WesWorld

Gentlemen,

using the new experience gained during the process of designing and developing Design 29K into something useful I started two other projects to replace my aging battle line. One of these design studies can be found below.

Background:

In 1931 the RSAN is allowed - as already explained elsewhere - to immediately replace the HERTOGs and to lay down replacements for the four KONINGs and MAURITIUS/RÉUNION. That´s a total of 8 hulls of which the MAUTITIUS-class vessels are the most modern and can be kept for a few more years. So dispite being currently rebuild (1927) the KONINGs will be replaces asap.

The math underlying my planning goes like this: Substracting the HERTOGs and KONINGs from the RSAN´s fleet list only 285kts of 440kts are used. This includes two vessels each of the MAURITIUS-, SOUTH AFRICA-, MOCAMBIQUE- and OPHION-classes. Of those only the OPHION-class is officially rated as 40kts per unit (unofficially it´s 40,018ts *shrug*). Of the remaining 155kts 138000ts will be used immediately for 4 units in 1931. What is left will be used later to increase the diplacement of the replacements for the two MAURITIUS-class vessels (from 28,5kts to 37kts officially).

The total capital ship replacement program then reads like this:

1931: Keels laid down of 2x Design 29N (each rated as 38,500ts standard excluding an overweight of 3,1%) and 2x BC31 (modified variant of what was formerly known as LÄNDER-class, rated as 30,500ts officially -> unofficially 2,1% more)
1932: None
1933: 2x replacement for MAURITIUS and RÈUNION currently called Design 33L (officially rated at 37kts, hiding 1,6% overweight)
1934: Entry into Service (EIS) of the units laid down 1931.
1935: None
1936: EIS of Design 33L

So in 1936 the RSAN will consist of a total of 12 capital ships (440kts total). Of those units 10 will have a 38cm main battery and the battle line will have a fleet speed of at least 27kn - dictated by their slowest units (SOUTH AFRICA-class unless not modified).

I wonder if it would be a good idea to lessen the stress on my yards by shifting the two BCs from the 1931er program into the following year? It also slightly helps to avoid block obsolecence in the future by a small margin - but then again who knows what the world will look like in 1952 (twenty years after EIS)?

Side effects of the program as developed above:

- I have to enlarge some type 2 or type 3 slips to type 4 standard
- My cruiser building program has to be thinned in 1931-1934 (general idea is to build 2 cruisers per annum for 20 years and start a loop - similar to the German Flottengesetz of the Tirpitz era)
- I have to make sure my DD building program has been fruitill until many resources are tied up in the capital ship program

What do you think? Does the above sound resonable to you?

Below´s the Design 33L mentioned above. Input of all kind welcome of course.

Thanks in advance...

HoOmAn

BB33L, South African Battleship laid down 1933

Displacement:
35.689 t light; 37.594 t standard; 41.465 t normal; 44.562 t full load

Dimensions: Length overall / water x beam x draught
815,63 ft / 797,24 ft x 95,14 ft (Bulges 113,19 ft) x 28,22 ft (normal load)
248,60 m / 243,00 m x 29,00 m (Bulges 34,50 m) x 8,60 m

Armament:
9 - 14,96" / 380 mm guns (3x3 guns), 1.818,81lbs / 825,00kg shells, 1933 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, majority forward, 1 raised mount - superfiring
20 - 4,53" / 115 mm guns (10x2 guns), 46,30lbs / 21,00kg shells, 1933 Model
Dual purpose guns in deck mounts with hoists
on side ends, evenly spread, 4 raised mounts - superfiring
30 - 1,57" / 40,0 mm guns (10x3 guns), 1,95lbs / 0,88kg shells, 1933 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
24 - 0,79" / 20,0 mm guns (4x6 guns), 0,24lbs / 0,11kg shells, 1933 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
Weight of broadside 17.360 lbs / 7.874 kg
Shells per gun, main battery: 110

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 15,0" / 380 mm 457,19 ft / 139,35 m 12,14 ft / 3,70 m
Ends: Unarmoured
Main Belt covers 88% of normal length

