Aztec Ship Designs 1918-1920

[TacCovert4]

I have done WAAAAY too much gun research over the years.  The US actually had a 7in gun in play when they were looking at a uniform intermediate/secondary on their pre-dreadnoughts.  By that point all US cruisers had really been built, and the next round of heavy cruisers wasn't until after the WNT.  Personally, I think that if there hadn't been a WNT, the USN would have let the Omahas be their one 6in cruiser class and would have gone with a 7in gunned cruiser as a general purpose ship, with some odds and ends like Atlantas, and then a 10in gunned super cruiser or the BCs (god help us with those awful American BC designs)

[Jefgte]

Vindictive and Hawkins classes

http://www.navweaps.com/Weapons/WNBR_75-45_mk6.php

[TacCovert4]

Vindictive and Hawkins classes

http://www.navweaps.com/Weapons/WNBR_75-45_mk6.php

And the US Version, well where it would have gone if not for WNT making 8in the defacto gun

http://www.navweaps.com/Weapons/WNUS_7-45_mk2.php

[TacCovert4]

And now for something completely different.  An R-Class Razee with heavier armor is already in construction as part of the 1919 project.  However, while there's not the budget to build another one to that spec, a lighter spec, sacrificing armor down to cruiser levels while maintaining the serious firepower of the R-Class.....could be possible:

Renown, Aztec Razee laid down 1920

Displacement:
   19,047 t light; 19,891 t standard; 21,673 t normal; 23,099 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (730.12 ft / 721.78 ft) x 77.77 ft (Bulges 77.79 ft) x (23.29 / 24.53 ft)
   (222.54 m / 220.00 m) x 23.71 m (Bulges 23.71 m)  x (7.10 / 7.48 m)

Armament:
      6 - 11.02" / 280 mm 50.0 cal guns - 709.07lbs / 321.63kg shells, 120 per gun
     Breech loading guns in turret on barbette mounts, 1920 Model
     3 x Twin mounts on centreline ends, majority forward
      1 raised mount - superfiring
      14 - 5.12" / 130 mm 50.0 cal guns - 70.97lbs / 32.19kg shells, 200 per gun
     Quick firing guns in deck and hoist mounts, 1920 Model
     6 x Twin mounts on sides, evenly spread
     1 x Single mount on centreline, aft deck centre
      1 raised mount
      8 - 2.76" / 70.0 mm 50.0 cal guns - 11.08lbs / 5.03kg shells, 300 per gun
     Anti-air guns in deck mounts, 1920 Model
     4 x Single mounts on sides, aft evenly spread
      2 raised mounts
     4 x Single mounts on sides, forward evenly spread
      2 raised mounts
      24 - 0.47" / 12.0 mm 70.0 cal guns - 0.06lbs / 0.03kg shells, 3,000 per gun
     Machine guns in deck mounts, 1920 Model
     12 x Twin mounts on sides, evenly spread
      Weight of broadside 5,338 lbs / 2,421 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   4.72" / 120 mm   590.55 ft / 180.00 m   16.40 ft / 5.00 m
   Ends:   1.97" / 50 mm   131.23 ft / 40.00 m   16.40 ft / 5.00 m
     Main Belt covers 126 % of normal length

   - Torpedo Bulkhead - Additional damage containing bulkheads:
      0.79" / 20 mm   590.55 ft / 180.00 m   26.25 ft / 8.00 m
   Beam between torpedo bulkheads 65.62 ft / 20.00 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   5.91" / 150 mm   2.95" / 75 mm      4.72" / 120 mm
   2nd:   2.36" / 60 mm   1.18" / 30 mm      2.36" / 60 mm

   - Armoured deck - single deck:
   For and Aft decks: 2.36" / 60 mm
   Forecastle: 1.06" / 27 mm  Quarter deck: 1.26" / 32 mm

   - Conning towers: Forward 3.15" / 80 mm, Aft 3.15" / 80 mm

Machinery:
   Oil fired boilers, steam turbines,
   Electric motors, 4 shafts, 123,982 shp / 92,491 Kw = 31.50 kts
   Range 8,900nm at 14.00 kts
   Bunker at max displacement = 3,208 tons

Complement:
   893 - 1,161

Cost:
   £4.316 million / $17.262 million

Distribution of weights at normal displacement:
   Armament: 1,127 tons, 5.2 %
      - Guns: 1,127 tons, 5.2 %
   Armour: 4,766 tons, 22.0 %
      - Belts: 1,988 tons, 9.2 %
      - Torpedo bulkhead: 452 tons, 2.1 %
      - Armament: 588 tons, 2.7 %
      - Armour Deck: 1,633 tons, 7.5 %
      - Conning Towers: 105 tons, 0.5 %
   Machinery: 4,335 tons, 20.0 %
   Hull, fittings & equipment: 7,562 tons, 34.9 %
   Fuel, ammunition & stores: 2,627 tons, 12.1 %
   Miscellaneous weights: 1,257 tons, 5.8 %
      - Hull below water: 1,094 tons
      - Hull above water: 63 tons
      - Above deck: 100 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     25,680 lbs / 11,648 Kg = 38.3 x 11.0 " / 280 mm shells or 3.2 torpedoes
   Stability (Unstable if below 1.00): 1.13
   Metacentric height 4.4 ft / 1.3 m
   Roll period: 15.7 seconds
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 0.60
   Seaboat quality  (Average = 1.00): 1.10

