Logi's Design Studies

[Logi]

The Superstructure is unusual - any particular reason for the large raised section on the big tripod (?) structure. Does look rather top heavy - Jean Bart had something looked a bit like that but was a lot smaller.

The forward big tripod structure just came out that way. It was supposed to be smaller. I guess I'll see what I can do to fix the picture.

How about integrating the 'tripod' and 'topbox' into the rear of the fwd superstructure - giving mutual support

Will look into it.

Also - would give more space for funnels - looks like current funnels - very close together would involve a lot of trunking / all boilers together - bad for damage control.

There was a lack of space on the ship. However fixing the forward bridge's size should fix this.

[Jefgte]

Place the tripod on the bridge to have the funnels more forward.


;)

[Logi]

An idea I had, purpose is to provide cover fire during a landing on a port. I have a feeling this will get an NEDS but I'm not too sure.

Arrangement of guns 
          T                             T
T - T - S - F - T - F - T - F - S - T - T
          T                             T

T= Turret  S= Superstructure    F = Funnel

Bombardier, RRC Port Assault Ship laid down 1916 (Engine 1912)

Displacement:
   409 t light; 450 t standard; 725 t normal; 945 t full load

Dimensions: Length overall / water x beam x draught
   300.00 ft / 300.00 ft x 30.00 ft x 6.00 ft (normal load)
   91.44 m / 91.44 m x 9.14 m  x 1.83 m

Armament:
      4 - 2.95" / 75.0 mm guns in single mounts, 12.87lbs / 5.84kg shells, 1916 Model
     Breech loading guns in casemate mounts
     on centreline ends, evenly spread, 2 raised mounts - superfiring
      4 - 2.95" / 75.0 mm guns in single mounts, 12.87lbs / 5.84kg shells, 1916 Model
     Breech loading guns in casemate mounts
     on side, evenly spread
      2 - 2.95" / 75.0 mm guns in single mounts, 12.87lbs / 5.84kg shells, 1916 Model
     Breech loading guns in casemate mounts
     on centreline, all amidships
   Weight of broadside 129 lbs / 58 kg
   Shells per gun, main battery: 300

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   3.00" / 76 mm   1.00" / 25 mm      1.00" / 25 mm
   2nd:   3.00" / 76 mm   1.00" / 25 mm      1.00" / 25 mm
   3rd:   3.00" / 76 mm   1.00" / 25 mm      1.00" / 25 mm

Machinery:
   Coal fired boilers, steam turbines,
   Direct drive, 2 shafts, 3,402 shp / 2,538 Kw = 20.00 kts
   Range 8,000nm at 12.00 kts
   Bunker at max displacement = 496 tons (100% coal)

Complement:
   69 - 90

Cost:
   £0.080 million / $0.319 million

Distribution of weights at normal displacement:
   Armament: 16 tons, 2.2 %
   Armour: 45 tons, 6.3 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 45 tons, 6.3 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 0 tons, 0.0 %
   Machinery: 149 tons, 20.6 %
   Hull, fittings & equipment: 174 tons, 24.0 %
   Fuel, ammunition & stores: 316 tons, 43.5 %
   Miscellaneous weights: 25 tons, 3.4 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     852 lbs / 386 Kg = 66.2 x 3.0 " / 75 mm shells or 0.6 torpedoes
   Stability (Unstable if below 1.00): 1.94
   Metacentric height 2.4 ft / 0.7 m
   Roll period: 8.2 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.09
   Seaboat quality  (Average = 1.00): 1.41

Hull form characteristics:
   Hull has rise aft of midbreak
   Block coefficient: 0.470
   Length to Beam Ratio: 10.00 : 1
   'Natural speed' for length: 17.32 kts
   Power going to wave formation at top speed: 44 %
   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 (% = measuring location as a percentage of overall length):
      - Stem:      12.00 ft / 3.66 m
      - Forecastle (20 %):   11.00 ft / 3.35 m
      - Mid (50 %):      7.00 ft / 2.13 m (10.00 ft / 3.05 m aft of break)
      - Quarterdeck (15 %):   7.00 ft / 2.13 m
      - Stern:      7.00 ft / 2.13 m
      - Average freeboard:   9.01 ft / 2.74 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 90.4 %
      - Above water (accommodation/working, high = better): 140.7 %
   Waterplane Area: 5,838 Square feet or 542 Square metres
   Displacement factor (Displacement / loading): 146 %
   Structure weight / hull surface area: 21 lbs/sq ft or 103 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.51
      - Longitudinal: 0.50
      - Overall: 0.51
   Caution: Hull subject to strain in open-sea
   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
   Good seaboat, rides out heavy weather easily

Trial Speed: 21.15 kts

[maddox]

That's a nasty piece of work. A sloop ideal for river purposes.

