WesWorld

HMAS Ballarat
HMAS Bathurst

Ballarat class, Australia Seaplane Escort Cruiser laid down 1932

Displacement:
3,605 t light; 3,790 t standard; 5,014 t normal; 5,994 t full load

Dimensions: Length overall / water x beam x draught
509.79 ft / 500.00 ft x 52.00 ft x 15.00 ft (normal load)
155.38 m / 152.40 m x 15.85 m x 4.57 m

Armament:
6 - 6.00" / 152 mm guns (2x3 guns), 108.00lbs / 48.99kg shells, 1932 Model
Breech loading guns in turrets (on barbettes)
on centreline, all forward, 1 raised mount - superfiring
8 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1932 Model
Breech loading guns in deck mounts
on side, evenly spread, 4 raised mounts
12 - 1.57" / 40.0 mm guns (3x4 guns), 1.95lbs / 0.88kg shells, 1932 Model
Breech loading guns in deck mounts
on centreline, evenly spread
20 - 0.79" / 20.0 mm guns (10x2 guns), 0.24lbs / 0.11kg shells, 1932 Model
Breech loading guns in deck mounts
on side, evenly spread
Weight of broadside 932 lbs / 423 kg
Shells per gun, main battery: 150
12 - 21.0" / 533.4 mm above water torpedoes

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 2.90" / 74 mm 240.00 ft / 73.15 m 9.00 ft / 2.74 m
Ends: Unarmoured
Main Belt covers 74 % of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 2.90" / 74 mm 1.20" / 30 mm 2.00" / 51 mm
2nd: 1.20" / 30 mm - -

- Armour deck: 1.20" / 30 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 19,343 shp / 14,430 Kw = 24.20 kts
Range 15,000nm at 15.00 kts
Bunker at max displacement = 2,203 tons

Complement:
297 - 387

Cost:
£1.382 million / $5.527 million

Distribution of weights at normal displacement:
Armament: 117 tons, 2.3 %
Armour: 744 tons, 14.8 %
- Belts: 275 tons, 5.5 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 101 tons, 2.0 %
- Armour Deck: 368 tons, 7.3 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 571 tons, 11.4 %
Hull, fittings & equipment: 1,924 tons, 38.4 %
Fuel, ammunition & stores: 1,409 tons, 28.1 %
Miscellaneous weights: 250 tons, 5.0 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
10,403 lbs / 4,719 Kg = 96.3 x 6.0 " / 152 mm shells or 2.2 torpedoes
Stability (Unstable if below 1.00): 1.34
Metacentric height 3.2 ft / 1.0 m
Roll period: 12.3 seconds
Steadiness - As gun platform (Average = 50 %): 71 %
- Recoil effect (Restricted arc if above 1.00): 0.29
Seaboat quality (Average = 1.00): 1.50

Hull form characteristics:
Hull has low quarterdeck
Block coefficient: 0.450
Length to Beam Ratio: 9.62 : 1
'Natural speed' for length: 22.36 kts
Power going to wave formation at top speed: 43 %
Trim (Max stability = 0, Max steadiness = 100): 47
Bow angle (Positive = bow angles forward): 25.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 21.00 ft / 6.40 m
- Forecastle (20 %): 14.00 ft / 4.27 m
- Mid (50 %): 14.00 ft / 4.27 m
- Quarterdeck (15 %): 12.00 ft / 3.66 m (14.00 ft / 4.27 m before break)
- Stern: 12.00 ft / 3.66 m
- Average freeboard: 14.26 ft / 4.35 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 61.4 %
- Above water (accommodation/working, high = better): 101.6 %
Waterplane Area: 16,585 Square feet or 1,541 Square metres
Displacement factor (Displacement / loading): 163 %
Structure weight / hull surface area: 78 lbs/sq ft or 381 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.93
- Longitudinal: 1.07
- Overall: 0.95
Caution: Hull subject to strain in open-sea
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is adequate
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather