## Thursday, September 30, 2004

### Rick Robinson's program is useless for designing small ships

## Wednesday, September 29, 2004

### I struggled to get a stable version of the "Super-Fast Light Battlecruiser"

One of the ships that I kepted working and reworking (with Rick Robinson's "Spring Style" ship design program) was the "Super-Fast Light Battlecruiser". What I finally ended up with was not so "Super-Fast", although 35 knots is pretty fast. This is what was produced, although it is not pretty:

fastcbl, laid down 1920 Length, 804 ft x Beam, 87.0 ft x Depth, 29.5 ft 34312 tons normal displacement (31571 tons standard) Main battery: 4 x 17.0-inch (2 x 2) Secondary battery: 16 x 4.0-inch Weight of broadside: 10338 lbs Main belt, 4.0 inches; ends unarmored Upper belt, 4.0 inches Torpedo bulkhead, 1.0 inches Armor deck, average 2.0 inches C.T., 4.0 inches Battery armor: Main, 4.0" Maximum speed for 225027 shp = 34.43 knots Approximate cruising radius, 14500 nm / 12 kts Typical complement: 1261-1639 Estimated cost, $30.612 million (£7.653 million) Remarks: Relative extent of belt armor, 55 percent of 'typical' coverage. Main belt does not fully protect magazines and engineering spaces. Magazines and engineering spaces are cramped, with poor watertight subdivision. Roomy upper decks; superior accommodation and working space. Distribution of weights: Percent normal displacement: Armament ......................... 1292 tons = 4 pct Armor, total ..................... 4014 tons = 12 pct Belt 912 tons = 3 pct Torpedo bulkhead 570 tons = 2 pct Deck 1801 tons = 5 pct C.T. 91 tons = 0 pct Armament 640 tons = 2 pct Machinery ........................ 7868 tons = 23 pct Hull and fittings; equipment ..... 14289 tons = 42 pct Fuel, ammunition, stores ......... 4289 tons = 13 pct Miscellaneous weights ............ 2560 tons = 7 pct ----- 34312 tons = 100 pct Estimated metacentric height, 5.6 ft Displacement summary: Light ship: 30023 tons Standard displacement: 31571 tons Normal service: 34312 tons Full load: 36368 tons Loading submergence 1391 tons/foot +++++++++++++++++++++++++ Estimated overall survivability and seakeeping ability: Relative margin of stability: 1.19 Shellfire needed to sink: 18353 lbs = 7.5 x 17.0-inch shells (Approximates weight of penetrating shell hits needed to sink ship, not counting critical hits) Torpedoes needed to sink: 2.1 (Approximates number of 'typical' torpedo hits needed to sink ship) Relative steadiness as gun platform, 48 percent (50 percent is 'average') Relative rocking effect from firing to beam, 0.65 Relative quality as a seaboat: 1.02 +++++++++++++++++++++++++ Hull form characteristics: Block coefficient: 0.58 Sharpness coefficient: 0.37 Hull speed coefficient 'M' = 7.57 'Natural speed' for length = 28.4 knots Power going to wave formation at top speed: 56 percent Estimated hull characteristics and strength: Relative underwater volume absorbed by magazines and engineering spaces: 145 percent Relative accommodation and working space: 191 percent Displacement factor: 106 percent (Displacement relative to loading factors) Relative cross-sectional hull strength: 1.08 (Structure weight per square foot of hull surface: 187 lbs) Relative longitudinal hull strength: 1.45 (for 26.0 ft average freeboard; freeboard adjustment +6.6 ft) Relative composite hull strength: 1.11

### I find that the "Spring Style" program is addictive

- laid down 1914
- length: 800 ft
- beam: 120ft
- draft: 33.1ft
- normal displacement: 48,489 tons
- "standard" displacement: 45,446 tons
- main battery: 9-18in/45 (3x3)
- secondary battery: 20-5in (10x2)
- broadside weight: 24578 lbs
- main belt: 15in, ends unarmored
- upper belt: 10in
- torpedo bulkhead: 2in
- armor deck average 5.0 inches
- conning tower: 12in
- battery armor: main 15in, secondary 2in
- maximum speed for 97,017 SHP 26.16 knots
- approximate cruising radius: 15,200 nm at 10 knots
- typical complement: 1634 to 2124 men
- estimated cost; $23.361 million (£ 5.840 million)

There are more details generated by the program, but this is a start. I would like to try generating a power curve with my own program to see how it compares. Anyway, I like Rick Robinson's program. I want to study it to see what he is doing.

