Design Bureau Hong Kong

[Logi]

Nasty little Boomstick equipped with the 6"/62. The main point of the boomstick is it's ability to penetrate thick deck armor, just short of battleship level 3" thick deck with a "HC" shell.

However, due to the heavy armament, the ship is a *bit* slow at 29.5 kts (trial speed).

22DD-001, RRC Boomstick laid down 1922

Displacement:
   1,000 t light; 1,072 t standard; 1,147 t normal; 1,207 t full load

Dimensions: Length overall / water x beam x draught
   393.00 ft / 385.00 ft x 36.70 ft x 7.00 ft (normal load)
   119.79 m / 117.35 m x 11.19 m  x 2.13 m

Armament:
      4 - 6.00" / 152 mm guns in single mounts, 200.00lbs / 90.72kg shells, 1922 Model
     Breech loading guns in deck mounts with hoists
     on centreline ends, evenly spread, 2 raised mounts - superfiring
   Weight of broadside 800 lbs / 363 kg
   Shells per gun, main battery: 110
   3 - 21.0" / 533.4 mm above water torpedoes

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 17,006 shp / 12,686 Kw = 29.00 kts
   Range 3,000nm at 12.00 kts
   Bunker at max displacement = 135 tons

Trial Speed: 29.50 kts

Complement:
   98 - 128

Cost:
   £0.389 million / $1.554 million

Distribution of weights at normal displacement:
   Armament: 54 tons, 4.7 %
   Machinery: 443 tons, 38.7 %
   Hull, fittings & equipment: 475 tons, 41.4 %
   Fuel, ammunition & stores: 147 tons, 12.8 %
   Miscellaneous weights: 28 tons, 2.4 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     357 lbs / 162 Kg = 3.3 x 6.0 " / 152 mm shells or 0.3 torpedoes
   Stability (Unstable if below 1.00): 1.27
   Metacentric height 1.7 ft / 0.5 m
   Roll period: 11.8 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.81
   Seaboat quality  (Average = 1.00): 0.68

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.406
   Length to Beam Ratio: 10.49 : 1
   'Natural speed' for length: 19.62 kts
   Power going to wave formation at top speed: 55 %
   Trim (Max stability = 0, Max steadiness = 100): 74
   Bow angle (Positive = bow angles forward): 32.00 degrees
   Stern overhang: 0.50 ft / 0.15 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      12.00 ft / 3.66 m
      - Forecastle (15 %):   11.00 ft / 3.35 m
      - Mid (50 %):      9.00 ft / 2.74 m
      - Quarterdeck (10 %):   8.00 ft / 2.44 m
      - Stern:      8.00 ft / 2.44 m
      - Average freeboard:   9.41 ft / 2.87 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 164.7 %
      - Above water (accommodation/working, high = better): 133.2 %
   Waterplane Area: 8,728 Square feet or 811 Square metres
   Displacement factor (Displacement / loading): 71 %
   Structure weight / hull surface area: 40 lbs/sq ft or 198 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 0.53
      - Overall: 0.50
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is excellent
   Caution: Lacks seaworthiness - very limited seakeeping ability

[Sachmle]

I read the write up on the idea, and it's very interesting in general. Now I see the ship. I have only but 1 comments.

1) Open mounts, with or without a hoist to bring the shells up, on a 1,000t destroyer, with a steadiness of 50%? Shell handling is going to be a nightmare, especially if RRC sailors are of the same stature as OTL Chinese sailors. This isn't powerloading/ramming, it's hoist to bring the shell up, manual loading. That means that you'll still be manhandling 200lbs shells, plus powder, on a pitching/yawing/rolling deck w/ spray, in an open mount..while being shot at. Not a good idea, IMHO.

[Logi]

Oh god the turrets have nothing but paper armor! But Boomsticks have to make compromises, else it wouldn't be possible to carry its armament.

