## Saturday, October 30, 2004

### This is the drawing of my "fast escort" (GB/DD/1921)

### This is my GB/CL/1921b light cruiser design

### Drawing of the GB/CL/1921a design

### A fast escort

### A 36-knot light cruiser

## Friday, October 29, 2004

### My 1921-style light cruiser

## Thursday, October 28, 2004

### Picture of the "Super-Fast Battlecruiser Alternative 2"

### More about the "Alternative Super Fast Battlecruiser" design

### I'm working on an "alternative" 1921-style "Super Fast Battlecruiser"

My modified design is flush decked with a transom stern. The bow is flared and rises to about 36ft above the waterline. To accommodate very highpower machinery, I have had to lengthen the citadel. That pushes the forward 17in/45 twin turret at least 50ft further forward. The bridge structure is reminiscent of what Edward Attwood and Stanley Goodall were using on the "1921" ships that were being designed prior to the Washington Naval Treaty. The machinery follows the "unit system", and pushing the forward turret further towards the bow gives more of a cruiser look than the design previously had.

## Wednesday, October 27, 2004

### Volume analysis is difficult, due to lack of data

### I'm surprised (but maybe shouldn't be) that the shorter ship could be faster

*Glorious*and

*Courageous*and the German design studies from 1917 and 1918. The

*GK 3022*was designed for 34 knots and had four large guns in two turrets.

## Tuesday, October 26, 2004

### Six shafts on a narrow ship

### Hitting the wall...

### The "so-called" 29,000 ton battlecruiser has the usual issue

### The 29,000 ton battleship design

Thanks to Blogger, I just lost what I had written about testing my Warship General Design computer program. The 29,000 ton battleship design seemed like a good test case for the program. There was the drawback that I did not have as much information that I would have liked from 30 years ago. I just had the basics, and would have to augment that in the ship specification. This is the basic specifications as originally conceived:

- 29,000 tons displacement at normal load
- dimensions: 620ft x 95ft x 30.2ft
- Cp=0.59
- Cm=0.97
- Armament: 6-13.5in/45 and 10-6in/50
- Machinery: 40,000 SHP

I found out quickly that I needed to decrease the Cp. I decided to go with 0.54, although lower would have given a higher speed. That alone raised the maximum speed to over 23 knots. I also found out that I needed to raise weights to decrease the metacentric height (GM). The ship is basically short and wide, so that inherently implies a high GM. I decreased the lower belt to 13in and increased the upper deck to 5in. I also included "upper deck side" armor. That lowered the GM at normal load to 4.92ft and at deep load to 6.77ft. The latter is still almost too large, but that is what seems reasonable.

## Monday, October 25, 2004

### Machinery volume and SHP/ton

### I'm doing all this empirical work to calculate volumes

## Sunday, October 24, 2004

### The next step is to add "volume" analysis

## Saturday, October 23, 2004

### New features to my Warship General Design program

### I want to add range calculations for specified cruising speed

### There is a different optimal Cp at legend and deep load displacements

### I've tryed opimizing and found that the smaller the Cm as possible, the better

### Winston Churchill on Destroyers

## Friday, October 22, 2004

### The "Super Fast Battlecruiser": experiments

- main battery turrets: 11in basis (greatest thickness)
- main battery barbettes: 9in basis
- lower belt: 9in
- upper belt: 6in
- deck forward: 2in
- deck aft: 3in
- a/t bulkhead: 1.5in
- shields on 4in guns: 1in

Metacentric height at legend displacement (GM)=5.25 ft

### I have looked at Greg Locock's DreadCAD Excel spreadsheet

## Thursday, October 21, 2004

### I've been doing some experiments with Cp and Cm

I have been tweaking the specs for my Ger/CS/1905 scout cruiser and the "Super-fast" battlecruiser to maximum speed. For the battlecruiser, there is the 70,000SHP/shaft limitation that has an effect. I thought it odd, but the lowest Cp doesn't give the highest speed. This is close to the best that can be done:

At Displacement=30949.2 tons Length=804.0 ft Beam=87.0 ft Draft=28.2078 ft Cp=0.61 Cm=0.9 Cb=0.549 DLR=59.5498 Wetted Surface=79812.8 sq. ft. B/H=3.08425 At speed of 35knots power is 223938.0 SHP At speed of 36knots power is 258375.0 SHP At speed of 37knots power is 301770.0 SHP actual speed for 280000.0 SHP is 36.4983 knots

I've wondered if optimizing Cp and Cm would be a worthwhile exercise. I would iterate over two ranges, looking for the highest speed for the maximum SHP.

### The modified "Super-fast" battlecruiser design (circa 1920)

ook the basic design for the really fast battlecruiser and modified them to try and get the Spring Style program to "work". I've used a variant of those specs to see what my program would produce with them:

- year: 1920
- length: 804.0 ft
- beam: 87.0 ft
- depth: 55.5 ft
- displacement: 34,312.0 tons
- cp: 0.60
- cm: 0.97
- machineryWtBasis: 28.6 SHP/ton of machinery
- hullWtBasis: 3.0x10^-3
- freeboardForward: 35.0 ft
- freeboardAmid: 26.0 ft
- freeboardAft: 26.0 ft
- forecastleLength: 270.0 ft
- designedShp: 275,000.0
- designedSpeed: 35.0
- boardMargin: 100.0 tons
- electricalPowerKW: 800.0KW
- mainBattType: 17in/45
- mainBattNum: 4.0
- mainBattMount: turret
- mainBattNumMounts: 2.0
- secBattType: 4in/50
- secBattNum: 16.0
- secBattMount: shield
- secBattNumMounts: 6.0
- forecastleDeck: 0.0 in
- upperDeck: 2.0 in
- lowerDeckSlopes:0.0 in
- lowerDeckFlat:0.0 in
- mainBattBarbette: 9.0 in
- mainBattTurret: 11.0 in
- upperDeckSide: 0.0 in
- upperBelt: 6.0 in
- lowerBelt: 6.0 in
- beltLength: 430.0 ft
- beltForward: 0.0 in
- beltAft: 0.0 in
- deckForward: 0.0 in
- deckAft: 3.0 in
- antiTorpBh: 1.5 in
- secBattArmor: 1.0 in
- uptakeArmor: 1.5 in

