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Wednesday, January 31, 2007

An anachronistic Defence, after the 1861 ironclad battleship

Wikipedia has a good site about old British ironclad battleships. I looked there to get information about the Defence, built in 1861. I was interested to see that the Defence was not finally broken up until after 1940. These old iron hulls lasted a long time. The ships served as hulks for many decades. The Defence had dimensions of 302ft x 54ft x 25ft and had a displacement of 6,150 tons. The armament, as built was 8-110pdr Armstrong BLR, 10-68pdr MLSB, and 4-5in BLR (the 40pdr). An anchronistic armament for the Defence would consist of 8-5in/51, 10-5.5in/50, and 4-4in/40 guns. I created a Springsharp design using much of the same parameters as the Warrior design, except that the ship has less capability, which is a good description of the Defence and Resistance, compared to the Warrior and Black Prince. The design is very reasonable and is capable, even if just as a "convoy cruiser". This is the Springsharp report:
Defence, anachronistic version, Great Britain Armoured Cruiser laid down 1907

Displacement:
 5,255 t light; 5,516 t standard; 6,150 t normal; 6,657 t full load

Dimensions: Length overall / water x beam x draught
 305.10 ft / 302.00 ft x 54.00 ft x 25.00 ft (normal load)
 92.99 m / 92.05 m x 16.46 m  x 7.62 m

Armament:
      8 - 5.00" / 127 mm guns (4x2 guns), 62.50lbs / 28.35kg shells, 1907 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      10 - 5.50" / 140 mm guns in single mounts, 85.00lbs / 38.56kg shells, 1907 Model
   Breech loading guns in casemate mounts 
   on side, evenly spread
   10 guns in hull casemates - Limited use in heavy seas
      4 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1907 Model
   Breech loading guns in deck mounts with hoists
   on side, all amidships
 Weight of broadside 1,478 lbs / 670 kg
 Shells per gun, main battery: 150

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.50" / 114 mm 235.00 ft / 71.63 m 24.00 ft / 7.32 m
 Ends: Unarmoured
   Main Belt covers 120 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 235.00 ft / 71.63 m 26.00 ft / 7.92 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.50" / 114 mm 3.00" / 76 mm  4.50" / 114 mm
 2nd: 2.00" / 51 mm 2.00" / 51 mm  2.00" / 51 mm
 3rd: 1.00" / 25 mm 1.00" / 25 mm  1.00" / 25 mm

   - Armour deck: 1.00" / 25 mm, Conning tower: 4.50" / 114 mm

Machinery:
 Coal fired boilers, complex reciprocating steam engines, 
 Direct drive, 2 shafts, 13,567 ihp / 10,121 Kw = 20.00 kts
 Range 4,500nm at 12.00 kts
 Bunker at max displacement = 1,140 tons (100% coal)

Complement:
 346 - 451

Cost:
 £0.548 million / $2.193 million

Distribution of weights at normal displacement:
 Armament: 182 tons, 3.0 %
 Armour: 1,859 tons, 30.2 %
    - Belts: 1,069 tons, 17.4 %
    - Torpedo bulkhead: 226 tons, 3.7 %
    - Armament: 326 tons, 5.3 %
    - Armour Deck: 206 tons, 3.4 %
    - Conning Tower: 33 tons, 0.5 %
 Machinery: 1,507 tons, 24.5 %
 Hull, fittings & equipment: 1,706 tons, 27.7 %
 Fuel, ammunition & stores: 895 tons, 14.6 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   5,717 lbs / 2,593 Kg = 91.5 x 5.0 " / 127 mm shells or 1.2 torpedoes
 Stability (Unstable if below 1.00): 1.10
 Metacentric height 2.4 ft / 0.7 m
 Roll period: 14.7 seconds
 Steadiness - As gun platform (Average = 50 %): 85 %
   - Recoil effect (Restricted arc if above 1.00): 0.57
 Seaboat quality  (Average = 1.00): 1.39

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.528
 Length to Beam Ratio: 5.59 : 1
 'Natural speed' for length: 17.38 kts
 Power going to wave formation at top speed: 59 %
 Trim (Max stability = 0, Max steadiness = 100): 61
 Bow angle (Positive = bow angles forward): 3.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  21.00 ft / 6.40 m
    - Forecastle (20 %): 17.00 ft / 5.18 m
    - Mid (50 %):  17.00 ft / 5.18 m
    - Quarterdeck (15 %): 17.00 ft / 5.18 m
    - Stern:  17.00 ft / 5.18 m
    - Average freeboard: 17.32 ft / 5.28 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 163.5 %
  - Above water (accommodation/working, high = better): 104.3 %
 Waterplane Area: 11,149 Square feet or 1,036 Square metres
 Displacement factor (Displacement / loading): 97 %
 Structure weight / hull surface area: 89 lbs/sq ft or 433 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.87
  - Longitudinal: 3.85
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is adequate
 Ship has slow, easy roll, a good, steady gun platform
 Good seaboat, rides out heavy weather easily

Tuesday, January 30, 2007

Alternate armament for the anachronistic Warrior

Eventually, the Warrior was armed with 4-8in MLR, 28-7in MLR, and 4-20pdr BLR. These would translate, using my system for choosing more modern guns, to 4-6.5in/45, 28-5.5in/50, and 4-57mm (6pdr) QF guns. I just made a Springsharp design for the Warrior with this armament. I tweaked some things and decided that the ship needed a torpedo bulkhead. The cruising speed needed to be reduced, to allow for the new armament and torpedo bulkhead. This is the Springsharp report:
Warrior, anachronistic version, Great Britain Armoured Cruiser laid down 1907

Displacement:
 7,949 t light; 8,360 t standard; 9,210 t normal; 9,890 t full load

Dimensions: Length overall / water x beam x draught
 401.15 ft / 398.00 ft x 58.25 ft x 26.00 ft (normal load)
 122.27 m / 121.31 m x 17.75 m  x 7.92 m

Armament:
      4 - 6.50" / 165 mm guns (2x2 guns), 140.00lbs / 63.50kg shells, 1907 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread
      28 - 5.50" / 140 mm guns in single mounts, 85.00lbs / 38.56kg shells, 1907 Model
   Breech loading guns in casemate mounts 
   on side, evenly spread
   16 guns in hull casemates - Limited use in heavy seas
      4 - 2.24" / 57.0 mm guns in single mounts, 6.00lbs / 2.72kg shells, 1907 Model
   Breech loading guns in deck mounts with hoists
   on side, all amidships, all raised mounts - superfiring
 Weight of broadside 2,964 lbs / 1,344 kg
 Shells per gun, main battery: 120

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.50" / 114 mm 235.00 ft / 71.63 m 24.00 ft / 7.32 m
 Ends: Unarmoured
   Main Belt covers 91 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 235.00 ft / 71.63 m 26.00 ft / 7.92 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.50" / 114 mm 3.00" / 76 mm  4.50" / 114 mm
 2nd: 2.00" / 51 mm 2.00" / 51 mm  2.00" / 51 mm
 3rd: 1.00" / 25 mm 1.00" / 25 mm  1.00" / 25 mm

   - Armour deck: 1.00" / 25 mm, Conning tower: 4.50" / 114 mm

Machinery:
 Coal fired boilers, complex reciprocating steam engines, 
 Direct drive, 2 shafts, 26,614 ihp / 19,854 Kw = 23.00 kts
 Range 4,800nm at 12.00 kts
 Bunker at max displacement = 1,530 tons (100% coal)

Complement:
 469 - 611

Cost:
 £0.997 million / $3.987 million

Distribution of weights at normal displacement:
 Armament: 363 tons, 3.9 %
 Armour: 2,039 tons, 22.1 %
    - Belts: 1,121 tons, 12.2 %
    - Torpedo bulkhead: 226 tons, 2.5 %
    - Armament: 354 tons, 3.8 %
    - Armour Deck: 295 tons, 3.2 %
    - Conning Tower: 43 tons, 0.5 %
 Machinery: 2,957 tons, 32.1 %
 Hull, fittings & equipment: 2,590 tons, 28.1 %
 Fuel, ammunition & stores: 1,261 tons, 13.7 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   5,587 lbs / 2,534 Kg = 40.7 x 6.5 " / 165 mm shells or 1.0 torpedoes
 Stability (Unstable if below 1.00): 1.33
 Metacentric height 3.7 ft / 1.1 m
 Roll period: 12.7 seconds
 Steadiness - As gun platform (Average = 50 %): 89 %
   - Recoil effect (Restricted arc if above 1.00): 0.50
 Seaboat quality  (Average = 1.00): 1.45

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.535
 Length to Beam Ratio: 6.83 : 1
 'Natural speed' for length: 19.95 kts
 Power going to wave formation at top speed: 56 %
 Trim (Max stability = 0, Max steadiness = 100): 61
 Bow angle (Positive = bow angles forward): 3.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  22.00 ft / 6.71 m
    - Forecastle (20 %): 18.00 ft / 5.49 m
    - Mid (50 %):  18.00 ft / 5.49 m
    - Quarterdeck (15 %): 18.00 ft / 5.49 m
    - Stern:  18.00 ft / 5.49 m
    - Average freeboard: 18.32 ft / 5.58 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 204.1 %
  - Above water (accommodation/working, high = better): 116.6 %
 Waterplane Area: 15,951 Square feet or 1,482 Square metres
 Displacement factor (Displacement / loading): 85 %
 Structure weight / hull surface area: 96 lbs/sq ft or 468 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.90
  - Longitudinal: 2.76
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is extremely poor
 Room for accommodation and workspaces is adequate
 Ship has slow, easy roll, a good, steady gun platform
 Good seaboat, rides out heavy weather easily

Monday, January 29, 2007

A nice converter for British weights

I found a nice converter for British weights. I used it to convert tons, cwt, and qtrs to fractional tons.

My anachronistic Warrior design

I thought that I would try the original Warrior design, as an anachronistic Springsharp design. I tried out the new gun concept, as well. I assumed a more modern stern design, so the length on the waterline is greater than the original Warrior. The Warrior was completed with the following guns: 26-68pdr, 10-110pdr Armstrong BLR, and 4-70pdr Armstrong BLR. I did not have good figures on the 70pdr gun, so I used a 4in QF gun in place of it. For the other guns, I have 4-5in BLR in place of the 110pdrs. I have 26-5.5in BLR in place of the 68pdr SB guns. In place of the 70pdr, I have what would be shorter 5in guns. This is the Springsharp report:
Warrior, anachronistic version, Great Britain Armoured Cruiser laid down 1907

Displacement:
 7,735 t light; 8,150 t standard; 9,210 t normal; 10,058 t full load

Dimensions: Length overall / water x beam x draught
 401.15 ft / 398.00 ft x 58.25 ft x 26.00 ft (normal load)
 122.27 m / 121.31 m x 17.75 m  x 7.92 m

Armament:
      4 - 6.50" / 165 mm guns (2x2 guns), 137.31lbs / 62.28kg shells, 1907 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread
      28 - 5.50" / 140 mm guns in single mounts, 83.19lbs / 37.73kg shells, 1907 Model
   Breech loading guns in casemate mounts 
   on side, evenly spread
   16 guns in hull casemates - Limited use in heavy seas
      4 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1907 Model
   Quick firing guns in deck mounts with hoists
   on side, all amidships
 Weight of broadside 3,007 lbs / 1,364 kg
 Shells per gun, main battery: 120

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.50" / 114 mm 235.00 ft / 71.63 m 24.00 ft / 7.32 m
 Ends: Unarmoured
   Main Belt covers 91 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.50" / 114 mm 3.00" / 76 mm  4.50" / 114 mm
 2nd: 2.00" / 51 mm 2.00" / 51 mm  2.00" / 51 mm
 3rd: 1.00" / 25 mm 1.00" / 25 mm  1.00" / 25 mm

   - Armour deck: 1.00" / 25 mm, Conning tower: 4.50" / 114 mm

Machinery:
 Coal fired boilers, complex reciprocating steam engines, 
 Direct drive, 2 shafts, 26,614 ihp / 19,854 Kw = 23.00 kts
 Range 5,000nm at 13.00 kts
 Bunker at max displacement = 1,907 tons (100% coal)

