Aztec Ship Designs 1921-1924

[TacCovert4]

And a quick regun of the same ship with 12 x 360mm guns.  Therein lies the rub........

Blazing, Aztec Battleship laid down 1924

Displacement:
   40,115 t light; 42,151 t standard; 46,618 t normal; 50,191 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (759.68 ft / 754.59 ft) x 118.11 ft x (30.51 / 32.43 ft)
   (231.55 m / 230.00 m) x 36.00 m  x (9.30 / 9.88 m)

Armament:
      12 - 14.17" / 360 mm 45.0 cal guns - 1,435.70lbs / 651.22kg shells, 100 per gun
     Breech loading guns in turret on barbette mounts, 1924 Model
     4 x 2-gun mounts on centreline ends, evenly spread
      2 raised mounts - superfiring
      16 - 5.12" / 130 mm 50.0 cal guns - 70.97lbs / 32.19kg shells, 200 per gun
     Quick firing guns in deck and hoist mounts, 1924 Model
     8 x Single mounts on sides, evenly spread
      6 - 2.76" / 70.0 mm 50.0 cal guns - 11.08lbs / 5.03kg shells, 300 per gun
     Anti-air guns in deck mounts, 1924 Model
     6 x Single mounts on centreline, evenly spread
      6 raised mounts
      20 - 1.18" / 30.0 mm 50.0 cal guns - 0.87lbs / 0.40kg shells, 1,000 per gun
     Anti-air guns in deck and hoist mounts, 1924 Model
     10 x Twin mounts on sides, evenly spread
      Weight of broadside 18,448 lbs / 8,368 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   13.4" / 340 mm   447.83 ft / 136.50 m   16.40 ft / 5.00 m
   Ends:   2.76" / 70 mm   241.11 ft / 73.49 m   11.48 ft / 3.50 m
     65.65 ft / 20.01 m Unarmoured ends
     Main Belt covers 91 % of normal length

   - Torpedo Bulkhead - Additional damage containing bulkheads:
      1.97" / 50 mm   447.83 ft / 136.50 m   27.85 ft / 8.49 m
   Beam between torpedo bulkheads 98.43 ft / 30.00 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   15.0" / 380 mm   7.87" / 200 mm      13.4" / 340 mm
   2nd:   2.76" / 70 mm   1.57" / 40 mm      2.76" / 70 mm
   4th:         -            -         0.98" / 25 mm

   - Armoured deck - multiple decks:
   For and Aft decks: 5.71" / 145 mm
   Forecastle: 1.97" / 50 mm  Quarter deck: 3.94" / 100 mm

   - Conning towers: Forward 5.91" / 150 mm, Aft 5.91" / 150 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 4 shafts, 112,798 shp / 84,147 Kw = 27.00 kts
   Range 15,000nm at 14.00 kts
   Bunker at max displacement = 8,040 tons