### Another interesting piece of software from Rick Robinson: "Spring Style" (warship design)

### Gun performance: 9.2in/45

- 1.1 deg 2600 yards 18in belt
- 1.8 deg 4200 yards 16in belt
- 2.8 deg 5900 yards 14in belt
- 4.2 deg 8000 yards 12in belt
- 5.3 deg 9500 yards 1in deck
- 6.1 deg 10500 yards 10in belt
- 9.1 deg 13500 yards 8in belt
- 12.6 deg 16400 yards 2in deck
- 14.4 deg 17600 yards 6in belt
- 19.8 deg 20700 yards 3in deck
- 25.9 deg 23400 yards 4in belt
- 26.7 deg 23600 yards 4in deck
- 34.2 deg 25800 yards 5in deck
- 42.9 deg 27000 yards 6in deck

## Tuesday, September 28, 2004

### I'm tweaking my residual resistance tables and testing

*Queen Elizabeth*class and the

*Bayern*class battleships. They both show too little SHP required to meet their designed speeds. I have been tweaking values in the tables to correct the results. I probably need to go back and reanalyze the tables to clean them up, as they are probably pretty rough, as they stand now.

## Monday, September 27, 2004

### Sanity checking power calculations: Lion class battlecruisers

- displacement: 26,779 tons
- dimensions: 700ft x 88.5ft x 28.6ft
- Cp: 0.575
- Cm: 0.92
- propulsive efficiency: 0.49
- speed: 27 knots
- SHP: 69,184.4
- residual EHP: 12,831.7
- frictional EHP: 21,068.7
- speed-length ratio: 1.0205

I thought that this was reasonable result, given the inherent sloppiness of the program vis-a-vis hand calculations where I looked up exact Cr values from *The Speed and Power of Ships*.

### My 48,000 ton 1921-style battlecruiser

This is what my 1921-style 48,000 ton battlecruiser looked like:

Specs:

- displacement: 48.054.2 tons
- dimensions: 855ft x 105ft x 33.3ft
- armament: 9-16in/45 (105 tons) and 20-5in (5 tons)
- Cp: 0.58
- Cm: 0.97
- propulsive efficiency: 0.51
- designed power: 143,500 SHP

Power curve:

- 25 knots 66,274.9 SHP (SLR=0.854982)
- 26 knots 77,441.9 SHP (SLR=0.889181)
- 27 knots 89,452.3 SHP (SLR=0.92338)
- 28 knots 102,271.0 SHP (SLR=0.95758)
- 29 knots 115,953.0 SHP (SLR=0.991779)
- 30 knots 135,782.0 SHP (SLR=1.02598)
- 31 knots 160,286.0 SHP (SLR=1.06018)

### The German L20eα battleship design

As WWI progressed, the Germans kept working on designs for new battleship and battlecruiser construction. The war situation kept anything from being started, but that didn't keep the designers from continuing to refine their designs. One ship that has been prominently mentioned was the L20eα. Her dimensions were: 780ft-10in x 109.9ft x 29.53ft. Her displacement was something like 43,797 tons. Her armament was intended to be 8-16.5in/45, 12-5.9in/45, and 8-88mm or 4.1in AA guns. Her protection was on a 350mm scale (13.78in). That was the thickness of the lower belt, the barbettes, and flat turret faces. Her power plant was designed to achieve 26 knots at 100,000 SHP.

I just ran my propulsion calculation program for this ship. This is part of that output:

- 24 knots 72,850.0 SHP (SLR=0.858881)
- 25 knots 87,950.6 SHP (SLR=0.894668)
- 26 knots 104,169.0 SHP (SLR=0.930454)
- 27 knots 121,494.0 SHP (SLR=0.966241)

My reference for WWI-era German capital ships is:

Friedrich Forstmeier, Siegfried Breyer, *Deutsche Grosskampschiffe 1915-1918* (1970)

## Sunday, September 26, 2004

### Linienschiffe/Schlachtschiffe (45,000 tons)

- displacement: 45,000 tons
- dimensions: 755ft x 110ft x 32ft
- Cp: 0.61
- Cm: 0.97
- armament: 9-16.5in/45 (130 tons) and 10-6in/50 (6 tons)
- power: 120,000 SHP
- speed: 25 knots

