs / 17.76kg shells, 400 per gun
Anti-air guns in deck and hoist mounts, 1933 Model
8 x 2-gun mounts on side ends, evenly spread
16 - 1.46" / 37.0 mm 93.0 cal guns - 1.80lbs / 0.82kg shells, 2,000 per gun
Anti-air guns in deck mounts, 1930 Model
8 x Twin mounts on sides, evenly spread
8 raised mounts
16 - 0.79" / 20.0 mm 65.0 cal guns - 0.27lbs / 0.12kg shells, 2,000 per gun
Anti-air guns in deck mounts, 1930 Model
4 x Twin mounts on sides, evenly spread
4 raised mounts
4 x Twin mounts on centreline, aft deck forward
4 raised mounts
Weight of broadside 15,085 lbs / 6,842 kg

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 11.8" / 300 mm 557.74 ft / 170.00 m 17.72 ft / 5.40 m
Ends: 2.76" / 70 mm 196.85 ft / 60.00 m 9.84 ft / 3.00 m
77.10 ft / 23.50 m Unarmoured ends
Upper: 3.94" / 100 mm 557.74 ft / 170.00 m 14.76 ft / 4.50 m
Main Belt covers 103 % of normal length

- Torpedo Bulkhead:
1.69" / 43 mm 492.13 ft / 150.00 m 45.93 ft / 14.00 m

- Hull Bulges:
0.39" / 10 mm 492.13 ft / 150.00 m 19.69 ft / 6.00 m

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 14.2" / 360 mm 7.87" / 200 mm 13.4" / 340 mm
2nd: 0.79" / 20 mm 0.79" / 20 mm 0.79" / 20 mm
3rd: 0.79" / 20 mm 0.79" / 20 mm 0.79" / 20 mm

- Protected deck - multiple decks: 5.24" / 133 mm For and Aft decks
Forecastle: 0.79" / 20 mm Quarter deck: 4.72" / 120 mm

- Conning towers: Forward 13.39" / 340 mm, Aft 0.00" / 0 mm

Machinery:
Diesel Internal combustion motors,
Geared drive, 3 shafts, 139,785 shp / 104,280 Kw = 30.00 kts
Range 8,000nm at 12.12 kts [19kts diesel]
Bunker at max displacement = 3,212 tons

Complement:
1,568 - 2,039

Cost:
£19.082 million / $76.327 million

Distribution of weights at normal displacement:
Armament: 3,563 tons, 7.8 %
Armour: 17,264 tons, 37.6 %
- Belts: 6,469 tons, 14.1 %
- Torpedo bulkhead: 1,416 tons, 3.1 %
- Bulges: 141 tons, 0.3 %
- Armament: 3,102 tons, 6.8 %
- Armour Deck: 5,766 tons, 12.6 %
- Conning Tower: 370 tons, 0.8 %
Machinery: 3,922 tons, 8.5 %
Hull, fittings & equipment: 16,092 tons, 35.0 %
Fuel, ammunition & stores: 3,889 tons, 8.5 %
Miscellaneous weights: 1,203 tons, 2.6 %
- Hull below water: 1,150 tons
- Bulge void weights: 3 tons
- Above deck: 50 tons

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
68,461 lbs / 31,053 Kg = 39.9 x 15.1 " / 383 mm shells or 11.5 torpedoes
Stability (Unstable if below 1.00): 1.15
Metacentric height 6.3 ft / 1.9 m
Roll period: 17.6 seconds
Steadiness - As gun platform (Average = 50 %): 50 %
- Recoil effect (Restricted arc if above 1.00): 0.47
Seaboat quality (Average = 1.00): 1.00

Hull form characteristics:
Hull has a flush deck,
a straight bulbous bow and large transom stern
Block coefficient (normal/deep): 0.610 / 0.613
Length to Beam Ratio: 7.92 : 1
'Natural speed' for length: 33.13 kts
Power going to wave formation at top speed: 50 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 32.00 degrees
Stern overhang: 9.68 ft / 2.95 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 16.00 %, 31.20 ft / 9.51 m, 22.57 ft / 6.88 m
- Forward deck: 34.00 %, 22.57 ft / 6.88 m, 18.08 ft / 5.51 m
- Aft deck: 37.00 %, 18.08 ft / 5.51 m, 18.73 ft / 5.71 m
- Quarter deck: 13.00 %, 18.73 ft / 5.71 m, 21.36 ft / 6.51 m
- Average freeboard: 20.49 ft / 6.25 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 79.1 %
- Above water (accommodation/working, high = better): 147.8 %
Waterplane Area: 62,997 Square feet or 5,853 Square metres
Displacement factor (Displacement / loading): 111 %
Structure weight / hull surface area: 206 lbs/sq ft or 1,006 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.09
- Longitudinal: 0.97
- Overall: 1.00
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent

Modified Bismarck made lighter by replacing the propulsion system with the more compact V 12 Diesels. The three 30 x 10m ; 1700t V12 diesel propulsion units are installed to generate the144,000hp needed to reach 30 kts deep and 150,000 hp forced to reach 30.8 kts standard displacement.