- Torpedo Bulkhead and Bulges:
0,98" / 25 mm 457,19 ft / 139,35 m 27,23 ft / 8,30 m

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 15,7" / 400 mm 12,6" / 320 mm 14,2" / 360 mm
2nd: 1,57" / 40 mm 0,79" / 20 mm 1,18" / 30 mm
3rd: 0,59" / 15 mm - -
4th: 0,39" / 10 mm - -

- Armour deck: 5,91" / 150 mm, Conning tower: 0,98" / 25 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 140.750 shp / 105.000 Kw = 29,40 kts
Range 8.500nm at 18,00 kts
Bunker at max displacement = 6.968 tons

Complement:
1.452 - 1.888

Cost:
£16,591 million / $66,364 million

Distribution of weights at normal displacement:
Armament: 2.008 tons, 4,8%
Armour: 13.235 tons, 31,9%
- Belts: 3.607 tons, 8,7%
- Torpedo bulkhead: 453 tons, 1,1%
- Armament: 3.256 tons, 7,9%
- Armour Deck: 5.893 tons, 14,2%
- Conning Tower: 25 tons, 0,1%
Machinery: 4.101 tons, 9,9%
Hull, fittings & equipment: 16.246 tons, 39,2%
Fuel, ammunition & stores: 5.776 tons, 13,9%
Miscellaneous weights: 100 tons, 0,2%

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
54.078 lbs / 24.529 Kg = 32,3 x 15,0 " / 380 mm shells or 8,4 torpedoes
Stability (Unstable if below 1.00): 1,09
Metacentric height 5,5 ft / 1,7 m
Roll period: 20,3 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0,51
Seaboat quality (Average = 1.00): 1,02

Hull form characteristics:
Hull has a flush deck
Block coefficient: 0,570
Length to Beam Ratio: 7,04 : 1
'Natural speed' for length: 28,24 kts
Power going to wave formation at top speed: 51 %
Trim (Max stability = 0, Max steadiness = 100): 69
Bow angle (Positive = bow angles forward): 25,00 degrees
Stern overhang: 4,92 ft / 1,50 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 28,87 ft / 8,80 m
- Forecastle (25%): 20,01 ft / 6,10 m
- Mid (50%): 20,01 ft / 6,10 m
- Quarterdeck (15%): 20,01 ft / 6,10 m
- Stern: 20,01 ft / 6,10 m
- Average freeboard: 20,90 ft / 6,37 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 88,2%
- Above water (accommodation/working, high = better): 141,6%
Waterplane Area: 53.940 Square feet or 5.011 Square metres
Displacement factor (Displacement / loading): 110%
Structure weight / hull surface area: 206 lbs/sq ft or 1.004 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1,00
- Longitudinal: 1,00
- 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

Quoted

Bulges 113,19 ft

Hmmm. Something tells me that you are not planning to use the Panama Canal. :-)
... and are you sure about the 25mm Conning Tower??

Quoted

... and are you sure about the 25mm Conning Tower??

Hmm a perfect target for planes later on. 20mm shells will penetrate this at around 300m. Then even later with 37mm this increases out to 750m or so. It all depends whether pilots can actually hit the conning Tower, but wtih strafing a few hits might be possible.

The weight distributed in SS for her CT will be used for anti-splinter protection on her bridge. There won´t be a classical coning tower.

The Panama Canal is of no interest to me. Sitting that far south makes it much easier to use the historical way into the Pacific rather sailing up the coast of South America.

No comments on the building plan in general? No more input? How does this plan compare to your own? Or did it inspire you to change your own planning?

Do you think it is a mistake to build no additional 40kts units and go for numbers instead? I could give away one BC easily enough to gain more tonnage which can then be spend to upsize the other units...

Quoted

Originally posted by Red Admiral

Quoted

... and are you sure about the 25mm Conning Tower??

Hmm a perfect target for planes later on. 20mm shells will penetrate this at around 300m. Then even later with 37mm this increases out to 750m or so. It all depends whether pilots can actually hit the conning Tower, but wtih strafing a few hits might be possible.