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.580 / 0.587
   Length to Beam Ratio: 9.28 : 1
   'Natural speed' for length: 26.87 kts
   Power going to wave formation at top speed: 53 %
   Trim (Max stability = 0, Max steadiness = 100): 65
   Bow angle (Positive = bow angles forward): 12.00 degrees
   Stern overhang: 3.28 ft / 1.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   15.43 %,  23.79 ft / 7.25 m,  22.15 ft / 6.75 m
      - Forward deck:   30.00 %,  22.15 ft / 6.75 m,  20.51 ft / 6.25 m
      - Aft deck:   39.14 %,  20.51 ft / 6.25 m,  20.51 ft / 6.25 m
      - Quarter deck:   15.43 %,  20.51 ft / 6.25 m,  20.51 ft / 6.25 m
      - Average freeboard:      21.11 ft / 6.43 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 111.8 %
      - Above water (accommodation/working, high = better): 179.3 %
   Waterplane Area: 40,294 Square feet or 3,743 Square metres
   Displacement factor (Displacement / loading): 109 %
   Structure weight / hull surface area: 136 lbs/sq ft or 666 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.99
      - Longitudinal: 1.02
      - Overall: 1.00
   Cramped machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform



1094t  - Electric Drives

113t - 1918 FC
25t - NF Devices
25t - LR Radio

[Kaiser Kirk]

I understood the Hawkins' 7.5" to be sort of the end-point in M&H cruiser guns, though.  Did somebody come along with a heavier weapon afterward?

As Tac alludes, there were a range of such weapons in the period as different navies sought the heaviest option. The USN had the 7 and 8", the French had multiple iterations of the 194mm, the RN fielded the 7.5" a couple different times, while the Germans had the 6.75".  All went away with the treaty as folks migrated to 8".

[Kaiser Kirk]

But yeah, the US did twin mount and hoist 8in guns on the Pensacolas and Northamptons, those aren't actual turrets.  So I went with a 7in twin mounting, but with the caveat on my ships that have it that I toss on 15t per mount to account for electrically powered training and elevation motors, cable runs, and controls.

Interesting, I had missed that feature. Fun little tidbit to learn :)

I recently got Friedman's US Cruisers and it keeps alternating but generally calls them turrets. Which is persistant problem in literature.  The cut away seems to show a semi-stalked like the Brit 5.25" (also ~77t and the first version powered, but to slow for good AA), but the discussion on Navweaps is that they didn't have a rotating stem below the handling rooms.

To me, the downside  they were provided with powered gear, and such a design should be lighter than a turret, they didn't continue that design, which raises the question of why. I think if simply fitting more electric motors achieved the result, they would have stuck to that to stay below the 10,000 standard. The Northhamptons were designed and laid down in 1928 before the Pensacolas were in service. It does look like they considered keeping the light design, but, they switched to a rotating stalk turret in CA-32 on. That could be in order to fit the enhanced protection, or because they were finding the prior mounts unsatisfactory.

[Desertfox]

The US mounts also had the slight problem of all the guns being on a single sleeve and unable to be trained independently. The mounts were probably maxed out and unable to be improved anymore.

Meanwhile the Japanese couldn't handle intermediate sizes as well and where the ones who pushed for the 8" limit as that was where powered loading was required. Here as well, I'll be using 8" and 6" guns and not developing intermediate sizes, but without a treaty I see everyone else has plenty of designs in that range.

[TacCovert4]

But yeah, the US did twin mount and hoist 8in guns on the Pensacolas and Northamptons, those aren't actual turrets.  So I went with a 7in twin mounting, but with the caveat on my ships that have it that I toss on 15t per mount to account for electrically powered training and elevation motors, cable runs, and controls.

Interesting, I had missed that feature. Fun little tidbit to learn :)

I recently got Friedman's US Cruisers and it keeps alternating but generally calls them turrets. Which is persistant problem in literature.  The cut away seems to show a semi-stalked like the Brit 5.25" (also ~77t and the first version powered, but to slow for good AA), but the discussion on Navweaps is that they didn't have a rotating stem below the handling rooms.

To me, the downside  they were provided with powered gear, and such a design should be lighter than a turret, they didn't continue that design, which raises the question of why. I think if simply fitting more electric motors achieved the result, they would have stuck to that to stay below the 10,000 standard. The Northhamptons were designed and laid down in 1928 before the Pensacolas were in service. It does look like they considered keeping the light design, but, they switched to a rotating stalk turret in CA-32 on. That could be in order to fit the enhanced protection, or because they were finding the prior mounts unsatisfactory.

With the lighter 180mm gun as compared to the US 203, it's one of those things I'm willing to take on to do the ships within the tonnage I need.  Mainly I don't want to have a cruiser with paper armor to fit in those weights.    I anticipate though,  a shift to a triple turret in the mid to late 20s.