[mentat]

Yes - agree with above - a little porcupine - and given she will be in the thick of things as well as the great handling characteristics - I think there might be scope to add a little splinter protection to the bridge and say 2 small CTs - as well as possibly upgrading the centreline ends to be 4" - for a bit extra firepower and range 

[Logi]

Its going to double in weight with that stuff added, I don't care for the extra weight. I'm pretty sure I don't have a 4" gun only a 120mm one, I could be wrong though.
The point is these ships could be mass produced to bombard the harbour or land (whatever they are).

But here's the ss with the suggestions anyways. (btw what are CTs? Forgive my question)

Bombardier, RRC Port Assault Ship laid down 1916 (Engine 1912)

Displacement:
   884 t light; 979 t standard; 1,377 t normal; 1,695 t full load

Dimensions: Length overall / water x beam x draught
   300.00 ft / 300.00 ft x 30.00 ft x 9.00 ft (normal load)
   91.44 m / 91.44 m x 9.14 m  x 2.74 m

Armament:
      4 - 4.72" / 120 mm guns in single mounts, 52.72lbs / 23.92kg shells, 1916 Model
     Breech loading guns in casemate mounts
     on centreline ends, evenly spread, 2 raised mounts - superfiring
      4 - 2.95" / 75.0 mm guns in single mounts, 12.87lbs / 5.84kg shells, 1916 Model
     Breech loading guns in casemate mounts
     on side, evenly spread
      2 - 4.72" / 120 mm guns in single mounts, 52.72lbs / 23.92kg shells, 1916 Model
     Breech loading guns in casemate mounts
     on centreline, all amidships
   Weight of broadside 368 lbs / 167 kg
   Shells per gun, main battery: 300

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   2.00" / 51 mm   300.00 ft / 91.44 m   10.00 ft / 3.05 m
   Ends:   Unarmoured
     Main Belt covers 154 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   3.00" / 76 mm   1.00" / 25 mm      1.00" / 25 mm
   2nd:   3.00" / 76 mm   1.00" / 25 mm      1.00" / 25 mm
   3rd:   3.00" / 76 mm   1.00" / 25 mm      1.00" / 25 mm

   - Armour deck: 0.50" / 13 mm, Conning tower: 2.00" / 51 mm

Machinery:
   Coal fired boilers, steam turbines,
   Direct drive, 2 shafts, 5,183 shp / 3,867 Kw = 20.00 kts
   Range 8,000nm at 12.00 kts
   Bunker at max displacement = 716 tons (100% coal)

Complement:
   112 - 146

Cost:
   £0.166 million / $0.664 million

Distribution of weights at normal displacement:
   Armament: 46 tons, 3.3 %
   Armour: 354 tons, 25.7 %
      - Belts: 222 tons, 16.1 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 66 tons, 4.8 %
      - Armour Deck: 61 tons, 4.4 %
      - Conning Tower: 5 tons, 0.4 %
   Machinery: 227 tons, 16.5 %
   Hull, fittings & equipment: 231 tons, 16.8 %
   Fuel, ammunition & stores: 493 tons, 35.8 %
   Miscellaneous weights: 25 tons, 1.8 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1,182 lbs / 536 Kg = 22.4 x 4.7 " / 120 mm shells or 0.7 torpedoes
   Stability (Unstable if below 1.00): 1.71
   Metacentric height 2.0 ft / 0.6 m
   Roll period: 8.9 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.24
   Seaboat quality  (Average = 1.00): 1.34