This is part of the result from my program:

Designed draft=29.4996 ft Hull Weight=11646.3 tons Secondary Battery Weight=80.96 Armament Weight= 2474.16 Total Armor Weight=4199.17 Machinery Weight=9615.38 General Equipment Weight=1029.36 Normal Fuel Weight=1029.36 Maximum Fuel added Weight=2573.4 Reserve Feedwater Weight=2004.75 Legend Displacement=31230.0 Legend Draft=26.8499 Submergence of 1390.61 of actual displacement per foot At Displacement=31230.0 Length=804.0 Beam=87.0 Draft=26.8499 Cp=0.6 Cm=0.97 Cb=0.582 DLR=60.0903 Wetted Surface=80174.1 B/H=3.24024 At speed of 35 knots power is 225983.0 SHP At speed of 36 knots power is 260739.0 SHP At speed of 37 knots power is 303780.0 SHP actual speed for 275000.0 SHP is 36.3313 knots Deep Load Displacement=35808.2 Deep Load Draft=30.1823 Submergence of 1409.25 of actual displacement per foot At speed of 34 knots power is 232583.0 SHP At speed of 35 knots power is 261412.0 SHP At speed of 36 knots power is 305432.0 SHP actual speed for 275000.0 SHP is 35.3087 knots Metacentric height at legend displacement (GM)=4.73343 ft Metacentric height at deep load displacement (GM)=6.97987 ft

## Wednesday, October 20, 2004

### British weight groups

## Monday, October 18, 2004

### My latest attempt at specifying the "super fast battlecruiser"

At Displacement=28708.8 Length=800.0 ft Beam=85.0 ft Draft=25.3893 ft Cp=0.6 Cm=0.97 Cb=0.582 Total Armor Weight=4166.51 tons Designed SHP=410000.0 Mach Wt Basis=40.0 SHP/Ton of machinery Machinery Weight=10250.0 tons General Equipment Weight=960.0 tons Normal Fuel Weight=960.0 tons Maximum Fuel added Weight=2400.0 tons Reserve Feedwater Weight=2988.9 tons Legend Displacement=28708.8 tons Legend Draft=25.3893 ft Submergence of 1351.88 of actual displacement per foot At Displacement=28708.8 tons DLR=56.0719 Wetted Surface=76678.3 B/H=3.34786 At speed of 10knots power is 2873.4 SHP At speed of 11knots power is 3774.54 SHP At speed of 12knots power is 4835.44 SHP At speed of 13knots power is 6072.19 SHP At speed of 14knots power is 7502.44 SHP At speed of 15knots power is 9324.9 SHP At speed of 16knots power is 11431.4 SHP At speed of 17knots power is 13784.6 SHP At speed of 18knots power is 16407.0 SHP At speed of 19knots power is 19312.1 SHP At speed of 20knots power is 22514.5 SHP At speed of 21knots power is 26004.9 SHP At speed of 22knots power is 31165.9 SHP At speed of 23knots power is 37151.1 SHP At speed of 24knots power is 43607.0 SHP At speed of 25knots power is 50598.1 SHP At speed of 26knots power is 58102.8 SHP At speed of 27knots power is 66131.4 SHP At speed of 28knots power is 74693.9 SHP At speed of 29knots power is 88418.3 SHP At speed of 30knots power is 104903.0 SHP At speed of 31knots power is 123016.0 SHP At speed of 32knots power is 142806.0 SHP At speed of 33knots power is 163796.0 SHP At speed of 34knots power is 185916.0 SHP At speed of 35knots power is 209122.0 SHP At speed of 36knots power is 240865.0 SHP At speed of 37knots power is 278425.0 SHP At speed of 38knots power is 318175.0 SHP At speed of 39knots power is 362385.0 SHP At speed of 40knots power is 408577.0 SHP At speed of 41knots power is 456762.0 SHP actual speed for 410000.0 SHP is 40.0295 knots Metacentric height at legend displacement (GM)= 3.30897 ft

### My 17in/45 gun design

I ran my 17in/45 gun design through Rick Robinson's gun calculation program with the following results. This is the sort of gun that would have been built after 1920, if there had not been a Washington Naval Treaty:

Caliber = 17.0 inch (43.2 cm) Shell weight = 2555 lbs (1159 kg) Muzzle velocity = 2650 fps (808 m/s) Relative ballistic performance: 0.80 Muzzle energy = 378.3 megajoules = 139421.9 foot-tons Relative muzzle energy: 0.89 Typical barrel length: 46 calibers Elevation Range Time Velocity Fall Angle 2.5 deg 5700 yards 7.0 sec 2254 fps 2.8 deg 5.0 deg 10300 yards 13.7 sec 1980 fps 6.1 deg 7.5 deg 14200 yards 20.0 sec 1790 fps 9.8 deg 10.0 deg 17600 yards 26.0 sec 1656 fps 13.7 deg 12.5 deg 20500 yards 31.8 sec 1560 fps 17.7 deg 15.0 deg 23100 yards 37.4 sec 1493 fps 21.7 deg 20.0 deg 27600 yards 48.1 sec 1421 fps 29.5 deg 25.0 deg 31300 yards 58.2 sec 1404 fps 36.5 deg 30.0 deg 34300 yards 67.9 sec 1418 fps 42.8 deg 35.0 deg 36600 yards 77.1 sec 1451 fps 48.1 deg 40.0 deg 38100 yards 85.8 sec 1493 fps 52.6 deg 45.0 deg 38800 yards 94.1 sec 1539 fps 56.8 deg 50.0 deg 38600 yards 101.8 sec 1584 fps 60.5 deg Armor Penetration - Vertical Belt Armor (Relative armor quality, 0.83) Maximum penetration: 41.00 inches Elevation Range Belt Deck 1.4 deg 3400 yards 36 in 2.1 deg 4900 yards 34 in 2.7 deg 6100 yards ... 1 in 2.9 deg 6400 yards 32 in 3.8 deg 8200 yards 30 in 4.8 deg 10000 yards 28 in 5.0 deg 10400 yards ... 2 in 6.0 deg 11900 yards 26 in 7.4 deg 14100 yards 24 in 7.4 deg 14100 yards ... 3 in 9.1 deg 16400 yards 22 in 10.1 deg 17700 yards ... 4 in 11.2 deg 19000 yards 20 in 13.6 deg 21600 yards ... 5 in 13.9 deg 22000 yards 18 in 17.4 deg 25400 yards 16 in 17.5 deg 25500 yards ... 6 in 20.2 deg 27700 yards ... 7 in 22.3 deg 29400 yards 14 in 22.8 deg 29800 yards ... 8 in 25.6 deg 31600 yards ... 9 in 28.3 deg 33300 yards ... 10 in 29.2 deg 33800 yards 12 in 31.1 deg 34800 yards ... 11 in 34.0 deg 36100 yards ... 12 in 37.0 deg 37300 yards ... 13 in 39.0 deg 37900 yards 10 in 39.9 deg 38100 yards ... 14 in 43.0 deg 38700 yards ... 15 in 46.2 deg 38900 yards ... 16 in 49.5 deg 38700 yards ... 17 in Maximum range = 38900 yards at 46.4 deg elevation

