TGBs studies

Jefgte · June 19, 2018, 04:09:06 PM

I have studying the futur of TGBs with the
"Destroyer, Torpedo Boat, and Motor Torpedo Boat Architecture:
...1912: max displacement 1500t Type C, D MTB... "
Always 50% weight for engines.

TGB1500-3x152, Byzantine Empire TGB1500 laid down 1915

Displacement:
   1 500 t light; 1 579 t standard; 1 750 t normal; 1 886 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (390,00 ft / 390,00 ft) x 42,00 ft x (9,03 / 9,50 ft)
   (118,87 m / 118,87 m) x 12,80 m x (2,75 / 2,90 m)

Armament:
3 - 6,00" / 152 mm 45,0 cal guns - 108,93lbs / 49,41kg shells, 140 per gun
     Quick firing guns in deck mounts, 1915 Model
     3 x Single mounts on centreline, evenly spread
4 - 4,00" / 102 mm 45,0 cal guns - 32,28lbs / 14,64kg shells, 250 per gun
     Quick firing guns in deck mounts, 1915 Model
     4 x Single mounts on side ends, evenly spread
2 - 0,30" / 7,7 mm 92,0 cal guns - 0,02lbs / 0,01kg shells, 5 000 per gun
     Machine guns in deck mounts, 1915 Model
     2 x Single mounts on sides, forward deck forward
Weight of broadside 456 lbs / 207 kg

Armour:
- Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0,47" / 12 mm     -           -
   3rd:   0,39" / 10 mm     -           -
   4th:   0,39" / 10 mm     -           -

Machinery:
   Coal and oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 26 800 shp / 19 993 Kw = 30,32 kts
   Range 5 000nm at 10,00 kts
   Bunker at max displacement = 308 tons (90% coal)

Complement:
   134 - 175

Cost:
   £0,286 million / $1,145 million

Distribution of weights at normal displacement:
   Armament: 79 tons, 4,5 %
     - Guns: 79 tons, 4,5 %
   Armour: 10 tons, 0,6 %
     - Armament: 10 tons, 0,6 %
   Machinery: 875 tons, 50,0 %
   Hull, fittings & equipment: 457 tons, 26,1 %
   Fuel, ammunition & stores: 249 tons, 14,3 %
   Miscellaneous weights: 80 tons, 4,6 %
     - On freeboard deck: 68 tons
     - Above deck: 12 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     591 lbs / 268 Kg = 5,5 x 6,0 " / 152 mm shells or 0,4 torpedoes
   Stability (Unstable if below 1.00): 1,36
   Metacentric height 2,3 ft / 0,7 m
   Roll period: 11,5 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0,19
   Seaboat quality (Average = 1.00): 1,00

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0,414 / 0,424
   Length to Beam Ratio: 9,29 : 1
   'Natural speed' for length: 19,75 kts
   Power going to wave formation at top speed: 60 %
   Trim (Max stability = 0, Max steadiness = 100): 70
   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:   22,00 %, 18,00 ft / 5,49 m, 16,20 ft / 4,94 m
     - Forward deck:   25,00 %, 16,20 ft / 4,94 m, 14,00 ft / 4,27 m
     - Aft deck:   38,00 %, 14,00 ft / 4,27 m, 13,00 ft / 3,96 m
     - Quarter deck:   15,00 %, 13,00 ft / 3,96 m, 12,00 ft / 3,66 m
     - Average freeboard:      14,50 ft / 4,42 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 174,4 %
      - Above water (accommodation/working, high = better): 204,3 %
   Waterplane Area: 10 170 Square feet or 945 Square metres
   Displacement factor (Displacement / loading): 70 %
   Structure weight / hull surface area: 33 lbs/sq ft or 161 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,50
      - Longitudinal: 0,91
      - Overall: 0,53
   Cramped machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform

10t for Marconi
2t for top mast rangefinder
16t for 4xTT x 450
52t reserved

Jefgte · June 19, 2018, 04:29:22 PM

"Destroyer, Torpedo Boat, and Motor Torpedo Boat Architecture:
...1918: quad TTs, 2000t Type E, F MTB "

TGB2000-3x191, Byzantine Empire TGB2000 laid down 1921

Displacement:
   2 000 t light; 2 117 t standard; 2 300 t normal; 2 446 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (400,00 ft / 400,00 ft) x 42,12 ft x (11,54 / 12,03 ft)
   (121,92 m / 121,92 m) x 12,84 m x (3,52 / 3,67 m)