Complement:
 469 - 611

Cost:
 £1.000 million / $4.002 million

Distribution of weights at normal displacement:
 Armament: 376 tons, 4.1 %
 Armour: 1,819 tons, 19.8 %
    - Belts: 1,121 tons, 12.2 %
    - Torpedo bulkhead: 0 tons, 0.0 %
    - Armament: 360 tons, 3.9 %
    - Armour Deck: 295 tons, 3.2 %
    - Conning Tower: 43 tons, 0.5 %
 Machinery: 2,957 tons, 32.1 %
 Hull, fittings & equipment: 2,583 tons, 28.1 %
 Fuel, ammunition & stores: 1,475 tons, 16.0 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   5,696 lbs / 2,584 Kg = 41.5 x 6.5 " / 165 mm shells or 0.9 torpedoes
 Stability (Unstable if below 1.00): 1.43
 Metacentric height 4.1 ft / 1.3 m
 Roll period: 12.1 seconds
 Steadiness - As gun platform (Average = 50 %): 73 %
   - Recoil effect (Restricted arc if above 1.00): 0.42
 Seaboat quality  (Average = 1.00): 1.46

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.535
 Length to Beam Ratio: 6.83 : 1
 'Natural speed' for length: 19.95 kts
 Power going to wave formation at top speed: 56 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 3.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  22.00 ft / 6.71 m
    - Forecastle (20 %): 18.00 ft / 5.49 m
    - Mid (50 %):  18.00 ft / 5.49 m
    - Quarterdeck (15 %): 18.00 ft / 5.49 m
    - Stern:  18.00 ft / 5.49 m
    - Average freeboard: 18.32 ft / 5.58 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 135.0 %
  - Above water (accommodation/working, high = better): 116.6 %
 Waterplane Area: 15,951 Square feet or 1,482 Square metres
 Displacement factor (Displacement / loading): 86 %
 Structure weight / hull surface area: 96 lbs/sq ft or 467 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.89
  - Longitudinal: 2.81
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is adequate
 Ship has slow, easy roll, a good, steady gun platform
 Good seaboat, rides out heavy weather easily

Guns for anachronistic ships

I want to try taking the weights of old pieces and substituting more modern guns of the same weight. Here is a proposal:
Old gun             Wt          New gun   Wt
110pdr Armstrong BL 4 tons      5in/51    4 tons
 40pdr Armstrong BL 1.5 tons    4in/40    1.5 tons
 20pdr Armstrong BL 0.5 tons    57mm      0.5 tons
9in SB Somerset     6.25 tons   5.5in/50  6.5 tons
10.5in Woolwich    12 tons      7.6in/40 12.5 tons
13in Armstrong     22.5 tons    9.4in/40 22.75 tons
1864 6.3in 64cwt    3.2 tons    5in/40    3.1 tons
1864 6.6in 71cwt    3.55 tons   4.7in/50  3.7 tons
1865 7in            6.5 tons    5.5in/50  6.5 tons
1866 8in            9 tons      6.5in/45  9.0 tons
1865 9in           12 tons      7.6in/40 12.5 tons
1868 10in          18 tons      8in/40   18.1 tons
1867 11in          25 tons      9.4in/50 24 tons
1870 12in          25 tons      9.2in/40 24.338 tons
1871 12in          35 tons     10in/40   34.6 tons
1875 12.5in        38 tons     10.8in/45 35.5 tons
1878 16in          80 tons     13.5in/45 80 tons

One of my favorite books: Dr. Oscar Parkes' book British Battleships

I am a fan of Fred Jane and his early books, such as the All the World's Fighting Ships from the early years (although not the 1898 volume). Dr. Oscar Parkes' book, British Battleships is one of my favorite books, as I see that he followed closely in Jane's tradition. Dr. Parkes, like Fred Jane, was a good artist and his pen and ink drawings in British Battleships are a pleasure to behold. While British Battleships needs to be supplemented with more modern works, such as David Brown's Warrior to Dreadnought: Warship Development, 1860-1905, Dr. Parkes' book has a wealth of little-known "trivia" from the 1860's on to the early 1900's. Dr. Parkes also has a very nice painting of the G3 battlecruiser design, seemingly the final version, that answers some questions that I could not resolve from David Brown's reproduction of the plan view. I have had my copy of both books out in the last two weeks, collecting grist for Springsharp designs.

Sunday, January 28, 2007

A bit off-topic: EA-3Bs in the Mediterranean Sea

I had my attention drawn back to my experience from 30 years ago. I made the last Med cruise of the USS Franklin D Roosevelt (CV-42). We operated strictly in the Western Mediterranean, as we were not very well equipped. We only had F-4 Phantoms, while the Forrestal class ships and better had F-14 Tomcats. I was an ensign, assigned to the CIC, which meant that I stood bridge and CIC Surface Watch Officer watches on the flag bridge. Being JOOW and JOOD on the bridge allowed me to get a good view, during daylight, of flight ops. Several times, we took on board an EA-3B on board. They were huge and were called "Whales". Their code name was "Ranger". Twenty years ago, about, Ranger 12, and EA-3B had a mishap on the USS Nimitz in the Ionian Sea, went over the side, broke up. The entire aircrew was lost. The Nimitz (CVN-68) page has the story, although you have to do a lot of scrolling. When we had an EA-3B on board, it took up a tremendous amount of real estate on the flight deck. When the EA-3B came forward to be catapulted, the entire forward flight deck had to kept clear. The EA-3B kept its wings folded until just before the cat shot, when they were unfolded. My memory is that they were launched from the left catapult of the Roosevelt. It is inconceivable, but true, that the A-3's were intended for use on board ships like the Roosevelt.

Saturday, January 27, 2007

My Mersey class cruiser anachronistic design

The next design I tried was for a Mersey class 2nd Class cruiser (anachronistic, of course). This ship had mixed results, in that the speed is just 21 knots. The protection is so much better and I do not understand why. This ship has a twin 8in turret forward with a superfiring twin 6in turret above it. To the stern are two twin 6in turrets. There are twin 6in turrets on each beam. This would be a ship with a single stack. This is the Springsharp report:
Mersey, anachronistic version, Great Britain 2nd Class Cruiser laid down 1908 (Engine 1912)

Displacement:
 3,573 t light; 3,781 t standard; 4,470 t normal; 5,021 t full load

Dimensions: Length overall / water x beam x draught
 318.05 ft / 315.00 ft x 46.00 ft x 19.50 ft (normal load)
 96.94 m / 96.01 m x 14.02 m  x 5.94 m

Armament:
      2 - 8.00" / 203 mm guns (1x2 guns), 256.00lbs / 116.12kg shells, 1908 Model
   Breech loading guns in a turret (on a barbette)
   on centreline forward
      2 - 6.00" / 152 mm guns (1x2 guns), 108.00lbs / 48.99kg shells, 1908 Model
   Quick firing guns in a turret (on a barbette)
   on centreline forward, all raised guns - superfiring
      4 - 6.00" / 152 mm guns (2x2 guns), 108.00lbs / 48.99kg shells, 1908 Model
   Quick firing guns in turrets (on barbettes)
   on centreline, all aft, 1 raised mount - superfiring
      4 - 6.00" / 152 mm guns (2x2 guns), 108.00lbs / 48.99kg shells, 1908 Model
   Quick firing guns in turrets (on barbettes)
   on side, all amidships
 Weight of broadside 1,592 lbs / 722 kg
 Shells per gun, main battery: 120
 2 - 18.0" / 457.2 mm submerged torpedo tubes

Armour:
   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 2.00" / 51 mm 2.00" / 51 mm  2.00" / 51 mm
 2nd: 2.00" / 51 mm 2.00" / 51 mm  2.00" / 51 mm
 3rd: 2.00" / 51 mm 2.00" / 51 mm  2.00" / 51 mm
 4th: 2.00" / 51 mm 2.00" / 51 mm  2.00" / 51 mm

   - Armour deck: 3.00" / 76 mm, Conning tower: 9.00" / 229 mm

Machinery:
 Coal fired boilers, complex reciprocating steam engines, 
 Direct drive, 2 shafts, 13,079 ihp / 9,757 Kw = 21.00 kts
 Range 6,500nm at 12.00 kts
 Bunker at max displacement = 1,240 tons (100% coal)

Complement:
 273 - 355

Cost:
 £0.413 million / $1.654 million

Distribution of weights at normal displacement:
 Armament: 199 tons, 4.5 %
 Armour: 839 tons, 18.8 %
    - Belts: 0 tons, 0.0 %
    - Torpedo bulkhead: 0 tons, 0.0 %
    - Armament: 223 tons, 5.0 %
    - Armour Deck: 563 tons, 12.6 %
    - Conning Tower: 53 tons, 1.2 %
 Machinery: 866 tons, 19.4 %
 Hull, fittings & equipment: 1,669 tons, 37.3 %
 Fuel, ammunition & stores: 897 tons, 20.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   4,407 lbs / 1,999 Kg = 17.2 x 8.0 " / 203 mm shells or 1.0 torpedoes
 Stability (Unstable if below 1.00): 1.09
 Metacentric height 1.8 ft / 0.6 m
 Roll period: 14.2 seconds
 Steadiness - As gun platform (Average = 50 %): 54 %
   - Recoil effect (Restricted arc if above 1.00): 0.96
 Seaboat quality  (Average = 1.00): 1.22

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.554
 Length to Beam Ratio: 6.85 : 1
 'Natural speed' for length: 17.75 kts
 Power going to wave formation at top speed: 58 %
 Trim (Max stability = 0, Max steadiness = 100): 44
 Bow angle (Positive = bow angles forward): 3.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  20.00 ft / 6.10 m
    - Forecastle (20 %): 15.00 ft / 4.57 m
    - Mid (50 %):  15.00 ft / 4.57 m
    - Quarterdeck (15 %): 15.00 ft / 4.57 m
    - Stern:  15.00 ft / 4.57 m
    - Average freeboard: 15.40 ft / 4.69 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 102.2 %
  - Above water (accommodation/working, high = better): 106.2 %
 Waterplane Area: 10,148 Square feet or 943 Square metres
 Displacement factor (Displacement / loading): 107 %
 Structure weight / hull surface area: 97 lbs/sq ft or 476 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.87
  - Longitudinal: 3.35
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is adequate
 Good seaboat, rides out heavy weather easily

Friday, January 26, 2007

2nd Class Cruiser Amphion, anachronistic version

The next design I tried was an anachronistic version of a Leander class 2nd Class Cruiser. I chose the Amphion. The ship has four turrets, two twin and two triple, with 6in QF guns. There is also a thin armoured deck. The speed is still 24 knots, with coal-fired boilers and complex reciprocrating engines. The range is greater: 6,700nm at 12 knots. This is the Springsharp report:
Amphion, anachronistic version, Great Britain 2nd Class Cruiser laid down 1908 (Engine 1910)

Displacement:
 3,431 t light; 3,589 t standard; 4,300 t normal; 4,868 t full load

Dimensions: Length overall / water x beam x draught
 318.05 ft / 315.00 ft x 46.00 ft x 20.50 ft (normal load)
 96.94 m / 96.01 m x 14.02 m  x 6.25 m

Armament:
      10 - 6.00" / 152 mm guns (4 mounts), 108.00lbs / 48.99kg shells, 1908 Model
   Quick firing guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
 Weight of broadside 1,080 lbs / 490 kg
 Shells per gun, main battery: 120
 4 - 18.0" / 457.2 mm above water torpedoes

Armour:
   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 1.50" / 38 mm 1.50" / 38 mm  1.50" / 38 mm

   - Armour deck: 1.50" / 38 mm

Machinery:
 Coal fired boilers, complex reciprocating steam engines, 
 Direct drive, 2 shafts, 21,724 ihp / 16,206 Kw = 24.00 kts
 Range 6,700nm at 12.00 kts
 Bunker at max displacement = 1,279 tons (100% coal)

Complement:
 265 - 345

Cost:
 £0.436 million / $1.743 million

Distribution of weights at normal displacement:
 Armament: 135 tons, 3.1 %
 Armour: 406 tons, 9.4 %
    - Belts: 0 tons, 0.0 %
    - Torpedo bulkhead: 0 tons, 0.0 %
    - Armament: 137 tons, 3.2 %
    - Armour Deck: 270 tons, 6.3 %
    - Conning Tower: 0 tons, 0.0 %
 Machinery: 1,444 tons, 33.6 %
 Hull, fittings & equipment: 1,446 tons, 33.6 %
 Fuel, ammunition & stores: 869 tons, 20.2 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   2,498 lbs / 1,133 Kg = 23.1 x 6.0 " / 152 mm shells or 0.7 torpedoes
 Stability (Unstable if below 1.00): 1.02
 Metacentric height 1.6 ft / 0.5 m
 Roll period: 15.2 seconds
 Steadiness - As gun platform (Average = 50 %): 78 %
   - Recoil effect (Restricted arc if above 1.00): 0.93
 Seaboat quality  (Average = 1.00): 1.07

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.507
 Length to Beam Ratio: 6.85 : 1
 'Natural speed' for length: 17.75 kts
 Power going to wave formation at top speed: 63 %
 Trim (Max stability = 0, Max steadiness = 100): 73
 Bow angle (Positive = bow angles forward): 3.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  20.00 ft / 6.10 m
    - Forecastle (20 %): 16.00 ft / 4.88 m
    - Mid (50 %):  16.00 ft / 4.88 m
    - Quarterdeck (15 %): 16.00 ft / 4.88 m
    - Stern:  16.00 ft / 4.88 m
    - Average freeboard: 16.32 ft / 4.97 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 132.5 %
  - Above water (accommodation/working, high = better): 96.1 %
 Waterplane Area: 9,713 Square feet or 902 Square metres
 Displacement factor (Displacement / loading): 98 %
 Structure weight / hull surface area: 83 lbs/sq ft or 406 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.87
  - Longitudinal: 3.42
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is adequate
 Ship has slow, easy roll, a good, steady gun platform

Thursday, January 25, 2007

My anachronistic Mercury cruiser

I have planned to try some of the early British cruisers as anachronistic Springsharp designs. Tonight, I tried a Mercury design. This is an unarmoured 2nd Class Cruiser. My ship has 12-5in QF guns and 4-47mm (3pdr) QF guns. The speed is a pretty fast 24 knots. My ship would have twin funnels and a rather high flush deck. I had to raise the freeboard to help increase the roll period to over 13 seconds. This is the Springsharp report:
Mercury, anachronistic version, Great Britain 2nd Class Cruiser laid down 1906 (Engine 1908)

Displacement:
 3,473 t light; 3,640 t standard; 4,250 t normal; 4,738 t full load

Dimensions: Length overall / water x beam x draught
 318.21 ft / 315.00 ft x 46.00 ft x 21.00 ft (normal load)
 96.99 m / 96.01 m x 14.02 m  x 6.40 m

Armament:
      8 - 5.00" / 127 mm guns (4x2 guns), 62.50lbs / 28.35kg shells, 1906 Model
   Quick firing guns in deck mounts with hoists
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      4 - 5.00" / 127 mm guns (2x2 guns), 62.50lbs / 28.35kg shells, 1906 Model
   Quick firing guns in deck mounts with hoists
   on side, all amidships
      4 - 1.85" / 47.0 mm guns in single mounts, 3.17lbs / 1.44kg shells, 1906 Model
   Quick firing guns in deck mounts with hoists
   on side, all amidships, all raised mounts - superfiring
 Weight of broadside 763 lbs / 346 kg
 Shells per gun, main battery: 180
 4 - 18.0" / 457.2 mm above water torpedoes

Machinery:
 Coal fired boilers, complex reciprocating steam engines, 
 Direct drive, 2 shafts, 21,380 ihp / 15,950 Kw = 24.00 kts
 Range 5,600nm at 12.00 kts
 Bunker at max displacement = 1,098 tons (100% coal)

Complement:
 263 - 342

Cost:
 £0.470 million / $1.880 million

Distribution of weights at normal displacement:
 Armament: 95 tons, 2.2 %
 Machinery: 1,918 tons, 45.1 %
 Hull, fittings & equipment: 1,460 tons, 34.3 %
 Fuel, ammunition & stores: 777 tons, 18.3 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   1,895 lbs / 859 Kg = 30.3 x 5.0 " / 127 mm shells or 0.5 torpedoes
 Stability (Unstable if below 1.00): 1.16
 Metacentric height 2.1 ft / 0.6 m
 Roll period: 13.5 seconds
 Steadiness - As gun platform (Average = 50 %): 100 %
   - Recoil effect (Restricted arc if above 1.00): 0.83
 Seaboat quality  (Average = 1.00): 1.67

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.489
 Length to Beam Ratio: 6.85 : 1
 'Natural speed' for length: 17.75 kts
 Power going to wave formation at top speed: 63 %
 Trim (Max stability = 0, Max steadiness = 100): 73
 Bow angle (Positive = bow angles forward): 3.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  23.00 ft / 7.01 m
    - Forecastle (20 %): 19.00 ft / 5.79 m
    - Mid (50 %):  19.00 ft / 5.79 m
    - Quarterdeck (15 %): 19.00 ft / 5.79 m
    - Stern:  19.00 ft / 5.79 m
    - Average freeboard: 19.32 ft / 5.89 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 163.5 %
  - Above water (accommodation/working, high = better): 113.1 %
 Waterplane Area: 9,557 Square feet or 888 Square metres
 Displacement factor (Displacement / loading): 91 %
 Structure weight / hull surface area: 76 lbs/sq ft or 369 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.82
  - Longitudinal: 5.56
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 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

More Google Book Search stuff: the Journal of the Royal United Services Institute

I have seen frequent references to the Journal of the Royal United Services Institute in Dr. Oscar Parkes' and David Brown's writing. I find that at least some of the issues are available online, through Google Book Search. I was searching with the string "Mersey Class Cruiser", with the "Full view books" radio button selected. I didn't find what I was looking for, but Google Book Search did take me to a page in an article titled "WAR VESSELS FOR THE BRITISH NAVY", from the 1877 RUSI journal. The table of contents listed some provocative titles, besides the one I found. Was one was SIr Edward Reed, called "On circular Iron-clads".

Wednesday, January 24, 2007

A more interesting book: Ironclads in Action

A book that interests me much more is available from Google Book Search:
Ironclads in action; a sketch of naval warfare from 1855 to 1895, 
by Herbert Wrigley Wilson

Type: English :  Book 
Publisher: London, S. Low, Marston and Co., 1896.  

This is a classic, if you are interested in naval warfare in the period covered.

Google Book Search is starting to have material on warships

I see that Google Book Search now has a PDF copy for download of William Hovgaard's original publication about submarines from 1887. These are the details:
SUBMARINE BOATS: By William Hovgaard 
Published 1887
E. & F. N. Spon 
98 pages 
Original from the University of Michigan 

Tuesday, January 23, 2007

The Springsharp report for a British "13 Class" ship

I did as I said and tried a British "13 Class" ship in Springsharp. Except for being much heavier than the Japanese design, the ship works quite well, especially considering the relatively narrow beam for 18in guns. This is the Springsharp report:
GB/BB/1921 "13", Great Britain Battlecruiser laid down 1923

Displacement:
 51,067 t light; 53,474 t standard; 56,200 t normal; 58,381 t full load

Dimensions: Length overall / water x beam x draught
 900.00 ft / 900.00 ft x 108.00 ft x 32.00 ft (normal load)
 274.32 m / 274.32 m x 32.92 m  x 9.75 m

Armament:
      8 - 18.00" / 457 mm guns (4x2 guns), 2,916.00lbs / 1,322.68kg shells, 1923 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      14 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1923 Model
   Quick firing guns in casemate mounts 
   on side, all amidships
   14 guns in hull casemates - Limited use in heavy seas
      8 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1923 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships, all raised mounts - superfiring
      16 - 1.57" / 40.0 mm guns (4x4 guns), 2.00lbs / 0.91kg shells, 1923 Model
   Breech loading guns in deck mounts 
   on side, all amidships, all raised mounts - superfiring
 Weight of broadside 25,287 lbs / 11,470 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 13.0" / 330 mm 600.00 ft / 182.88 m 8.00 ft / 2.44 m
 Ends: 5.00" / 127 mm 220.00 ft / 67.06 m 12.00 ft / 3.66 m
   80.00 ft / 24.38 m Unarmoured ends
 Upper: 10.0" / 254 mm 600.00 ft / 182.88 m 8.00 ft / 2.44 m
   Main Belt covers 103 % of normal length

   - Torpedo Bulkhead:
  4.00" / 102 mm 600.00 ft / 182.88 m 32.00 ft / 9.75 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 13.0" / 330 mm 9.00" / 229 mm  13.0" / 330 mm
 2nd: 6.00" / 152 mm 4.00" / 102 mm  6.00" / 152 mm

   - Armour deck: 5.00" / 127 mm, Conning tower: 13.00" / 330 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 175,851 shp / 131,185 Kw = 30.00 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 4,907 tons

Complement:
 1,824 - 2,372

Cost:
 £15.317 million / $61.269 million

Distribution of weights at normal displacement:
 Armament: 3,161 tons, 5.6 %
 Armour: 19,699 tons, 35.1 %
    - Belts: 5,170 tons, 9.2 %
    - Torpedo bulkhead: 2,842 tons, 5.1 %
    - Armament: 4,499 tons, 8.0 %
    - Armour Deck: 6,777 tons, 12.1 %
    - Conning Tower: 411 tons, 0.7 %
 Machinery: 5,877 tons, 10.5 %
 Hull, fittings & equipment: 22,331 tons, 39.7 %
 Fuel, ammunition & stores: 5,133 tons, 9.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   72,606 lbs / 32,933 Kg = 24.9 x 18.0 " / 457 mm shells or 11.4 torpedoes
 Stability (Unstable if below 1.00): 1.10
 Metacentric height 6.8 ft / 2.1 m
 Roll period: 17.4 seconds
 Steadiness - As gun platform (Average = 50 %): 58 %
   - Recoil effect (Restricted arc if above 1.00): 0.82
 Seaboat quality  (Average = 1.00): 1.16

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.632
 Length to Beam Ratio: 8.33 : 1
 'Natural speed' for length: 30.00 kts
 Power going to wave formation at top speed: 48 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): -2.00 degrees
 Stern overhang: -2.00 ft / -0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  31.00 ft / 9.45 m
    - Forecastle (20 %): 28.00 ft / 8.53 m
    - Mid (50 %):  28.00 ft / 8.53 m (20.00 ft / 6.10 m aft of break)
    - Quarterdeck (15 %): 20.00 ft / 6.10 m
    - Stern:  20.00 ft / 6.10 m
    - Average freeboard: 24.24 ft / 7.39 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 93.5 %
  - Above water (accommodation/working, high = better): 181.3 %
 Waterplane Area: 73,264 Square feet or 6,806 Square metres
 Displacement factor (Displacement / loading): 99 %
 Structure weight / hull surface area: 220 lbs/sq ft or 1,074 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 1.01
  - Longitudinal: 0.99
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent

I will try a British analog to the Japanese "13 Class"

The Japanese "13 Class" ships are often called either battleships or battlecruisers. In the "8-8 Plan", they were classed as battlecruisers. They were very long and narrow, with dimensions of 900ft x 101ft x 32ft. The armament was 8-18/45, 16-5.5 QF and 8-4.7 AA guns. They were also armed with 8-24 inch TT, mounted above water. The belt was to be 13in and the deck was 5in. They also had a maximum speed of 30 knots.

For a British analog to the "13 Class", I would use dimensions of 900ft x 108ft x 32ft. The main armament would be 8-18in/45 guns. The British, in 1921, wanted to push limits of the displacement, while going with what they thought was leading-edge design principles, so they would have used triple 18in turrets and twin secondary turrets. I will stay close to the "13 Class" and use twin 18in turrets and 6in QF guns in casemates. That would give an armament of 8-18in, 14-6in QF guns. I would try using a 13in armour basis for protection, with a 5in deck. The 30-knot speed would be adequate, so I would retain that, as well. I will be interested to see how great the displacement ends up being.

