Siren, Ancrath DDL laid down 1941

Siren, Ancrath DDL laid down 1941

Displacement:
	4,685 t light; 4,999 t standard; 5,786 t normal; 6,415 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
	(487.08 ft / 475.07 ft) x 52.49 ft x (18.04 / 19.38 ft)
	(148.46 m / 144.80 m) x 16.00 m  x (5.50 / 5.91 m)

Armament:
      10 - 5.51" / 140 mm 40.0 cal guns - 83.78lbs / 38.00kg shells, 300 per gun
	  Dual purpose guns in deck and hoist mounts, 1938 Model
	  3 x 2-gun mounts on centreline, forward deck forward
		1 raised mount - superfiring
	  2 x 2-gun mounts on centreline, aft deck aft
		1 raised mount aft - superfiring
      6 - 2.56" / 65.0 mm 45.0 cal guns - 9.04lbs / 4.10kg shells, 1,200 per gun
	  Anti-air guns in deck mounts, 1938 Model
	  2 x Twin mounts on sides, aft deck forward
	  1 x Twin mount on centreline, aft deck aft
      12 - 1.18" / 30.0 mm 80.0 cal guns - 0.84lbs / 0.38kg shells, 4,000 per gun
	  Anti-air guns in deck mounts, 1938 Model
	  6 x Twin mounts on sides, evenly spread
      Weight of broadside 902 lbs / 409 kg

Armour:
   - Belts:		Width (max)	Length (avg)		Height (avg)
	Main:	3.15" / 80 mm	348.43 ft / 106.20 m	8.69 ft / 2.65 m
	Ends:	Unarmoured
	  Main Belt covers 113 % of normal length

   - Torpedo Bulkhead - Strengthened structural bulkheads:
		1.57" / 40 mm	348.43 ft / 106.20 m	14.80 ft / 4.51 m
	Beam between torpedo bulkheads 42.65 ft / 13.00 m

   - Gun armour:	Face (max)	Other gunhouse (avg)	Barbette/hoist (max)
	Main:	1.97" / 50 mm	1.97" / 50 mm		3.15" / 80 mm
	2nd:	1.18" / 30 mm	0.79" / 20 mm		      -
	3rd:	0.79" / 20 mm	      -			      -

   - Armoured deck - multiple decks:
	For and Aft decks: 1.57" / 40 mm

   - Conning towers: Forward 1.97" / 50 mm, Aft 0.00" / 0 mm

Machinery:
	Diesel Internal combustion motors,
	Geared drive, 4 shafts, 52,003 shp / 38,794 Kw = 31.50 kts
	Range 7,000nm at 16.50 kts
	Bunker at max displacement = 1,415 tons

Complement:
	331 - 431

Cost:
	£2.647 million / $10.588 million

Distribution of weights at normal displacement:
	Armament: 217 tons, 3.8 %
	   - Guns: 217 tons, 3.8 %
	Armour: 1,229 tons, 21.2 %
	   - Belts: 387 tons, 6.7 %
	   - Torpedo bulkhead: 300 tons, 5.2 %
	   - Armament: 105 tons, 1.8 %
	   - Armour Deck: 422 tons, 7.3 %
	   - Conning Tower: 14 tons, 0.2 %
	Machinery: 1,374 tons, 23.8 %
	Hull, fittings & equipment: 1,865 tons, 32.2 %
	Fuel, ammunition & stores: 1,100 tons, 19.0 %
	Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
	Survivability (Non-critical penetrating hits needed to sink ship):
	  8,685 lbs / 3,940 Kg = 103.7 x 5.5 " / 140 mm shells or 1.6 torpedoes
	Stability (Unstable if below 1.00): 1.30
	Metacentric height 3.0 ft / 0.9 m
	Roll period: 12.7 seconds
	Steadiness	- As gun platform (Average = 50 %): 50 %
			- Recoil effect (Restricted arc if above 1.00): 0.32
	Seaboat quality  (Average = 1.00): 1.00

Hull form characteristics:
	Hull has a flush deck,
	  a normal bow and large transom stern
	Block coefficient (normal/deep): 0.450 / 0.465
	Length to Beam Ratio: 9.05 : 1
	'Natural speed' for length: 25.24 kts
	Power going to wave formation at top speed: 60 %
	Trim (Max stability = 0, Max steadiness = 100): 50
	Bow angle (Positive = bow angles forward): 20.00 degrees
	Stern overhang: 3.28 ft / 1.00 m
	Freeboard (% = length of deck as a percentage of waterline length):
				Fore end,	 Aft end
	   - Forecastle:	13.33 %,  23.98 ft / 7.31 m,  19.62 ft / 5.98 m
	   - Forward deck:	30.00 %,  19.62 ft / 5.98 m,  17.72 ft / 5.40 m
	   - Aft deck:	43.34 %,  17.72 ft / 5.40 m,  15.26 ft / 4.65 m
	   - Quarter deck:	13.33 %,  15.26 ft / 4.65 m,  15.26 ft / 4.65 m
	   - Average freeboard:		17.63 ft / 5.37 m

Ship space, strength and comments:
	Space	- Hull below water (magazines/engines, low = better): 112.8 %
		- Above water (accommodation/working, high = better): 165.2 %
	Waterplane Area: 16,524 Square feet or 1,535 Square metres
	Displacement factor (Displacement / loading): 124 %
	Structure weight / hull surface area: 87 lbs/sq ft or 424 Kg/sq metre
	Hull strength (Relative):
		- Cross-sectional: 0.94
		- Longitudinal: 1.76
		- Overall: 1.00
	Cramped machinery, storage, compartmentation space
	Excellent accommodation and workspace room