Armament:
3 - 7,50" / 191 mm 45,0 cal guns - 212,75lbs / 96,50kg shells, 140 per gun
     Breech loading guns in deck mounts, 1921 Model
     3 x Single mounts on centreline, evenly spread
4 - 4,00" / 102 mm 45,0 cal guns - 32,28lbs / 14,64kg shells, 240 per gun
     Quick firing guns in deck mounts, 1921 Model
     4 x Single mounts on side ends, evenly spread
4 - 1,46" / 37,0 mm 45,0 cal guns - 1,57lbs / 0,71kg shells, 1 200 per gun
     Anti-air guns in deck mounts, 1921 Model
     4 x Single mounts on sides, forward evenly spread
      4 raised mounts
2 - 0,30" / 7,7 mm 92,0 cal guns - 0,02lbs / 0,01kg shells, 5 000 per gun
     Machine guns in deck mounts, 1921 Model
     2 x Single mounts on sides, forward deck forward
Weight of broadside 774 lbs / 351 kg

Armour:
- Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   1,20" / 30 mm     -           -
   3rd:   0,39" / 10 mm     -           -
   4th:   0,39" / 10 mm     -           -

Machinery:
   Coal and oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 39 700 shp / 29 616 Kw = 32,15 kts
   Range 7 000nm at 10,00 kts
   Bunker at max displacement = 329 tons (20% coal)

Complement:
   165 - 215

Cost:
   £0,681 million / $2,724 million

Distribution of weights at normal displacement:
   Armament: 118 tons, 5,1 %
     - Guns: 118 tons, 5,1 %
   Armour: 15 tons, 0,7 %
     - Armament: 15 tons, 0,7 %
   Machinery: 1 149 tons, 50,0 %
   Hull, fittings & equipment: 585 tons, 25,4 %
   Fuel, ammunition & stores: 300 tons, 13,0 %
   Miscellaneous weights: 133 tons, 5,8 %
     - On freeboard deck: 96 tons
     - Above deck: 37 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     668 lbs / 303 Kg = 3,2 x 7,5 " / 191 mm shells or 0,4 torpedoes
   Stability (Unstable if below 1.00): 1,26
   Metacentric height 2,1 ft / 0,6 m
   Roll period: 12,3 seconds
   Steadiness   - As gun platform (Average = 50 %): 73 %
         - Recoil effect (Restricted arc if above 1.00): 0,36
   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): 0,414 / 0,422
   Length to Beam Ratio: 9,50 : 1
   'Natural speed' for length: 20,00 kts
   Power going to wave formation at top speed: 63 %
   Trim (Max stability = 0, Max steadiness = 100): 69
   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 %, 20,00 ft / 6,10 m, 18,00 ft / 5,49 m
     - Forward deck:   25,00 %, 18,00 ft / 5,49 m, 15,00 ft / 4,57 m
     - Aft deck:   40,00 %, 15,00 ft / 4,57 m, 14,00 ft / 4,27 m
     - Quarter deck:   15,00 %, 14,00 ft / 4,27 m, 13,00 ft / 3,96 m
     - Average freeboard:      15,71 ft / 4,79 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 177,8 %
      - Above water (accommodation/working, high = better): 184,4 %
   Waterplane Area: 10 461 Square feet or 972 Square metres
   Displacement factor (Displacement / loading): 70 %
   Structure weight / hull surface area: 38 lbs/sq ft or 183 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,50
      - Longitudinal: 1,23
      - Overall: 0,55
   Cramped machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform

25t for Marconi
12t for fire control
16t for 4xTT x 450
80t reserved

Jefgte · June 19, 2018, 04:44:41 PM

"Destroyer, Torpedo Boat, and Motor Torpedo Boat Architecture:
...1918: quad TTs, 2000t Type E, F MTB "

TGB2000-4x152, Byzantine Empire TGB2000 laid down 1921

Displacement:
   2 000 t light; 2 103 t standard; 2 285 t normal; 2 431 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (400,00 ft / 400,00 ft) x 42,12 ft x (11,47 / 11,95 ft)
   (121,92 m / 121,92 m) x 12,84 m x (3,49 / 3,64 m)

Armament:
4 - 6,00" / 152 mm 45,0 cal guns - 108,92lbs / 49,41kg shells, 150 per gun
     Breech loading guns in deck mounts, 1921 Model
     4 x Single mounts on centreline ends, evenly spread
      2 raised mounts - superfiring
4 - 4,00" / 102 mm 45,0 cal guns - 32,28lbs / 14,64kg shells, 240 per gun
     Quick firing guns in deck mounts, 1921 Model
     4 x Single mounts on side ends, evenly spread
4 - 1,46" / 37,0 mm 45,0 cal guns - 1,57lbs / 0,71kg shells, 1 200 per gun
     Anti-air guns in deck mounts, 1921 Model
     4 x Single mounts on sides, forward evenly spread
      4 raised mounts
2 - 0,30" / 7,7 mm 92,0 cal guns - 0,02lbs / 0,01kg shells, 5 000 per gun
     Machine guns in deck mounts, 1921 Model
     2 x Single mounts on sides, forward deck forward
Weight of broadside 571 lbs / 259 kg