The 16.5in/45 gun had the following specs:

- caliber: 16.5in
- weight of piece: 130 tons
- length: 45 calibers
- AP shot: 2,480 lbs.
- muzzle velocity: 2,800 ft/sec
- muzzle energy: 134,741 ft-tons

Here are the propulsion calculation details:

- displacement: 44,928.6 tons
- DLR=104.396
- wetted surface: 93,186.9 sq. ft.
- B/H=3.4375

It is unclear how useful the powercurve is, yet, as I need to do more testing. Here is what I just generated. Note the advantages of length, as the SLR stays below 1.0 up through 27 knots.

- 10 knots: 3,907.12 SHP (SLR=0.363937)
- 11 knots: 5,138.67 SHP (SLR=0.400331)
- 12 knots: 6,587.29 SHP (SLR=0.436725)
- 13 knots: 8,268.46 SHP (SLR=0.473118)
- 14 knots: 10,174.50 SHP (SLR=0.509512)
- 15 knots: 12,382.70 SHP (SLR=0.545906)
- 16 knots: 15,039.30 SHP (SLR=0.5823)
- 17 knots: 18,017.20 SHP (SLR=0.618693)
- 18 knots: 21,324.20 SHP (SLR=0.655087)
- 19 knots: 24,973.40 SHP (SLR=0.691481)
- 20 knots: 29,017.10 SHP (SLR=0.727875)
- 21 knots: 35,536.80 SHP (SLR=0.764268)
- 22 knots: 46,076.70 SHP (SLR=0.800662)
- 23 knots: 57,531.00 SHP (SLR=0.837056)
- 24 knots: 69,935.00 SHP (SLR=0.873449)
- 25 knots: 83,283.90 SHP (SLR=0.909843)
- 26 knots: 97,791.80 SHP (SLR=0.946237)
- 27 knots: 113,667.00 SHP (SLR=0.982631)
- 28 knots: 135,716.00 SHP (SLR=1.01902)

## Saturday, September 25, 2004

### I find that I need to add more residual resistance data

*Dreadnought*comes in about 27,000 SHP to reach 21 knots instead of 23,000 SHP. At higher speeds, the difference is more pronounced. The

*Invincible*class battlecruisers have a jump up in power to reach 25 knots that is unrealistic, but which I believe is caused by the fact the the DLR is about 97.5 (higher than anything that I had tested, to date). On the other hand, a

*Chatham*class light cruiser came in about right: 25,000 SHP to reach 25 knots.

### Power calculations for the "Super Fast Battlecruiser"

- 25 knots: 60,404.6 SHP
- 26 knots: 67,869.1 SHP
- 27 knots: 75,832.5 SHP
- 28 knots: 84,305.9 SHP
- 29 knots: 106,515.0 SHP
- 30 knots: 135,587.0 SHP
- 31 knots: 166,478.0 SHP
- 32 knots: 199,153.0 SHP
- 33 knots: 233,762.0 SHP
- 34 knots: 270,231.0 SHP
- 35 knots: 308,512 SHP
- 36 knots: 348,665 SHP
- 37 knots: 390,772.0 SHP
- 38 knots: 434,861.0 SHP
- 39 knots: 480,793.0 SHP
- 40 knots: 528,651.0 SHP

### I just calculated the power curve for my "Compact Large Battleship"

- displacement: 85,484.2 tons
- dimensions: 900ft x 150ft x 35.7ft
- Cp: 0.64
- Cm: 0.97

I ran a curve from 10 knots to 23 knots:

- 10 knots: 6,124.24 SHP
- 11 knots: 7,904.5 SHP
- 12 knots: 9,995.1 SHP
- 13 knots: 12,408.4 SHP
- 14 knots: 15,182.8 SHP
- 15 knots: (found a bug at this point: SLR 0.5)
- 16 knots: 27,082.1 SHP
- 17 knots: 36,911.9 SHP
- 18 knots: 47,839.7 SHP
- 19 knots: 60,018.2 SHP
- 20 knots: 73,454.9 SHP
- 21 knots: 88,066.5 SHP
- 22 knots: 103,897.0 SHP
- 23 knots: 120,946.0 SHP

Obviously, I have a bug that happens Speed-Length Ratios that are exact multiples of 0.5.

