Vilnius Union Ships, 1911 - 1919

[The Rock Doctor]

A basic refit of the J-class torpedo-boats would replace oil-fired coal bunkerage, add a basic hydrophone package, and update the weapons and fire control, allowing for a few tons of ASW kit.  Cost would be $0.08 and 0.034 BP per unit, which seems quite reasonable.  Moving to oil allows an increase of range from 2500 to 3400 nm, which is not unhelpful and certainly makes crossing the Atlantic less challenging.

I investigated a refurbishment that would update the machinery and it reduced the stability a bit alarmingly.  Also problematic, the cash cost of replacing the machinery alone is higher than a new-build hull of the same size.  So we won't go there.

J-class refit, laid down 1908

Displacement:
   533 t light; 554 t standard; 614 t normal; 662 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (229.66 ft / 226.38 ft) x 22.97 ft x (9.84 / 10.36 ft)
   (70.00 m / 69.00 m) x 7.00 m  x (3.00 / 3.16 m)

Armament:
      2 - 3.94" / 100 mm 45.0 cal guns - 30.77lbs / 13.96kg shells, 200 per gun
     Quick firing guns in deck and hoist mounts, 1908 Model
     2 x Single mounts on centreline, evenly spread
      2 raised mounts
      2 - 1.97" / 50.0 mm 45.0 cal guns - 3.85lbs / 1.75kg shells, 200 per gun
     Quick firing guns in deck and hoist mounts, 1908 Model
     2 x Single mounts on sides amidships
      2 raised mounts
      4 - 0.39" / 10.0 mm 45.0 cal guns - 0.03lbs / 0.01kg shells, 15,000 per gun
     Machine guns in deck mounts, 1908 Model
     4 x Single mounts on sides, evenly spread
      4 raised mounts
      Weight of broadside 69 lbs / 31 kg

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.79" / 20 mm   0.20" / 5 mm            -
   2nd:   0.79" / 20 mm   0.20" / 5 mm            -
   3rd:   0.20" / 5 mm         -               -

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 10,456 shp / 7,800 Kw = 26.56 kts
   Range 3,300nm at 10.00 kts
   Bunker at max displacement = 107 tons

Complement:
   61 - 80

Cost:
   £0.068 million / $0.271 million

Distribution of weights at normal displacement:
   Armament: 20 tons, 3.2 %
      - Guns: 20 tons, 3.2 %
   Armour: 8 tons, 1.3 %
      - Armament: 8 tons, 1.3 %
   Machinery: 301 tons, 49.1 %
   Hull, fittings & equipment: 170 tons, 27.7 %
   Fuel, ammunition & stores: 81 tons, 13.1 %
   Miscellaneous weights: 34 tons, 5.5 %
      - Hull below water: 5 tons
      - On freeboard deck: 26 tons
      - Above deck: 3 tons

Fittings:
-5 t:  Basic hydrophone, below water
-10 t:  S/R wireless, on deck
-2 t:  1912 fire control, above deck
-8 t:  1x2 1913 torpedoes, no reloads
-8 t:  ASW weapons
-1 t:  Weight reserve, above deck

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     147 lbs / 67 Kg = 4.8 x 3.9 " / 100 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.08
   Metacentric height 0.6 ft / 0.2 m
   Roll period: 12.1 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.61
   Seaboat quality  (Average = 1.00): 1.01

Hull form characteristics:
   Hull has raised forecastle,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.420 / 0.430
   Length to Beam Ratio: 9.86 : 1
   'Natural speed' for length: 15.05 kts
   Power going to wave formation at top speed: 67 %
   Trim (Max stability = 0, Max steadiness = 100): 49
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 3.28 ft / 1.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   25.00 %,  16.40 ft / 5.00 m,  19.36 ft / 5.90 m
      - Forward deck:   20.00 %,  8.53 ft / 2.60 m,  8.53 ft / 2.60 m
      - Aft deck:   40.00 %,  8.53 ft / 2.60 m,  8.53 ft / 2.60 m
      - Quarter deck:   15.00 %,  8.53 ft / 2.60 m,  8.53 ft / 2.60 m
      - Average freeboard:      10.94 ft / 3.34 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 170.2 %
      - Above water (accommodation/working, high = better): 86.3 %
   Waterplane Area: 3,241 Square feet or 301 Square metres
   Displacement factor (Displacement / loading): 53 %
   Structure weight / hull surface area: 25 lbs/sq ft or 122 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 2.57
      - Overall: 0.58
   Cramped machinery, storage, compartmentation space
   Cramped accommodation and workspace room

[The Rock Doctor]

The Type 1908 cutter has heaps of available miscellaneous weight, and I'm honestly not sure why that is.  But regardless, it means I can do a simple refit to use some of that for an enhanced hydrophone package (15t), ASW munitions (10 t), new torpedos (1x2 1913, so 8 t) and new fire control (2 t).  Cost per unit is $0.03 and 0.029 BP, no problemo.

I won't bother posting a new sim, just update the existing one in the encyclopedia.

[eltf177]

*A basic refit of the J-class torpedo-boats...*

In what year is this refit performed?

[The Rock Doctor]

Second half of 1916, why?

[The Rock Doctor]

Given the length of its sealanes and the short range of some of its coastal defence stuff, the Union's going to build a couple of auxiliaries specifically designed to move small warships and submarines around from port to port.

Which, to be clear, does not include a combat-deployment mode.  They'll need the port facilities to load and unload the cargo.

The length and beam of the mid-deck is sufficient to accommodate 2 x 500 t or 3 x 250 t submarines, or six 40 t MTB, or some as-yet undetermined quantity of 20 t MTB.  Small river craft would also be transportable, but the submarines were the largest cargo and the design target.