Monday, January 22, 2007

My British battleship along the lines of the Kii and Owari

This is the photo of the British analog to the Kii and Owari:

I did what I was threatening to do and produced a Springsharp design to go with the photo:
GB/BB/1921 Fast, Great Britain Battleship laid down 1921

Displacement:
 43,133 t light; 45,212 t standard; 47,700 t normal; 49,690 t full load

Dimensions: Length overall / water x beam x draught
 824.00 ft / 824.00 ft x 104.00 ft x 31.00 ft (normal load)
 251.16 m / 251.16 m x 31.70 m  x 9.45 m

Armament:
      8 - 16.00" / 406 mm guns (4x2 guns), 2,048.00lbs / 928.96kg shells, 1921 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      2 - 16.00" / 406 mm guns (1x2 guns), 2,048.00lbs / 928.96kg shells, 1921 Model
   Breech loading guns in a turret (on a barbette)
   on side amidships
      14 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1921 Model
   Quick firing guns in casemate mounts 
   on side, evenly spread
   14 guns in hull casemates - Limited use in heavy seas
 Weight of broadside 21,992 lbs / 9,975 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 11.5" / 292 mm 505.00 ft / 153.92 m 8.00 ft / 2.44 m
 Ends: Unarmoured
 Upper: 9.00" / 229 mm 505.00 ft / 153.92 m 8.00 ft / 2.44 m
   Main Belt covers 94 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  2.00" / 51 mm 505.00 ft / 153.92 m 31.00 ft / 9.45 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 12.0" / 305 mm 9.00" / 229 mm  12.0" / 305 mm
 2nd: 12.0" / 305 mm 9.00" / 229 mm  12.0" / 305 mm
 3rd: 6.00" / 152 mm 4.00" / 102 mm  6.00" / 152 mm

   - Armour deck: 5.00" / 127 mm, Conning tower: 12.00" / 305 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 159,080 shp / 118,673 Kw = 29.75 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 4,478 tons

Complement:
 1,613 - 2,097

Cost:
 £11.673 million / $46.691 million

Distribution of weights at normal displacement:
 Armament: 2,749 tons, 5.8 %
 Armour: 15,534 tons, 32.6 %
    - Belts: 3,584 tons, 7.5 %
    - Torpedo bulkhead: 1,158 tons, 2.4 %
    - Armament: 4,499 tons, 9.4 %
    - Armour Deck: 5,953 tons, 12.5 %
    - Conning Tower: 340 tons, 0.7 %
 Machinery: 5,478 tons, 11.5 %
 Hull, fittings & equipment: 19,372 tons, 40.6 %
 Fuel, ammunition & stores: 4,567 tons, 9.6 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   58,852 lbs / 26,695 Kg = 28.7 x 16.0 " / 406 mm shells or 7.9 torpedoes
 Stability (Unstable if below 1.00): 1.08
 Metacentric height 6.2 ft / 1.9 m
 Roll period: 17.6 seconds
 Steadiness - As gun platform (Average = 50 %): 57 %
   - Recoil effect (Restricted arc if above 1.00): 0.83
 Seaboat quality  (Average = 1.00): 1.13

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.628
 Length to Beam Ratio: 7.92 : 1
 'Natural speed' for length: 28.71 kts
 Power going to wave formation at top speed: 51 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): -2.00 degrees
 Stern overhang: -2.00 ft / -0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  31.00 ft / 9.45 m
    - Forecastle (20 %): 28.00 ft / 8.53 m
    - Mid (50 %):  28.00 ft / 8.53 m (20.00 ft / 6.10 m aft of break)
    - Quarterdeck (15 %): 20.00 ft / 6.10 m
    - Stern:  20.00 ft / 6.10 m
    - Average freeboard: 24.24 ft / 7.39 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 99.7 %
  - Above water (accommodation/working, high = better): 180.1 %
 Waterplane Area: 64,357 Square feet or 5,979 Square metres
 Displacement factor (Displacement / loading): 98 %
 Structure weight / hull surface area: 215 lbs/sq ft or 1,051 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.98
  - Longitudinal: 1.15
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent

Hazegray.org has a good Japanese dreadnought page

I was looking for information about the battleship version of the Amagi class battleship class. The two named ships were the Kii and the Owari. Hazegray.org has a good page about the Japanese dreadnoughts. I would be interested in trying both a British fast battleship with 10-16in guns, as well as a similar ship to the Japanese "13" class ships, which were 900ft long and had 8-18in guns.

Sunday, January 21, 2007

I thought I should try a more Amagi-like British battlecruiser

I believe that the Japanese Amagi class ships only had a 10in belt, so I thought that I should redesign my British ship to be more like that. I was also not happy with the great displacement that was required. This is the Springsharp report for the revised design:
GB/CB/1921 Modified, Great Britain Battlecruiser laid down 1921

Displacement:
 41,058 t light; 43,093 t standard; 45,500 t normal; 47,425 t full load

Dimensions: Length overall / water x beam x draught
 814.00 ft / 814.00 ft x 104.00 ft x 31.00 ft (normal load)
 248.11 m / 248.11 m x 31.70 m  x 9.45 m

Armament:
      8 - 16.00" / 406 mm guns (4x2 guns), 2,048.00lbs / 928.96kg shells, 1921 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      2 - 16.00" / 406 mm guns (1x2 guns), 2,048.00lbs / 928.96kg shells, 1921 Model
   Breech loading guns in a turret (on a barbette)
   on side amidships
      14 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1921 Model
   Quick firing guns in casemate mounts 
   on side, evenly spread
   14 guns in hull casemates - Limited use in heavy seas
 Weight of broadside 21,992 lbs / 9,975 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 10.0" / 254 mm 505.00 ft / 153.92 m 8.00 ft / 2.44 m
 Ends: Unarmoured
 Upper: 8.00" / 203 mm 505.00 ft / 153.92 m 8.00 ft / 2.44 m
   Main Belt covers 95 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  2.00" / 51 mm 505.00 ft / 153.92 m 31.00 ft / 9.45 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 12.0" / 305 mm 8.00" / 203 mm  12.0" / 305 mm
 2nd: 12.0" / 305 mm 8.00" / 203 mm  12.0" / 305 mm
 3rd: 6.00" / 152 mm 4.00" / 102 mm  6.00" / 152 mm

   - Armour deck: 4.00" / 102 mm, Conning tower: 12.00" / 305 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 159,219 shp / 118,777 Kw = 30.00 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 4,332 tons

Complement:
 1,556 - 2,024

Cost:
 £11.490 million / $45.959 million

Distribution of weights at normal displacement:
 Armament: 2,749 tons, 6.0 %
 Armour: 13,643 tons, 30.0 %
    - Belts: 3,143 tons, 6.9 %
    - Torpedo bulkhead: 1,158 tons, 2.5 %
    - Armament: 4,401 tons, 9.7 %
    - Armour Deck: 4,611 tons, 10.1 %
    - Conning Tower: 330 tons, 0.7 %
 Machinery: 5,483 tons, 12.0 %
 Hull, fittings & equipment: 19,183 tons, 42.2 %
 Fuel, ammunition & stores: 4,442 tons, 9.8 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   53,947 lbs / 24,470 Kg = 26.3 x 16.0 " / 406 mm shells or 7.2 torpedoes
 Stability (Unstable if below 1.00): 1.08
 Metacentric height 6.1 ft / 1.9 m
 Roll period: 17.7 seconds
 Steadiness - As gun platform (Average = 50 %): 55 %
   - Recoil effect (Restricted arc if above 1.00): 0.84
 Seaboat quality  (Average = 1.00): 1.11

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.607
 Length to Beam Ratio: 7.83 : 1
 'Natural speed' for length: 28.53 kts
 Power going to wave formation at top speed: 51 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): -2.00 degrees
 Stern overhang: -2.00 ft / -0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  31.00 ft / 9.45 m
    - Forecastle (20 %): 28.00 ft / 8.53 m
    - Mid (50 %):  28.00 ft / 8.53 m (20.00 ft / 6.10 m aft of break)
    - Quarterdeck (15 %): 20.00 ft / 6.10 m
    - Stern:  20.00 ft / 6.10 m
    - Average freeboard: 24.24 ft / 7.39 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 104.4 %
  - Above water (accommodation/working, high = better): 180.7 %
 Waterplane Area: 62,311 Square feet or 5,789 Square metres
 Displacement factor (Displacement / loading): 98 %
 Structure weight / hull surface area: 219 lbs/sq ft or 1,070 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.98
  - Longitudinal: 1.20
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent

Saturday, January 20, 2007

My anachronistic German light cruiser Koenigsberg design

I was inspired by seeing a movie with a raiding German light cruiser with what appeared to be 12-4.1in guns. The movie was set in WWII, but I thought that I would try a German WWI light cruiser along those lines. I made a drawing, circa 1988, of such a ship. This is the Springsharp design for my Koenigsberg design:
Ger-CL Koeningsberg, Germany Light Cruiser laid down 1912

Displacement:
 3,169 t light; 3,296 t standard; 3,700 t normal; 4,023 t full load

Dimensions: Length overall / water x beam x draught
 378.70 ft / 376.00 ft x 43.00 ft x 17.00 ft (normal load)
 115.43 m / 114.60 m x 13.11 m  x 5.18 m

Armament:
      12 - 4.13" / 105 mm guns (4x3 guns), 35.32lbs / 16.02kg shells, 1912 Model
   Quick firing guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      8 - 2.05" / 52.0 mm guns (4x2 guns), 4.29lbs / 1.95kg shells, 1912 Model
   Breech loading guns in deck mounts with hoists
   on side, all amidships, all raised mounts - superfiring
 Weight of broadside 458 lbs / 208 kg
 Shells per gun, main battery: 200
 2 - 17.7" / 450 mm submerged torpedo tubes

Armour:
   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 2.00" / 51 mm 2.00" / 51 mm  2.00" / 51 mm
 2nd: 1.00" / 25 mm 1.00" / 25 mm  1.00" / 25 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 4.00" / 102 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Direct drive, 2 shafts, 27,928 shp / 20,834 Kw = 27.00 kts
 Range 4,500nm at 12.00 kts
 Bunker at max displacement = 728 tons (100% coal)

Complement:
 236 - 308

Cost:
 £0.331 million / $1.322 million

Distribution of weights at normal displacement:
 Armament: 57 tons, 1.5 %
 Armour: 533 tons, 14.4 %
    - Belts: 0 tons, 0.0 %
    - Torpedo bulkhead: 0 tons, 0.0 %
    - Armament: 124 tons, 3.4 %
    - Armour Deck: 388 tons, 10.5 %
    - Conning Tower: 21 tons, 0.6 %
 Machinery: 1,225 tons, 33.1 %
 Hull, fittings & equipment: 1,354 tons, 36.6 %
 Fuel, ammunition & stores: 531 tons, 14.3 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   2,781 lbs / 1,261 Kg = 78.7 x 4.1 " / 105 mm shells or 0.7 torpedoes
 Stability (Unstable if below 1.00): 1.14
 Metacentric height 1.8 ft / 0.5 m
 Roll period: 13.5 seconds
 Steadiness - As gun platform (Average = 50 %): 63 %
   - Recoil effect (Restricted arc if above 1.00): 0.39
 Seaboat quality  (Average = 1.00): 1.10

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.471
 Length to Beam Ratio: 8.74 : 1
 'Natural speed' for length: 19.39 kts
 Power going to wave formation at top speed: 60 %
 Trim (Max stability = 0, Max steadiness = 100): 57
 Bow angle (Positive = bow angles forward): 2.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  20.00 ft / 6.10 m
    - Forecastle (20 %): 15.00 ft / 4.57 m
    - Mid (50 %):  15.00 ft / 4.57 m
    - Quarterdeck (15 %): 15.00 ft / 4.57 m
    - Stern:  16.00 ft / 4.88 m
    - Average freeboard: 15.48 ft / 4.72 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 125.3 %
  - Above water (accommodation/working, high = better): 127.1 %
 Waterplane Area: 10,499 Square feet or 975 Square metres
 Displacement factor (Displacement / loading): 108 %
 Structure weight / hull surface area: 73 lbs/sq ft or 356 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.92
  - Longitudinal: 2.15
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

Friday, January 19, 2007

Springsharp report for a "British Amagi"

I tried the ship I suggested in Springhsharp. I found that I needed to raise the displacment a great deal, for the design to be acceptable in Springsharp:
GB/CB/1921, Great Britain Battlecruiser laid down 1921

Displacement:
 42,912 t light; 44,987 t standard; 47,500 t normal; 49,510 t full load

Dimensions: Length overall / water x beam x draught
 814.00 ft / 814.00 ft x 104.00 ft x 29.00 ft (normal load)
 248.11 m / 248.11 m x 31.70 m  x 8.84 m

Armament:
      8 - 16.00" / 406 mm guns (4x2 guns), 2,048.00lbs / 928.96kg shells, 1921 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      2 - 16.00" / 406 mm guns (1x2 guns), 2,048.00lbs / 928.96kg shells, 1921 Model
   Breech loading guns in a turret (on a barbette)
   on side amidships
      14 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1921 Model
   Quick firing guns in casemate mounts 
   on side, evenly spread
   14 guns in hull casemates - Limited use in heavy seas
 Weight of broadside 21,992 lbs / 9,975 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 12.0" / 305 mm 505.00 ft / 153.92 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 95 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  2.00" / 51 mm 505.00 ft / 153.92 m 29.00 ft / 8.84 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 12.0" / 305 mm 9.00" / 229 mm  12.0" / 305 mm
 2nd: 12.0" / 305 mm 9.00" / 229 mm  12.0" / 305 mm
 3rd: 6.00" / 152 mm 4.00" / 102 mm  6.00" / 152 mm

   - Armour deck: 4.00" / 102 mm, Conning tower: 12.00" / 305 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 168,959 shp / 126,044 Kw = 30.00 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 4,523 tons