### Actually, the designed speed for the Japanese 5,500 ton light cruisers was 36 knots

### I just duplicated what I have in my spreadsheet for power calculations for the Japanese light cruiser Nagara

*Nagara*). I will be doing some runs for some of my ship designs and publishing the results. I may be doing other historical ships, as well.

## Friday, September 24, 2004

### I found the bug in my propulsion calculation program

I just found the bug that was in my propulsion calculation program. I had not been sure if it was a residual resistance table problem or a program bug. It turned out to be caused by a bug. I had the columns in the residual resistance table switched between where it was initialized and where it was used. I may still have table issues, but I will first have to reenter my residual resistance data, so that I can test.

I have found the book *Japanese Cruisers of the Pacific War* to be extremely useful. It is perhaps the best ship book, ever. The book gives the data necessary to to do propulsion calculations. I am using the data for the light cruiser *Nagara* for debugging purposes. I should see something like 90,000 SHP to achieve a speed of 35 knots, at a normal displacement. The *Nagara* was nominally 5,500 tons. This is the data I am using:

- displacement: 5,492.13 tons
- length on the waterline: 520ft
- beam: 46.5ft
- mean draft: 15.875ft
- Cp: 0.619
- Cm: 0.809
- Displacement-Length Ratio: 39.0599
- Beam/Height ratio: 2.92913

The 5,500 ton light cruisers were very destroyer-like. Their stern was wide and round, similar to a destroyer, and the machinery was that of two destroyers, as a high-output plant with light weight was needed to achieve 90,000 SHP in such a small ship.

## Thursday, September 23, 2004

### Japanese guns

I was to look at Japanese gun data in *Japanese Cruisers of the Pacific War:*

20in/45 (510mm)

- length of barrel: 77.3ft
- weight with breach: 227 tons
- AP shot: 4,299 lbs
- charge: 1,058 lbs
- twin turret weight: 2,780 tons
- date: 1940

18.1in/45 (460mm)

- length of barrel: 69.3ft
- weight with breach: 165.76 tons
- AP shot: 3218.75 lbs
- charge: 793.66 lbs
- triple turret weight: 2,565 tons
- date: 1934-1939

18.9in/45

- length of barrel: unknown
- weight with breach: 167 tons
- AP shot: 3,417.17 lbs
- charge: 751.78 lbs
- twin turret weight: 2,500 tons
- date: 1916

## Wednesday, September 22, 2004

### I have gotten my program for calculating power curves working

## Tuesday, September 21, 2004

### Edward Attwood and Stanley Goodall

*Arethusa*class light cruisers. Edward Attwood lead the design of the 1915 battlecruisers, of which one, the

*Hood*, was completed. D.K. Brown notes that by the time the

*Hood*was completed, her designers had lost faith in her. To solve the problem, they had the design approach up their sleave that would have resulted in the 1921 battlecruisers. That was eventually adapted for the battleships

*Rodney*and

*Nelson*. Too often, during this period, requirements given to the design staff resulted in flawed ships being produced. In the flailing around after the Battle of Jutland, the

*Hood*design was altered, in many ways, for the worse. One feature of the Hood and the 1921 ships was a huge conning tower. We know, from the work done examining the wreck of the

*Hood*, that when she capsized, the conning tower fell out. An alternate view is that the conning tower was ejected by the force of the explosion. I am somewhat skeptical about that, given that the conning tower weighed over 200 tons. The

*Hood*would have been a better ship if they had used a lighter conning tower. This was a problem of "design by committee" (or specifications by committee). In any case, I very much like the direction taken in the 1921 designs. There was a flush deck, with a bow that flared and rose to give a good freeboard forward. There was the small transom stern that saved weight and gave a small increase to the effective length, slightly lowering the propulsion cost. These ships also finally included triple turrets for the main armament and twin turrets for the secondary armament. They also employed the "all-or-nothing" armoring scheme. I think that placing the three turrets forward was overkill. They would have been better ships with a conventional layout. At this point, Stanley Goodall was into some of these radical features, so the designs had them.