This allows for a narrower hull also reducing the armor mass from 19,500 tons to 17,300tons. However this also requires deleting the 6`inch secondaries and replace with twin 4 inch flaks.

"Eine mal is kein mal"

JAG
Junior Member
Posts: 11
Joined: Fri Aug 21, 2015 6:38 pm

Re: Bismarck Alternate Propulsion

Postby JAG » Sun Sep 25, 2016 1:55 am

Sorry for the delay it has been a crazy week and somehow this fell through the cracks.

Thanks for the sim, I was thinking that we could even go further and simply downgrade the main battery to 35cm guns as was considered at one point, maybe we can squeeze a couple knots that way. Would you mind reassessing with that modification?

Thanks in advance.

Paul L
Senior Member
Posts: 268
Joined: Sat Jan 29, 2005 9:04 pm
Location: Vancouver Canada

Re: Bismarck Alternate Propulsion

Postby Paul L » Sun Sep 25, 2016 5:09 am

Bismarck light, Deutschland Battleship laid down 1936

Displacement:
36,628 t light; 38,602 t standard; 40,280 t normal; 41,623 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(797.83 ft / 767.72 ft) x 98.43 ft (Bulges 104.99 ft) x (28.67 / 29.48 ft)
(243.18 m / 234.00 m) x 30.00 m (Bulges 32.00 m) x (8.74 / 8.99 m)

Armament:
8 - 13.78" / 350 mm 50.0 cal guns - 1,384.91lbs / 628.18kg shells, 150 per gun
Breech loading guns in turret on barbette mounts, 1936 Model
4 x 2-gun mounts on centreline ends, evenly spread
2 raised mounts - superfiring
8 - 4.13" / 105 mm 65.0 cal guns - 39.16lbs / 17.76kg shells, 400 per gun
Breech loading guns in deck and hoist mounts, 1928 Model
4 x 2-gun mounts on side ends, evenly spread
4 raised mounts
16 - 4.13" / 105 mm 65.0 cal guns - 39.16lbs / 17.76kg shells, 400 per gun
Anti-air guns in deck and hoist mounts, 1933 Model
8 x 2-gun mounts on side ends, evenly spread
16 - 1.46" / 37.0 mm 93.0 cal guns - 1.80lbs / 0.82kg shells, 2,000 per gun
Anti-air guns in deck mounts, 1930 Model
8 x Twin mounts on sides, evenly spread
8 raised mounts
16 - 0.79" / 20.0 mm 65.0 cal guns - 0.27lbs / 0.12kg shells, 2,000 per gun
Anti-air guns in deck mounts, 1930 Model
4 x Twin mounts on sides, evenly spread
4 raised mounts
4 x Twin mounts on centreline, aft deck forward
4 raised mounts
Weight of broadside 12,052 lbs / 5,467 kg

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 11.8" / 300 mm 524.93 ft / 160.00 m 17.72 ft / 5.40 m
Ends: 2.76" / 70 mm 196.85 ft / 60.00 m 9.84 ft / 3.00 m
45.93 ft / 14.00 m Unarmoured ends
Upper: 2.36" / 60 mm 524.93 ft / 160.00 m 14.76 ft / 4.50 m
Main Belt covers 105 % of normal length

- Torpedo Bulkhead:
1.69" / 43 mm 492.13 ft / 150.00 m 45.93 ft / 14.00 m

- Hull Bulges:
0.39" / 10 mm 492.13 ft / 150.00 m 19.69 ft / 6.00 m

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 17.7" / 450 mm 7.87" / 200 mm 14.2" / 360 mm
2nd: 0.79" / 20 mm 0.79" / 20 mm 0.79" / 20 mm
3rd: 0.79" / 20 mm 0.79" / 20 mm 0.79" / 20 mm