Complement:
 1,608 - 2,091

Cost:
 £11.774 million / $47.097 million

Distribution of weights at normal displacement:
 Armament: 2,749 tons, 5.8 %
 Armour: 15,044 tons, 31.7 %
    - Belts: 4,203 tons, 8.8 %
    - Torpedo bulkhead: 1,084 tons, 2.3 %
    - Armament: 4,499 tons, 9.5 %
    - Armour Deck: 4,919 tons, 10.4 %
    - Conning Tower: 339 tons, 0.7 %
 Machinery: 5,818 tons, 12.2 %
 Hull, fittings & equipment: 19,301 tons, 40.6 %
 Fuel, ammunition & stores: 4,588 tons, 9.7 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   58,612 lbs / 26,586 Kg = 28.6 x 16.0 " / 406 mm shells or 7.6 torpedoes
 Stability (Unstable if below 1.00): 1.12
 Metacentric height 6.6 ft / 2.0 m
 Roll period: 17.0 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.78
 Seaboat quality  (Average = 1.00): 1.03

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.677
 Length to Beam Ratio: 7.83 : 1
 'Natural speed' for length: 28.53 kts
 Power going to wave formation at top speed: 53 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): -2.00 degrees
 Stern overhang: -2.00 ft / -0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  31.00 ft / 9.45 m
    - Forecastle (20 %): 28.00 ft / 8.53 m
    - Mid (50 %):  28.00 ft / 8.53 m (20.00 ft / 6.10 m aft of break)
    - Quarterdeck (15 %): 20.00 ft / 6.10 m
    - Stern:  20.00 ft / 6.10 m
    - Average freeboard: 24.24 ft / 7.39 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 102.9 %
  - Above water (accommodation/working, high = better): 186.6 %
 Waterplane Area: 66,477 Square feet or 6,176 Square metres
 Displacement factor (Displacement / loading): 98 %
 Structure weight / hull surface area: 213 lbs/sq ft or 1,038 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.99
  - Longitudinal: 1.09
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent

What if the British built ships similar to the Japanese Amagi design of 1921?

I have a photo on my cubical wall of the three-funnel British ship with five twin turrets with large guns:

What if the British built ships like this that were similar to the Japanese 8-8 program ships, such as the Amagi class? This ship design could have 10-16in guns and a speed of 30 knots without much problem. The dimensions would be 814ft x 104ft x 29ft. The secondary armament would be 14-6in QF guns. The belt would be 12in and the deck would be 4in. I will do a Springsharp design, later in the day, to test the idea.

Thursday, January 18, 2007

The G3 Battlecruisers

The G3 battlecruisers were much better ships than the German Bismarck class ships built much later. The G3's were faster, at 31-32 knots, had thicker side armour (14in vs. 12.5in) and had thicker deck armour (8in vs. 4.5in). The G3's also out-gunned the Bismarck, with 9-16in, against the Bismarck's 8-15in. The G3's were marred by the bizarre layout, but aside from that, they would have been really extraordinary ships. E. L. Attwood and Stanley Goodall were to some degree running amock, in the sense that they wanted to take all sorts of extreme measures to achieve the best possible performance from a given displacement. D. K. Brown has a good discussion of what happened in this book The Grand Fleet.

Wednesday, January 17, 2007

A version of the anachronistic Lion with oil-fired boilers

As you might expect, the anachronistic version of the Lion, when given oil-fired boilers, is more capable. My choice is to mostly use the added capability to provide an 18 knot cruising speed for 5,700nm. I hesitate to give the ship a higher maximum speed, given the relatively low freeboard. This is the Springsharp report:
Lion, Great Britain Battlecruiser laid down 1912

Displacement:
 24,566 t light; 25,668 t standard; 28,900 t normal; 31,485 t full load

Dimensions: Length overall / water x beam x draught
 700.91 ft / 700.00 ft x 88.00 ft x 27.00 ft (normal load)
 213.64 m / 213.36 m x 26.82 m  x 8.23 m

Armament:
      8 - 13.50" / 343 mm guns (3 mounts), 1,230.19lbs / 558.00kg shells, 1912 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 1 raised mount - superfiring
      16 - 4.00" / 102 mm guns (8x2 guns), 32.00lbs / 14.51kg shells, 1912 Model
   Quick firing guns in deck mounts with hoists
   on side, evenly spread, all raised mounts
 Weight of broadside 10,354 lbs / 4,696 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 9.00" / 229 mm 440.00 ft / 134.11 m 16.00 ft / 4.88 m
 Ends: 5.00" / 127 mm 260.00 ft / 79.25 m 12.00 ft / 3.66 m
   Main Belt covers 97 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  2.00" / 51 mm 440.00 ft / 134.11 m 27.00 ft / 8.23 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 9.00" / 229 mm 7.00" / 178 mm  9.00" / 229 mm
 2nd: 4.00" / 102 mm 3.00" / 76 mm  4.00" / 102 mm

   - Armour deck: 3.00" / 76 mm, Conning tower: 9.00" / 229 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 4 shafts, 96,584 shp / 72,051 Kw = 28.00 kts
 Range 5,700nm at 18.00 kts
 Bunker at max displacement = 5,817 tons

Complement:
 1,107 - 1,440

Cost:
 £2.486 million / $9.944 million

Distribution of weights at normal displacement:
 Armament: 1,294 tons, 4.5 %
 Armour: 8,769 tons, 30.3 %
    - Belts: 3,304 tons, 11.4 %
    - Torpedo bulkhead: 879 tons, 3.0 %
    - Armament: 1,885 tons, 6.5 %
    - Armour Deck: 2,520 tons, 8.7 %
    - Conning Tower: 183 tons, 0.6 %
 Machinery: 3,851 tons, 13.3 %
 Hull, fittings & equipment: 10,651 tons, 36.9 %
 Fuel, ammunition & stores: 4,334 tons, 15.0 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   37,875 lbs / 17,180 Kg = 30.8 x 13.5 " / 343 mm shells or 5.6 torpedoes
 Stability (Unstable if below 1.00): 1.19
 Metacentric height 5.7 ft / 1.7 m
 Roll period: 15.5 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.55
 Seaboat quality  (Average = 1.00): 1.04

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.608
 Length to Beam Ratio: 7.95 : 1
 'Natural speed' for length: 26.46 kts
 Power going to wave formation at top speed: 51 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 2.00 degrees
 Stern overhang: -2.00 ft / -0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  26.00 ft / 7.92 m
    - Forecastle (20 %): 19.00 ft / 5.79 m
    - Mid (50 %):  19.00 ft / 5.79 m
    - Quarterdeck (15 %): 19.00 ft / 5.79 m
    - Stern:  19.00 ft / 5.79 m
    - Average freeboard: 19.56 ft / 5.96 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 99.7 %
  - Above water (accommodation/working, high = better): 148.4 %
 Waterplane Area: 45,398 Square feet or 4,218 Square metres
 Displacement factor (Displacement / loading): 108 %
 Structure weight / hull surface area: 168 lbs/sq ft or 818 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 1.00
  - Longitudinal: 1.05
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent

Tuesday, January 16, 2007

My anachronistic Lion design

Another anachronistic design from 1988 had the battlecruiser Lion with a flush deck, a raked bow, and a Renown look. There were twin funnels and pole masts with tripod legs. The secondary armament 8 twin 4in QF mounts. This is the Springsharp report:
Lion, Great Britain Battlecruiser laid down 1912

Displacement:
 24,988 t light; 26,092 t standard; 29,000 t normal; 31,326 t full load

Dimensions: Length overall / water x beam x draught
 700.91 ft / 700.00 ft x 88.00 ft x 27.00 ft (normal load)
 213.64 m / 213.36 m x 26.82 m  x 8.23 m

Armament:
      8 - 13.50" / 343 mm guns (3 mounts), 1,230.19lbs / 558.00kg shells, 1912 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 1 raised mount - superfiring
      16 - 4.00" / 102 mm guns (8x2 guns), 32.00lbs / 14.51kg shells, 1912 Model
   Quick firing guns in deck mounts with hoists
   on side, evenly spread, all raised mounts
 Weight of broadside 10,354 lbs / 4,696 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 9.00" / 229 mm 440.00 ft / 134.11 m 16.00 ft / 4.88 m
 Ends: 5.00" / 127 mm 260.00 ft / 79.25 m 12.00 ft / 3.66 m
   Main Belt covers 97 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  2.00" / 51 mm 440.00 ft / 134.11 m 27.00 ft / 8.23 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 9.00" / 229 mm 7.00" / 178 mm  9.00" / 229 mm
 2nd: 4.00" / 102 mm 3.00" / 76 mm  4.00" / 102 mm

   - Armour deck: 3.00" / 76 mm, Conning tower: 9.00" / 229 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Direct drive, 4 shafts, 96,871 shp / 72,266 Kw = 28.00 kts
 Range 5,600nm at 15.00 kts
 Bunker at max displacement = 5,234 tons (100% coal)

Complement:
 1,110 - 1,444

Cost:
 £2.557 million / $10.226 million

Distribution of weights at normal displacement:
 Armament: 1,294 tons, 4.5 %
 Armour: 8,775 tons, 30.3 %
    - Belts: 3,304 tons, 11.4 %
    - Torpedo bulkhead: 879 tons, 3.0 %
    - Armament: 1,885 tons, 6.5 %
    - Armour Deck: 2,525 tons, 8.7 %
    - Conning Tower: 183 tons, 0.6 %
 Machinery: 4,249 tons, 14.7 %
 Hull, fittings & equipment: 10,670 tons, 36.8 %
 Fuel, ammunition & stores: 4,012 tons, 13.8 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   36,077 lbs / 16,364 Kg = 29.3 x 13.5 " / 343 mm shells or 5.1 torpedoes
 Stability (Unstable if below 1.00): 1.19
 Metacentric height 5.7 ft / 1.7 m
 Roll period: 15.5 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.55
 Seaboat quality  (Average = 1.00): 1.04

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.610
 Length to Beam Ratio: 7.95 : 1
 'Natural speed' for length: 26.46 kts
 Power going to wave formation at top speed: 51 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 2.00 degrees
 Stern overhang: -2.00 ft / -0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  26.00 ft / 7.92 m
    - Forecastle (20 %): 19.00 ft / 5.79 m
    - Mid (50 %):  19.00 ft / 5.79 m
    - Quarterdeck (15 %): 19.00 ft / 5.79 m
    - Stern:  19.00 ft / 5.79 m
    - Average freeboard: 19.56 ft / 5.96 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 105.1 %
  - Above water (accommodation/working, high = better): 148.3 %
 Waterplane Area: 45,487 Square feet or 4,226 Square metres
 Displacement factor (Displacement / loading): 105 %
 Structure weight / hull surface area: 168 lbs/sq ft or 818 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 1.00
  - Longitudinal: 1.04
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent

Monday, January 15, 2007

A different approach to anachronistic ship designs: the cruiser Shannon

A different approach to anachronistic ship designs is to take the real gun calibers and numbers, and try and make that work on a ship of the original dimensions. This does not work as easily or as well as the other approach, which is based on choosing a reasonable armament for the size ship. I have a drawing dating from 1988 that uses this approach to HMS Shannon, the classic belted cruiser. To get an acceptable Springsharp design, I had to alter dimensions and increase the displacement. I decided that if altering the design was necessary, the speed needed to be increased to 15 knots. This is the Springsharp report:
Shannon, Great Britain Belted Cruiser laid down 1912 (Engine 1908)

Displacement:
 5,879 t light; 6,237 t standard; 6,580 t normal; 6,855 t full load

Dimensions: Length overall / water x beam x draught
 275.00 ft / 275.00 ft x 59.00 ft x 24.00 ft (normal load)
 83.82 m / 83.82 m x 17.98 m  x 7.32 m

Armament:
      2 - 10.00" / 254 mm guns in single mounts, 500.00lbs / 226.80kg shells, 1912 Model
   Breech loading guns in turrets (on barbettes)
   on centreline, all forward
      3 - 9.00" / 229 mm guns (1x3 guns), 364.50lbs / 165.33kg shells, 1912 Model
   Breech loading guns in a turret (on a barbette)
   on centreline aft
      4 - 9.00" / 229 mm guns (2x2 guns), 364.50lbs / 165.33kg shells, 1912 Model
   Breech loading guns in turrets (on barbettes)
   on side, all amidships
      2 - 4.00" / 102 mm guns (1x2 guns), 32.00lbs / 14.51kg shells, 1912 Model
   Quick firing guns in a deck mount with hoist
   on centreline aft, all raised guns - superfiring
      4 - 4.00" / 102 mm guns (2x2 guns), 32.00lbs / 14.51kg shells, 1912 Model
   Quick firing guns in deck mounts with hoists
   on side, all amidships, all raised mounts - superfiring
 Weight of broadside 3,744 lbs / 1,698 kg
 Shells per gun, main battery: 100