The ship is otherwise lightly armed for anti-boarding purposes, long-legged and reasonably mobile.  Two units - Borys and Ledeper - will be named after Union folk heroes.

Note:  Deck cargo is SM U-9, which I'm using to approximate our 500 t boats.

Borys the Boat Mover, laid down 1916

Displacement:
   3,399 t light; 3,479 t standard; 3,856 t normal; 4,158 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (326.87 ft / 321.52 ft) x 49.21 ft x (13.12 / 14.00 ft)
   (99.63 m / 98.00 m) x 15.00 m  x (4.00 / 4.27 m)

Armament:
      4 - 1.97" / 50.0 mm 45.0 cal guns - 3.85lbs / 1.74kg shells, 250 per gun
     Quick firing guns in deck mounts, 1916 Model
     4 x Single mounts on side ends, evenly spread
      4 raised mounts
      4 - 0.39" / 10.0 mm 45.0 cal guns - 0.03lbs / 0.01kg shells, 4,000 per gun
     Machine guns in deck mounts, 1916 Model
     4 x Single mounts on side ends, evenly spread
      4 raised mounts
      Weight of broadside 16 lbs / 7 kg

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.79" / 20 mm   0.39" / 10 mm            -
   2nd:   0.39" / 10 mm         -               -

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 6,702 shp / 5,000 Kw = 17.94 kts
   Range 10,000nm at 10.00 kts
   Bunker at max displacement = 679 tons

Complement:
   244 - 318

Cost:
   £0.253 million / $1.014 million

Distribution of weights at normal displacement:
   Armament: 3 tons, 0.1 %
      - Guns: 3 tons, 0.1 %
   Armour: 14 tons, 0.4 %
      - Armament: 14 tons, 0.4 %
   Machinery: 250 tons, 6.5 %
   Hull, fittings & equipment: 1,008 tons, 26.1 %
   Fuel, ammunition & stores: 457 tons, 11.9 %
   Miscellaneous weights: 2,124 tons, 55.1 %
      - Hull above water: 1,000 tons
      - On freeboard deck: 1,099 tons
      - Above deck: 25 tons

Fittings:
-1,000 t:  Deck cargo on deck
-1,099 t:  Bracing, ballast and such to keep the deck cargo in place
-25 t:  L/R wireless

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     8,879 lbs / 4,027 Kg = 2,328.0 x 2.0 " / 50 mm shells or 2.4 torpedoes
   Stability (Unstable if below 1.00): 1.16
   Metacentric height 2.3 ft / 0.7 m
   Roll period: 13.7 seconds
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 0.01
   Seaboat quality  (Average = 1.00): 1.82

Hull form characteristics:
   Hull has raised forecastle, raised quarterdeck ,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.650 / 0.657
   Length to Beam Ratio: 6.53 : 1
   'Natural speed' for length: 17.93 kts
   Power going to wave formation at top speed: 50 %
   Trim (Max stability = 0, Max steadiness = 100): 39
   Bow angle (Positive = bow angles forward): 10.00 degrees
   Stern overhang: 1.64 ft / 0.50 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   15.00 %,  21.00 ft / 6.40 m,  21.00 ft / 6.40 m
      - Forward deck:   40.00 %,  13.12 ft / 4.00 m,  13.12 ft / 4.00 m
      - Aft deck:   30.00 %,  13.12 ft / 4.00 m,  13.12 ft / 4.00 m
      - Quarter deck:   15.00 %,  21.00 ft / 6.40 m,  21.00 ft / 6.40 m
      - Average freeboard:      15.49 ft / 4.72 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 50.6 %
      - Above water (accommodation/working, high = better): 124.2 %
   Waterplane Area: 12,121 Square feet or 1,126 Square metres
   Displacement factor (Displacement / loading): 146 %
   Structure weight / hull surface area: 57 lbs/sq ft or 280 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.93
      - Longitudinal: 1.76
      - Overall: 1.00
   Excellent machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather

[Desertfox]

Jingei got a bigger brother!

[The Rock Doctor]

Jingei got a bigger brother!

Please don't sue me.

[Desertfox]

Its only fair after I stole some of your stuff!

[eltf177]

Second half of 1916, why?

Mentioned new engines but not what year refit was performed. And 1911 seemed too soon for a major refit of this class.

[The Rock Doctor]

Second half of 1916, why?

Mentioned new engines but not what year refit was performed. And 1911 seemed too soon for a major refit of this class.

True, I did contemplate new engines but ended up rejecting it for cost reasons.

[The Rock Doctor]

Sketch of the L-class torpedo-boats.  The incoming M-class (1917) will be almost identical.

[Jefgte]

...The incoming M-class (1917) will be almost identical.

...With 130mm/45 guns (?)

[The Rock Doctor]

...The incoming M-class (1917) will be almost identical.

...With 130mm/45 guns (?)

Just 100/45 weapons.  Even three of the 130/45s are a bit much for the 1,000 t hull.

They're more or less V&W clones.

[TacCovert4]

...The incoming M-class (1917) will be almost identical.

...With 130mm/45 guns (?)

Just 100/45 weapons.  Even three of the 130/45s are a bit much for the 1,000 t hull.

They're more or less V&W clones.

And here I am making 6 x 100mm DDs on 1000t hulls, and soon will be quickly producing 4 x 130mm DDs on 1000t hulls.

But then again I think you're making yours a bit more 'total spectrum' than mine are.

[The Rock Doctor]

We found in earlier versions of the sim that it was not difficult to exceed historical armaments on destroyers if one didn't go quite as hard on the speed.

At any rate, I'm wanting the L/M type to be a "good but not great" anti-surface and anti-submarine escort available in consider numbers for my battleline.  I'll make the move to something larger when I'm happy with those numbers.