Destroyer classes

Heila class

The Heila class destroyers were Antara's first ocean-going, long-range destroyers. They were decently well armed with six 76mm guns and four 450mm single torpedo launchers with reloads.

SS report:
_______________________

Displacement:

662 t light; 683 t standard; 708 t normal; 727 t full load



Dimensions: Length (overall / waterline) x beam x draught (normal/deep)

(279,80 ft / 271,65 ft) x 36,09 ft x (8,20 / 8,32 ft)

(85,28 m / 82,80 m) x 11,00 m x (2,50 / 2,53 m)



Armament:

5 - 2,99" / 76,0 mm 45,0 cal guns - 13,51lbs / 6,13kg shells, 200 per gun

Breech loading guns in deck mounts, 1907 Model

3 x Single mounts on centreline ends, majority aft

2 x Single mounts on sides, forward deck forward

Weight of broadside 68 lbs / 31 kg

Main Torpedoes

4 - 17,7" / 450 mm, 26,25 ft / 8,00 m torpedoes - 1,173 t each, 4,691 t total

In 4 sets of deck mounted side rotating tubes



Armour:

- Protected deck - single deck:

For and Aft decks: 0,98" / 25 mm

Forecastle: 0,98" / 25 mm Quarter deck: 0,98" / 25 mm



- Conning towers: Forward 0,98" / 25 mm, Aft 0,98" / 25 mm



Machinery:

Oil fired boilers, steam turbines,

Direct drive, 2 shafts, 10930 shp / 8154 Kw = 28,00 kts

Range 1000nm at 10,00 kts

Bunker at max displacement = 43 tons



Complement:

68 - 89



Cost:

?0,075 million / $0,301 million



Distribution of weights at normal displacement:

Armament: 21 tons, 2,9%

- Guns: 11 tons, 1,6%

- Weapons: 9 tons, 1,3%

Armour: 112 tons, 15,8%

- Armour Deck: 108 tons, 15,3%

- Conning Towers: 3 tons, 0,5%

Machinery: 349 tons, 49,3%

Hull, fittings & equipment: 181 tons, 25,5%

Fuel, ammunition & stores: 46 tons, 6,5%

Miscellaneous weights: 0 tons, 0,0%



Overall survivability and seakeeping ability:

Survivability (Non-critical penetrating hits needed to sink ship):

232 lbs / 105 Kg = 17,3 x 3,0 " / 76 mm shells or 0,3 torpedoes

Stability (Unstable if below 1.00): 1,25

Metacentric height 1,6 ft / 0,5 m

Roll period: 11,9 seconds

Steadiness - As gun platform (Average = 50 %): 82 %

- Recoil effect (Restricted arc if above 1.00): 0,05

Seaboat quality (Average = 1.00): 0,82



Hull form characteristics:

Hull has rise forward of midbreak,

a normal bow and small transom stern

Block coefficient (normal/deep): 0,308 / 0,312

Length to Beam Ratio: 7,53 : 1

'Natural speed' for length: 18,30 kts

Power going to wave formation at top speed: 63 %

Trim (Max stability = 0, Max steadiness = 100): 100

Bow angle (Positive = bow angles forward): 15,00 degrees

Stern overhang: 3,28 ft / 1,00 m

Freeboard (% = length of deck as a percentage of waterline length):

Fore end, Aft end

- Forecastle: 15,00%, 18,14 ft / 5,53 m, 14,83 ft / 4,52 m

- Forward deck: 15,00%, 14,83 ft / 4,52 m, 14,83 ft / 4,52 m

- Aft deck: 55,00%, 7,41 ft / 2,26 m, 7,41 ft / 2,26 m

- Quarter deck: 15,00%, 7,41 ft / 2,26 m, 7,41 ft / 2,26 m

- Average freeboard: 9,84 ft / 3,00 m



Ship space, strength and comments:

Space - Hull below water (magazines/engines, low = better): 164,4%

- Above water (accommodation/working, high = better): 134,7%

Waterplane Area: 5902 Square feet or 548 Square metres

Displacement factor (Displacement / loading): 51%

Structure weight / hull surface area: 23 lbs/sq ft or 114 Kg/sq metre

Hull strength (Relative):

- Cross-sectional: 0,47

- Longitudinal: 1,00

- Overall: 0,50
_______________________

Ships in class:

• Heila
• Haley
• Hazel
• Holly
• Heather
• Hanna
• Helena