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 9.00" / 229 mm 160.00 ft / 48.77 m 10.00 ft / 3.05 m
 Ends: 6.00" / 152 mm   65.00 ft / 19.81 m 10.00 ft / 3.05 m
   50.00 ft / 15.24 m Unarmoured ends
   Main Belt covers 90 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 160.00 ft / 48.77 m 22.00 ft / 6.71 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 9.00" / 229 mm 6.00" / 152 mm  9.00" / 229 mm
 2nd: 6.00" / 152 mm 4.00" / 102 mm  6.00" / 152 mm
 3rd: 6.00" / 152 mm 4.00" / 102 mm  6.00" / 152 mm
 4th: 2.00" / 51 mm 1.00" / 25 mm  2.00" / 51 mm
 5th: 2.00" / 51 mm 1.00" / 25 mm  2.00" / 51 mm

   - Armour deck: 3.00" / 76 mm, Conning tower: 9.00" / 229 mm

Machinery:
 Coal fired boilers, complex reciprocating steam engines, 
 Direct drive, 2 shafts, 4,850 ihp / 3,618 Kw = 15.00 kts
 Range 3,500nm at 10.00 kts
 Bunker at max displacement = 618 tons (100% coal)

Complement:
 364 - 474

Cost:
 £0.661 million / $2.642 million

Distribution of weights at normal displacement:
 Armament: 468 tons, 7.1 %
 Armour: 2,469 tons, 37.5 %
    - Belts: 820 tons, 12.5 %
    - Torpedo bulkhead: 130 tons, 2.0 %
    - Armament: 797 tons, 12.1 %
    - Armour Deck: 653 tons, 9.9 %
    - Conning Tower: 68 tons, 1.0 %
 Machinery: 441 tons, 6.7 %
 Hull, fittings & equipment: 2,500 tons, 38.0 %
 Fuel, ammunition & stores: 701 tons, 10.7 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   8,058 lbs / 3,655 Kg = 16.1 x 10.0 " / 254 mm shells or 1.9 torpedoes
 Stability (Unstable if below 1.00): 1.04
 Metacentric height 2.4 ft / 0.7 m
 Roll period: 15.9 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.97
 Seaboat quality  (Average = 1.00): 1.68

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.591
 Length to Beam Ratio: 4.66 : 1
 'Natural speed' for length: 16.58 kts
 Power going to wave formation at top speed: 50 %
 Trim (Max stability = 0, Max steadiness = 100): 31
 Bow angle (Positive = bow angles forward): -1.00 degrees
 Stern overhang: -2.00 ft / -0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  18.00 ft / 5.49 m
    - Forecastle (20 %): 16.00 ft / 4.88 m
    - Mid (50 %):  16.00 ft / 4.88 m
    - Quarterdeck (15 %): 16.00 ft / 4.88 m
    - Stern:  16.00 ft / 4.88 m
    - Average freeboard: 16.16 ft / 4.93 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 114.4 %
  - Above water (accommodation/working, high = better): 98.6 %
 Waterplane Area: 11,772 Square feet or 1,094 Square metres
 Displacement factor (Displacement / loading): 93 %
 Structure weight / hull surface area: 135 lbs/sq ft or 659 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.84
  - Longitudinal: 4.85
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is adequate
 Excellent seaboat, comfortable, can fire her guns in the heaviest weather

Sunday, January 14, 2007

My anachronistic version of the armoured corvette Penelope

In my papers from 1988, I had a sketch plan of my anachronistic design for the armoured corvette Penelope (originally completed in 1868). I kept the general dimensions, gun calibers, and armour thicknesses. The speed is greater, as the design has greater capacity for performance, due to the later period. My design has a normal displacement of 4,470 tons, 4-8in, 2-5in, and 2-4in guns. The belt is 6in and I have a 2in deck. The speed is 15.5 knots, with a range of 3,750nm at 12 knots. My ship looks like a 1890's cruiser, with a flush deck and clipper bow. This is the Springsharp report:
Penelope, Great Britain Armoured Corvette laid down 1908 (Engine 1904)

Displacement:
 3,839 t light; 3,991 t standard; 4,470 t normal; 4,853 t full load

Dimensions: Length overall / water x beam x draught
 277.00 ft / 275.00 ft x 50.00 ft x 16.75 ft (normal load)
 84.43 m / 83.82 m x 15.24 m  x 5.11 m

Armament:
      4 - 8.00" / 203 mm guns (2x2 guns), 256.00lbs / 116.12kg shells, 1908 Model
   Breech loading guns in turrets (on barbettes)
   on centreline, all forward
      2 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1908 Model
   Quick firing guns in casemate mounts 
   on centreline, all amidships
      2 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1908 Model
   Quick firing guns in casemate mounts 
   on centreline, all aft
 Weight of broadside 1,213 lbs / 550 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 6.00" / 152 mm 160.00 ft / 48.77 m 8.00 ft / 2.44 m
 Ends: 6.00" / 152 mm 115.00 ft / 35.05 m 8.00 ft / 2.44 m
 Upper: 6.00" / 152 mm   65.00 ft / 19.81 m 8.00 ft / 2.44 m
   Main Belt covers 90 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 160.00 ft / 48.77 m 16.00 ft / 4.88 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 6.00" / 152 mm 4.00" / 102 mm  6.00" / 152 mm
 2nd: 4.50" / 114 mm 3.00" / 76 mm  4.50" / 114 mm
 3rd: 4.50" / 114 mm 3.00" / 76 mm  4.50" / 114 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 6.00" / 152 mm

Machinery:
 Coal fired boilers, complex reciprocating steam engines, 
 Direct drive, 2 shafts, 4,435 ihp / 3,308 Kw = 15.50 kts
 Range 3,750nm at 12.00 kts
 Bunker at max displacement = 862 tons (100% coal)

Complement:
 273 - 355

Cost:
 £0.353 million / $1.412 million

Distribution of weights at normal displacement:
 Armament: 152 tons, 3.4 %
 Armour: 1,600 tons, 35.8 %
    - Belts: 757 tons, 16.9 %
    - Torpedo bulkhead: 95 tons, 2.1 %
    - Armament: 314 tons, 7.0 %
    - Armour Deck: 400 tons, 9.0 %
    - Conning Tower: 35 tons, 0.8 %
 Machinery: 652 tons, 14.6 %
 Hull, fittings & equipment: 1,435 tons, 32.1 %
 Fuel, ammunition & stores: 631 tons, 14.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   7,021 lbs / 3,185 Kg = 27.4 x 8.0 " / 203 mm shells or 1.7 torpedoes
 Stability (Unstable if below 1.00): 1.12
 Metacentric height 2.2 ft / 0.7 m
 Roll period: 14.2 seconds
 Steadiness - As gun platform (Average = 50 %): 97 %
   - Recoil effect (Restricted arc if above 1.00): 0.76
 Seaboat quality  (Average = 1.00): 1.94

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.679
 Length to Beam Ratio: 5.50 : 1
 'Natural speed' for length: 16.58 kts
 Power going to wave formation at top speed: 51 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 0.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  20.00 ft / 6.10 m
    - Forecastle (20 %): 17.00 ft / 5.18 m
    - Mid (50 %):  17.00 ft / 5.18 m
    - Quarterdeck (15 %): 17.00 ft / 5.18 m
    - Stern:  17.00 ft / 5.18 m
    - Average freeboard: 17.24 ft / 5.25 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 122.1 %
  - Above water (accommodation/working, high = better): 128.3 %
 Waterplane Area: 10,818 Square feet or 1,005 Square metres
 Displacement factor (Displacement / loading): 109 %
 Structure weight / hull surface area: 85 lbs/sq ft or 415 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.88
  - Longitudinal: 3.26
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent
 Ship has slow, easy roll, a good, steady gun platform
 Excellent seaboat, comfortable, can fire her guns in the heaviest weather

Saturday, January 13, 2007

I struggled with Springsharp to try and get an anachronistic Viper to work

A reader asked if I had ever thought about doing an anachronistic destroyer. I thought I would attempt my favorite 1890's destroyer, HMS Viper. I ran into the usual problem with Springsharp, in that the empirical equation for powering destroyers does not perform well. I had to settle for a 30.5 knot ship with too deep a draft. Unlike the designers of the early destroyers, I was not willing to settle for inadequate seakeeping. That perjudice on my part just aggravated the other Springsharp problem. The resulting design has too short a roll period and too high freeboard, in addition to a draft that is too deep. I guess that I should be happy to have a coal-burning turbine destroyer that can even make 30.5 knots, much less 33 or 36 knots. This is my painting of the original HMS Viper making 36 knots on trials:

The anachronistic Viper doesn't look anything like that. It looks like a WWII small destroyer or torpedo boat. The 18in TT are in a twin mount. The 3in QF gun is superfiring over the 6pdr QF forward. There is a twin 6pdr amidships and another twin 6pdr aft, on a bandstand, as is the midships 6pdr mount. The hull is flush-decked with a flared bow and twin funnels. This is the Springsharp report:
Viper, Great Britain Destroyer laid down 1912 (Engine 1950)

Displacement:
 352 t light; 365 t standard; 415 t normal; 455 t full load

Dimensions: Length overall / water x beam x draught
 213.31 ft / 210.00 ft x 21.00 ft x 11.00 ft (normal load)
 65.02 m / 64.01 m x 6.40 m  x 3.35 m

Armament:
      1 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1912 Model
   Quick firing gun in a deck mount with hoist
   on centreline forward, 1 raised gun
      2 - 2.24" / 57.0 mm guns (1x2 guns), 5.65lbs / 2.56kg shells, 1912 Model
   Breech loading guns in deck mount 
   on centreline amidships, all raised guns - superfiring
      2 - 2.24" / 57.0 mm guns (1x2 guns), 5.65lbs / 2.56kg shells, 1912 Model
   Breech loading guns in deck mount 
   on centreline aft, all raised guns - superfiring
      1 - 2.24" / 57.0 mm guns in single mounts, 5.65lbs / 2.56kg shells, 1912 Model
   Breech loading gun in deck mount 
   on centreline forward
 Weight of broadside 42 lbs / 19 kg
 Shells per gun, main battery: 150
 2 - 18.0" / 457.2 mm above water torpedoes

Machinery:
 Coal fired boilers, steam turbines, 
 Direct drive, 2 shafts, 14,242 shp / 10,625 Kw = 30.50 kts
 Range 3,500nm at 12.00 kts
 Bunker at max displacement = 90 tons (100% coal)

Complement:
 45 - 59

Cost:
 £0.046 million / $0.186 million

Distribution of weights at normal displacement:
 Armament: 5 tons, 1.3 %
 Machinery: 212 tons, 51.2 %
 Hull, fittings & equipment: 135 tons, 32.4 %
 Fuel, ammunition & stores: 63 tons, 15.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   131 lbs / 59 Kg = 9.7 x 3.0 " / 76 mm shells or 0.2 torpedoes
 Stability (Unstable if below 1.00): 1.42
 Metacentric height 0.9 ft / 0.3 m
 Roll period: 9.4 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.25
 Seaboat quality  (Average = 1.00): 1.04

Hull form characteristics:
 Hull has low forecastle
 Block coefficient: 0.299
 Length to Beam Ratio: 10.00 : 1
 'Natural speed' for length: 14.49 kts
 Power going to wave formation at top speed: 68 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 5.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  15.00 ft / 4.57 m
    - Forecastle (20 %): 0.00 ft / 0.00 m (11.00 ft / 3.35 m aft of break)
    - Mid (50 %):  11.00 ft / 3.35 m
    - Quarterdeck (15 %): 11.00 ft / 3.35 m
    - Stern:  11.00 ft / 3.35 m
    - Average freeboard: 10.00 ft / 3.05 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 175.2 %
  - Above water (accommodation/working, high = better): 101.8 %
 Waterplane Area: 2,839 Square feet or 264 Square metres
 Displacement factor (Displacement / loading): 52 %
 Structure weight / hull surface area: 21 lbs/sq ft or 104 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.41
  - Longitudinal: 3.88
  - Overall: 0.52
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is adequate

Friday, January 12, 2007

A rather nice anachronistic Monmouth class design

One of the better anachronistic designs that I have is of a Monmouth class armoured cruiser that looks like a late 1920's ship. There is a fairly modern bridge structure, two raked funnels, the fore funnel being larger, and two pole masts. The hull is flush decked. The 14-6in guns are in six turrets. There are two triple turrets, one at each end. There are twin 6in turrets in the superfiring position at each end. On each side is a twin 6in turret, for a total of 14. The 3in guns are in twin mounts with shields. The armour belt is 4in and the deck is 2in. This is the Springsharp report:
Monmouth class (anachronistic), Great Britain Armoured Cruiser laid down 1912 (Engine 1908)