## Monday, September 20, 2004

### Compact very large battleship

- standard displacement: 80,000 tons
- full load displacement: 85,650 tons
- dimensions: 900ft x 150ft x 35.7ft (hull depth: 65ft)
- armament: 10-21in/45 and 24-5in/50
- Cp: 0.64
- Cm: 0.97
- designed speed: 20 knots
- machinery: 85,000 SHP
- machinery: 2,840 tons
- auxiliary machinery: 3,000 tons
- hull: 24,000 tons
- armament: 6,876 tons
- protection: 36,884 tons
- miscellaneous: 6,400 tons
- max. oil fuel: 5,000 tons
- feed water: 650 tons

## Sunday, September 19, 2004

### My ship power curve calculation computer program

## Saturday, September 18, 2004

### A "straight" German battlecruiser design

- standard displacement: 45,000 tons
- dimensions: 850ft x 110ft x 30.3ft
- hull depth: 48 ft
- Cp: 0.57
- Cm: 0.97
- armament: 9-16.5in/45 and 10-6in/50
- power: 200,000 SHP
- speed: 33 knots
- machinery weight basis: 30 SHP/ton of plant
- hull weight: 15,250 tons
- hull weight factor c: 0.34 x 10^-2
- armament: 2,830 tons
- protection: 16,650 tons
- machinery: 6,670 tons
- miscellaneous: 3,600 tons
- fuel: 8,000 tons max.
- feed water: 900 tons

The ship had a long forecastle with a step aft, just forward of the after turret. The main armament was mounted in three triple turrets, while the secondary armament just had shields, and were mounted singly.

## Friday, September 17, 2004

### The battlecruiser version of my alternate world design pattern

This is is the battlecruiser analog to my battleship built to the German *Nassau* class Dreadnoughts. This is approximately built to the dimensions of the Von der Tann.

Therefore, this ship would have four twin 11in/45 turrets and 12-5.9in/45 guns. The pencil drawing that I worked from was not as clean as that for the battleship, so I don't like the look of this version as well as the battleship of this design pattern. The pattern is a Derfflinger-style hull and secondary armament with a British-looking superstructure and masts. This is slightly enhanced version of the drawing.

### An "alternate world" version of the German Nassau type battleships

This drawing follows a design pattern that I have used at various times over the past 30 years. This is a battleship built to the dimensions of the German *Nassau* class Dreadnoughts, but with a flush deck and my version of a British upperworks.

Therefore, this ship would have four triple 11in/45 turrets and 12-5.9in/45 guns. There is a battlecruiser analog to this design that is approximately to the dimensions of the *Von Der Tann*, but with this sort of "look". When I finish cleaning up that drawing, I will post it as well.

### I've simplified the residual resistance tables so that I can make progress

*The Speed and Power of Ships*. The data most often used will be reasonably accurate, as some of the extrapolation is pretty low-risk. Where the values may never be used, as they are so extreme, the data is less reliable.

## Thursday, September 16, 2004

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

This is my drawing of the "super-fast battlecruiser". I took the 30-some year old pencil drawing and did some digital editing to enhance it.

As I previously noted, this was intended to be a 32,000 ton ship (actually, 33,500 tons normal) with 4-17in/45 and 16-4in QF guns. The armor was to be thin, as in the preceding light battlecruiser designs.

## Wednesday, September 15, 2004

### My 1905 building program for Germany (from 1971)

- 3 battleships
- 1 light battlecruiser
- 6 scout cruisers
- 12 destroyers

Ger/BB/1905

- displacement: 22,000 tons
- dimensions: 580ft x 90ft x 26.6ft
- Cp: 0.57
- Cm: 0.97
- armament: 8-12in/45, 12-4in QF
- armor belt: 10in
- speed: 24 knots

Ger/CB/1905

- displacement: 19,000 tons
- dimensions: 700ft x 80ft x 24.4ft
- Cp: 0.54
- Cm: 0.90
- armament: 4-12in/45, 12-4in QF
- armor belt: 4in
- speed: 31 knots

Ger/CS/1905

- displacement: 2,480 tons
- dimensions: 370ft x 38ft x 13ft
- Cp: 0.56
- Cm: 0.85
- armament: 5-4in QF, 2-18in TT
- armor: 2in H/T steel over machinery
- speed: 36 knots

Ger/DD/1905

- displacement: 870 tons
- dimensions: 270ft x 28ft x 9ft
- Cp: 0.56
- Cm: 0.80
- armament: 2-4in QF, 2-18in TT
- speed: 32 knots

## Tuesday, September 14, 2004

### I used to be very big on deck armor for capital ships

This is an example of what I used to think was the right way to protect a battlecruiser:

The design had 5in + 4in deck armor, and tapered side armor, tapering from a4in at the top to 8in at the bottom. The belt was backed by 3in armor on the slopes. the anti-torpedo bulkhead, which continued the belt to the bottom, was 2in thick. Between the decks, the funnel protection was 2in, and above the decks was 4in.

