WesWorld

A planned rebuild of the British Cambrian class light cruisers. Mainly a life extension, weight reduction reffit.

HMAS Cairns, Australia Light Cruiser laid down 1914 (Engine 1930)

Displacement:
3,207 t light; 3,350 t standard; 4,532 t normal; 5,477 t full load

Dimensions: Length overall / water x beam x draught
420.00 ft / 420.00 ft x 41.50 ft x 16.25 ft (normal load)
128.02 m / 128.02 m x 12.65 m x 4.95 m

Armament:
4 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1930 Model
Breech loading guns in deck mounts
on centreline, evenly spread
Aft Main mounts separated by engine room
4 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1930 Model
Dual purpose guns in deck mounts
on side, evenly spread
8 - 1.57" / 40.0 mm guns (2x4 guns), 1.95lbs / 0.88kg shells, 1930 Model
Anti-aircraft guns in deck mounts
on centreline, evenly spread
10 - 0.79" / 20.0 mm guns (5x2 guns), 0.24lbs / 0.11kg shells, 1930 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
Weight of broadside 578 lbs / 262 kg
Shells per gun, main battery: 150
8 - 21.0" / 533.4 mm above water torpedoes

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 3.00" / 76 mm 330.00 ft / 100.58 m 8.00 ft / 2.44 m
Ends: 2.50" / 64 mm 90.00 ft / 27.43 m 8.00 ft / 2.44 m
Main Belt covers 121 % of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 2.00" / 51 mm - -
2nd: 1.00" / 25 mm - -
3rd: 0.50" / 13 mm - -
4th: 0.50" / 13 mm - -

- Armour deck: 1.00" / 25 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 41,283 shp / 30,797 Kw = 29.00 kts
Range 15,000nm at 15.00 kts
Bunker at max displacement = 2,127 tons

Complement:
276 - 359

Cost:
£0.443 million / $1.772 million

Distribution of weights at normal displacement:
Armament: 72 tons, 1.6 %
Armour: 653 tons, 14.4 %
- Belts: 388 tons, 8.6 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 38 tons, 0.8 %
- Armour Deck: 227 tons, 5.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 1,251 tons, 27.6 %
Hull, fittings & equipment: 1,156 tons, 25.5 %
Fuel, ammunition & stores: 1,324 tons, 29.2 %
Miscellaneous weights: 75 tons, 1.7 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
4,188 lbs / 1,900 Kg = 38.8 x 6.0 " / 152 mm shells or 0.9 torpedoes
Stability (Unstable if below 1.00): 1.42
Metacentric height 2.4 ft / 0.7 m
Roll period: 11.1 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.18
Seaboat quality (Average = 1.00): 1.26

Hull form characteristics:
Hull has raised forecastle
Block coefficient: 0.560
Length to Beam Ratio: 10.12 : 1
'Natural speed' for length: 20.49 kts
Power going to wave formation at top speed: 61 %
Trim (Max stability = 0, Max steadiness = 100): 55
Bow angle (Positive = bow angles forward): 0.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 25.00 ft / 7.62 m
- Forecastle (30 %): 22.00 ft / 6.71 m (15.00 ft / 4.57 m aft of break)
- Mid (50 %): 15.00 ft / 4.57 m
- Quarterdeck (15 %): 14.00 ft / 4.27 m
- Stern: 14.00 ft / 4.27 m
- Average freeboard: 17.14 ft / 5.22 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 104.1 %
- Above water (accommodation/working, high = better): 85.1 %
Waterplane Area: 12,279 Square feet or 1,141 Square metres
Displacement factor (Displacement / loading): 119 %
Structure weight / hull surface area: 50 lbs/sq ft or 246 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.73
- Longitudinal: 1.61
- Overall: 0.79
Caution: Hull subject to strain in open-sea
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is cramped
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily

Is this small cruiser worth the effort and material?

In 1930+ such a unit doesn´t seem to offer much...

Well I was going to do this cause I have an excess of production material. But your right Im not gaining much for 3,200 tons expended. Maybe Ill just go with the 15% refit as it just about gives me everything but the range and they are already due for their 15 year refit. Originaly I was going to make them 32kts so a major rebuild was worth it, but I didnt notice that its not worth it anymore.

Usually when I have an excess of materials I put it into smaller vessels such as MTB's or smaller antisub vessels.

I have to agree with Hoo though, these ships are obsolete. Give them a minor refit, maybe add a few light AA guns and keep them in service till replacements come on line.

You might be able to sell them to another smaller nation like Siam perhaps.....

Il probably give them a small refit and convert them to CDS by removing half the boilers, that would make them eligible as training vessels by simply removing the TT.

Im also thinking about selling one of them and 4 R class destroyers, if anyone is interested.