Complement:
   1,586 - 2,062

Cost:
   £11.305 million / $45.221 million

Distribution of weights at normal displacement:
   Armament: 3,928 tons, 8.4 %
      - Guns: 3,928 tons, 8.4 %
   Armour: 15,975 tons, 34.3 %
      - Belts: 4,674 tons, 10.0 %
      - Torpedo bulkhead: 909 tons, 1.9 %
      - Armament: 3,736 tons, 8.0 %
      - Armour Deck: 6,326 tons, 13.6 %
      - Conning Towers: 330 tons, 0.7 %
   Machinery: 3,715 tons, 8.0 %
   Hull, fittings & equipment: 15,379 tons, 33.0 %
   Fuel, ammunition & stores: 6,503 tons, 13.9 %
   Miscellaneous weights: 1,117 tons, 2.4 %
      - Hull below water: 200 tons
      - Hull above water: 346 tons
      - On freeboard deck: 350 tons
      - Above deck: 221 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     72,747 lbs / 32,997 Kg = 51.1 x 14.2 " / 360 mm shells or 12.7 torpedoes
   Stability (Unstable if below 1.00): 1.16
   Metacentric height 8.5 ft / 2.6 m
   Roll period: 17.1 seconds
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 0.44
   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): 0.600 / 0.608
   Length to Beam Ratio: 6.39 : 1
   'Natural speed' for length: 27.47 kts
   Power going to wave formation at top speed: 50 %
   Trim (Max stability = 0, Max steadiness = 100): 65
   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 %,  28.87 ft / 8.80 m,  23.62 ft / 7.20 m
      - Forward deck:   30.00 %,  23.62 ft / 7.20 m,  18.37 ft / 5.60 m
      - Aft deck:   35.00 %,  18.37 ft / 5.60 m,  18.37 ft / 5.60 m
      - Quarter deck:   15.00 %,  18.37 ft / 5.60 m,  18.37 ft / 5.60 m
      - Average freeboard:      20.63 ft / 6.29 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 73.8 %
      - Above water (accommodation/working, high = better): 153.3 %
   Waterplane Area: 65,185 Square feet or 6,056 Square metres
   Displacement factor (Displacement / loading): 114 %
   Structure weight / hull surface area: 204 lbs/sq ft or 998 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.99
      - Longitudinal: 1.16
      - Overall: 1.00
   Excellent machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform

292t - 1918 FC
50t - 1918 NF Devices x 2
25t - LR Radio
200t - Flag Facilities
150t - Aviation Provisions
400t - Builder's Reserve

120mm Deck w/ 25mm Splinter

[The Rock Doctor]

You've got 2-gun turrets where I think you want 3-gun on that last one.

[TacCovert4]

I do.  Basically the last one isn't a serious design,  more a note that the 8 x 420 is ton for ton the same as a 12 x 360.  Debating which of the two routes to ultimately take.

[The Rock Doctor]

Have you got the 420mm gun designed or underway?

Given that other major powers are fielding stuff in the 400-420 range, I'd think the Aztecs might benefit from introducing them as well.  IF something comes up, like arms control treaties, easy enough to fall back on the 360 if needed.

[TacCovert4]

It's part of the debate on whether to build the 420mm gun at all.  I could have it by  1hy24.

[TacCovert4]

If I were to go a completely different direction, and stay as Admiral Fisher's fantasies:

Conqueror, Aztec Battlecruiser laid down 1924

Displacement:
   34,848 t light; 36,235 t standard; 38,976 t normal; 41,168 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (818.85 ft / 813.65 ft) x 104.99 ft x (29.04 / 30.32 ft)
   (249.59 m / 248.00 m) x 32.00 m  x (8.85 / 9.24 m)

Armament:
      6 - 14.17" / 360 mm 45.0 cal guns - 1,435.70lbs / 651.22kg shells, 100 per gun
     Breech loading guns in turret on barbette mounts, 1924 Model
     2 x 3-gun mounts on centreline, forward evenly spread
      1 raised mount
      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, 1924 Model
     6 x Twin mounts on sides, evenly spread
     1 x Twin mount on centreline, aft deck centre
      1 raised mount
      6 - 2.76" / 70.0 mm 50.0 cal guns - 11.08lbs / 5.03kg shells, 300 per gun
     Anti-air guns in deck mounts, 1924 Model
     6 x Single mounts on sides, evenly spread
      6 raised mounts
      16 - 1.18" / 30.0 mm 50.0 cal guns - 0.87lbs / 0.40kg shells, 1,000 per gun
     Anti-air guns in deck and hoist mounts, 1924 Model
     8 x Twin mounts on side ends, evenly spread
      4 raised mounts - superfiring
      Weight of broadside 9,688 lbs / 4,394 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   11.8" / 300 mm   528.87 ft / 161.20 m   13.12 ft / 4.00 m
   Ends:   2.36" / 60 mm   284.74 ft / 86.79 m   11.48 ft / 3.50 m
     Main Belt covers 100 % of normal length

   - Torpedo Bulkhead - Additional damage containing bulkheads:
      1.57" / 40 mm   528.87 ft / 161.20 m   27.10 ft / 8.26 m
   Beam between torpedo bulkheads 88.58 ft / 27.00 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   13.8" / 350 mm   5.91" / 150 mm      13.0" / 330 mm
   2nd:   2.76" / 70 mm   1.38" / 35 mm      2.76" / 70 mm
   4th:         -            -         0.98" / 25 mm

   - Armoured deck - multiple decks:
   For and Aft decks: 4.72" / 120 mm
   Forecastle: 1.18" / 30 mm  Quarter deck: 2.76" / 70 mm

   - Conning towers: Forward 5.51" / 140 mm, Aft 5.51" / 140 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 4 shafts, 207,255 shp / 154,612 Kw = 33.00 kts
   Range 10,000nm at 14.00 kts
   Bunker at max displacement = 4,933 tons

Complement:
   1,386 - 1,803

Cost:
   £9.551 million / $38.202 million

Distribution of weights at normal displacement:
   Armament: 2,042 tons, 5.2 %
      - Guns: 2,042 tons, 5.2 %
   Armour: 11,442 tons, 29.4 %
      - Belts: 3,757 tons, 9.6 %
      - Torpedo bulkhead: 835 tons, 2.1 %
      - Armament: 1,887 tons, 4.8 %
      - Armour Deck: 4,690 tons, 12.0 %
      - Conning Towers: 273 tons, 0.7 %
   Machinery: 6,827 tons, 17.5 %
   Hull, fittings & equipment: 14,197 tons, 36.4 %
   Fuel, ammunition & stores: 4,128 tons, 10.6 %
   Miscellaneous weights: 340 tons, 0.9 %
      - Hull above water: 105 tons
      - On freeboard deck: 85 tons
      - Above deck: 150 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     53,406 lbs / 24,224 Kg = 37.5 x 14.2 " / 360 mm shells or 7.4 torpedoes
   Stability (Unstable if below 1.00): 1.13
   Metacentric height 6.8 ft / 2.1 m
   Roll period: 16.9 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.44
   Seaboat quality  (Average = 1.00): 1.06

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.550 / 0.556
   Length to Beam Ratio: 7.75 : 1
   'Natural speed' for length: 28.52 kts
   Power going to wave formation at top speed: 55 %
   Trim (Max stability = 0, Max steadiness = 100): 66
   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 %,  29.53 ft / 9.00 m,  26.25 ft / 8.00 m
      - Forward deck:   30.00 %,  26.25 ft / 8.00 m,  22.97 ft / 7.00 m
      - Aft deck:   35.00 %,  22.97 ft / 7.00 m,  22.97 ft / 7.00 m
      - Quarter deck:   15.00 %,  22.97 ft / 7.00 m,  22.97 ft / 7.00 m
      - Average freeboard:      24.38 ft / 7.43 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 93.6 %
      - Above water (accommodation/working, high = better): 194.4 %
   Waterplane Area: 59,615 Square feet or 5,538 Square metres
   Displacement factor (Displacement / loading): 114 %
   Structure weight / hull surface area: 182 lbs/sq ft or 889 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.98
      - Longitudinal: 1.23
      - Overall: 1.00
   Adequate machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform

85t - Provision for 2x Spotter Plane, Catapults, and Crane
205t - 1918 FC
25t - NF Devices
25t - LR Wireless

[TacCovert4]

A little outside the 1924, but this is a prospective rebuild of the Implacable class that's been the workhorse BB of the Aztec fleet since the rest of the Aztec fleet got sunk at Ironclad Bay.  They've been my only battleships until the Monarchs came out, and with the Mk2 Monarchs coming out in 1925, I think it's time to take these old tubs in for a substantial refurbishment.  This one emphasizes replacing the casemate/deck mount battery with a uniform deck/hoist battery, bringing the speed up substantially, and including modern amenities like aviation facilities.