Are you sure about the 20mm cannons? Can you give a source in the web where one can find penetration tables for airborne weapons?

Quoted

The Panama Canal is of no interest to me. Sitting that far south makes it much easier to use the historical way into the Pacific rather sailing up the coast of South America.

That's obvious, but I just wanted to make the remark. I guess that a closed Panama would be more useful to you.

Quoted

No comments on the building plan in general? No more input? How does this plan compare to your own? Or did it inspire you to change your own planning?

Nothing special to say about it. It has good armor, good armament and reasonable speed.
Compared to what I have planned, it is a bit lighter. Mine has the same main gun armament, uses heavier secondaries, slightly better armor for the main turret, slightly faster, but probably has a shorter range (I'm not sure since I use 15 knots as cruising speed and you use 18 knots).

Quoted

How does this plan compare to your own? Or did it inspire you to change your own planning?

I'm still in the larger number of smaller ships. My tonnage cuts 40k 3 ways or 30k for 4 ships. From memory I don't think I have any new battleships planned before 1936 and I doubt that I'd build any.

Cheers,

Quoted

Originally posted by Rooijen10

Quoted

The Panama Canal is of no interest to me. but probably has a shorter range (I'm not sure since I use 15 knots as cruising speed and you use 18 knots).

Her range is equal to ~13000nm at 15kn...

I generally prefer not to go public with designs that are several years down the road, but that's just me.

I think I'm in agreement with Walter. Technically, the design looks very capable, but more or less what I'd expect from a 3x3 15" design using ~max tonnage.

But if it's questions ye be wanting, it's questions ye be gettin':

-First, does the world of the mid-thirties have a place for a LANDER-style ship? Your battleships are themselves quite fast, and your carriers will offer a potent strike package by then. Have you considered six vessels in the ~35,000 t range instead?

-Seccond, whatever your program looks like, have you considered spreading it out further - with a pair of lay-downs in 1931, 1933, and 1935? This should reduce the number of large slips you need, and should reduce the possible block obsolescence down the road. As a side effect, it may also make it easier to continue some destroyer/cruiser construction in this time period.

Yes, it means the Mauritius class has to soldier on until ~1938, but that's a twenty year career; with a rebuild they should be capable of remaining useful until then.

Quoted

Her range is equal to ~13000nm at 15kn...

Then your ship has the greater range. Mine's about 11,000 at 15.

Quoted

I'm still in the larger number of smaller ships. My tonnage cuts 40k 3 ways or 30k for 4 ships. From memory I don't think I have any new battleships planned before 1936 and I doubt that I'd build any.

I hear ya. My own tonnage either lets me build a third Akbar or two over-sized CAs. While I thought an Akbar was reasonable for a 1924 lay-down, I'm not so certain it's worth doing ten years later. I may just wind up with two Akbars and two big CAs, joined by four other CAs built with my cruiser tonnage.

Losing 14,000 t at the table in Cleito certainly didn't help me out any, but I'll try to get that rectified in 1928. Getting that back would let me build a full-sized ship to lead my little battle division...

Quoted

Originally posted by HoOmAn
Are you sure about the 20mm cannons? Can you give a source in the web where one can find penetration tables for airborne weapons?

From memory, IIRC, the Vickers K gun (sorry, can't remember the calibre!)carried by "Hurribombers" during the North African campaign could open up any tank short of the Tiger, and Ju87's in the Russian campaign with pod mounted 37mm cannon could defeat the T34!
And the 37mm cannon carried in the nose of the "airacobra" was regularly salvaged by PT Boat crews because of it's "Barge-busting" capabilities.

So even if these examples are bigger than 20mm, bear in mind that we are talking about multiple strikes in a small area with a decent chance of two or more on the same spot, and I think you really should re-think your 20mm conning tower!!!

Quoted

Originally posted by The Rock Doctor
I generally prefer not to go public with designs that are several years down the road, but that's just me.

In general I agree and there´s still a chance I will have to modify the whole program. Think of your latest SPEARFISH reports....

However, I wanted some input if I was entirely wrong or not. See the discussion about Design 29K - I learned quite a few things during the process, especially about the use of bulges. I´ve never tried that before after all.