- Protected deck - multiple decks: 5.12" / 130 mm For and Aft decks
Forecastle: 0.79" / 20 mm Quarter deck: 3.94" / 100 mm

- Conning towers: Forward 14.17" / 360 mm, Aft 0.00" / 0 mm

Machinery:
Diesel Internal combustion motors,
Geared drive, 3 shafts, 132,462 shp / 98,816 Kw = 30.00 kts
Range 8,700nm at 11.80 kts [19knots diesel]
Bunker at max displacement = 3,020 tons

Complement:
1,421 - 1,848

Cost:
£16.272 million / $65.089 million

Distribution of weights at normal displacement:
Armament: 2,962 tons, 7.4 %
Armour: 15,662 tons, 38.9 %
- Belts: 5,621 tons, 14.0 %
- Torpedo bulkhead: 1,416 tons, 3.5 %
- Bulges: 141 tons, 0.3 %
- Armament: 2,983 tons, 7.4 %
- Armour Deck: 5,142 tons, 12.8 %
- Conning Tower: 359 tons, 0.9 %
Machinery: 3,717 tons, 9.2 %
Hull, fittings & equipment: 13,084 tons, 32.5 %
Fuel, ammunition & stores: 3,653 tons, 9.1 %
Miscellaneous weights: 1,203 tons, 3.0 %
- Hull below water: 1,150 tons
- Bulge void weights: 3 tons
- Above deck: 50 tons

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
64,438 lbs / 29,228 Kg = 49.3 x 13.8 " / 350 mm shells or 11.2 torpedoes
Stability (Unstable if below 1.00): 1.20
Metacentric height 6.8 ft / 2.1 m
Roll period: 16.9 seconds
Steadiness - As gun platform (Average = 50 %): 50 %
- Recoil effect (Restricted arc if above 1.00): 0.39
Seaboat quality (Average = 1.00): 1.00

Hull form characteristics:
Hull has a flush deck,
a straight bulbous bow and large transom stern
Block coefficient (normal/deep): 0.610 / 0.613
Length to Beam Ratio: 7.31 : 1
'Natural speed' for length: 32.04 kts
Power going to wave formation at top speed: 53 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 32.00 degrees
Stern overhang: 9.68 ft / 2.95 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 16.00 %, 32.71 ft / 9.97 m, 24.08 ft / 7.34 m
- Forward deck: 34.00 %, 24.08 ft / 7.34 m, 19.59 ft / 5.97 m
- Aft deck: 37.00 %, 19.59 ft / 5.97 m, 20.24 ft / 6.17 m
- Quarter deck: 13.00 %, 20.24 ft / 6.17 m, 22.87 ft / 6.97 m
- Average freeboard: 22.00 ft / 6.71 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 79.7 %
- Above water (accommodation/working, high = better): 162.3 %
Waterplane Area: 58,151 Square feet or 5,402 Square metres
Displacement factor (Displacement / loading): 110 %
Structure weight / hull surface area: 182 lbs/sq ft or 889 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.99
- Longitudinal: 1.06
- Overall: 1.00
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent

Modified Bismarck made lighter by replacing the 8 x 15" with 8 x 14" guns and replacing the propulsion system with the more compact V 12 Diesels. The three 30 x 10m ; 1700t V12 diesel propulsion units are installed to generate the133,000hp needed to reach 30 kts deep and 140,000 hp forced to reach 30.6 kts standard displacement. .


This allows for a narrower hull also reducing the armor mass from 19,500 tons to 15,500. However this also requires deleting the 6`inch secondaries and replace with twin 4 inch flaks.

"Eine mal is kein mal"

JAG
Junior Member
Posts: 11
Joined: Fri Aug 21, 2015 6:38 pm

Re: Bismarck Alternate Propulsion

Postby JAG » Sun Sep 25, 2016 6:44 pm

Thx Paul, I was hoping to obtain a better speed by lightening and slimming the ship, was the 2m bulging necessary?

I guess we could put a triple 15cm superfiring over the main turrets to regain the 6x15cm broadside given how much weight we actually saved in the main battery.

A couple more knots might have made such a ship viable as a raider forcing the potential enemy navies to make some unpleasant choices.

Paul L
Senior Member
Posts: 268
Joined: Sat Jan 29, 2005 9:04 pm
Location: Vancouver Canada

Re: Bismarck Alternate Propulsion

Postby Paul L » Mon Sep 26, 2016 12:00 am

OK getting speed up to 31 knots DEEP was difficult as well as keep propulsion weights close and strength/sea keeping average. Shifting to 15" guns maybe well impossible...and keep to same protection /diesel speed and displacement parameters.


I tried it with three twin 15" turrets and it did work.



Bismarck 14", Deutschland Battleship laid down 1936

Displacement:
36,685 t light; 38,661 t standard; 40,350 t normal; 41,701 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(823.55 ft / 793.96 ft) x 98.43 ft (Bulges 98.75 ft) x (29.53 / 30.31 ft)
(251.02 m / 242.00 m) x 30.00 m (Bulges 30.10 m) x (9.00 / 9.24 m)

Armament:
8 - 13.78" / 350 mm 50.0 cal guns - 1,384.91lbs / 628.18kg shells, 150 per gun
Breech loading guns in turret on barbette mounts, 1936 Model
4 x 2-gun mounts on centreline ends, evenly spread
2 raised mounts - superfiring
8 - 4.13" / 105 mm 65.0 cal guns - 39.16lbs / 17.76kg shells, 400 per gun
Breech loading guns in deck and hoist mounts, 1928 Model
4 x 2-gun mounts on side ends, evenly spread
4 raised mounts
16 - 4.13" / 105 mm 65.0 cal guns - 39.16lbs / 17.76kg shells, 400 per gun
Anti-air guns in deck and hoist mounts, 1933 Model
8 x 2-gun mounts on side ends, evenly spread
16 - 1.46" / 37.0 mm 93.0 cal guns - 1.80lbs / 0.82kg shells, 2,000 per gun
Anti-air guns in deck mounts, 1930 Model
8 x Twin mounts on sides, evenly spread
8 raised mounts
16 - 0.79" / 20.0 mm 65.0 cal guns - 0.27lbs / 0.12kg shells, 2,000 per gun
Anti-air guns in deck mounts, 1930 Model
4 x Twin mounts on sides, evenly spread
4 raised mounts
4 x Twin mounts on centreline, aft deck forward
4 raised mounts
Weight of broadside 12,052 lbs / 5,467 kg

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 11.8" / 300 mm 524.93 ft / 160.00 m 17.72 ft / 5.40 m
Ends: 2.76" / 70 mm 196.85 ft / 60.00 m 9.84 ft / 3.00 m
72.18 ft / 22.00 m Unarmoured ends
Upper: 2.36" / 60 mm 524.93 ft / 160.00 m 14.76 ft / 4.50 m
Main Belt covers 102 % of normal length

- Torpedo Bulkhead:
1.69" / 43 mm 492.13 ft / 150.00 m 45.93 ft / 14.00 m

- Hull Bulges:
0.39" / 10 mm 492.13 ft / 150.00 m 19.69 ft / 6.00 m

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 16.9" / 430 mm 7.87" / 200 mm 14.2" / 360 mm
2nd: 0.79" / 20 mm 0.79" / 20 mm 0.79" / 20 mm
3rd: 0.79" / 20 mm 0.79" / 20 mm 0.79" / 20 mm

- Protected deck - multiple decks: 5.12" / 130 mm For and Aft decks
Forecastle: 0.79" / 20 mm Quarter deck: 3.94" / 100 mm

- Conning towers: Forward 14.17" / 360 mm, Aft 0.00" / 0 mm

Machinery:
Diesel Internal combustion motors,
Geared drive, 3 shafts, 147,867 shp / 110,309 Kw = 31.00 kts
Range 8,500nm at 12.00 kts
Bunker at max displacement = 3,040 tons

Complement:
1,423 - 1,850

Cost:
£16.602 million / $66.407 million

Distribution of weights at normal displacement:
Armament: 2,962 tons, 7.3 %
Armour: 15,493 tons, 38.4 %
- Belts: 5,632 tons, 14.0 %
- Torpedo bulkhead: 1,416 tons, 3.5 %
- Bulges: 141 tons, 0.4 %
- Armament: 2,906 tons, 7.2 %
- Armour Deck: 5,039 tons, 12.5 %
- Conning Tower: 359 tons, 0.9 %
Machinery: 4,149 tons, 10.3 %
Hull, fittings & equipment: 13,028 tons, 32.3 %
Fuel, ammunition & stores: 3,665 tons, 9.1 %
Miscellaneous weights: 1,053 tons, 2.6 %
- Hull below water: 1,000 tons
- Bulge void weights: 3 tons
- Above deck: 50 tons