Displacement:
 8,457 t light; 8,834 t standard; 10,000 t normal; 10,933 t full load

Dimensions: Length overall / water x beam x draught
 460.84 ft / 460.00 ft x 65.00 ft x 25.00 ft (normal load)
 140.46 m / 140.21 m x 19.81 m  x 7.62 m

Armament:
      10 - 6.00" / 152 mm guns (4 mounts), 108.00lbs / 48.99kg shells, 1912 Model
   Quick firing guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      4 - 6.00" / 152 mm guns (2x2 guns), 108.00lbs / 48.99kg shells, 1912 Model
   Quick firing guns in turrets (on barbettes)
   on side, all amidships
      8 - 3.00" / 76.2 mm guns (4x2 guns), 13.50lbs / 6.12kg shells, 1912 Model
   Quick firing guns in deck mounts with hoists
   on side, all amidships, all raised mounts - superfiring
      2 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1912 Model
   Quick firing guns in deck mounts with hoists
   on centreline, all aft, all raised mounts - superfiring
 Weight of broadside 1,647 lbs / 747 kg
 Shells per gun, main battery: 180

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 310.00 ft / 94.49 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 104 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 310.00 ft / 94.49 m 25.00 ft / 7.62 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 5.00" / 127 mm 3.00" / 76 mm  5.00" / 127 mm
 2nd: 5.00" / 127 mm 3.00" / 76 mm  5.00" / 127 mm
 3rd: 2.00" / 51 mm 1.00" / 25 mm  2.00" / 51 mm
 4th: 2.00" / 51 mm 1.00" / 25 mm  2.00" / 51 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 4.00" / 102 mm

Machinery:
 Coal fired boilers, complex reciprocating steam engines, 
 Direct drive, 2 shafts, 25,675 ihp / 19,154 Kw = 23.00 kts
 Range 4,500nm at 14.00 kts
 Bunker at max displacement = 2,099 tons (100% coal)

Complement:
 499 - 650

Cost:
 £0.796 million / $3.183 million

Distribution of weights at normal displacement:
 Armament: 206 tons, 2.1 %
 Armour: 2,518 tons, 25.2 %
    - Belts: 844 tons, 8.4 %
    - Torpedo bulkhead: 287 tons, 2.9 %
    - Armament: 631 tons, 6.3 %
    - Armour Deck: 717 tons, 7.2 %
    - Conning Tower: 40 tons, 0.4 %
 Machinery: 2,334 tons, 23.3 %
 Hull, fittings & equipment: 3,399 tons, 34.0 %
 Fuel, ammunition & stores: 1,543 tons, 15.4 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   11,559 lbs / 5,243 Kg = 107.0 x 6.0 " / 152 mm shells or 2.0 torpedoes
 Stability (Unstable if below 1.00): 1.09
 Metacentric height 3.1 ft / 0.9 m
 Roll period: 15.5 seconds
 Steadiness - As gun platform (Average = 50 %): 95 %
   - Recoil effect (Restricted arc if above 1.00): 0.48
 Seaboat quality  (Average = 1.00): 1.64

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.468
 Length to Beam Ratio: 7.08 : 1
 'Natural speed' for length: 21.45 kts
 Power going to wave formation at top speed: 49 %
 Trim (Max stability = 0, Max steadiness = 100): 58
 Bow angle (Positive = bow angles forward): 2.00 degrees
 Stern overhang: -1.00 ft / -0.30 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  24.00 ft / 7.32 m
    - Forecastle (20 %): 19.00 ft / 5.79 m
    - Mid (50 %):  19.00 ft / 5.79 m
    - Quarterdeck (15 %): 19.00 ft / 5.79 m
    - Stern:  19.00 ft / 5.79 m
    - Average freeboard: 19.40 ft / 5.91 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 133.6 %
  - Above water (accommodation/working, high = better): 140.5 %
 Waterplane Area: 19,367 Square feet or 1,799 Square metres
 Displacement factor (Displacement / loading): 113 %
 Structure weight / hull surface area: 108 lbs/sq ft or 525 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.92
  - Longitudinal: 2.12
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent
 Ship has slow, easy roll, a good, steady gun platform
 Excellent seaboat, comfortable, can fire her guns in the heaviest weather

Thursday, January 11, 2007

An anchronistic Cressy class armoured cruiser

Another of the anachronistic ship designs from my 1988 page is a Cressy class armoured cruiser drawing. I used that drawing to help me specify armoured lengths. The ship has 2-9.2in guns in a twin turret forward, a twin 6in turret in the superfiring position, forward, two triple 6in turrets aft, with one superfiring. There are also two twin 6in turrets, one on each beam. The 3in QF armament is in 6 twin mounts on the first level above the main deck. The hull is flush-decked and there are two funnels, close together. The speed is 21.5 knots. The armour basis is 6in with a 3in deck. This is the Springsharp report:
Defence class (anachronistic), Great Britain Armoured Cruiser laid down 1912 (Engine 1904)

Displacement:
 11,746 t light; 12,187 t standard; 13,700 t normal; 14,910 t full load

Dimensions: Length overall / water x beam x draught
 470.84 ft / 470.00 ft x 70.00 ft x 25.00 ft (normal load)
 143.51 m / 143.26 m x 21.34 m  x 7.62 m

Armament:
      2 - 9.20" / 234 mm guns (1x2 guns), 389.34lbs / 176.60kg shells, 1912 Model
   Breech loading guns in a turret (on a barbette)
   on centreline forward
      2 - 6.00" / 152 mm guns (1x2 guns), 108.00lbs / 48.99kg shells, 1912 Model
   Quick firing guns in a turret (on a barbette)
   on centreline forward, all raised guns - superfiring
      6 - 6.00" / 152 mm guns (2x3 guns), 108.00lbs / 48.99kg shells, 1912 Model
   Quick firing guns in turrets (on barbettes)
   on centreline, all aft, 1 raised mount - superfiring
      4 - 6.00" / 152 mm guns (2x2 guns), 108.00lbs / 48.99kg shells, 1912 Model
   Quick firing guns in turrets (on barbettes)
   on side, all amidships
      12 - 3.00" / 76.2 mm guns (6x2 guns), 13.50lbs / 6.12kg shells, 1912 Model
   Quick firing guns in deck mounts with hoists
   on side, evenly spread, all raised mounts
 Weight of broadside 2,237 lbs / 1,015 kg
 Shells per gun, main battery: 120

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 6.00" / 152 mm 305.00 ft / 92.96 m 16.00 ft / 4.88 m
 Ends: 2.00" / 51 mm 165.00 ft / 50.29 m 16.00 ft / 4.88 m
   Main Belt covers 100 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 305.00 ft / 92.96 m 25.00 ft / 7.62 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 6.00" / 152 mm 4.00" / 102 mm  6.00" / 152 mm
 2nd: 4.00" / 102 mm 3.00" / 76 mm  4.00" / 102 mm
 3rd: 4.00" / 102 mm 3.00" / 76 mm  4.00" / 102 mm
 4th: 2.00" / 51 mm 1.00" / 25 mm  2.00" / 51 mm

   - Armour deck: 3.00" / 76 mm, Conning tower: 6.00" / 152 mm

Machinery:
 Coal fired boilers, complex reciprocating steam engines, 
 Direct drive, 2 shafts, 24,939 ihp / 18,604 Kw = 21.50 kts
 Range 4,500nm at 14.00 kts
 Bunker at max displacement = 2,723 tons (100% coal)

Complement:
 633 - 823

Cost:
 £1.159 million / $4.638 million

Distribution of weights at normal displacement:
 Armament: 280 tons, 2.0 %
 Armour: 3,640 tons, 26.6 %
    - Belts: 1,469 tons, 10.7 %
    - Torpedo bulkhead: 282 tons, 2.1 %
    - Armament: 501 tons, 3.7 %
    - Armour Deck: 1,314 tons, 9.6 %
    - Conning Tower: 74 tons, 0.5 %
 Machinery: 3,667 tons, 26.8 %
 Hull, fittings & equipment: 4,159 tons, 30.4 %
 Fuel, ammunition & stores: 1,954 tons, 14.3 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   13,831 lbs / 6,274 Kg = 35.5 x 9.2 " / 234 mm shells or 2.1 torpedoes
 Stability (Unstable if below 1.00): 1.21
 Metacentric height 4.2 ft / 1.3 m
 Roll period: 14.4 seconds
 Steadiness - As gun platform (Average = 50 %): 95 %
   - Recoil effect (Restricted arc if above 1.00): 0.43
 Seaboat quality  (Average = 1.00): 1.64

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.583
 Length to Beam Ratio: 6.71 : 1
 'Natural speed' for length: 21.68 kts
 Power going to wave formation at top speed: 50 %
 Trim (Max stability = 0, Max steadiness = 100): 58
 Bow angle (Positive = bow angles forward): 2.00 degrees
 Stern overhang: -1.00 ft / -0.30 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  24.00 ft / 7.32 m
    - Forecastle (20 %): 19.00 ft / 5.79 m
    - Mid (50 %):  19.00 ft / 5.79 m
    - Quarterdeck (15 %): 19.00 ft / 5.79 m
    - Stern:  19.00 ft / 5.79 m
    - Average freeboard: 19.40 ft / 5.91 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 143.9 %
  - Above water (accommodation/working, high = better): 135.4 %
 Waterplane Area: 23,682 Square feet or 2,200 Square metres
 Displacement factor (Displacement / loading): 104 %
 Structure weight / hull surface area: 115 lbs/sq ft or 561 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.93
  - Longitudinal: 1.94
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent
 Ship has slow, easy roll, a good, steady gun platform
 Excellent seaboat, comfortable, can fire her guns in the heaviest weather

Wednesday, January 10, 2007

An anachronistic Defence class armoured cruiser

this is my attempt to render a 1988 anachronistic drawing of Defence class armoured cruisers with a late 1930's look to them. The armour basis is 6in with a 2in deck. The speed is a standard 23 knots witha coal-fired boilers and very lightweight machinery. The armament is carried in two twin 9.2in turrets, two triple 7.5in gun turrets in supefiring position, and two twin 7.5in turrets on the side. There are also 8 twin 3in QF gun mounts. This is the Springsharp report:
Defence class (anachronistic), Great Britain Armoured Cruiser laid down 1912 (Engine 1908)

Displacement:
 12,757 t light; 13,337 t standard; 14,900 t normal; 16,150 t full load

Dimensions: Length overall / water x beam x draught
 520.84 ft / 520.00 ft x 75.00 ft x 24.00 ft (normal load)
 158.75 m / 158.50 m x 22.86 m  x 7.32 m

Armament:
      4 - 9.20" / 234 mm guns (2x2 guns), 389.34lbs / 176.60kg shells, 1912 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread
      6 - 7.50" / 191 mm guns (2x3 guns), 210.94lbs / 95.68kg shells, 1912 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, all raised mounts
      4 - 7.50" / 191 mm guns (2x2 guns), 210.94lbs / 95.68kg shells, 1912 Model
   Breech loading guns in turrets (on barbettes)
   on side, all amidships, all raised mounts - superfiring
      16 - 3.00" / 76.2 mm guns (8x2 guns), 13.50lbs / 6.12kg shells, 1912 Model
   Quick firing guns in deck mounts with hoists
   on side, evenly spread, all raised mounts
 Weight of broadside 3,883 lbs / 1,761 kg
 Shells per gun, main battery: 120

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 6.00" / 152 mm 350.00 ft / 106.68 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 104 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 350.00 ft / 106.68 m 24.00 ft / 7.32 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 6.00" / 152 mm 4.00" / 102 mm  6.00" / 152 mm
 2nd: 5.00" / 127 mm 3.00" / 76 mm  5.00" / 127 mm
 3rd: 5.00" / 127 mm 3.00" / 76 mm  5.00" / 127 mm
 4th: 2.00" / 51 mm 1.00" / 25 mm  2.00" / 51 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 6.00" / 152 mm

Machinery:
 Coal fired boilers, complex reciprocating steam engines, 
 Direct drive, 2 shafts, 32,706 ihp / 24,399 Kw = 23.00 kts
 Range 4,700nm at 14.00 kts
 Bunker at max displacement = 2,814 tons (100% coal)

