Byzantine Empire 1918-1922

[Jefgte]

Posted in "Parthian Vessels 1916 onwards"

Byzantium has a similar approach with the Colonial Cruisers (AGB4600). 3000t to 6000t and able of escorting BBs. From 2T2x152 , 2T2x191 to 2T2x254 all 27kts.
However, older 27kts cruisers are going to be affected to colonies.
27kts is a correct speed for Colonial Cruisers.

Jef forget TGB concept...

"Destroyers have over 50% of engine displacement, often 52, 53, or 54%.
TGBs only have 50% of the displacement reserved for the engines.
Weight saving is reserved for the installation of a powerful artillery, often 120mm guns and 4 torpedo tubes.
The first TGBs were built in 1892 with a speed of 21kts, sufficient at the time. The most recent show 28 or 29 kts.

In 1915, The Byzantine Empire confirmed this concept and the missions for the next TGBs.
1 - Colonial work, patrols, escorts.
2 - Close protection of large combat ships vs Destroyers and MTBs.
3 - Scouting & reinforcement of the combat fleet."

Last Byzantine TGB were 1000t & LD 1910.
1918 DD2000t techno could be interresting...LD in 1922.

[Jefgte]

1922 Engines techno give engines too light & speed too high to have 3x191 => the TGB must be over 2200t.

Out of rules...

Just 3x152 to have poor ship...

b]TGB1700, Byzantine Empire 3x152 laid down 1922[/b]

Displacement:
   1 700 t light; 1 773 t standard; 1 982 t normal; 2 149 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (370,93 ft / 367,45 ft) x 36,09 ft x (12,45 / 13,16 ft)
   (113,06 m / 112,00 m) x 11,00 m  x (3,80 / 4,01 m)

Armament:
      3 - 5,98" / 152 mm 45,0 cal guns - 108,07lbs / 49,02kg shells, 150 per gun
     Breech loading guns in deck and hoist mounts, 1922 Model
     3 x Single mounts on centreline, evenly spread
      1 - 3,00" / 76,2 mm 45,0 cal gun - 13,62lbs / 6,18kg shells, 250 per gun
     Anti-air gun in deck mount, 1922 Model
     1 x Single mount on centreline, forward deck aft
      1 raised mount
      2 - 1,85" / 47,0 mm 50,0 cal guns - 3,35lbs / 1,52kg shells, 1 000 per gun
     Quick firing guns in deck mounts, 1922 Model
     2 x Single mounts on sides, forward deck aft
      2 raised mounts
      2 - 0,30" / 7,7 mm 90,0 cal guns - 0,02lbs / 0,01kg shells, 4 000 per gun
     Machine guns in deck mounts, 1922 Model
     2 x Single mounts on sides, forward deck forward
      Weight of broadside 345 lbs / 156 kg

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0,39" / 10 mm         -               -
   2nd:   0,39" / 10 mm         -               -
   3rd:   0,39" / 10 mm         -               -
   4th:   0,39" / 10 mm         -               -

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 36 755 shp / 27 420 Kw = 32,00 kts
   Range 6 500nm at 12,00 kts
   Bunker at max displacement = 377 tons

Complement:
   148 - 193

Cost:
   £0,627 million / $2,509 million

Distribution of weights at normal displacement:
   Armament: 91 tons, 4,6 %
      - Guns: 91 tons, 4,6 %
   Armour: 8 tons, 0,4 %
      - Armament: 8 tons, 0,4 %
   Machinery: 991 tons, 50,0 %
   Hull, fittings & equipment: 515 tons, 26,0 %
   Fuel, ammunition & stores: 282 tons, 14,2 %
   Miscellaneous weights: 96 tons, 4,8 %
      - On freeboard deck: 62 tons
      - Above deck: 34 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     516 lbs / 234 Kg = 4,8 x 6,0 " / 152 mm shells or 0,3 torpedoes
   Stability (Unstable if below 1.00): 1,12
   Metacentric height 1,3 ft / 0,4 m
   Roll period: 13,1 seconds
   Steadiness   - As gun platform (Average = 50 %): 75 %
         - Recoil effect (Restricted arc if above 1.00): 0,56
   Seaboat quality  (Average = 1.00): 1,09