Hull form characteristics:
   Hull has rise aft of midbreak
   Block coefficient: 0.595
   Length to Beam Ratio: 10.00 : 1
   'Natural speed' for length: 17.32 kts
   Power going to wave formation at top speed: 50 %
   Trim (Max stability = 0, Max steadiness = 100): 52
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      12.00 ft / 3.66 m
      - Forecastle (20 %):   11.00 ft / 3.35 m
      - Mid (50 %):      7.00 ft / 2.13 m (10.00 ft / 3.05 m aft of break)
      - Quarterdeck (15 %):   7.00 ft / 2.13 m
      - Stern:      7.00 ft / 2.13 m
      - Average freeboard:   9.01 ft / 2.74 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 84.7 %
      - Above water (accommodation/working, high = better): 97.3 %
   Waterplane Area: 6,552 Square feet or 609 Square metres
   Displacement factor (Displacement / loading): 115 %
   Structure weight / hull surface area: 24 lbs/sq ft or 116 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.51
      - Longitudinal: 0.51
      - Overall: 0.51
   Caution: Hull subject to strain in open-sea
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is adequate
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

[maddox]

CT= conning tower.

With so much guns,  why not remove the 75mm's and replace them with machine gun nests- I know the MK has a nice 25mm twin, and use the weight and space freed for a destroyer FC setup? 

with the 4 75mm's removed and the machine guns in superfiring positions, the midships  becomes available for an extra 120mm gun.

Also, the MK has the following guns.

10mm rifle
25mm heavy machine gun
75mm QF
105mm QF
140mm BL L45
195 BL L45 (French pattern- Phoenix has a story somewere about these guns)
250mm BL L35- also used on the many  railguns the MK had
330mm BL L35 - ACM Macau technology- if you capture the arsenal and manufactoring capacity and the people willingly working it , it tends to boost the R&D.

[Logi]

hmm I'm also sure they have a 120mm, I've seen it on many of their ships.

I will try the design tomorrow.

[Guinness]

I'd thin the shields on the 75 mms a little bit to save weight for a CT. 3" is probably overkill for the planned environment. 2.5" or 2" should suffice against all small arms and splinters.

[mentat]

Fun topic - and you seem very serious on your intents in this direction - 'can be mass produced'

Given that - why not go for a hi-low mix?


  'Nasty' Bombardier - 500 ton version - for close in work

   6 x 75mmQF (on the centre lines) - very quick rate of fire
   4 x 25mm Hvy Cannon MGs - in the wing positions

   + vs original spec. might need an MG proof Upper Belt - 30mm  - as well as light Bridge/CT protn


   'Baaaddd' Bombardier  -  1000 ton version - to back up little Bro'

     4 x 105mm QF superfiring centreline ends and amidships
     4 x 75mm QF wing positions 
 
    + For indirect fire needs - (impt for some land targets) - 2 Large Mortars (6"?) -  centreline ends



Say have 3 of each of these - and team them up in pairs ... ... very Rambo ...

[Logi]

@ Maddox

The ship already has 25t allocated to a destroy FC ;)

Here's the design with your suggestions:

Bombardier, RRC Port Assault Ship laid down 1916 (Engine 1912)

Displacement:
   874 t light; 970 t standard; 1,365 t normal; 1,682 t full load

Dimensions: Length overall / water x beam x draught
   300.00 ft / 300.00 ft x 30.00 ft x 9.00 ft (normal load)
   91.44 m / 91.44 m x 9.14 m  x 2.74 m

Armament:
      4 - 4.72" / 120 mm guns in single mounts, 52.72lbs / 23.91kg shells, 1916 Model
     Breech loading guns in casemate mounts
     on centreline ends, evenly spread, 2 raised mounts - superfiring
      8 - 0.98" / 25.0 mm guns (4x2 guns), 0.48lbs / 0.22kg shells, 1916 Model
     Breech loading guns in deck mounts
     on side, evenly spread, all raised mounts
      3 - 4.72" / 120 mm guns in single mounts, 52.72lbs / 23.91kg shells, 1916 Model
     Breech loading guns in casemate mounts
     on centreline, all amidships
   Weight of broadside 373 lbs / 169 kg
   Shells per gun, main battery: 300

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   2.00" / 51 mm   300.00 ft / 91.44 m   10.00 ft / 3.05 m
   Ends:   Unarmoured
     Main Belt covers 154 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   3.00" / 76 mm   1.00" / 25 mm      1.00" / 25 mm
   2nd:   1.00" / 25 mm         -               -
   3rd:   3.00" / 76 mm   1.00" / 25 mm      1.00" / 25 mm