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
59,517 lbs / 26,996 Kg = 45.5 x 13.8 " / 350 mm shells or 9.6 torpedoes
Stability (Unstable if below 1.00): 1.13
Metacentric height 6.1 ft / 1.9 m
Roll period: 16.8 seconds
Steadiness - As gun platform (Average = 50 %): 50 %
- Recoil effect (Restricted arc if above 1.00): 0.49
Seaboat quality (Average = 1.00): 1.00

Hull form characteristics:
Hull has a flush deck,
a straight bulbous bow and large transom stern
Block coefficient (normal/deep): 0.610 / 0.614
Length to Beam Ratio: 8.04 : 1
'Natural speed' for length: 32.33 kts
Power going to wave formation at top speed: 53 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 32.00 degrees
Stern overhang: 9.68 ft / 2.95 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 25.00 %, 31.86 ft / 9.71 m, 23.23 ft / 7.08 m
- Forward deck: 34.00 %, 23.23 ft / 7.08 m, 18.73 ft / 5.71 m
- Aft deck: 28.00 %, 18.73 ft / 5.71 m, 19.39 ft / 5.91 m
- Quarter deck: 13.00 %, 19.39 ft / 5.91 m, 23.79 ft / 7.25 m
- Average freeboard: 21.95 ft / 6.69 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 83.4 %
- Above water (accommodation/working, high = better): 161.8 %
Waterplane Area: 60,139 Square feet or 5,587 Square metres
Displacement factor (Displacement / loading): 109 %
Structure weight / hull surface area: 177 lbs/sq ft or 866 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.99
- Longitudinal: 1.01
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent

Modified Bismarck made lighter by replacing the 8 x 15" with 8 x 14" guns and replacing the propulsion system with the more compact V 12 Diesels. The three 30 x 10m ; 1700t V12 diesel propulsion units are installed to generate the133,000hp needed to reach 30 kts deep and 140,000 hp forced to reach 30.6 kts standard displacement. .


This allows for a narrower hull also reducing the armor mass from 19,500 tons to 15,500. However this also requires deleting the 6`inch secondaries and replace with twin 4 inch flaks.
"Eine mal is kein mal"

Steve Crandell
Senior Member
Posts: 630
Joined: Wed Feb 05, 2014 7:05 pm

Re: Bismarck Alternate Propulsion

Postby Steve Crandell » Mon Sep 26, 2016 3:02 am

So planning to develop an entirely new 14" gun, a caliber never before used by the German Navy.

Also, reducing the beam also reduces the effectiveness of the TDS.

JAG
Junior Member
Posts: 11
Joined: Fri Aug 21, 2015 6:38 pm

Re: Bismarck Alternate Propulsion

Postby JAG » Mon Sep 26, 2016 3:53 am

Looks great, thx Paul!

I think this would have been a better use of tonnage than either Scharnhorst or Bismarck, it may not have the staying power, but it does have a decent speed (31kts and better when light) and the good range necessary for a raider.

It just needs to hope not to run into Richelieu!

Oh, and I meant 15cm, for the secondaries, not 15in. :D

Re the 35cm gun, it was used, just not at sea, the Mackensen guns were used on land, and in WW2 its development would actually have had a head start over the 38cm since it was originally intended to replace the 28cm in the twins with them.

30m was the beam of the Scharnhorst and its TDS had a depth of 5m IIRC plus unused space due to the hasty redesign of the ships to take a smaller powerplant.

Paul L
Senior Member
Posts: 268
Joined: Sat Jan 29, 2005 9:04 pm
Location: Vancouver Canada

Re: Bismarck Alternate Propulsion

Postby Paul L » Mon Sep 26, 2016 5:01 am

Steve Crandell wrote:So planning to develop an entirely new 14" gun, a caliber never before used by the German Navy.

Also, reducing the beam also reduces the effectiveness of the TDS.



This is a common misunderstanding. the 15" gun was started in 1934 by Krupp along with the 16" gun and the 11"C34 gun. However at that moment the only orders from the KM were for a dozen 11"C28 guns for the Panzerschiffe D & E. The follow on Panzerschiffe armament was either to be triple 33cm turrets or twin 35cm guns..there was no 15" gun turrets ordered at that time and anyway Hitler interfered with the whole process forcing the KM to alter designs back to the 11"gun turrets, to placate the British.


BTW the 35cm gun was built in WW-I for the Makensen Grobb Kreuzers.
http://navypedia.org/ships/germany/ger_bb_mackensen.htm
"Eine mal is kein mal"


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