### Weight groups

Yesterday, I ran into the issue of weight groups and how they are defined. I have data for an American battleship design and started to enter that into my program. I quickly found that I couldn't make the design work as specified, and then realized that to make it work, I would need to transform the data into the British weight groups, not the American. In Chapter III of *General Design of Warships*, William Hovgaard has a comparison of the British, American, and French weight groups. My program is hard-wired to use the British weight group scheme, and could not easily be modified to use the American (at least not without many code changes).

## Sunday, October 17, 2004

### Specs for a version of "The Ideal Battleship for the British Navy"

The following is what I used for the version of Colonel Cuniberti's "Ideal Battleship for the British Navy". I had to reduce the armor to be able to keep the size under 18,000 tons with the specified length and beam:

### The first run from my program for Colonel Cuniberti's battleship

I found that if I severely cut back the armor protection, I could get a reasonable result for Colonel Cuniberti's "Ideal Battleship for the British Navy" from 1903. Instead of a 12in armor basis, I found that a 9in basis was more workable. I also had to give pretty powerful machinery to achieve the desired speed, and to use a lighter-weight machinery to do it:

Designed draft=27.8055 ft Hull Weight=6511.95 tons Tertiary Battery Weight=3.8916 Armament Weight= 3013.89 Total Armor Weight=3261.92 Machinery Weight=3375.0 General Equipment Weight=510.0 Normal Fuel Weight=510.0 Maximum Fuel added Weight=1275.0 Reserve Feedwater Weight=393.66 Legend Displacement=17630.8 Legend Draft=28.8372 Submergence of 768.321 of actual displacement per foot At Displacement=17630.8 Length=521.5 ft Beam=82.0 ft Draft=28.8372 ft Cp=0.556 Cm=0.9 Cb=0.5004 DLR=124.311 Wetted Surface=48515.7 B/H=2.84355 At speed of 10knots power is 1983.53 SHP At speed of 11knots power is 2596.19 SHP At speed of 12knots power is 3404.1 SHP At speed of 13knots power is 4408.89 SHP At speed of 14knots power is 5567.12 SHP At speed of 15knots power is 6881.56 SHP At speed of 16knots power is 8365.81 SHP At speed of 17knots power is 10018.2 SHP At speed of 18knots power is 12518.6 SHP At speed of 19knots power is 15375.7 SHP At speed of 20knots power is 18522.1 SHP At speed of 21knots power is 21955.0 SHP At speed of 22knots power is 25689.7 SHP At speed of 23knots power is 31378.4 SHP At speed of 24knots power is 46152.3 SHP At speed of 25knots power is 61598.7 SHP actual speed for 54000.0 SHP is 24.5081 Deep Load Displacement=19299.4 Deep Load Draft=30.9476 Submergence of 778.621 of actual displacement per foot At Displacement=19299.4 Length=521.5 Beam=82.0 Draft=30.9453 Cp=0.56434 Cm=0.9045 Cb=0.510445 DLR=136.076 Wetted Surface=50759.7 B/H=2.64984 At speed of 10knots power is 2093.98 SHP At speed of 11knots power is 2740.18 SHP At speed of 12knots power is 3593.29 SHP At speed of 13knots power is 4654.88 SHP At speed of 14knots power is 5878.19 SHP At speed of 15knots power is 7266.12 SHP At speed of 16knots power is 8832.88 SHP At speed of 17knots power is 10576.8 SHP At speed of 18knots power is 13371.3 SHP At speed of 19knots power is 16583.1 SHP At speed of 20knots power is 20119.5 SHP At speed of 21knots power is 23977.4 SHP At speed of 22knots power is 28173.0 SHP At speed of 23knots power is 34664.5 SHP At speed of 24knots power is 51432.0 SHP At speed of 25knots power is 68328.5 SHP actual speed for 54000.0 SHP is 24.152 At Legend Displacement: Waterline Coeff=0.671089 Block Coefficient=0.5004 CG of hull=21.7742 Hull Wt=6511.95 CG of machinery=11.3933 Mach Wt=3375.0 Armor Center of gravity=43.6179 CG of armor=43.6179 Armor Wt=5324.78 CG of normal fuel=12.1954 Normal Fuel Wt=765.0 CG of max fuel= n/a Additional Max Fuel Wt=0.0 CG of upper works=69.12 Upper Works Wt=71.3698 CG of general equipment=28.08 General Equip Wt=510.0 Main Armament CG=50.0 Main armament wt=3013.89 Secondary Batt CG=0.0 Secondary Batt wt: 0.0 Tertiary Batt CG=0.0 Tertiary Batt wt: 3.8916 CG above keel = 30.23 Stability Coeff (nu)=0.559814 Height of CG as a fraction of the depth=0.559814 Freeboard=25.1628 ft Draft=28.8372 ft Beam=82.0 ft Metacentric height at legend displacement (GM)=5.20457 ft At Deep Load Displacement: Waterline Coeff=0.671089 Block Coefficient=0.5004 CG of hull=21.7742 Hull Wt=6511.95 CG of machinery=11.3933 Mach Wt=3375.0 Armor Center of gravity=44.4982 CG of armor=44.4982 Armor Wt=5324.78 CG of normal fuel=12.6479 Normal Fuel Wt=765.0 CG of max fuel=12.6479 Additional Max Fuel Wt=1275.0 CG of upper works=69.12 Upper Works Wt=71.3698 CG of general equipment=28.08 General Equip Wt=510.0 Main Armament CG=50.0 Main armament wt=3013.89 Secondary Batt CG=0.0 Secondary Batt wt: 0.0 Tertiary Batt CG=0.0 Tertiary Batt wt: 3.8916 CG above keel = 28.6229 Stability Coeff (nu)=0.530053 Height of CG as a fraction of the depth=0.530053 Freeboard=23.0524 Draft=30.9476 Beam=82.0 Metacentric height at deep load displacement (GM)=6.77938 ft