   - Armour deck: 0.50" / 13 mm, Conning tower: 2.00" / 51 mm

Machinery:
   Coal fired boilers, steam turbines,
   Direct drive, 2 shafts, 5,146 shp / 3,839 Kw = 20.00 kts
   Range 8,000nm at 12.00 kts
   Bunker at max displacement = 712 tons (100% coal)

Complement:
   112 - 146

Cost:
   £0.166 million / $0.663 million

Distribution of weights at normal displacement:
   Armament: 47 tons, 3.4 %
   Armour: 346 tons, 25.4 %
      - Belts: 222 tons, 16.3 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 59 tons, 4.3 %
      - Armour Deck: 60 tons, 4.4 %
      - Conning Tower: 5 tons, 0.4 %
   Machinery: 226 tons, 16.5 %
   Hull, fittings & equipment: 231 tons, 16.9 %
   Fuel, ammunition & stores: 491 tons, 36.0 %
   Miscellaneous weights: 25 tons, 1.8 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1,161 lbs / 527 Kg = 22.0 x 4.7 " / 120 mm shells or 0.7 torpedoes
   Stability (Unstable if below 1.00): 1.70
   Metacentric height 2.0 ft / 0.6 m
   Roll period: 9.0 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.25
   Seaboat quality  (Average = 1.00): 1.34

Hull form characteristics:
   Hull has rise aft of midbreak
   Block coefficient: 0.590
   Length to Beam Ratio: 10.00 : 1
   'Natural speed' for length: 17.32 kts
   Power going to wave formation at top speed: 50 %
   Trim (Max stability = 0, Max steadiness = 100): 52
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      12.00 ft / 3.66 m
      - Forecastle (20 %):   11.00 ft / 3.35 m
      - Mid (50 %):      7.00 ft / 2.13 m (10.00 ft / 3.05 m aft of break)
      - Quarterdeck (15 %):   7.00 ft / 2.13 m
      - Stern:      7.00 ft / 2.13 m
      - Average freeboard:   9.01 ft / 2.74 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 85.4 %
      - Above water (accommodation/working, high = better): 96.8 %
   Waterplane Area: 6,521 Square feet or 606 Square metres
   Displacement factor (Displacement / loading): 114 %
   Structure weight / hull surface area: 24 lbs/sq ft or 116 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.51
      - Longitudinal: 0.51
      - Overall: 0.51
   Caution: Hull subject to strain in open-sea
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is adequate
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

@ guinness

I was thinking about that. here the design with YOUR suggestions:

Bombardier, RRC Port Assault Ship laid down 1916 (Engine 1912)

Displacement:
   849 t light; 944 t standard; 1,333 t normal; 1,644 t full load

Dimensions: Length overall / water x beam x draught
   300.00 ft / 300.00 ft x 30.00 ft x 9.00 ft (normal load)
   91.44 m / 91.44 m x 9.14 m  x 2.74 m

Armament:
      4 - 4.72" / 120 mm guns in single mounts, 52.72lbs / 23.91kg shells, 1916 Model
     Breech loading guns in casemate mounts
     on centreline ends, evenly spread, 2 raised mounts - superfiring
      4 - 2.95" / 75.0 mm guns in single mounts, 12.87lbs / 5.84kg shells, 1916 Model
     Breech loading guns in casemate mounts
     on side, evenly spread
      2 - 4.72" / 120 mm guns in single mounts, 52.72lbs / 23.91kg shells, 1916 Model
     Breech loading guns in casemate mounts
     on centreline, all amidships
   Weight of broadside 368 lbs / 167 kg
   Shells per gun, main battery: 300

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   2.00" / 51 mm   300.00 ft / 91.44 m   10.00 ft / 3.05 m
   Ends:   Unarmoured
     Main Belt covers 154 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   2.00" / 51 mm   1.00" / 25 mm      1.00" / 25 mm
   2nd:   2.00" / 51 mm   1.00" / 25 mm      1.00" / 25 mm
   3rd:   2.00" / 51 mm   1.00" / 25 mm      1.00" / 25 mm