Quoted

I think I'm in agreement with Walter. Technically, the design looks very capable, but more or less what I'd expect from a 3x3 15" design using ~max tonnage.

Obviously those ships are a further step forward from Design 29N, achieving about the same on a smaller displacement thus buying money, material and time. They also allow me to field a homogenous battleline of 6 ships with nearly identical attributes (OPHION-, 29N and 33L-classes).

[QOUTE]But if it's questions ye be wanting, it's questions ye be gettin':

-First, does the world of the mid-thirties have a place for a LANDER-style ship? Your battleships are themselves quite fast, and your carriers will offer a potent strike package by then. Have you considered six vessels in the ~35,000 t range instead?[/QUOTE]

Yes, I really think so. The ships will enter service late in 1934 and be ready after trials in 1935. AFAIK from a 1927er perspective it is reasonable to assume large warships with huge guns will still be the tools to have at hand during a war at sea. Taking OTL into consideration doesn´t change the facts. In the mid-30s carrier capabilites surely were much enhanced compared to the early years but still capital ships were seen as the most powerful warships.

I also think it would be good to have a fast wing to the battle line. Standard speed will be in the 27-29kn range but to hunt down enemy scout cruisers or super-ACs one probably needs something much faster which still wields enough firepower and armor to overwhelm any such ship.

The concept may be flawed in the advent of seaborne air strikes and the like. But that would be using hindsight...

Quoted

-Seccond, whatever your program looks like, have you considered spreading it out further - with a pair of lay-downs in 1931, 1933, and 1935? This should reduce the number of large slips you need, and should reduce the possible block obsolescence down the road. As a side effect, it may also make it easier to continue some destroyer/cruiser construction in this time period.

I´ve run some claculations meanwhile. The SAE has enough capacity to continously build a fleet the size of India´s every two years. Three - if we include re-builds. As planned I´ll have 6 capital ships on my slips and still 12+ factories left to handle a cruiser building program etc. That should do, methinks, and it doesn´t include material from scrapping.

Manpower might be a problem, though. However, the RSAN is not only building new ships, old ships will be decommissioned and scrapped. Giving away a total of 8 old capital ships will buy me enough experienced crews for 6 new ones. I roughly need 9,400 men and the old BBs are providing ~9,700....

Block obsolescence could be a problem but I think it is less so than having 4 aging KONINGs now. :o/

Quoted

Yes, it means the Mauritius class has to soldier on until ~1938, but that's a twenty year career; with a rebuild they should be capable of remaining useful until then.

The MAURITIUS-class has to soldier on into 1937 anyway. They were laid down 1914, entered service late in 1917 and will be replaced by Design 33L which will have EIS in 1937. That´s your twenty year career.

Of course you´re right. They will still be ships with 8x 38cm guns and at least decent armor (albeit of some age and lesser quality). Surely they remain useful to some degree. Nevertheless, their low speed render them obsolete in the (Wes)world I foresee for the 1930s. In OTL the british R-class, quite similar to the MAURITIUS-class, was only good enough for convoy duties - more or less - during world war two. Do I want to waste the tonnage and hulls of two capital ships for that purpose? I don´t think so... :o)

Thanks for your input,

HoOmAn

Quoted

Originally posted by Commodore Green
So even if these examples are bigger than 20mm, bear in mind that we are talking about multiple strikes in a small area with a decent chance of two or more on the same spot, and I think you really should re-think your 20mm conning tower!!!

Well, thanks. On the other hand I can´t really believe it because it looks like you´ll need, what?, 80mm or armor or something to have your bridge bullet proof? I can´t remember to have read in any of my books that "splinter protection" was that thick. :o/

So what is wrong here?

http://www.tarrif.net/cgi/production/all_penetration_adv.php

Penetration data for guns. Probably best to go for 70-100mm thickness. Then DD guns can't penetrate either.

As to the overall program it doesn't really matter if some ships are 2000tons larger than others or not. There is little reduction in strength. Though what use you think the Länder Class are, I'm not sure.