## Monday, September 13, 2004

### More machinery weights

*Warrior to Dreadnought*, there are a few other nuggets:

- destroyer Arab: 41.3 IHP/ton of machinery (1896)
- destroyer Express: 44.5 IHP/ton of machinery (1896)
- destroyer Albatross: 39.5 IHP/ton of machinery (1896)
- large cruiser reciprocating 41,000 IHP plant: 11 IHP/ton of machinery (1905)
- large cruiser turbine 41,000 SHP plant: 13.7 SHP/ton of machinery (1905)
- flotilla leader Swift: 32.7 SHP/ton of machinery (1905)

The lack of better weight data for British ships from 1890 to 1921 is particularly bothersome.

There is much better data for USN ships. For example, the Omaha class cruisers had a plant that produced 52.3 SHP/ton of machinery, and this was in a plant designed circa 1918. The Lexington class battlecruisers were designed with a plant that produced something like 31.4 SHP/ton of machinery. This was a 1919 design.

### A little perpective on SHP per ton of machinery weight

*Nelson to Vanguard*, where I was looking for data about machinery weight. In one table, he lists pounds per SHP. I prefer to turn that around to SHP per ton of machinery weight. The

*Queen Elizabeth*class battleships were originally 26 SHP/ton of machinery. The WWII-era

*King George V*class were 60 SHP/ton of machinery. The former used large tube boilers, and was designed about 1912. Using D.K. Brown's figures, the battlecruiser

*Hood*, with small tube boilers achieved 34 SHP/ton of machinery. This was a 1916 design. The modernized Queen Elizabeth class ships had a plant that was 51 SHP per ton of machinery. Cruisers had long had lighter-weight machinery. Again, using D.K. Brown's figures:

- Kent: 43.7 SHP/ton
- Exeter: 45.7 SHP/ton
- Leander: 47.8 SHP/ton
- Amphion: 55 SHP/ton
- Arethusa: 52.4 SHP/ton

These are all 1920's-early 1930's ships.

Destroyer machinery weight bases seem harder to find. The WWI Admiralty R-class had machinery weighing 395 tons. The power output was 27,000 SHP designed. This gives us 68.35 SHP/ton for a ship designed in 1915. For comparison, the WWII Hunt class machinery was 285 tons. The power output was 19,000 SHP. That gives a machinery weight basis of 66.67 SHP/ton. That was for a plant designed in 1938-1939. There was no improvement in output.

### Strategic Mobility

*Capitani Romani*class. These were ships like the

*Attilio Regolo*, the

*Pompeo Magno*, and

*Scipione Africano*. Their dimensions were: 469ft x 47.25ft x 16ft. Their initial armament was 8-5.3in (135mm)45, 8-37mm/54 AA, and 8-20mm AA. They had a 110,000 SHP power plant. Their normal displacement was 5,035 tons. Their nominal speed was 40 knots, but in service they were able to sustain as much as 43 knots! They carried 1,400 tons of fuel and had a nominal range of 4,352 miles at 18 knots. The only ships even close to these in their speed-range combination were the British

*Abdiel*class minelayers. They were much smaller ships, with a standard displacement of 2,600 tons. They only had 6-4in guns, and had a nominal speed of 40 knots. They were very overweight (about 3,450 tons), so that 35 knots was a more realistic speed with 73,000 SHP. Even that speed, with their ample internal volume allowed them to be fast supply carriers to Malta. The Italian vessels were much superior ships. They were really the precursors of the large destroyers built postwar, especially by the USN. They were flush-decked and had a flared bow, and were decent seaboats. Their guns were rather unsatisfactory, as 13cm (5.1in) would have been a better choice, but if their opponents had been the French contre-torpilleurs, they might well have had need for a gun as big as 135mm.