   - Armour deck: 0.50" / 13 mm, Conning tower: 2.00" / 51 mm

Machinery:
   Coal fired boilers, steam turbines,
   Direct drive, 2 shafts, 5,042 shp / 3,762 Kw = 20.00 kts
   Range 8,000nm at 12.00 kts
   Bunker at max displacement = 700 tons (100% coal)

Complement:
   109 - 143

Cost:
   £0.163 million / $0.650 million

Distribution of weights at normal displacement:
   Armament: 46 tons, 3.4 %
   Armour: 331 tons, 24.8 %
      - Belts: 222 tons, 16.7 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 44 tons, 3.3 %
      - Armour Deck: 60 tons, 4.5 %
      - Conning Tower: 5 tons, 0.4 %
   Machinery: 221 tons, 16.6 %
   Hull, fittings & equipment: 226 tons, 17.0 %
   Fuel, ammunition & stores: 484 tons, 36.3 %
   Miscellaneous weights: 25 tons, 1.9 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1,132 lbs / 513 Kg = 21.5 x 4.7 " / 120 mm shells or 0.7 torpedoes
   Stability (Unstable if below 1.00): 1.71
   Metacentric height 2.0 ft / 0.6 m
   Roll period: 8.9 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.25
   Seaboat quality  (Average = 1.00): 1.37

Hull form characteristics:
   Hull has rise aft of midbreak
   Block coefficient: 0.576
   Length to Beam Ratio: 10.00 : 1
   'Natural speed' for length: 17.32 kts
   Power going to wave formation at top speed: 49 %
   Trim (Max stability = 0, Max steadiness = 100): 51
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      12.00 ft / 3.66 m
      - Forecastle (20 %):   11.00 ft / 3.35 m
      - Mid (50 %):      7.00 ft / 2.13 m (10.00 ft / 3.05 m aft of break)
      - Quarterdeck (15 %):   7.00 ft / 2.13 m
      - Stern:      7.00 ft / 2.13 m
      - Average freeboard:   9.01 ft / 2.74 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 86.0 %
      - Above water (accommodation/working, high = better): 98.2 %
   Waterplane Area: 6,436 Square feet or 598 Square metres
   Displacement factor (Displacement / loading): 114 %
   Structure weight / hull surface area: 23 lbs/sq ft or 115 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.51
      - Longitudinal: 0.52
      - Overall: 0.51
   Caution: Hull subject to strain in open-sea
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is adequate
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

@ mentat

Close in Work Bombardier

Bombardier, RRC Port Assault Ship laid down 1916 (Engine 1912)

Displacement:
   500 t light; 532 t standard; 824 t normal; 1,058 t full load

Dimensions: Length overall / water x beam x draught
   300.00 ft / 300.00 ft x 30.00 ft x 7.00 ft (normal load)
   91.44 m / 91.44 m x 9.14 m  x 2.13 m

Armament:
      4 - 2.95" / 75.0 mm guns in single mounts, 12.87lbs / 5.84kg shells, 1916 Model
     Breech loading guns in casemate mounts
     on centreline ends, evenly spread, 2 raised mounts - superfiring
      8 - 0.98" / 25.0 mm guns (4x2 guns), 0.48lbs / 0.22kg shells, 1916 Model
     Breech loading guns in deck mounts
     on side, evenly spread, all raised mounts
      2 - 2.95" / 75.0 mm guns in single mounts, 12.87lbs / 5.84kg shells, 1916 Model
     Breech loading guns in casemate mounts
     on centreline, all amidships
   Weight of broadside 81 lbs / 37 kg
   Shells per gun, main battery: 300

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Ends:   Unarmoured
   Upper:   1.20" / 30 mm   300.00 ft / 91.44 m   8.00 ft / 2.44 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   2.00" / 51 mm   1.00" / 25 mm      1.00" / 25 mm
   2nd:   1.00" / 25 mm         -               -
   3rd:   2.00" / 51 mm   1.00" / 25 mm      1.00" / 25 mm

   - Conning tower: 2.00" / 51 mm

Machinery:
   Coal fired boilers, steam turbines,
   Direct drive, 2 shafts, 3,620 shp / 2,701 Kw = 20.00 kts
   Range 8,000nm at 12.00 kts
   Bunker at max displacement = 526 tons (100% coal)