[TacCovert4]

After the near disaster in the Atlantic in 1919, the Sultan requested the Navy take a more active role in peacetime protection of shipping.  This has resulted in the existing DD-E class destroyers and the existing small fleet of fleet replenishment ships being heavily used to maintain mere presence in the area of major sealanes.  The 1920 build program already set, the Navy begins looking at options to take on this role in a more permanent way.  Additionally, the need for more fleet replenishment ships able to keep up with the fleet in wartime rears its head.  A 'halfway house' ship is designed, with some capacity for moving passengers or troops, potentially Royal Passengers, as well as having the ability to function as a modest hospital ship, replenishment ship for smaller vessels, and trade patrol and rescue vessel.  Electric drives are retained, even while geared drives are added, for the purpose of giving her tight maneuvering if called upon to take a ship under tow.  Armament is downright minimal and obviously defensive in nature, and the size is kept small and draft shallow to allow this class to be permanently deployed in the colonies abroad where its services are more likely to be required.

RS-2, Aztec Replenishment Ship laid down 1921

Displacement:
   4,150 t light; 4,273 t standard; 5,022 t normal; 5,621 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (413.29 ft / 410.11 ft) x 45.93 ft x (12.96 / 14.32 ft)
   (125.97 m / 125.00 m) x 14.00 m  x (3.95 / 4.37 m)

Armament:
      4 - 3.94" / 100 mm 50.0 cal guns - 32.30lbs / 14.65kg shells, 200 per gun
     Quick firing guns in deck mounts, 1921 Model
     5 x Twin mounts on centreline ends, majority forward
      2 raised mounts - superfiring
      4 - 2.76" / 70.0 mm 50.0 cal guns - 11.08lbs / 5.03kg shells, 300 per gun
     Anti-air guns in deck mounts, 1921 Model
     2 x Single mounts on centreline, forward deck aft
      2 raised mounts - superfiring
     2 x Single mounts on sides, forward deck aft
      16 - 0.47" / 12.0 mm 70.0 cal guns - 0.06lbs / 0.03kg shells, 2,500 per gun
     Machine guns in deck mounts, 1921 Model
     8 x Twin mounts on sides, evenly spread
      Weight of broadside 174 lbs / 79 kg

Machinery:
   Oil fired boilers, steam turbines,
   Electric cruising motors plus geared drives, 2 shafts, 22,628 shp / 16,880 Kw = 24.00 kts
   Range 9,000nm at 14.00 kts
   Bunker at max displacement = 1,347 tons

Complement:
   297 - 387

Cost:
   £0.673 million / $2.691 million

Distribution of weights at normal displacement:
   Armament: 32 tons, 0.6 %
      - Guns: 32 tons, 0.6 %
   Machinery: 779 tons, 15.5 %
   Hull, fittings & equipment: 1,407 tons, 28.0 %
   Fuel, ammunition & stores: 872 tons, 17.4 %
   Miscellaneous weights: 1,931 tons, 38.5 %
      - Hull below water: 1,092 tons
      - Hull above water: 650 tons
      - On freeboard deck: 160 tons
      - Above deck: 29 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     7,414 lbs / 3,363 Kg = 243.0 x 3.9 " / 100 mm shells or 1.3 torpedoes
   Stability (Unstable if below 1.00): 1.32
   Metacentric height 2.5 ft / 0.8 m
   Roll period: 12.1 seconds
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 0.06
   Seaboat quality  (Average = 1.00): 1.20

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.720 / 0.729
   Length to Beam Ratio: 8.93 : 1
   'Natural speed' for length: 20.25 kts
   Power going to wave formation at top speed: 56 %
   Trim (Max stability = 0, Max steadiness = 100): 59
   Bow angle (Positive = bow angles forward): 10.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   20.00 %,  18.04 ft / 5.50 m,  16.73 ft / 5.10 m
      - Forward deck:   30.00 %,  16.73 ft / 5.10 m,  14.76 ft / 4.50 m
      - Aft deck:   35.00 %,  14.76 ft / 4.50 m,  14.76 ft / 4.50 m
      - Quarter deck:   15.00 %,  14.76 ft / 4.50 m,  11.48 ft / 3.50 m
      - Average freeboard:      15.31 ft / 4.67 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 90.6 %
      - Above water (accommodation/working, high = better): 150.0 %
   Waterplane Area: 15,368 Square feet or 1,428 Square metres
   Displacement factor (Displacement / loading): 140 %
   Structure weight / hull surface area: 63 lbs/sq ft or 309 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.99
      - Longitudinal: 1.15
      - Overall: 1.00
   Adequate machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform

192t - Electric Drives
4t - 1912 FC
25t - LR Wireless
30t - Cranes and MHE
100t - Repair Facilities
100t - Additional Fire pumps and 4 Water Cannons
100t - 20 Bed Hospital w/ 4 Surgical/Exam Suites
200t - Berthing for 100 PAX (800 Emergency PAX)
400t - Stores (Empty Storerooms can be converted to emergency berths)
900t - Oil Fuel
80t - 2 x 20t Landing Craft (size of a B class MTB, 30 man capacity max, 1 token MG)