## Sunday, September 12, 2004

### My variant of the light battlecruiser

## Saturday, September 11, 2004

### Superfast light battlecruiser

- light displacement: 32,000 tons
- normal displacement: 33,500 tons
- dimensions: 800ft x 85ft x 29.7ft (45ft hull depth)
- armament: 4-17in/45 and 16-4in/50 QF
- Cp: 0.60
- Cm: 0.97
- hull weight: 8,890 tons
- machinery: 12,750 tons
- auxiliary machinery: 1,232 tons
- armament: 2,088 tons
- protection: 4,480 tons
- miscellaneous: 2,560 tons
- machinery weight basis: 40 SHP/ton of machinery (too high)
- machinery: 510,000 SHP (probably wildly overoptimistic)

The fundamental problem with this ship is now to deliver that much power. Frank Fox has spoken to me about a fundamental limit of about 70,000 SHP per shaft, before the shaft would give way. It might actually be slightly higher, but not with 1921 technology.

Another factor is the shallow draft, which also complicates shafting, along with the narrow beam.

### The specs for the Ger/CB/1906

- legend displacement: 25,000 tons
- dimensions: 800ft x 85ft x 25.6ft
- Cp: 0.53
- Cm: 0.95
- armament: 8-12/45 (50 tons), 8-6in/50 (6 ton)
- machinery: 120,000 SHP
- speed: 32 knots
- armor belt: 4in, angled outwards

I have some weights calculated, but I am sceptical of them, so I will not list them until I can do a new calculation.

### My Ger/CB/1906 design (picture from 2002)

Ger/CB/1906 design. Drawing from August 2002. If you have seen any of the other drawings, you can see that it "looks like it came from my main shipyard".

## Friday, September 10, 2004

### Residual resistance tables

## Thursday, September 09, 2004

### Port Arthur map

*All the World's Fighting Ships*(Fred T. Jane) to see was there. I don't expect there are too many copies of this work "running around". The Russian section has a small map of Kronstadt that shows the harbor layout and water depths. There is also a nice map of Vladivostok. It only has a rudimentary map of Port Arthur, although it does point out the forts. I would thing that this small snippet is pretty accurate. The map that appears in the 1914 and 1919 Jane's replaces this one, although it might be instructive to compare the two.

### The Midship Coefficient (Cm)

## Wednesday, September 08, 2004

### Calculating electrical and auxiliary power usage

### Computing range, considering electrical power generation

- The starting point is to know the "sea speed" and the SHP required to make that speed.
- Add 10% to that power to allow for "sea state"
- Then, add to that SHP the "SHP" needed to generate the electric power (I will discuss that separately)
- Add 10% for deterioration of the plant
- Multiply the SHP by 1.045 to allow for split plant operation, where applicable
- Compute the burnable fuel rate: (SHP x 0.9 lbs/SHP/hour)/2240 lbs per ton
- Compute normal range: sea speed x normal fuel load x 0.97895/(burnable fuel rate) (the factor accounts for unusable fuel, among other things)
- Compute max. range: sea speed x max. fuel load x 0.978595/(burnable fuel rate)

There are issues caused by the variable displacement and the power required to reach the sea speed under different loading. I'm pretty sure that the calculations described here are just designed to give the average performance. I suppose that you could integrate over time to get a more accurate figure, as the required power decreased, as fuel is burned.

### I rediscovered how to compute a ship's range, using Frank Fox's system

*The Speed and Power of Ships*approach that I learned from Frank Fox. I am ready to pick up where I had left off, and push towards making it usable. The program is an important component, as it will be a critical timesaver in the design process. Essentially "one button" spped and power calculations are then possible. I had done a lot of the work, when I converted graphical data into Excel spreadsheets, extrapolating from what is in

*The Speed and Power of Ships*.

## Tuesday, September 07, 2004

### My "Project Ger/BB/1915" battleship design

- legend displacement: 72,000 tons
- armament: 9-18in/45 (180 ton) and 24-5in QF (5 ton)
- speed: 20 knots
- power: 120,000 SHP (original concept was 60,000 SHP)
- Cp: 0.66
- Cm: 0.98
- dimensions: 750ft x 130ft x 40ft (65ft hull depth)
- machinery weight basis: 40SHP/ton of machinery
- hull weight basis c: 0.29 (x 10^-4)
- machinery weight: 3,000 tons
- hull: 18,400 tons
- auxiliary machinery: 2,770 tons
- armament: 4,000 tons
- protection: 38,070 tons
- miscellaneous: 5,760 tons

I believe that the armor basis was intended to be 16in (belt, barbettes, CT, etc.)