Complement:
   76 - 100

Cost:
   £0.079 million / $0.316 million

Distribution of weights at normal displacement:
   Armament: 10 tons, 1.2 %
   Armour: 131 tons, 15.9 %
      - Belts: 107 tons, 12.9 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 21 tons, 2.6 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 4 tons, 0.5 %
   Machinery: 159 tons, 19.3 %
   Hull, fittings & equipment: 175 tons, 21.2 %
   Fuel, ammunition & stores: 324 tons, 39.3 %
   Miscellaneous weights: 25 tons, 3.0 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     966 lbs / 438 Kg = 75.1 x 3.0 " / 75 mm shells or 0.7 torpedoes
   Stability (Unstable if below 1.00): 1.66
   Metacentric height 1.9 ft / 0.6 m
   Roll period: 9.1 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.07
   Seaboat quality  (Average = 1.00): 1.46

Hull form characteristics:
   Hull has rise aft of midbreak
   Block coefficient: 0.458
   Length to Beam Ratio: 10.00 : 1
   'Natural speed' for length: 17.32 kts
   Power going to wave formation at top speed: 45 %
   Trim (Max stability = 0, Max steadiness = 100): 48
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      12.00 ft / 3.66 m
      - Forecastle (20 %):   11.00 ft / 3.35 m
      - Mid (50 %):      7.00 ft / 2.13 m (10.00 ft / 3.05 m aft of break)
      - Quarterdeck (15 %):   7.00 ft / 2.13 m
      - Stern:      7.00 ft / 2.13 m
      - Average freeboard:   9.01 ft / 2.74 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 77.2 %
      - Above water (accommodation/working, high = better): 126.5 %
   Waterplane Area: 5,779 Square feet or 537 Square metres
   Displacement factor (Displacement / loading): 149 %
   Structure weight / hull surface area: 21 lbs/sq ft or 101 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.51
      - Longitudinal: 0.51
      - Overall: 0.51
   Caution: Hull subject to strain in open-sea
   Hull space for machinery, storage, compartmentation is excellent
   Room for accommodation and workspaces is excellent
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

'Baaaddd' Bombardier

Bombardier, RRC Port Assault Ship laid down 1916 (Engine 1912)

Displacement:
   1,000 t light; 1,101 t standard; 1,515 t normal; 1,846 t full load

Dimensions: Length overall / water x beam x draught
   300.00 ft / 300.00 ft x 30.00 ft x 11.00 ft (normal load)
   91.44 m / 91.44 m x 9.14 m  x 3.35 m

Armament:
      2 - 4.13" / 105 mm guns in single mounts, 35.32lbs / 16.02kg shells, 1916 Model
     Quick firing guns in casemate mounts
     on centreline ends, evenly spread
      2 - 5.51" / 140 mm guns in single mounts, 83.72lbs / 37.98kg shells, 1916 Model
     Breech loading guns in casemate mounts
     on centreline ends, evenly spread, all raised mounts
      2 - 4.13" / 105 mm guns in single mounts, 35.32lbs / 16.02kg shells, 1916 Model
     Breech loading guns in casemate mounts
     on centreline, all amidships
      4 - 2.95" / 75.0 mm guns in single mounts, 12.87lbs / 5.84kg shells, 1916 Model
     Breech loading guns in casemate mounts
     on side, evenly spread
   Weight of broadside 360 lbs / 163 kg
   Shells per gun, main battery: 300

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   2.00" / 51 mm   200.00 ft / 60.96 m   6.00 ft / 1.83 m
   Ends:   1.00" / 25 mm   100.00 ft / 30.48 m   6.00 ft / 1.83 m
     Main Belt covers 103 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   2.00" / 51 mm   1.00" / 25 mm      1.00" / 25 mm
   2nd:   2.00" / 51 mm   1.00" / 25 mm      1.00" / 25 mm
   3rd:   2.00" / 51 mm   1.00" / 25 mm      1.00" / 25 mm
   4th:   1.00" / 25 mm   1.00" / 25 mm      1.00" / 25 mm

   - Conning tower: 1.00" / 25 mm

Machinery:
   Coal fired boilers, steam turbines,
   Direct drive, 2 shafts, 5,338 shp / 3,982 Kw = 20.00 kts
   Range 8,000nm at 12.00 kts
   Bunker at max displacement = 745 tons (100% coal)