Armour:
- Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   1,20" / 30 mm     -           -
   3rd:   0,39" / 10 mm     -           -
   4th:   0,39" / 10 mm     -           -

Machinery:
   Coal and oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 38 800 shp / 28 945 Kw = 32,00 kts
   Range 7 000nm at 10,00 kts
   Bunker at max displacement = 327 tons (20% coal)

Complement:
   164 - 214

Cost:
   £0,654 million / $2,618 million

Distribution of weights at normal displacement:
   Armament: 90 tons, 3,9 %
     - Guns: 90 tons, 3,9 %
   Armour: 17 tons, 0,7 %
     - Armament: 17 tons, 0,7 %
   Machinery: 1 141 tons, 50,0 %
   Hull, fittings & equipment: 591 tons, 25,9 %
   Fuel, ammunition & stores: 285 tons, 12,5 %
   Miscellaneous weights: 160 tons, 7,0 %
     - On freeboard deck: 126 tons
     - Above deck: 34 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     692 lbs / 314 Kg = 6,4 x 6,0 " / 152 mm shells or 0,4 torpedoes
   Stability (Unstable if below 1.00): 1,24
   Metacentric height 2,0 ft / 0,6 m
   Roll period: 12,4 seconds
   Steadiness   - As gun platform (Average = 50 %): 73 %
         - Recoil effect (Restricted arc if above 1.00): 0,32
   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): 0,414 / 0,422
   Length to Beam Ratio: 9,50 : 1
   'Natural speed' for length: 20,00 kts
   Power going to wave formation at top speed: 62 %
   Trim (Max stability = 0, Max steadiness = 100): 69
   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 %, 20,00 ft / 6,10 m, 18,00 ft / 5,49 m
     - Forward deck:   25,00 %, 18,00 ft / 5,49 m, 15,00 ft / 4,57 m
     - Aft deck:   40,00 %, 15,00 ft / 4,57 m, 14,00 ft / 4,27 m
     - Quarter deck:   15,00 %, 14,00 ft / 4,27 m, 13,00 ft / 3,96 m
     - Average freeboard:      15,71 ft / 4,79 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 173,9 %
      - Above water (accommodation/working, high = better): 185,5 %
   Waterplane Area: 10 461 Square feet or 972 Square metres
   Displacement factor (Displacement / loading): 72 %
   Structure weight / hull surface area: 37 lbs/sq ft or 181 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,50
      - Longitudinal: 1,22
      - Overall: 0,55
   Cramped machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform

25t for Marconi
9t for fire control
16t for 4xTT x 450
110t reserved

Jefgte · June 19, 2018, 04:54:05 PM

"Destroyer, Torpedo Boat, and Motor Torpedo Boat Architecture:
...1924: quintuple tubes, 2,500t Type G, H MTB..."

TGB2500-4x191, Byzantine Empire TGB2500 laid down 1927

Displacement:
   2 500 t light; 2 644 t standard; 2 844 t normal; 3 004 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (450,00 ft / 450,00 ft) x 45,00 ft x (12,29 / 12,74 ft)
   (137,16 m / 137,16 m) x 13,72 m x (3,75 / 3,88 m)

Armament:
4 - 7,50" / 191 mm 45,0 cal guns - 212,75lbs / 96,50kg shells, 140 per gun
     Breech loading guns in deck mounts, 1927 Model
     4 x Single mounts on centreline ends, evenly spread
      2 raised mounts - superfiring
4 - 4,00" / 102 mm 45,0 cal guns - 32,28lbs / 14,64kg shells, 240 per gun
     Quick firing guns in deck mounts, 1927 Model
     4 x Single mounts on side ends, evenly spread
4 - 1,46" / 37,0 mm 45,0 cal guns - 1,57lbs / 0,71kg shells, 1 200 per gun
     Anti-air guns in deck mounts, 1927 Model
     4 x Single mounts on sides, forward evenly spread
      4 raised mounts
2 - 0,30" / 7,7 mm 92,0 cal guns - 0,02lbs / 0,01kg shells, 5 000 per gun
     Machine guns in deck mounts, 1927 Model
     2 x Single mounts on sides, forward deck forward
Weight of broadside 986 lbs / 447 kg

Armour:
- Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   1,20" / 30 mm     -           -
   3rd:   0,39" / 10 mm     -           -
   4th:   0,39" / 10 mm     -           -

