When this whole thing started out, I wanted to make a British ship that was able to perform a very large number of duties. Such a vessel would need to have a cruiser's range, a destroyer's firepower, an escort's ASW abilities, and over-the-horizon spotting capabilities. All of these roles would have to be fulfilled without infringing upon Great Britain's cruiser tonnage- so the ship would have to fall under the gunboat classification- and the ship would have to have low manpower requirements and be relatively inexpensive.
I started out on the design, couldn't ever make it look like I wanted, so I pushed it to the back burner and began working on the smaller
Excelsior... but I never forgot what I wanted the ship to really look like. Now that I've rounded out my N-verse nation and started on it's budget, I've pulled this 'super gunboat' out of the 'never gonna be' pile and started to finish her.
The
Island class 'colonial cruiser' mounts four dual-purpose 4.72" guns suitable for use against surface targets or aircraft; 500 rounds per gun are carried to allow for extended engagements. Four octuple 2-pounder AA mounts are mounted (two on either beam) to provide with heavy short-range anti-aircraft fire; 5000 rounds per gun are carried, along with spare barrels for each gun. A trio of 3" twelve-pounder guns are also carried for use against small craft, submarines, and for providing illumination; 500 rounds per gun are carried- 200 of which are are star shells. The vessel also carries a Fairey Seafox floatplane for use in reconnaissance, giving the ship over-the-horizon scouting capabilities. A sonar set with a pair of depth charge rails and two depth charge throwers provide good anti-submarine capability. In addition to all this, the ship requires only 1/3 the manpower of a light cruiser (180 - 230 men) and carries an additional detachment of 25 Marines.
Island Class, Great Britian Colonial Cruiser laid down 1936
Displacement:
1,706 t light; 2,000 t standard; 2,500 t normal; 2,900 t full load
Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(415.00 ft / 400.00 ft) x 40.00 ft x (12.00 / 13.36 ft)
(126.49 m / 121.92 m) x 12.19 m x (3.66 / 4.07 m)
Armament:
4 - 4.72" / 120 mm 45.0 cal guns - 50.00lbs / 22.68kg shells, 500 per gun
Dual purpose guns in deck and hoist mounts, 1930 Model
2 x Single mounts on centreline, forward deck forward
1 raised mount - superfiring
2 x Single mounts on centreline, aft deck aft
1 raised mount aft - superfiring
3 - 3.00" / 76.2 mm 45.0 cal guns - 11.99lbs / 5.44kg shells, 500 per gun
Quick firing guns in deck mounts, 1936 Model
2 x Single mounts on sides, forward deck
2 double raised mounts
1 x Single mount on centreline, aft deck
1 double raised mount
32 - 1.57" / 40.0 mm 39.0 cal guns - 2.01lbs / 0.91kg shells, 5,000 per gun
Breech loading guns in deck mounts, 1936 Model
4 x 2 row octuple mounts on sides, evenly spread
4 raised mounts
Weight of broadside 300 lbs / 136 kg
Main DC/AS Mortars
2 - 240.00 lbs / 108.86 kg Depth Charges + 50 reloads - 5.571 t total
in Stern depth charge racks
2nd DC/AS Mortars
2 - 240.00 lbs / 108.86 kg Depth Charges + 50 reloads - 5.571 t total
in Depth charge throwers
Armour:
- Box over machinery & magazines:
2.00" / 51 mm
- Conning towers: Forward 3.00" / 76 mm, Aft 0.00" / 0 mm
Machinery:
Diesel Internal combustion generators,
Electric motors, 2 shafts, 6,600 shp / 4,924 Kw = 20.03 kts
Range 11,225nm at 14.00 kts
Bunker at max displacement = 900 tons
Complement:
176 - 229
Cost:
£0.586 million / $2.345 million
Distribution of weights at normal displacement:
Armament: 96 tons, 3.8 %
- Guns: 80 tons, 3.2 %
- Weapons: 15 tons, 0.6 %
Armour: 218 tons, 8.7 %
- Armour Deck: 206 tons, 8.2 %
- Conning Tower: 12 tons, 0.5 %
Machinery: 185 tons, 7.4 %
Hull, fittings & equipment: 1,107 tons, 44.3 %
Fuel, ammunition & stores: 794 tons, 31.8 %
Miscellaneous weights: 100 tons, 4.0 %
- Hull below water: 40 tons
- Hull above water: 40 tons
- On freeboard deck: 20 tons
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
8,581 lbs / 3,892 Kg = 163.2 x 4.7 " / 120 mm shells or 2.3 torpedoes
Stability (Unstable if below 1.00): 1.22
Metacentric height 1.8 ft / 0.6 m
Roll period: 12.5 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.39
Seaboat quality (Average = 1.00): 2.00
Hull form characteristics:
Hull has a flush deck,
a normal bow and a cruiser stern
Block coefficient (normal/deep): 0.456 / 0.475
Length to Beam Ratio: 10.00 : 1
'Natural speed' for length: 20.00 kts
Power going to wave formation at top speed: 39 %
Trim (Max stability = 0, Max steadiness = 100): 35
Bow angle (Positive = bow angles forward): 22.63 degrees
Stern overhang: 5.00 ft / 1.52 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 20.00 %, 24.00 ft / 7.32 m, 18.00 ft / 5.49 m
- Forward deck: 30.00 %, 18.00 ft / 5.49 m, 17.00 ft / 5.18 m
- Aft deck: 32.50 %, 17.00 ft / 5.18 m, 16.00 ft / 4.88 m
- Quarter deck: 17.50 %, 16.00 ft / 4.88 m, 16.00 ft / 4.88 m
- Average freeboard: 17.49 ft / 5.33 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 47.8 %
- Above water (accommodation/working, high = better): 188.5 %
Waterplane Area: 10,257 Square feet or 953 Square metres
Displacement factor (Displacement / loading): 268 %
Structure weight / hull surface area: 59 lbs/sq ft or 287 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.88
- Longitudinal: 2.97
- Overall: 1.00
Excellent machinery, storage, compartmentation space
Excellent accommodation and workspace room
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather
Any thoughts- improvements that need to be made, etc; I haven't put the antenna on yet, but they are coming.
I'm also thinking about doing a wartime refit, and perhaps even a 'life-extension' refit bringing them into the realms of 'modern' weapons.