## Monday, September 06, 2004

### My concept of a good German light cruiser for 1914

- legend displacement: 3,500 tons
- armament: 9-5in QF, 4-21in TT, 40 mines
- dimensions: 430ft x 40ft x 15.9ft
- speed: 32 nots
- power: 60,000 SHP
- machinery weight basis: 45 SHP/ton of machinery
- Cp: 0.56
- Cm: 0.80
- hull weight basis (c): 0.30 (x 10^-4)

I had to rediscover my notation, as I did not remember how my "c" factor was scaled. The way this is used is:

hull weight in tons = length in feet x beam in feet x hull depth in feet x c x 10^-4

- protection: 1in deck, amidships
- oil fuel: 700 tons
- feed water: 100 tons
- machinery weight: 1,335 tons
- hull weight: 1,500 tons
- armament: 103.5 tons + 6 tons of mines
- full load displacement: 4,305 tons

## Sunday, September 05, 2004

### Above water torpedo tubes on large ships

*Hood's*back, although I am not sure what the current assessment is. One or more Japanese cruisers were lost from damage sustained when torpedo tubes were hit by bombs from the air. I believe that was what really decided things for Frank Fox. While Frank Fox's primary interest is in 17th Century English ships and naval history, he is also interested in WWII era ships. He is another person who likes to design his own warships, although he does it more infrequently. He is the one who taught me a system for calculating power for ships, using

*The Speed and Power of Ships*for residual resistance and Gertler's book for frictional resistance.

## Saturday, September 04, 2004

### I used to like tapered armor

## Friday, September 03, 2004

### Cliff's "BBX" design

- dimensions: 800ft x 135ft x 36.5ft (light displacement)
- legend displacement: 70,000 tons
- armament: 9-20in/45 (202 ton) and 24-5in QF (5 ton)
- speed: 20 knots
- power: 89,300 SHP
- machinery basis: 30SHP/ton of machinery

The weight breakdown:

- hull: 18,800 tons
- aux. machinery: 2,450 tons
- machinery: 2,980 tons
- armament: 4,461 tons
- protection: 35,709 tons
- miscellaneous: 5,600 tons

## Thursday, September 02, 2004

### The Super-Swift

*super-Swift*(as he wrote the name) as having 6-4in guns, 600 tons of oil fuel, and able to make 37 knots. The cost was to be £250,000. The question is how large the type was to be. The

*super-Swift*type would have been built under the 1912 estimates, so we could use the Laforey class destroyers as a guide. The

*Hotspur*cost the most, being £107,800. The

*Laforey*class were designed to be 1112.5 tons. That is a cost of £96.9 per ton of displacement. If the

*super-Swift*cost £250,000, that would be displacement of about 2,580 tons. I had previously guessed a much lower displacement: about 2,250 tons.

### I found the more detailed specs for the "Super Lion"

It turns out that I have the more detailed specs for my version of the "Super Lion" battlecruiser. I will just lay out the specs as a list:

- light displacement: 27,000 t0ns
- normal displacement: 28,500 tons
- full load displacement: 31,500 tons
- Dimensions: 800ft x 90ft x 26.5ft (normal)
- hull depth: 48ft
- Cp=0.55
- Cm=0.95
- hull weight basis: 2.9 x 10^-3
- Armament: 10-15in/45 (97 tons), 16-5in/50 (5 tons)
- Protection: 6in belt, 9in turrets, 9in barbettes
- Speed: 32 knots
- Power: 114,000 SHP normal, 136,600 SHP max.
- V/sqrt(L) (normal): 1.175
- V/sqrt(L) (max.): 1.26
- machinery basis: 30 SHP/ton machinery
- power/wt: 4 SHP/ton of displacement (normal), 4.8 SHP/ton (max.)

Weights:

- Hull: 10,050 tons
- Aux. Mach.: 1,060 tons
- Machinery: 3,800 tons
- Armament: 2,410 tons
- Protection: 7,520 tons
- Miscellaneous: 2,160 tons

## Wednesday, September 01, 2004

### Admiral Fisher's Super Lion battlecruiser (my drawing)

*Jane's Fighting Ships*.

### My "Super Lion" design

*over 30 knots*" .