Machinery:
   Coal and oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 50 700 shp / 37 822 Kw = 33,63 kts
   Range 7 000nm at 10,00 kts
   Bunker at max displacement = 360 tons (20% coal)

Complement:
   194 - 253

Cost:
   £1,212 million / $4,846 million

Distribution of weights at normal displacement:
   Armament: 149 tons, 5,2 %
     - Guns: 149 tons, 5,2 %
   Armour: 19 tons, 0,7 %
     - Armament: 19 tons, 0,7 %
   Machinery: 1 422 tons, 50,0 %
   Hull, fittings & equipment: 728 tons, 25,6 %
   Fuel, ammunition & stores: 345 tons, 12,1 %
   Miscellaneous weights: 182 tons, 6,4 %
     - On freeboard deck: 142 tons
     - Above deck: 40 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     783 lbs / 355 Kg = 3,7 x 7,5 " / 191 mm shells or 0,4 torpedoes
   Stability (Unstable if below 1.00): 1,23
   Metacentric height 2,2 ft / 0,7 m
   Roll period: 12,7 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0,42
   Seaboat quality (Average = 1.00): 1,01

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0,400 / 0,408
   Length to Beam Ratio: 10,00 : 1
   'Natural speed' for length: 21,21 kts
   Power going to wave formation at top speed: 61 %
   Trim (Max stability = 0, Max steadiness = 100): 70
   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 %, 20,00 ft / 6,10 m, 18,00 ft / 5,49 m
     - Forward deck:   25,00 %, 18,00 ft / 5,49 m, 15,50 ft / 4,72 m
     - Aft deck:   40,00 %, 15,50 ft / 4,72 m, 14,00 ft / 4,27 m
     - Quarter deck:   15,00 %, 14,00 ft / 4,27 m, 13,00 ft / 3,96 m
     - Average freeboard:      15,87 ft / 4,84 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 178,2 %
      - Above water (accommodation/working, high = better): 189,9 %
   Waterplane Area: 12 465 Square feet or 1 158 Square metres
   Displacement factor (Displacement / loading): 73 %
   Structure weight / hull surface area: 41 lbs/sq ft or 199 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,50
      - Longitudinal: 0,97
      - Overall: 0,54
   Cramped machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform

25t for Marconi
15t for fire control
32t for 2x4xTT x 450
110t reserved

snip · June 19, 2018, 09:09:26 PM

Some thoughts after a skim.

--Good lord of all that is fuzzy and cute that's a 7.5" gunned destroyer.
--The 1915 design is already over a knot slower than the Roman F-Class. Im not sure 30knts is going to cut it for a frontline destroyer by 1915.
--Big guns are going to hit hard, but will probably be far more difficult to service in anything other than flat seas. Especially in the open mounts. Sure they are loads better seaboats than there Imperial Roman contemporaries are likely to be, but one a Destroyer that does not mean much.

Personally I would drop the 4" guns, go for pure oil, and try and wring 2-3 more knots of speed out of each hull.

Jefgte · June 20, 2018, 03:48:29 PM

TGBs are not realy Destroyers.

They are fast gunboats for escorts, colonial works, patrols, squadron protection vs TBs & DDs.
A kind of Third class cruiser, Auxiliary cruisers, Spahkreuzer.

Kaiser Kirk · June 24, 2018, 12:18:41 AM

Interesting concepts.
Nice to see "out of the box" thinking.
Personally I don't mind being a little slower in speed vs same type if I win the firepower match. Especially since speed is the first attribute to decay with weather or damage.

The overall hulls are roughly the size of USS Erie, but with the .4 hull, I think they are more slender. The tonnage would support that.

Seakeeping is relative, and even with the "slow and steady roll" so I think such small vessels might have problems with the manually loaded larger shells on a pitching deck if the seas were up.

One thing that SS doesn't account for is that as guns get larger, they put more stress on the hull when firing. Sadly it's something I've only seen addressed a little, so I can't offer concrete guidelines. I bring it up as a practical consideration - fitting 6/7.5" guns on a hull with destroyer ribs might actually be a problem, and SS won't account for it well.

Jefgte · June 24, 2018, 03:40:22 PM

Quote...One thing that SS doesn't account for is that as guns get larger, they put more stress on the hull when firing. Sadly it's something I've only seen addressed a little, so I can't offer concrete guidelines. I bring it up as a practical consideration - fitting 6/7.5" guns on a hull with destroyer ribs might actually be a problem, and SS won't account for it well.

I agree ; the stress of the hull is higher with 7"5 than 6".

I think, in the futur, that TGB 2000 & 2500t w"ll have 2T2x6" (overall 0.5).
3000t cruiser could have 2T2x7"5 (overall 0.75).