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0,420 / 0,431
   Length to Beam Ratio: 10,18 : 1
   'Natural speed' for length: 19,17 kts
   Power going to wave formation at top speed: 64 %
   Trim (Max stability = 0, Max steadiness = 100): 69
   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:   17,50 %,  19,69 ft / 6,00 m,  16,73 ft / 5,10 m
      - Forward deck:   32,50 %,  16,73 ft / 5,10 m,  13,78 ft / 4,20 m
      - Aft deck:   32,50 %,  13,78 ft / 4,20 m,  13,78 ft / 4,20 m
      - Quarter deck:   17,50 %,  13,78 ft / 4,20 m,  13,78 ft / 4,20 m
      - Average freeboard:      14,98 ft / 4,57 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 176,4 %
      - Above water (accommodation/working, high = better): 154,5 %
   Waterplane Area: 8 268 Square feet or 768 Square metres
   Displacement factor (Displacement / loading): 68 %
   Structure weight / hull surface area: 36 lbs/sq ft or 176 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,50
      - Longitudinal: 1,62
      - Overall: 0,56
   Cramped machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform

16t for 4TT x 533 HW
9t for 1918 top mast rangefinder
25t for LR marconi
6t for additionnal engines ventillation
15t for improved Hydrophone
5t for 50x90DC
4t for paravanes
16t reserved for new material, armament, minen.

Trial speed: 32.5kts
Bonus: 0.5

[TacCovert4]

The thing I hate about 3 guns, especially when you start getting ranges that can really stretch out due to improved fire control, is that 3 guns gives you very few data points for adjusting fire, and cannot be fired in half-salvoes.  With 4 guns, you can 'barely' fire half-salvoes for adjustment, though you'd need either luck or full salvoes to register hits.  With 3 guns, even full salvoes have pretty low probability when you consider the '1 short, 1 long' straddles with the remainder being most likely to actually hit. 

I'd opine that if you're running 3 guns like 191s, which will have a RoF roughly 1/3 slower than guns in the 120-140mm range, and you're not running a ship with substantial armor to withstand the hail of fire from those guns out at 12+KM, then you're in a situation where you may not have a ship that's combat effective by the time you get a solution with the big guns....despite the fact that the big guns can mission kill a DD or small cruiser with 1-2 hits. 

Later on, when Radar and highly precise FC comes into play, smaller numbers of guns start to gain effectiveness because the FC systems allow for much better solutions and more hits with fewer adjustment rounds.

[Jefgte]

I agree with you.
This 1700t SS is made to see what is possible with TGB concept. It's not in my Building Plan.

I wrote:
"Just 3x152 to have poor ship..."

[Desertfox]

I did stuff 2x8" guns in a 1500t destroyer... although I figure their main role will be raiding/harassment shore bombardment.

[TacCovert4]

I agree with you.
This 1700t SS is made to see what is possible with TGB concept. It's not in my Building Plan.

I wrote:
"Just 3x152 to have poor ship..."

Yeah, I built a few E-class DDs with only 3 guns.  They're built as commerce raiders for long open ocean voyages though, so within that they work.

[Kaiser Kirk]

Not to derail Jefgte's thread :)

Tac is right, 4 guns is more desirable, 3 is 'workable' but less desirable - just how that shell ladder looks. 
There is a note in 'Ship Design' under fire control about this, but to expound further :

From what I've read, you want 2 short, 1 'straddle' and 1 over.   
The straddle though can be hard to see, so those 2 shorts are really your guide.
The overs are harder to see, so you can 'live' with 2 short and 1 straddle , and shift that to 1 short 1 straddle 1 over.
Just having 2 guns means only 2 splashes, which the literature indicates is not sufficient.
This is ostensibly the reason for 10 guns - 2 x 5gun salvos, the 5th gun being the 'safety' for any loading issues,
to ensure you would have 4.
With the 8 guns ships, they basically decided that the loading issues were infrequent enough it wasn't mandatory.

ROF should have bearing on this too. You need to be able to put that many (3-4) shells out every 30s
in order to make a track.  HMS Furious's 2x18" would just be too slow to even try to use the process.
While I think a Sverige with 4x 12"...but 3rpm, is a little slow, but could have a reasonable chance at making a plot.
Drop down a size class and ROF increases and a 4 gun battery becomes more acceptable.

Late in the period the optics got better, there was aerial spotting, and then there was radar, so this became less important.