### I want to revisit Colonel Cuniberti's 1903 battleship design

I will be reanalyzing Colonel Cunibert's 1903 all-big gun battleship design with my program in its current form. I expect that I will find, as before, that he was extravagantly over-optimistic about how small the ship could be (17,000 tons). What he described was clearly a battleship-cruiser, similar to William Hovgaard's original conception.

## Saturday, October 16, 2004

### Now, the Ger/CB/1906 with the latest version of my program

Trying out the Ger/CB/1906 design is not as traumatic, as it naturally has a higher center of gravity and lower GM (although still really high). This is another low-silhouette, fast battlecruiser design. The main difference is that the main armament is 8-12in/45 guns with a secondary armament of 12-4in/50 guns. The side armor is still only 4in and the upper deck is 3in. The main battery turrets and barbettes are 6in. Here is what the output from my program is like for this design:

Designed draft=25.5564 ft Hull Weight=11016.0 tons Secondary Battery Weight=60.72 tons Armament Weight= 2155.72 tons Total Armor Weight=2675.07 tons Machinery Weight=8428.57 tons General Equipment Weight=750.0 tons Normal Fuel Weight=750.0 tons Maximum Fuel added Weight=1875.0 tons Reserve Feedwater Weight=1075.28 tons Legend Displacement=26570.4 tons Legend Draft=27.1617 Submergence of 1226.82 of actual displacement per foot At Displacement=26570.4 Length=800.0 ft Beam=85.0 ft Draft=27.1617 ft Cp=0.53 Cm=0.95 Cb=0.5035 At Displacement=26570.4 tons DLR=51.8952 Wetted Surface=73767.3 B/H=3.12941 At speed of 10knots power is 2705.44 SHP At speed of 11knots power is 3546.97 SHP At speed of 12knots power is 4538.67 SHP At speed of 13knots power is 5695.98 SHP At speed of 14knots power is 7035.9 SHP At speed of 15knots power is 8695.54 SHP At speed of 16knots power is 10608.1 SHP At speed of 17knots power is 12746.2 SHP At speed of 18knots power is 15131.1 SHP At speed of 19knots power is 17776.2 SHP At speed of 20knots power is 20695.3 SHP At speed of 21knots power is 23879.4 SHP At speed of 22knots power is 27982.3 SHP At speed of 23knots power is 32612.8 SHP At speed of 24knots power is 37606.0 SHP At speed of 25knots power is 43023.9 SHP At speed of 26knots power is 48845.8 SHP At speed of 27knots power is 55081.6 SHP At speed of 28knots power is 61741.0 SHP At speed of 29knots power is 75542.8 SHP At speed of 30knots power is 92998.3 SHP At speed of 31knots power is 111556.0 SHP At speed of 32knots power is 131184.0 SHP At speed of 33knots power is 152017.0 SHP actual speed for 147500.0 SHP is 32.7832 knots Deep Load Displacement=29520.6 tons Deep Load Draft=29.5859 Submergence of 1243.27 of actual displacement per foot Metacentric height at legend displacement (GM)=8.84576 ft Metacentric height at deep load displacement (GM)=10.0769 ft

### I'm doing some outrageous things to try and lower the GM

After calibrating my program for the Queen Elizabeth class, I am now wrestling with the ship specification for my GB/CB/1905 design to try and lower the metacentric height (GM). I have had only moderate success at this, but I do have the GM at the legend displacement below 10ft (!). I must admit that the ship has a low silhouette, given that it doesn't have superfiring turrets. There are just the forward and aft 12in/45 twin turrets with 9 single 6in/50 guns in armored shields. As things stand right now, this is what I have:

Designed draft=26.0604 ft Hull Weight=10995.6 tons Secondary Battery Weight=165.6 tons (includes protection) Armament Weight= 1576.08 tons (includes protection) Total Armor Weight=4097.17 tons Machinery Weight=8428.57 tons General Equipment Weight=750.0 tons Normal Fuel Weight=750.0 tons Maximum Fuel added Weight=1875.0 tons Reserve Feedwater Weight=1075.28 tons Legend Displacement=27392.4 tons Legend Draft=28.5543 ft Submergence of 1195.69 of actual displacement per foot At Displacement=27392.4 Length=770.0 ft Beam=85.0 ft Draft=28.5543 ft Cp=0.54 Cm=0.95 Cb=0.513 At Displacement=27392.4 tons DLR=60.001 Wetted Surface=73481.9 B/H=2.97679 At speed of 30knots power is 104406.0 SHP At speed of 31knots power is 125104.0 SHP At speed of 32knots power is 147027.0 SHP At speed of 33knots power is 170186.0 SHP actual speed for 147500.0 SHP is 32.0204 Metacentric height at legend displacement (GM)=9.36508 Waterline Coeff=0.661362 Block Coefficient=0.513 Stability Coeff (nu)=0.445718 Freeboard=24.9905 Draft=31.0095 Beam=85.0 Metacentric height at deep load displacement (GM)=10.4897

### I'm still "wrestling" with the Queen Elizabeth class

Something about the Queen Elizabeth class battleships is challenging. It didn't work at all in Rick Robinson's "Spring Style" program (at least the way I specified it). In my program, I'm having trouble getting a large enough metacentric height (GM) at the legend displacement. The deep load is better, but still lower than the real ships. One good thing is that I have a more complete weight and stability model than I did, even earlier today. I have yet to deal with volumes and seakeeping ability, but that is coming soon. As it stands right now, I am getting the following results:

## Friday, October 15, 2004

### It seems like the Queen Elizabeth class metacentric height issue is related to the correct CG for the hull

## Thursday, October 14, 2004

### My Ger/CB/1906 design was intended to be able to make 33 knots

My ship was intended to be able to make 33 knots at 120,000 SHP. The dimensions were 800ft x 85ft x 25.6ft at 25,000 tons displacement. The coefficients were Cp=0.53 and Cm=0.95. To actually make 25 knots, the design is required to be pressed by about 25%. This is part of the generated output from my program:

Designed draft=25.5564 ft Hull Weight=10608.0 tons Armament Weight= 2167.84 Total Armor Weight=2477.87 Machinery Weight=8581.08 General Equipment Weight=750.0 Normal Fuel Weight=750.0 Maximum Fuel added Weight=1875.0 Reserve Feedwater Weight=1111.0 Legend Displacement=26139.6 Legend Draft=26.7214 Submergence of 1226.82 of actual displacement per foot At Displacement=26139.6 Length=800.0 Beam=85.0 Draft=26.7214 Cp=0.53 Cm=0.95 Cb=0.5035 At Displacement=26139.6 DLR=51.0539 Wetted Surface=73166.9 B/H=3.18098 At speed of 10knots power is 2681.28 SHP At speed of 11knots power is 3515.47 SHP At speed of 12knots power is 4498.56 SHP At speed of 13knots power is 5645.86 SHP At speed of 14knots power is 6974.24 SHP At speed of 15knots power is 8617.25 SHP At speed of 16knots power is 10510.3 SHP At speed of 17knots power is 12626.6 SHP At speed of 18knots power is 14987.3 SHP At speed of 19knots power is 17605.7 SHP At speed of 20knots power is 20495.4 SHP At speed of 21knots power is 23647.6 SHP At speed of 22knots power is 27712.4 SHP At speed of 23knots power is 32301.0 SHP At speed of 24knots power is 37249.1 SHP At speed of 25knots power is 42618.2 SHP At speed of 26knots power is 48387.9 SHP At speed of 27knots power is 54567.8 SHP At speed of 28knots power is 61167.7 SHP At speed of 29knots power is 74726.2 SHP At speed of 30knots power is 91848.3 SHP At speed of 31knots power is 110051.0 SHP At speed of 32knots power is 129304.0 SHP At speed of 33knots power is 149739.0 SHP At speed of 34knots power is 171291.0 SHP actual speed for 152400.0 SHP is 33.1235 Waterline Coeff=0.65521 Block Coefficient=0.5035 Stability Coeff (nu)=0.546438 Height of CG as a fraction of the depth=0.546438 Freeboard=25.2786 Draft=26.7214 Beam=85.0 Metacentric height at legend displacement (GM)=7.49797

### My original Ger/CB/1906 design was intended to be radical

As another test case, I wanted to run my Ger/CB/1906 design through my Warship General Design program. This design was intended to be radical, and incorporated some features that were inappropriate to the date. The biggest departure was the 25 degree inclined armor. The belt was thin. Oddly enough, over the magazines, it was 3 inches of KC (Krupp Cemented) armor while over the machinery spaces it was 4in of KC armor. There was a 3in upper armored deck, and this was the only horizontal armor. The turrets and barbettes for the main armament were 6in thick at the maximum. There was no anti-torpedo bulkhead, although there was subdivision as if there were. The citadel was extremely short, being 425ft long. This was a weight-saving device to keep the armor weight as low as possible, while securing some protection. The silhouette was low, with the turrets and barbettes, a small bridework and light tripod forward, and 12-4in/50 QF guns in shields with splinter protection only. The main armament was 8-12in/45 guns. The designed power plant was 120,000 SHP at 14 SHP/ton of machinery. However, the plant was intended to be able to forced by about 25%, to something like 152,400 SHP. I took the same numbers as the battlecruiser *Tiger*, which was designed for 85,000 SHP but was completed as being capable of being forced to 108,000 SHP. That was a 27% increase over the designed power.

### Output from my program for the Queen Elizabeth class

Specification filename: GBBB1912ShipSpec.txt Designed draft=27.0885 ft Hull Weight=8896.92 tons Armament Weight= 4173.59 Total Armor Weight=8559.14 Machinery Weight=3947.37 General Equipment Weight=810.0 Normal Fuel Weight=810.0 Reserve Feedwater Weight=546.75 Legend Displacement=27887.0 Legend Draft=27.9784 Submergence of 1177.65 of actual displacement per foot At Displacement=27887.0 Length=639.0 Beam=90.5 Draft=27.9784 Cp=0.635 Cm=0.95 Cb=0.60325 At Displacement=27887.0 DLR=106.881 Wetted Surface=67541.6 B/H=3.23463 At speed of 10knots power is 2755.54 SHP At speed of 11knots power is 3617.84 SHP At speed of 12knots power is 4631.78 SHP At speed of 13knots power is 5913.31 SHP At speed of 14knots power is 7577.03 SHP At speed of 15knots power is 9462.83 SHP At speed of 16knots power is 11596.3 SHP At speed of 17knots power is 13971.9 SHP At speed of 18knots power is 16622.4 SHP At speed of 19knots power is 19692.1 SHP At speed of 20knots power is 26705.0 SHP At speed of 21knots power is 34398.0 SHP At speed of 22knots power is 42760.0 SHP At speed of 23knots power is 51837.1 SHP At speed of 24knots power is 61601.3 SHP At speed of 25knots power is 72109.5 SHP At speed of 26knots power is 88870.7 SHP actual speed for 75000.0 SHP is 25.1725 Deep Load Displacement=30458.8 Deep Load Draft=29.9594 Submergence of 1193.43 of actual displacement per foot At Displacement=30458.8 Length=639.0 Beam=90.5 Draft=29.9572 Cp=0.644525 Cm=0.95475 Cb=0.61536 Hull Weight=8896.92 tons At Displacement=30458.8 DLR=116.737 Wetted Surface=70587.3 B/H=3.02097 At speed of 10knots power is 2912.55 SHP At speed of 11knots power is 3824.2 SHP At speed of 12knots power is 4895.63 SHP At speed of 13knots power is 6245.72 SHP At speed of 14knots power is 7991.76 SHP At speed of 15knots power is 9970.22 SHP At speed of 16knots power is 12207.9 SHP At speed of 17knots power is 14698.8 SHP At speed of 18knots power is 17477.5 SHP At speed of 19knots power is 20729.4 SHP At speed of 20knots power is 28960.3 SHP At speed of 21knots power is 37991.4 SHP At speed of 22knots power is 47811.2 SHP At speed of 23knots power is 58467.6 SHP At speed of 24knots power is 69931.5 SHP At speed of 25knots power is 82262.5 SHP actual speed for 75000.0 SHP is 24.411 Waterline Coeff=0.717182 Block Coefficient=0.60325 Stability Coeff (nu)=0.606506 Height of CG as a fraction of the depth=0.606506 Freeboard=26.7716 Draft=27.9784 Beam=90.5 Metacentric height at legend displacement (GM)=4.09912 Waterline Coeff=0.717182 Block Coefficient=0.60325 Stability Coeff (nu)=0.573974 Height of CG as a fraction of the depth=0.573974 Freeboard=24.7906 Draft=29.9594 Beam=90.5 Metacentric height at deep load displacement (GM)=5.5319

