WesWorld

A second batch of Admiralty class destroyers has been taken in hand in Q4/1930 to be refited to carry the latest weapons in the Atlantean inventory.

-Similar to the first refit the 3x4" guns have been replaced with 4.5" DP mounts.

-40mm, 20mm and 12.5mm guns have been added

-The original 4x18" torpedo tubes have been replaced with 2 quadruple 21" tubes.

-Four depth charge launchers have been added aft

-New main gun director installed

-Bridge structure extended and remodeled

-Refurbishment of internal fittings for life-extension purposes

Below is a picture of the planned refit above a picture of the existing Admiralty type configurations.




Admiralty class DD, Atlantis Destroyer laid down 1916 (Engine 1926)

Displacement:
1,125 t light; 1,171 t standard; 1,244 t normal; 1,303 t full load

Dimensions: Length overall / water x beam x draught
313.53 ft / 310.00 ft x 30.00 ft x 10.50 ft (normal load)
95.56 m / 94.49 m x 9.14 m x 3.20 m

Armament:
4 - 4.50" / 114 mm guns (2x2 guns), 45.56lbs / 20.67kg shells, 1926 Model
Quick firing guns in deck mounts with hoists
on centreline ends, evenly spread
2 - 1.57" / 40.0 mm guns (1x2 guns), 1.95lbs / 0.88kg shells, 1926 Model
Anti-aircraft guns in deck mount
on centreline amidships
8 - 0.79" / 20.0 mm guns (4x2 guns), 0.24lbs / 0.11kg shells, 1926 Model
Breech loading guns in deck mounts
on side, evenly spread
4 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1916 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
Weight of broadside 188 lbs / 85 kg
Shells per gun, main battery: 200
8 - 21.0" / 533.4 mm above water torpedoes

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.00" / 25 mm - -

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 30,570 shp / 22,805 Kw = 32.00 kts
Range 4,500nm at 10.00 kts
Bunker at max displacement = 131 tons

Complement:
104 - 136

Cost:
£0.244 million / $0.975 million

Distribution of weights at normal displacement:
Armament: 24 tons, 1.9 %
Armour: 9 tons, 0.7 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 9 tons, 0.7 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 641 tons, 51.5 %
Hull, fittings & equipment: 422 tons, 33.9 %
Fuel, ammunition & stores: 119 tons, 9.6 %
Miscellaneous weights: 30 tons, 2.4 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
317 lbs / 144 Kg = 6.9 x 4.5 " / 114 mm shells or 0.2 torpedoes
Stability (Unstable if below 1.00): 1.02
Metacentric height 0.9 ft / 0.3 m
Roll period: 13.7 seconds
Steadiness - As gun platform (Average = 50 %): 60 %
- Recoil effect (Restricted arc if above 1.00): 0.48
Seaboat quality (Average = 1.00): 0.77

Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.446
Length to Beam Ratio: 10.33 : 1
'Natural speed' for length: 17.61 kts
Power going to wave formation at top speed: 69 %
Trim (Max stability = 0, Max steadiness = 100): 78
Bow angle (Positive = bow angles forward): 10.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 20.00 ft / 6.10 m
- Forecastle (20 %): 18.00 ft / 5.49 m
- Mid (40 %): 10.00 ft / 3.05 m
- Quarterdeck (15 %): 10.00 ft / 3.05 m
- Stern: 10.00 ft / 3.05 m
- Average freeboard: 12.56 ft / 3.83 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 183.9 %
- Above water (accommodation/working, high = better): 49.5 %
Waterplane Area: 5,913 Square feet or 549 Square metres
Displacement factor (Displacement / loading): 57 %
Structure weight / hull surface area: 37 lbs/sq ft or 182 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.60
- Longitudinal: 1.89
- Overall: 0.68
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is extremely poor
Poor seaboat, wet and uncomfortable, reduced performance in heavy weather

Interesting.

I think you should avoid mounting a duple 114mm gun forwards where there was only a 102mm single before. A bit too much weight towards the bow.

Her plan view seems too fat compared to her Cb of ~0,45

Her plan view has little to do with her hull form for which the bc is an indicator, hasn´t it?

From what I understood the BC was at the waterline. Her hull form at plan veiw is similar to other DD's of the time period.

Egnore the "engine 1926", thats from the previous refit stats.

Just found a picture of HMS Intrepid with similar plan view.

Block Coefficient is the volume occupied by the hull divided by the maximum volume given by the hull dimensions.

i.e. a ship is 10x10x10 = 1000cu m maximum volume

hull holds 500cu m so 500/1000 = Cb = 0.500

The deckplan should roughly follow the Cb, with a lesser Cb resulting in more thinning towards the extremities.

The picture of Intrepid is definately usefull, for example where to place the sonar and how far back on the stern the main armament can be placed on a DD.

Then again, how many countries had SONAR in 1930/31?

p.s. the answer is two at my count

Still, its nice to know where its placed. Keep in mind, this is wesworld where everyone likely has SONAR by now...

What? You're still using that ancient device?!?
:-)

Heh.

Time Radar, its a little dated, but it works....

LIDAR should work well, and for cloaked ships Tacyon grids should suffice.

The RSAN is using a tool based on a special variant of Permant True Seeing which is an ancient spell few powerful masters of the Royal School of Wizardry can still cast today..... ;o)