Complement:
 673 - 876

Cost:
 £1.270 million / $5.082 million

Distribution of weights at normal displacement:
 Armament: 485 tons, 3.3 %
 Armour: 3,796 tons, 25.5 %
    - Belts: 1,443 tons, 9.7 %
    - Torpedo bulkhead: 311 tons, 2.1 %
    - Armament: 950 tons, 6.4 %
    - Armour Deck: 1,014 tons, 6.8 %
    - Conning Tower: 78 tons, 0.5 %
 Machinery: 2,973 tons, 20.0 %
 Hull, fittings & equipment: 5,502 tons, 36.9 %
 Fuel, ammunition & stores: 2,143 tons, 14.4 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   17,727 lbs / 8,041 Kg = 45.5 x 9.2 " / 234 mm shells or 2.7 torpedoes
 Stability (Unstable if below 1.00): 1.16
 Metacentric height 4.3 ft / 1.3 m
 Roll period: 15.3 seconds
 Steadiness - As gun platform (Average = 50 %): 73 %
   - Recoil effect (Restricted arc if above 1.00): 0.54
 Seaboat quality  (Average = 1.00): 1.46

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.557
 Length to Beam Ratio: 6.93 : 1
 'Natural speed' for length: 22.80 kts
 Power going to wave formation at top speed: 49 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 2.00 degrees
 Stern overhang: -1.00 ft / -0.30 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  24.00 ft / 7.32 m
    - Forecastle (20 %): 19.00 ft / 5.79 m
    - Mid (50 %):  19.00 ft / 5.79 m
    - Quarterdeck (15 %): 19.00 ft / 5.79 m
    - Stern:  19.00 ft / 5.79 m
    - Average freeboard: 19.40 ft / 5.91 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 122.7 %
  - Above water (accommodation/working, high = better): 147.3 %
 Waterplane Area: 27,401 Square feet or 2,546 Square metres
 Displacement factor (Displacement / loading): 109 %
 Structure weight / hull surface area: 136 lbs/sq ft or 665 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.65
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent
 Ship has slow, easy roll, a good, steady gun platform
 Good seaboat, rides out heavy weather easily

Sir Edward Reed

Readers with an interest in history of warship design should read about Sir Edward Reed, if you are not already familiar with him. He was prominent enough to warrent a Wikipedia page, with links. Reed was a great warship designer and structural engineer. His early work on structures formed the basis for the system used by the Royal Corps of Naval Contructors, up through WW I. Reed designed some of the early ironclads, and one of his best designs was the Bellerophon, which had a long service life. He also designed the revolutionary turret ship Devastation, which was the first major warship built without masts and sails. He had earlier built coast defense vessels, such as the Cerberus (extremely long-lived), which formed the basis for the Devastation and Thunderer design. Dr. Oscar Parkes writes more about Reed in his classic book British Battleships. D. K. Brown has a more recent perspective on Reed and his influence. Brown has two books that are relevant:
  1. D. K. Brown, A century of naval. construction: The history of the Royal. Corps of Naval Constructors, 1983
  2. D. K. Brown, Warrior to Dreadnought: Warship Development, 1860-1905, 2003

Tuesday, January 09, 2007

The Swiftsure and Triumph design requires very lightweight machinery

I had done a design for the light battleships Swiftsure and Triumph, in the usual anachronistic style. The hull is flush-decked, with a flared bow. The armament is in two twin 10in turrets, two triple 7.5in turrets, in the superfiring position, and four twin 7.5in turrets, on the beam. There are also 16-3in QF guns in twin mounts with shields. The armour basis is 7in with a 2in deck. The speed is 20 knots. This is the Springsharp report:
Swiftsure and Triumph (anachronistic), Great Britain Battleship laid down 1912 (Engine 1910)

Displacement:
 12,221 t light; 12,815 t standard; 14,050 t normal; 15,038 t full load

Dimensions: Length overall / water x beam x draught
 471.54 ft / 470.00 ft x 70.00 ft x 24.00 ft (normal load)
 143.72 m / 143.26 m x 21.34 m  x 7.32 m

Armament:
      4 - 10.00" / 254 mm guns (2x2 guns), 500.00lbs / 226.80kg shells, 1912 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread
      6 - 7.50" / 191 mm guns (2x3 guns), 210.94lbs / 95.68kg shells, 1912 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, all raised mounts
      8 - 7.50" / 191 mm guns (4x2 guns), 210.94lbs / 95.68kg shells, 1912 Model
   Breech loading guns in turrets (on barbettes)
   on side, all amidships
      16 - 3.00" / 76.2 mm guns (8x2 guns), 13.50lbs / 6.12kg shells, 1912 Model
   Quick firing guns in deck mounts with hoists
   on side, all amidships, all raised mounts - superfiring
 Weight of broadside 5,169 lbs / 2,345 kg
 Shells per gun, main battery: 100

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 7.00" / 178 mm 300.00 ft / 91.44 m 16.00 ft / 4.88 m
 Ends: 3.00" / 76 mm 170.00 ft / 51.82 m 16.00 ft / 4.88 m
   Main Belt covers 98 % of normal length

   - Torpedo Bulkhead:
  2.00" / 51 mm 300.00 ft / 91.44 m 24.00 ft / 7.32 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 10.0" / 254 mm 7.00" / 178 mm  10.0" / 254 mm
 2nd: 5.00" / 127 mm 4.00" / 102 mm  5.00" / 127 mm
 3rd: 5.00" / 127 mm 4.00" / 102 mm  5.00" / 127 mm
 4th: 2.00" / 51 mm 1.00" / 25 mm  2.00" / 51 mm

   - Armour deck: 3.00" / 76 mm, Conning tower: 10.00" / 254 mm

Machinery:
 Coal fired boilers, complex reciprocating steam engines, 
 Direct drive, 2 shafts, 19,430 ihp / 14,495 Kw = 20.00 kts
 Range 5,600nm at 12.00 kts
 Bunker at max displacement = 2,223 tons (100% coal)

Complement:
 644 - 838

Cost:
 £1.152 million / $4.607 million

Distribution of weights at normal displacement:
 Armament: 646 tons, 4.6 %
 Armour: 5,216 tons, 37.1 %
    - Belts: 1,773 tons, 12.6 %
    - Torpedo bulkhead: 533 tons, 3.8 %
    - Armament: 1,421 tons, 10.1 %
    - Armour Deck: 1,364 tons, 9.7 %
    - Conning Tower: 125 tons, 0.9 %
 Machinery: 1,295 tons, 9.2 %
 Hull, fittings & equipment: 5,064 tons, 36.0 %
 Fuel, ammunition & stores: 1,829 tons, 13.0 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   20,807 lbs / 9,438 Kg = 41.6 x 10.0 " / 254 mm shells or 4.0 torpedoes
 Stability (Unstable if below 1.00): 1.03
 Metacentric height 3.1 ft / 1.0 m
 Roll period: 16.6 seconds
 Steadiness - As gun platform (Average = 50 %): 75 %
   - Recoil effect (Restricted arc if above 1.00): 0.89
 Seaboat quality  (Average = 1.00): 1.51

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.623
 Length to Beam Ratio: 6.71 : 1
 'Natural speed' for length: 21.68 kts
 Power going to wave formation at top speed: 47 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 degrees
 Stern overhang: -2.00 ft / -0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  22.00 ft / 6.71 m
    - Forecastle (18 %): 18.00 ft / 5.49 m
    - Mid (50 %):  18.00 ft / 5.49 m
    - Quarterdeck (15 %): 18.00 ft / 5.49 m
    - Stern:  18.00 ft / 5.49 m
    - Average freeboard: 18.29 ft / 5.57 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 91.3 %
  - Above water (accommodation/working, high = better): 130.9 %
 Waterplane Area: 24,578 Square feet or 2,283 Square metres
 Displacement factor (Displacement / loading): 108 %
 Structure weight / hull surface area: 139 lbs/sq ft or 680 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.80
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent
 Ship has slow, easy roll, a good, steady gun platform
 Excellent seaboat, comfortable, can fire her guns in the heaviest weather

Anachronistic ship designs

I found that when I was teenager, it was rather fun to take real ship specifications from the 19th Century and early 20th Century, and give them more modern characteristics. Instead of muzzle loading guns, say, give them more modern breechloaders (perhaps 45 or 50 calibers long). Instead of masts and sails, give them WWI-looking masts and bridge. Maybe give them a flush deck and raked bow. Don't have iron armour, but give them Krupp Cemented armour. Keep about the same dimensions, as that is part of the deal. You can substitute smaller breechloaders for the larger muzzle loaders. Make drawings or wargame pieces. I have also tried creating photos of them with a certain amount of success. This is my photo of the Nelson and Northampton armoured cruisers:

Monday, January 08, 2007

The anachronistic "Invincible" class

My anachronistic "Invincible" class design has a flush deck, three turrets (two triple and one twin 12in) and 8 twin mounts with 4in QF guns. The armour basis is 6in with a 2in deck and torpedo bulkhead. There are three, closely spaced funnels with a late-model bridge, with tripod foremast and control top. The mainmast is a pole, equipped with a derrick and light topmast, with yards. The conningtower has a small range finder and controller, with a secondary conning tower aft. The design uses "all-or-nothing" principles. This is the Springsharp report:
Invincible (anachronistic), Great Britain Battlecruiser laid down 1912 (Engine 1908)

Displacement:
 15,267 t light; 16,000 t standard; 17,800 t normal; 19,240 t full load

Dimensions: Length overall / water x beam x draught
 565.00 ft / 565.00 ft x 78.00 ft x 25.00 ft (normal load)
 172.21 m / 172.21 m x 23.77 m  x 7.62 m

Armament:
      8 - 12.00" / 305 mm guns (3 mounts), 864.00lbs / 391.90kg shells, 1912 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 1 raised mount - superfiring
      16 - 4.00" / 102 mm guns (8x2 guns), 32.00lbs / 14.51kg shells, 1912 Model
   Quick firing guns in deck mounts with hoists
   on side, all amidships, all raised mounts - superfiring
 Weight of broadside 7,424 lbs / 3,367 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 6.00" / 152 mm 365.00 ft / 111.25 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 99 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  2.00" / 51 mm 365.00 ft / 111.25 m 25.00 ft / 7.62 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 6.00" / 152 mm 4.00" / 102 mm  6.00" / 152 mm
 2nd: 3.00" / 76 mm 2.00" / 51 mm  3.00" / 76 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 6.00" / 152 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Direct drive, 4 shafts, 49,083 shp / 36,616 Kw = 25.00 kts
 Range 4,500nm at 14.00 kts
 Bunker at max displacement = 3,240 tons (100% coal)

Complement:
 769 - 1,001

Cost:
 £1.696 million / $6.782 million

Distribution of weights at normal displacement:
 Armament: 928 tons, 5.2 %
 Armour: 4,534 tons, 25.5 %
    - Belts: 1,511 tons, 8.5 %
    - Torpedo bulkhead: 675 tons, 3.8 %
    - Armament: 1,104 tons, 6.2 %
    - Armour Deck: 1,155 tons, 6.5 %
    - Conning Tower: 88 tons, 0.5 %
 Machinery: 2,727 tons, 15.3 %
 Hull, fittings & equipment: 7,078 tons, 39.8 %
 Fuel, ammunition & stores: 2,533 tons, 14.2 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   21,409 lbs / 9,711 Kg = 24.8 x 12.0 " / 305 mm shells or 3.3 torpedoes
 Stability (Unstable if below 1.00): 1.14
 Metacentric height 4.4 ft / 1.3 m
 Roll period: 15.6 seconds
 Steadiness - As gun platform (Average = 50 %): 65 %
   - Recoil effect (Restricted arc if above 1.00): 0.81
 Seaboat quality  (Average = 1.00): 1.30

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.565
 Length to Beam Ratio: 7.24 : 1
 'Natural speed' for length: 23.77 kts
 Power going to wave formation at top speed: 51 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 0.00 degrees
 Stern overhang: -1.00 ft / -0.30 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  23.00 ft / 7.01 m
    - Forecastle (20 %): 20.00 ft / 6.10 m
    - Mid (50 %):  20.00 ft / 6.10 m
    - Quarterdeck (15 %): 20.00 ft / 6.10 m
    - Stern:  20.00 ft / 6.10 m
    - Average freeboard: 20.24 ft / 6.17 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 119.4 %
  - Above water (accommodation/working, high = better): 154.6 %
 Waterplane Area: 31,205 Square feet or 2,899 Square metres
 Displacement factor (Displacement / loading): 102 %
 Structure weight / hull surface area: 154 lbs/sq ft or 751 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.95
  - Longitudinal: 1.64
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent
 Good seaboat, rides out heavy weather easily

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