### Warship General Design Program status

*Queen Elizabeth*class battleships. I still haven't been able to account for all the armor weights that were supposed to make up the total weight (about 8600 tons). I still have to add coverage to the stability calculations for some new armor weights, as well. I still hope to have this completed by the end of the day tomorrow, depending on the impacts of other responsibilities (which are impeding progress today).

### Armor on the "upper deck sides"

## Wednesday, October 13, 2004

### Some approximations from Edward L Attwood

Rick Robinson's "Spring Style" program produces a "tons-per-inch immersion" figure for a ship design. He must be using some approximation such as that shown on page 200 of Edward L. Attwood's book, *War-Ships: A Text-Book on the Construction, Portection, Stability, Turning, Etc., of War Vessels*. I am looking at a copy of the 6th Edition from 1917.

For ships with a fine waterplane, the approximation is: tons per inch = (Length x Beam)/600 For fuller ships, such as a battleship, the approximation is: tons per inch = (Length x Beam)/530

There is a table that compares the approximation with the real figure for four ship types, and they all are within 3% (usually better) of the correct figure. For wargame-oriented ship design, this is perfectly acceptable.

## Tuesday, October 12, 2004

### I'm calibrating my program against the Queen Elizabeth class (1912)

*Queen Elizabeth*class, as that seems like a good example, and the "Spring Style" program seemed to fail with it (perhaps I was using the wrong inputs). One thing I noticed is that I need to include the protection for the armament, as well as ammunition, into the armament weight group, and remove it from the armor weight group. I don't think that I need to alter my stability calculations, but I do need to alter the weights.

### An important difference between what I am doing and what Rick Robinson's "Spring Style" program does

Rick Robinson's "Spring Style" program for warship design takes the approach that the designed displacement is sacrosanct, and that if you load the design up with large machinery, guns, and armor, that you will keep the displacement constant and start reducing the hull weight, even if it goes below what is feasible. Stability is another likely casualty, along with seakeeping and roominess.

My approach is to increase the displacement as you add weights. That will still affect the stability, and will increase the draft, and slow the speed. My plan is to calculate power curves for at the legend displacement and the deep load displacement, and not for the designed displacement that was desired. I do calculate a "designed draft" based on the "designed displacement", as that figure is required to do the weights analysis.

## Monday, October 11, 2004

### Issues for General Design of Warships

- dimensions
- form coefficients (prismatic and midships coefficients)
- displacement
- armament
- armor
- power and speed
- weights analysis
- volume analysis
- freeboard, stability, and seakeeping
- structural strength and hull weight

My warship general design program currently addresses eight of these issues. I am in the process of going through each issue, doing verification and fixing problems. When this list is complete, the next step is a warship design expert system that will choose characteristics which would be processed and fleshed out by this component.

## Sunday, October 10, 2004

### My warship general design program: status

*General Design of Warships*. This is some of what the program generates (some of it just for debugging purposes):

Ship: Ger/CB/1906 Submergence of 1277.66 of actual displacement per foot Displacement=30800.0 tons Length=814.0ft Beam=87.0ft Draft=30.2326ft Cp=0.53 Cm=0.95 Cb=0.5035 Displacement=30800.0 DLR=57.1055 Wetted Surface=80113.8 B/H=2.87769 At speed of 10knots power is 2949.25 SHP At speed of 11knots power is 3867.17 SHP At speed of 12knots power is 4946.95 SHP At speed of 13knots power is 6206.73 SHP At speed of 14knots power is 7661.17 SHP At speed of 15knots power is 9468.02 SHP At speed of 16knots power is 11564.1 SHP At speed of 17knots power is 13912.3 SHP At speed of 18knots power is 16531.2 SHP At speed of 19knots power is 19444.7 SHP At speed of 20knots power is 22639.6 SHP At speed of 21knots power is 26134.2 SHP At speed of 22knots power is 30474.6 SHP At speed of 23knots power is 35539.3 SHP At speed of 24knots power is 41019.4 SHP At speed of 25knots power is 46925.4 SHP At speed of 26knots power is 53291.7 SHP At speed of 27knots power is 60110.0 SHP At speed of 28knots power is 67420.9 SHP At speed of 29knots power is 80560.5 SHP At speed of 30knots power is 100888.0 SHP At speed of 31knots power is 122507.0 SHP At speed of 32knots power is 145428.0 SHP At speed of 33knots power is 169711.0 SHP actual speed for 146000.0 SHP is 32.0236 Hull Weight=12393.2 Main battery type=12in/45 found main battery gun: 12in/45 Main battery gun weight=57.67 found secondary battery gun Secondary Battery gun weight: 2.2 Lower Belt Weight: 480.0 Upper Belt Weight: 480.0 Upper deck weight: 1566.0 Lower deck weight: 848.25 Main Battery armor thickness: 6.0 Machinery Weight=8111.11 General Equipment Weight=924.0 Normal Fuel Weight=924.0 Legend Displacement=28540.5 Deep Load Displacement=30850.5 Deep Load Draft=29.6884 Waterline Coeff=0.65521 Block Coefficient=0.5035 CG of hull=29.4118 CG of machinery=29.2 CG Lower Armor Belt=30.2326 CG Lower Armor Belt M=14511.7 CG Upper Armor Belt=40.2326 CG Armor deck slopes=30.2326 CG lower armor deck=34.2326 CG upper armor deck=42.2326 Total Armor Wt=4483.48 CG of armor=36.3691 CG of normal fuel=24.1861 CG of upper works=82.5 CG of general equipment=42.5 Main battery type=12in/45 found main battery gun: 12in/45 Main battery gun weight=57.67 tons Armament Weight: 1088.73 tons Armament CG=52.7326ft CG above keel = 31.9127ft Stability Coeff (nu)=0.638254 Height of CG as a fraction of the depth=0.638254 Freeboard=19.7674ft Draft=30.2326ft Beam=87.0ft Metacentric height (GM)=4.50924

### I'm working on estimating the center of gravity of armor for ships

*The General Design of Warships*(pages 80 to 100). There is an equation for estimating GM that I have mechanized in my program (equation 20, the Stability Equation).