22DD-001, RRC Destroyer laid down 1922

Displacement:
   1,000 t light; 1,067 t standard; 1,142 t normal; 1,202 t full load

Dimensions: Length overall / water x beam x draught
   393.00 ft / 385.00 ft x 36.70 ft x 7.00 ft (normal load)
   119.79 m / 117.35 m x 11.19 m  x 2.13 m

Armament:
      4 - 6.00" / 152 mm guns in single mounts, 200.00lbs / 90.72kg shells, 1922 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, evenly spread, 2 raised mounts - superfiring
   Weight of broadside 800 lbs / 363 kg
   Shells per gun, main battery: 100

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.15" / 4 mm         -         0.10" / 3 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 16,940 shp / 12,637 Kw = 29.00 kts
   Range 3,000nm at 12.00 kts
   Bunker at max displacement = 134 tons

Complement:
   97 - 127

Cost:
   £0.388 million / $1.550 million

Distribution of weights at normal displacement:
   Armament: 54 tons, 4.7 %
   Armour: 3 tons, 0.3 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 3 tons, 0.3 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 0 tons, 0.0 %
   Machinery: 441 tons, 38.6 %
   Hull, fittings & equipment: 477 tons, 41.7 %
   Fuel, ammunition & stores: 142 tons, 12.4 %
   Miscellaneous weights: 25 tons, 2.2 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     358 lbs / 163 Kg = 3.3 x 6.0 " / 152 mm shells or 0.3 torpedoes
   Stability (Unstable if below 1.00): 1.26
   Metacentric height 1.7 ft / 0.5 m
   Roll period: 11.9 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.82
   Seaboat quality  (Average = 1.00): 0.67

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.404
   Length to Beam Ratio: 10.49 : 1
   'Natural speed' for length: 19.62 kts
   Power going to wave formation at top speed: 55 %
   Trim (Max stability = 0, Max steadiness = 100): 74
   Bow angle (Positive = bow angles forward): 32.00 degrees
   Stern overhang: 0.50 ft / 0.15 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      12.00 ft / 3.66 m
      - Forecastle (15 %):   11.00 ft / 3.35 m
      - Mid (50 %):      9.00 ft / 2.74 m
      - Quarterdeck (10 %):   8.00 ft / 2.44 m
      - Stern:      8.00 ft / 2.44 m
      - Average freeboard:   9.41 ft / 2.87 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 164.0 %
      - Above water (accommodation/working, high = better): 157.5 %
   Waterplane Area: 8,718 Square feet or 810 Square metres
   Displacement factor (Displacement / loading): 71 %
   Structure weight / hull surface area: 41 lbs/sq ft or 199 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 0.53
      - Overall: 0.50
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is excellent
   Caution: Lacks seaworthiness - very limited seakeeping ability

[Sachmle]

Not really about "armor" it's about weather shielding. I'd not worry about the hoist, it's not really 'armor'. Just get as much as you can on the face/other so the mount is enclosed. I'd try for at least 8mm, 5 in a pinch.

[P3D]

99% that the shell is too long to be spin-stabilized - especially if it has any significant HE filler. The reason why APDS gave way to APFSDS in tank ammo.

[Logi]

The gun is also very long? Its 62 caliber gun.

DD22, RRC Boomstick laid down 1922

Displacement:
   1,000 t light; 1,068 t standard; 1,142 t normal; 1,202 t full load

Dimensions: Length overall / water x beam x draught
   393.00 ft / 385.00 ft x 36.45 ft x 7.09 ft (normal load)
   119.79 m / 117.35 m x 11.11 m  x 2.16 m

Armament:
      4 - 6.00" / 152 mm guns in single mounts, 200.00lbs / 90.72kg shells, 1922 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, evenly spread, 2 raised mounts - superfiring
   Weight of broadside 800 lbs / 363 kg
   Shells per gun, main battery: 100

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.31" / 8 mm   0.20" / 5 mm      0.16" / 4 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 16,881 shp / 12,593 Kw = 29.00 kts
   Range 3,000nm at 12.00 kts
   Bunker at max displacement = 134 tons