Complement:
   120 - 157

Cost:
   £0.173 million / $0.691 million

Distribution of weights at normal displacement:
   Armament: 45 tons, 3.0 %
   Armour: 162 tons, 10.7 %
      - Belts: 122 tons, 8.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 37 tons, 2.5 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 3 tons, 0.2 %
   Machinery: 234 tons, 15.5 %
   Hull, fittings & equipment: 459 tons, 30.3 %
   Fuel, ammunition & stores: 515 tons, 34.0 %
   Miscellaneous weights: 100 tons, 6.6 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1,960 lbs / 889 Kg = 55.5 x 4.1 " / 105 mm shells or 0.8 torpedoes
   Stability (Unstable if below 1.00): 1.31
   Metacentric height 1.3 ft / 0.4 m
   Roll period: 10.9 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.28
   Seaboat quality  (Average = 1.00): 1.10

Hull form characteristics:
   Hull has rise aft of midbreak
   Block coefficient: 0.536
   Length to Beam Ratio: 10.00 : 1
   'Natural speed' for length: 17.32 kts
   Power going to wave formation at top speed: 49 %
   Trim (Max stability = 0, Max steadiness = 100): 64
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      12.00 ft / 3.66 m
      - Forecastle (20 %):   10.00 ft / 3.05 m
      - Mid (50 %):      6.00 ft / 1.83 m (9.00 ft / 2.74 m aft of break)
      - Quarterdeck (15 %):   6.00 ft / 1.83 m
      - Stern:      6.00 ft / 1.83 m
      - Average freeboard:   8.09 ft / 2.46 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 83.7 %
      - Above water (accommodation/working, high = better): 76.0 %
   Waterplane Area: 6,196 Square feet or 576 Square metres
   Displacement factor (Displacement / loading): 139 %
   Structure weight / hull surface area: 48 lbs/sq ft or 234 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 1.02
      - Longitudinal: 0.99
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is cramped
   Ship has slow, easy roll, a good, steady gun platform

Problem is my nation's DD/TB is maxed at 500 tons. I can't 0.50 composite hull strength the larger ones.

[mentat]

  Nice work - I like all of them!

  Given you have to use 1.0 hull strength on the bigger version - how about 4 'Little Bros' (my favourite) backed up by 2 'Big Bros' - working in 2 teams

  BTW - the bigger calibre (140mm) - is that actual naval gun or sim for the mortar idea - if mortar - what size? ;D

(If mortar is not available  :(  - I think best to stick with 2 main calibres, the extra complication in FC seems worthwhile if achieve heavy indirect fire, but probably not if mortar not available)

I'm not expert - but I would expect mortar to be about x2 shell wt with much reduced mv

CT - on Baaadddd - armour has slipped to 1" - not sure why


  Whatever you choose - my sympathies to the poor victims  ....

[The Rock Doctor]

The range and speed of these ships seems excessive:  RRC doesn't have a need to project amphibious power that far (...that I'm aware of). 

[Logi]

@ Rock

Destroyer and TB architecture - Top speed no less than 20kts, composite hull strength > 0.49

Note that DDs must have aleast 20kts of speed. If I lowered the speed I would have to build the ship to 1.00 composite hull strength. That was acutally my first design and I lost 8kts in exchange for 50 tons. Not a good trade if you ask me.

As for the speed, 8000nm @ 12kts becomes 2100nm @ 20kts. 2100nm (1050nm if one can't refuel) isn't all that long of a distance. At best it allows the ships to come close (a few hundred more nm needed) to reaching NS and Firanji.

BTW - the bigger calibre (140mm) - is that actual naval gun or sim for the mortar idea - if mortar - what size?

140mm BL L45
Its an actual naval gun.

I'm not expert - but I would expect mortar to be about x2 shell wt with much reduced mv

Makes sense but i don't know if I can adjust the weight of a shell that much on a predesigned naval gun.

[mentat]

Re - Mortar - seems a neat idea in this case (and some of your neighbours are also considering)

I don't know where you could build/obtain - but I think is a fairly low tech even though heavy item

Re simming - I think it would be case of simming:

Weight - eg 5.5" gun for 6" mortar?

Recoil - due to high angle (40-60 degrees) lateral recoil will be less but downward recoil greater - possibly call for some local strengthening around the barbette/turret - perhaps consult the moderators on this ...