Implacable, Aztec Battleship laid down 1913 (Engine 1925)

Displacement:
   24,300 t light; 25,364 t standard; 27,320 t normal; 28,884 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (629.29 ft / 623.36 ft) x 82.02 ft (Bulges 88.58 ft) x (26.64 / 28.04 ft)
   (191.81 m / 190.00 m) x 25.00 m (Bulges 27.00 m)  x (8.12 / 8.55 m)

Armament:
      8 - 11.02" / 280 mm 50.0 cal guns - 709.07lbs / 321.63kg shells, 120 per gun
     Breech loading guns in turret on barbette mounts, 1913 Model
     4 x Twin mounts on centreline ends, evenly spread
      2 raised mounts - superfiring
      16 - 5.12" / 130 mm 50.0 cal guns - 70.97lbs / 32.19kg shells, 200 per gun
     Quick firing guns in deck and hoist mounts, 1913 Model
     8 x Twin mounts on sides, evenly spread
      4 - 2.76" / 70.0 mm 50.0 cal guns - 11.08lbs / 5.03kg shells, 300 per gun
     Anti-air guns in deck mounts, 1913 Model
     4 x Single mounts on centreline, evenly spread
      4 raised mounts
      12 - 1.18" / 30.0 mm 50.0 cal guns - 0.87lbs / 0.39kg shells, 1,000 per gun
     Anti-air guns in deck mounts, 1913 Model
     12 x Single mounts on sides, evenly spread
      Weight of broadside 6,863 lbs / 3,113 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   13.4" / 340 mm   410.11 ft / 125.00 m   16.40 ft / 5.00 m
   Ends:   2.76" / 70 mm   213.25 ft / 65.00 m   16.40 ft / 5.00 m
   Upper:   5.91" / 150 mm   410.11 ft / 125.00 m   8.20 ft / 2.50 m
     Main Belt covers 101 % of normal length

   - Torpedo Bulkhead - Additional damage containing bulkheads:
      1.97" / 50 mm   410.11 ft / 125.00 m   29.53 ft / 9.00 m
   Beam between torpedo bulkheads 65.62 ft / 20.00 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   13.4" / 340 mm   8.86" / 225 mm      13.4" / 340 mm
   2nd:   2.76" / 70 mm   1.57" / 40 mm      2.76" / 70 mm

   - Armoured deck - multiple decks:
   For and Aft decks: 3.15" / 80 mm
   Forecastle: 1.18" / 30 mm  Quarter deck: 1.97" / 50 mm

   - Conning towers: Forward 13.39" / 340 mm, Aft 0.00" / 0 mm

Machinery:
   Oil fired boilers, steam turbines,
   Electric motors, 4 shafts, 93,919 shp / 70,064 Kw = 27.50 kts
   Range 9,000nm at 14.00 kts
   Bunker at max displacement = 3,520 tons

Complement:
   1,062 - 1,381

Cost:
   £2.170 million / $8.682 million

Distribution of weights at normal displacement:
   Armament: 1,431 tons, 5.2 %
      - Guns: 1,431 tons, 5.2 %
   Armour: 10,429 tons, 38.2 %
      - Belts: 5,049 tons, 18.5 %
      - Torpedo bulkhead: 882 tons, 3.2 %
      - Armament: 2,112 tons, 7.7 %
      - Armour Deck: 2,124 tons, 7.8 %
      - Conning Tower: 262 tons, 1.0 %
   Machinery: 3,049 tons, 11.2 %
   Hull, fittings & equipment: 8,234 tons, 30.1 %
   Fuel, ammunition & stores: 3,019 tons, 11.1 %
   Miscellaneous weights: 1,156 tons, 4.2 %
      - Hull below water: 763 tons
      - Hull above water: 72 tons
      - On freeboard deck: 150 tons
      - Above deck: 171 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     41,073 lbs / 18,631 Kg = 61.3 x 11.0 " / 280 mm shells or 7.0 torpedoes
   Stability (Unstable if below 1.00): 1.10
   Metacentric height 4.5 ft / 1.4 m
   Roll period: 17.6 seconds
   Steadiness   - As gun platform (Average = 50 %): 60 %
         - Recoil effect (Restricted arc if above 1.00): 0.47
   Seaboat quality  (Average = 1.00): 1.03