## Saturday, October 09, 2004

### Stability calculations

## Friday, October 08, 2004

### Experimenting with my Ger/CS/1905 design

Submergence of 244.002 of actual displacement per foot Displacement=2480.0 Length=370.0 Beam=38.0 Draft=12.9928 Cp=0.559 Cm=0.85 Cb=0.47515 Hull Weight=1254.85 tons Displacement=2480.0 DLR=48.9606 Wetted Surface=15326.6 B/H=2.92469 lowCpIndex=1 highCpIndex=2 lowCpFraction=0.55 highCpFraction=0.6 cp Interpolation Factor=0.18 At speed of 10knots power is 591.491 SHP At speed of 11knots power is 791.208 SHP At speed of 12knots power is 1026.65 SHP At speed of 13knots power is 1302.82 SHP At speed of 14knots power is 1620.28 SHP At speed of 15knots power is 2035.83 SHP At speed of 16knots power is 2548.21 SHP At speed of 17knots power is 3122.88 SHP At speed of 18knots power is 3764.19 SHP At speed of 19knots power is 4470.45 SHP At speed of 20knots power is 5788.18 SHP At speed of 21knots power is 7396.0 SHP At speed of 22knots power is 9142.03 SHP At speed of 23knots power is 11036.3 SHP At speed of 24knots power is 13078.6 SHP At speed of 25knots power is 16390.0 SHP At speed of 26knots power is 19953.2 SHP At speed of 27knots power is 23741.2 SHP At speed of 28knots power is 27780.7 SHP At speed of 29knots power is 32079.5 SHP At speed of 30knots power is 36735.5 SHP At speed of 31knots power is 41606.5 SHP At speed of 32knots power is 46645.3 SHP At speed of 33knots power is 51959.3 SHP At speed of 34knots power is 56880.4 SHP At speed of 35knots power is 60905.8 SHP actual speed for 60000.0 SHP is 34.775 Hull Weight=1254.85 Main battery type=4in/50 found main battery gun: 4in/50 Main battery gun weight=2.2 Machinery Weight=1000.0 General Equipment Weight=74.4 Normal Fuel Weight=74.4 Maximum Fuel added Weight=0.0 Reserve Feedwater Weight=0.0 Legend Displacement=2478.55 Deep Load Displacement=2664.55 Deep Load Draft=13.686

### More experimenting with the Hood-type ship

I was running through more experiments with the original design for the Hood this morning. I was adjusting the prismatic and midship coefficients to see what effect they had on speed. Leaving the displacement constant, lowering either coefficient has the effect of increasing the draft. When I reduced the Cp to 0.53, the speed actually fell off. I just tried a "light cruiser" Cp and Cm (a high Cp and a low Cm). That had the effect of lowering the speed.

The sure-fire way to increase speed without increasing power was to increase the waterline length. When I increased the length to 890ft, the speed calculated by my program goes up over 32 knots. The specs for the ship in this case were:

Part of the power curve:

At speed of 20knots power is 25410.8 SHP At speed of 21knots power is 29361.2 SHP At speed of 22knots power is 33665.3 SHP At speed of 23knots power is 39244.9 SHP At speed of 24knots power is 45789.9 SHP At speed of 25knots power is 52893.0 SHP At speed of 26knots power is 60556.0 SHP At speed of 27knots power is 68739.5 SHP At speed of 28knots power is 77479.4 SHP At speed of 29knots power is 86787.5 SHP At speed of 30knots power is 98317.3 SHP At speed of 31knots power is 118491.0 SHP At speed of 32knots power is 141457.0 SHP At speed of 33knots power is 167021.0 SHP actual speed for 144000.0 SHP is 32.0995 knots

## Thursday, October 07, 2004

### I was experimenting with a Hood-like ship

Displacement=42200.0 tons Length=850.0ft Beam=104.0ft Draft=30.0641ft Cp=0.585 Cm=0.95 Cb=0.55575 Hull Weight=13392.6 tons Displacement=42200.0 tons DLR=68.7156 Wetted Surface=95826.5 B/H=3.45927 At speed of 10knots power is 3633.33 SHP At speed of 11knots power is 4773.53 SHP At speed of 12knots power is 6117.54 SHP At speed of 13knots power is 7684.03 SHP At speed of 14knots power is 9486.35 SHP At speed of 15knots power is 11681.5 SHP At speed of 16knots power is 14369.1 SHP At speed of 17knots power is 17377.4 SHP At speed of 18knots power is 20738.2 SHP At speed of 19knots power is 24451.1 SHP At speed of 20knots power is 28529.1 SHP At speed of 21knots power is 32999.6 SHP At speed of 22knots power is 38195.1 SHP At speed of 23knots power is 45949.4 SHP At speed of 24knots power is 54340.8 SHP At speed of 25knots power is 63381.5 SHP At speed of 26knots power is 73112.8 SHP At speed of 27knots power is 83556.7 SHP At speed of 28knots power is 94665.1 SHP At speed of 29knots power is 106519.0 SHP At speed of 30knots power is 129111.0 SHP At speed of 31knots power is 155055.0 SHP actual speed for 151280.0 SHP is 30.8545

### "an Oldie but a Goodie" book on Naval Architecture

Edward L. Atwood was the head of the Battleship Section, working for Sir Eustace Tennyson d'Eyncourt, the Director of Naval Construction from 1912 to 1923. Edward L. Atwood lead the design of the battlecruiser *Hood* and the cancelled 1921 ships. He was also a prolific writer. I have a copy of four of his books (including multiple editions of one).