Complement:
   97 - 127

Cost:
   £0.387 million / $1.548 million

Distribution of weights at normal displacement:
   Armament: 54 tons, 4.7 %
   Armour: 7 tons, 0.6 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 7 tons, 0.6 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 0 tons, 0.0 %
   Machinery: 440 tons, 38.5 %
   Hull, fittings & equipment: 475 tons, 41.6 %
   Fuel, ammunition & stores: 142 tons, 12.4 %
   Miscellaneous weights: 25 tons, 2.2 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     357 lbs / 162 Kg = 3.3 x 6.0 " / 152 mm shells or 0.3 torpedoes
   Stability (Unstable if below 1.00): 1.25
   Metacentric height 1.7 ft / 0.5 m
   Roll period: 11.9 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.84
   Seaboat quality  (Average = 1.00): 0.67

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.402
   Length to Beam Ratio: 10.56 : 1
   'Natural speed' for length: 19.62 kts
   Power going to wave formation at top speed: 55 %
   Trim (Max stability = 0, Max steadiness = 100): 73
   Bow angle (Positive = bow angles forward): 32.00 degrees
   Stern overhang: 0.50 ft / 0.15 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      12.00 ft / 3.66 m
      - Forecastle (15 %):   11.00 ft / 3.35 m
      - Mid (50 %):      9.00 ft / 2.74 m
      - Quarterdeck (10 %):   8.00 ft / 2.44 m
      - Stern:      8.00 ft / 2.44 m
      - Average freeboard:   9.41 ft / 2.87 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 163.6 %
      - Above water (accommodation/working, high = better): 156.2 %
   Waterplane Area: 8,647 Square feet or 803 Square metres
   Displacement factor (Displacement / loading): 71 %
   Structure weight / hull surface area: 41 lbs/sq ft or 198 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 0.53
      - Overall: 0.50
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is excellent
   Caution: Lacks seaworthiness - very limited seakeeping ability

[P3D]

The length of the gun has hardly anything to do with it. It is an external ballistics phenomenon, if the projectile length:diameter ratio is getting too large. Also, even if stabilization is possible, the required twist might be so high that the grooves would be eroded in less than 50 shots.
Also shells are designed to withstand the forces in the gun. A 2x heavier shell would require thicker walls, most probably leaving inadequate/no space for any explosive filling.

[Logi]

The gun is designed for the shell? But yes, the shell seems long.

[P3D]

Heavy shells also erode the liner faster. It does not help that internal ballistics was more like an art than science, do designing a shell way off the chart won't work.

Scaling back the largest SAP shell with any significant HE filling (USSR 16", 2443lbs) you could have a 129lbs 6" SAP shell.

[Logi]

How much % was the filling? But that sounds like a decent number. Probably need to do a few things to the gun to make sure it can penetrate deck armor (cause it sure as hell can't penetrate ample belt armor!).

[Nobody]

If you take the US "super heavy" as a reference the maximum reasonable shell weight is about 67.2 kg, but that would be for an APC, not a HE or HC shell.

An short overview and my estimation on what I could find on short notice:

Name	kg	filler [%]	L [calibers]
US 16" AP	1225	1.5	4.5
US 16" HC	862	8.1	4
40.6 cm/52 APC	1030	2.35	4.4
40.6 cm/52 SAP	1030	4.1	4.6
40.6 cm/52 HE	1030	8	4.8
20mm Mine	0.092	21.7
30mm Mine	0.33
fictional 6" Mine	40.7	21.7
plausible 6" HE	54.3	8	4.8

[Logi]

Trial Speed at 31.5kts.

DD22, RRC Hunter laid down 1922

Displacement:
   1,000 t light; 1,080 t standard; 1,155 t normal; 1,215 t full load

Dimensions: Length overall / water x beam x draught
   393.00 ft / 385.00 ft x 33.00 ft x 7.50 ft (normal load)
   119.79 m / 117.35 m x 10.06 m  x 2.29 m

Armament:
      4 - 6.00" / 152 mm guns in single mounts, 128.00lbs / 58.06kg shells, 1922 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, evenly spread, 2 raised mounts - superfiring
   Weight of broadside 512 lbs / 232 kg
   Shells per gun, main battery: 200
   3 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.31" / 8 mm   0.20" / 5 mm      0.20" / 5 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 20,819 shp / 15,531 Kw = 30.53 kts
   Range 3,000nm at 12.00 kts
   Bunker at max displacement = 134 tons

Complement:
   98 - 128

Cost:
   £0.405 million / $1.618 million

Distribution of weights at normal displacement:
   Armament: 54 tons, 4.7 %
   Armour: 7 tons, 0.6 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 7 tons, 0.6 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 0 tons, 0.0 %
   Machinery: 486 tons, 42.0 %
   Hull, fittings & equipment: 425 tons, 36.8 %
   Fuel, ammunition & stores: 155 tons, 13.4 %
   Miscellaneous weights: 28 tons, 2.4 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     285 lbs / 129 Kg = 2.6 x 6.0 " / 152 mm shells or 0.3 torpedoes
   Stability (Unstable if below 1.00): 1.18
   Metacentric height 1.3 ft / 0.4 m
   Roll period: 12.2 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.76
   Seaboat quality  (Average = 1.00): 0.63

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.424
   Length to Beam Ratio: 11.67 : 1
   'Natural speed' for length: 19.62 kts
   Power going to wave formation at top speed: 57 %
   Trim (Max stability = 0, Max steadiness = 100): 78
   Bow angle (Positive = bow angles forward): 32.00 degrees
   Stern overhang: 0.50 ft / 0.15 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      12.00 ft / 3.66 m
      - Forecastle (15 %):   11.00 ft / 3.35 m
      - Mid (50 %):      9.00 ft / 2.74 m
      - Quarterdeck (10 %):   8.00 ft / 2.44 m
      - Stern:      8.00 ft / 2.44 m
      - Average freeboard:   9.41 ft / 2.87 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 176.0 %
      - Above water (accommodation/working, high = better): 118.9 %
   Waterplane Area: 7,945 Square feet or 738 Square metres
   Displacement factor (Displacement / loading): 61 %
   Structure weight / hull surface area: 37 lbs/sq ft or 183 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.55
      - Longitudinal: 0.49
      - Overall: 0.50
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is adequate
   Caution: Lacks seaworthiness - very limited seakeeping ability

[Nobody]

I just remembered that the French had unusually large fillers in their projectiles (over 10% of the shell weight).

	[kg]	explosive filler [%]	Length [calibers]
French 33 cm APC	560	3.6	5
French 33 cm HE	552	11.8	5
possible 6" HC	54.4	11.8	5

You could also base it on the 155 mm NATO guns which fire a 100 lbs HE (does anyone have more data about it?) which might have a ~17% filler and very thin walls. However the combination of large filler and high shell weight is impossible. Even if you fire a 4 caliber long solid (iron) cylinder (no filler at all!) its weight would hardly exceed 89 kg.

B.t.w: How did you evaluate those penetration numbers in your news thread? Some of them look questionable.

[Logi]

NAaB. Penetration vs Vertical belt.
P3D's Ballistic Program for Muzzle Velocity.

The thing is heavy shell weights are perfectly possible, they are just much longer than a normal shell. Hence the conclusion, it can not be adequately spin-stabilized. (The length of a 200lb shell would be too long)

[Guinness]

mount and hoist can include enclosed gunhouses, imho, so I don't think you need turrets on barbettes, which are likely impractical for single 6" guns anyway (the barbettes would probably be pretty small).

You could use mount and hoist but only armor the mounts. Although, on a ship like this, I'd be tempted to use completely unenclosed mounts at least aft, just to keep topweight down.

Still mounting even a "normal" 6" gun on such a ship is iffy to me. I think you definitely want more BC and forward freeboard so that there could be more flotation forward, otherwise this ship will dig into the waves. I'd also consider not having a superfiring arrangement forward for the same reason.