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.650 / 0.653
   Length to Beam Ratio: 7.04 : 1
   'Natural speed' for length: 24.97 kts
   Power going to wave formation at top speed: 56 %
   Trim (Max stability = 0, Max steadiness = 100): 58
   Bow angle (Positive = bow angles forward): 12.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   15.43 %,  27.89 ft / 8.50 m,  22.97 ft / 7.00 m
      - Forward deck:   30.00 %,  22.97 ft / 7.00 m,  19.69 ft / 6.00 m
      - Aft deck:   39.14 %,  19.69 ft / 6.00 m,  19.69 ft / 6.00 m
      - Quarter deck:   15.43 %,  19.69 ft / 6.00 m,  19.69 ft / 6.00 m
      - Average freeboard:      20.99 ft / 6.40 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 80.2 %
      - Above water (accommodation/working, high = better): 143.3 %
   Waterplane Area: 39,167 Square feet or 3,639 Square metres
   Displacement factor (Displacement / loading): 112 %
   Structure weight / hull surface area: 153 lbs/sq ft or 745 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.98
      - Longitudinal: 1.26
      - Overall: 1.00
   Excellent machinery, storage, compartmentation space
   Excellent accommodation and workspace room

890t - Electric Drives
50t - Flag Bridge
25t - LR Radio
25t - NF Devices 1918
143t - 1918 FC
150t - Aviation Facilities and 3 x Floatplane Amidships

[Jefgte]

Interesting rebuild for a second class Battleship, always useful.
Did you calculate the cost?

[TacCovert4]

It's 5082 tons in total.  I'm pretty garbage at upgrades and upgrade costs.

[The Rock Doctor]

Cash cost will be around double to triple that, probably.

[TacCovert4]

Yeah, it just might not be worth it.  We'll see in 1925.  These might wind up being the world's most expensive/extensive colonial station ships.

[TacCovert4]

Watching what's going on with shipping lately, I think that the RAN will need to invest more heavily in its support infrastructure, as the Vilnius Union is having issues.  While the RAN does not have intentions to perform such large ship movements, watching the issues at play demonstrates how important it is to have both small and large fleet tenders to provide fuel, stores, and maintenance services to ships at sea between the widely spread Aztec colonies. 

Another key issue, more important in the Caribbean, but necessary at most of our ports, is the lack of government owned and operated salvage and dredging equipment.  Fleet tenders can provide damage control and abatement and even some repairs at sea.  But a lot of Aztec possessions in the Caribbean theater of operations, including the strategic Caicos islands, are regularly sanded, and heavily so.  During the previous war, the lack of deep draft ships in the RAN forces stationed there kept it from being problematic.  However, with the significant development of the naval base there, including a floating drydock, plans for a permanent drydock, and heavy investment in facilities for maintaining submarines, destroyers, and even cruisers in that area means that there are a lot of merchant ships moving to and from the islands, and there are significant risks of shoaling and other problems due to storms. 

Thus, the Sultan has ordered the planned Tuna-class replenishment vessels, planned for laydown in January 1922, to be shelved, and for the Navy to produce a series of comprehensive salvage vessels, combining dredging capabilities with significant bollard power for towing and removal of grounded vessels.  These vessels are to be RAN ships of the Royal Fleet Auxiliary, same as the fleet replenishment ships, to ensure that such capabilities are strategically available and available in peacetime or wartime conditions and all sea states.

[TacCovert4]

Crab, Aztec Salvage Ship laid down 1922

Displacement:
   895 t light; 920 t standard; 1,022 t normal; 1,103 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (164.04 ft / 164.04 ft) x 39.37 ft x (7.38 / 7.91 ft)
   (50.00 m / 50.00 m) x 12.00 m  x (2.25 / 2.41 m)

Armament:
      1 - 3.94" / 100 mm 50.0 cal gun - 32.30lbs / 14.65kg shells, 150 per gun
     Quick firing gun in deck mount, 1922 Model
     1 x Single mount on centreline, forward deck forward
      4 - 1.18" / 30.0 mm 50.0 cal guns - 0.87lbs / 0.40kg shells, 1,000 per gun
     Anti-air guns in deck mounts, 1922 Model
     4 x Single mounts on sides, aft deck forward
      Weight of broadside 36 lbs / 16 kg