*Theoretical Naval Architecture *is a fine little book. I have an edition printed in March 1943. It is readily available at a moderate cost.

Another is *War-Ships: A Text-Book*. I am have a copy of the Sixth Edition from 1917 open, looking at a photograph of the battleship *Orion*.

Then, there is the book *The Modern Warship* from 1913. The picture opposite the cover page is a photograph of a large model of the battlecruiser *Queen Mary* (lost at Jutland). This book is odd, in that it is very small, but it has many small gems, such as the breakdown of the costs for the battleships *Neptune*, *Hercules*, and *Colossus*.

The fourth book is A Textbook of Laying Off. I have a copy printed in February 1943.

### Computer program status

## Wednesday, October 06, 2004

### A German light cruiser design for 1916Submergence of 410.25 of actual displacement per foot

I conceived of this light cruiser design in 1971. The idea was a German-looking ship with three funnels (with casings halfway up the stacks), three twin 6-inch gun mounts, with one forward and two aft, with one superfiring over the other (with blast shields). I will be expanding what is printed, as I add to the weight calculations.

Submergence of 410.25 of actual displacement per foot Displacement=5400.0 tons Length=475.0 ft Beam=48.0 ft Draft=16.5294 ft Cp=0.59 Cm=0.85 Cb=0.5015 Hull Weight=1778.4 tons DLR=50.3864 Wetted Surface=25625.0 B/H=2.90392 Power curve: At speed of 10knots power is 975.323 SHP At speed of 11knots power is 1283.41 SHP At speed of 12knots power is 1678.73 SHP At speed of 13knots power is 2141.78 SHP At speed of 14knots power is 2675.14 SHP At speed of 15knots power is 3281.73 SHP At speed of 16knots power is 3968.67 SHP At speed of 17knots power is 4921.3 SHP At speed of 18knots power is 6085.65 SHP At speed of 19knots power is 7373.01 SHP At speed of 20knots power is 8786.94 SHP At speed of 21knots power is 10334.9 SHP At speed of 22knots power is 12295.8 SHP At speed of 23knots power is 15526.8 SHP At speed of 24knots power is 18998.9 SHP At speed of 25knots power is 22713.3 SHP At speed of 26knots power is 26703.4 SHP At speed of 27knots power is 30958.2 SHP At speed of 28knots power is 37983.1 SHP At speed of 29knots power is 46159.3 SHP At speed of 30knots power is 54769.2 SHP At speed of 31knots power is 63886.6 SHP actual speed for 60000.0 SHP is 30.5737 Machinery Weight=1500.0

## Tuesday, October 05, 2004

### Hull strength

Frank Fox told me that he believed that a ship that has a length-to-depth ratio of 16 or under will have a normal weight structure. I noticed that the Renown, as built, had a length-to-depth ratio of about 16.2. My estimate of the weight basis for the hull is 3.084357 x 10^-3. Compare that with the Lion which had a length-to-depth ratio of about 13.2. I estimate that the weight basis for the Lion's hull was about 2.957 x 10^-3. Perhaps we could use the curve fitting tool to generate a function for computing hull weight basis. I doubt that it is that simple, as I suspect that light cruisers and destroyers might have a smaller weight basis (my term).

The Acasta (K-class) had a length-to-depth ratio of about 15.9. The weight basis was about 3.02x10^-3. I was amazed that this metric would be so consistent. I had trouble finding a destroyer for which I had a hull weight to do this calculation.

## Monday, October 04, 2004

### Capitani Romani class cruisers

*Attilio Regolo*or

*Scipione Africano*could have maintained 43 knots in service. Frank suggested that I run some calculations with my program. Apparently, the 43 knots claim is of the same value as the 40 knots claim for the

*Renown*and

*Repulse*when new, or 39 knots for the destroyer leader

*Swift*, or 40 knots for the

*Atlanta*. Namely, the claims were not any good at all. IF the

*Scipione Africano*were extremely light and was pressed to extreme overload, it would be capable of 43 knots. At a more normal load of 5,035 tons and at the designed SHP of 110,000, the speed would only be 36 knots. If pressed hard, the maximum speed would be on the order of 39 knots. There are many uncertainties, as I don't know the correct hull form coefficients. It seems very likely that at normal loaded condition, these ships would have had trouble reaching 40 knots, despite what has been published. IF they were very light, then that is another matter. If they could be run at a displacement of 4,035 tons and pressed to 137,000 SHP, then 43 knots is possible.

### Warship General Design program status

- Invincible: 0.002902 girder: 11.8
- Courageous: 0.00265 girder: 15.4
- Repulse: 0.00308 girder: 16.2
- Lion: 0.002975 girder: 13.2
- Queen Elizabeth: 0.00285 girder: 11.8

## Saturday, October 02, 2004

### I should have realized that Rick Robinson's "Spring Style" program has a lot of "hacks"

## Friday, October 01, 2004

### I tried designing a Queen Elizabeth class battleship, and found it didn't work in Rick Robinson's program

*Queen Elizabeth*class. I was disappointed that it didn't work, when entered in a straight-forward way. The program claimed about strength and stability, plus the calculated speed was too high: 26 knots. The real speed should be more like 24 knots. My program is more accurate than what he is doing. He also doesn't use prismatic coefficient, which is an essential factor (he is using block coefficient, instead, which isn't something that you use directly for speed calculations).

### I've started my program for doing general design of warships

- be able to calculate the weight of a hull that is strong enough, but lightly built
- be able to calculate a hull weight that is of typical strength and weight
- be able to calculate a hull weight that is stronger than needed
- be able to deal with destroyer and scout cruiser hulls

Armament:

- specify gun characteristics
- specify gun mounting

Armor:

- allow for two armor decks
- allow for funnel base armor
- allow for guns to be in turrets, casemates, batteries, open mounts, "en barbette", single mountings with shields

Speed:

- use my power curve calculations based on
*The Speed and Power of Ships* - use electrical load in calculating cruising range

This is a start on the specifications. I will be augmenting and modifying this list, as I proceed on my implementation