Armour:
   - Conning towers: Forward 0.79" / 20 mm, Aft 0.00" / 0 mm

Machinery:
   Oil fired boilers, steam turbines,
   Electric motors, 2 shafts, 1,636 shp / 1,221 Kw = 14.00 kts
   Range 6,000nm at 10.00 kts
   Bunker at max displacement = 183 tons

Complement:
   89 - 117

Cost:
   £0.112 million / $0.449 million

Distribution of weights at normal displacement:
   Armament: 8 tons, 0.8 %
      - Guns: 8 tons, 0.8 %
   Armour: 2 tons, 0.2 %
      - Conning Tower: 2 tons, 0.2 %
   Machinery: 56 tons, 5.4 %
   Hull, fittings & equipment: 305 tons, 29.8 %
   Fuel, ammunition & stores: 127 tons, 12.4 %
   Miscellaneous weights: 525 tons, 51.4 %
      - Hull below water: 139 tons
      - Hull above water: 40 tons
      - On freeboard deck: 220 tons
      - Above deck: 126 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     3,861 lbs / 1,751 Kg = 126.5 x 3.9 " / 100 mm shells or 2.0 torpedoes
   Stability (Unstable if below 1.00): 1.44
   Metacentric height 2.3 ft / 0.7 m
   Roll period: 10.9 seconds
   Steadiness   - As gun platform (Average = 50 %): 60 %
         - Recoil effect (Restricted arc if above 1.00): 0.01
   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): 0.750 / 0.756
   Length to Beam Ratio: 4.17 : 1
   'Natural speed' for length: 12.81 kts
   Power going to wave formation at top speed: 60 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   Bow angle (Positive = bow angles forward): 0.00 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 %,  11.15 ft / 3.40 m,  11.15 ft / 3.40 m
      - Forward deck:   30.00 %,  11.15 ft / 3.40 m,  9.84 ft / 3.00 m
      - Aft deck:   35.00 %,  9.84 ft / 3.00 m,  9.84 ft / 3.00 m
      - Quarter deck:   15.00 %,  9.84 ft / 3.00 m,  9.84 ft / 3.00 m
      - Average freeboard:      10.30 ft / 3.14 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 40.2 %
      - Above water (accommodation/working, high = better): 117.5 %
   Waterplane Area: 5,410 Square feet or 503 Square metres
   Displacement factor (Displacement / loading): 155 %
   Structure weight / hull surface area: 44 lbs/sq ft or 216 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.98
      - Longitudinal: 3.00
      - Overall: 1.09
   Excellent machinery, storage, compartmentation space
   Adequate accommodation and workspace room

100t - Additional Engine Weight for Towing
39t - Electric Drives
20t - Firefighting/DC Pumps

200t - Bollards and Dredging/Salvage/Firefighting Equipment

100t - Salvage/Dredging Derrick

1t - 1918 FC

25t - LR Wireless

[The Rock Doctor]

That'll come in handy some day.

[TacCovert4]

It's a ship type that I'm surprised I haven't built before.  Tugboats would be dime a dozen, but an oceangoing tug/salvage vessel that can be used to maintain shipping channels at bases, tow damaged ships, or free ships that are aground, that's useful.

I've got to do some changes to the design though.  Notes I came up with since designing it:

1 - Pull the 100mm gun, put a 70mm AA gun behind the wheelhouse superimposed on the aft superstructure.  That satisfies the AA and anti-TB or submarine gun requirement, gives more space, and takes away weight.  Probably increase the 30mm armament to 6 guns, or add some 12mm MGs (those could be pintles where the guns can be removed to a locker when not needed).

2 - Add a forward 'crash void' for pushing, and increased tonnage for extra structural girders for pushing/towing.

3 - Add Minesweeping Kit.

4 - Redistribute any remaining tonnage to lockers of damage control gear.