Looking at the monitor fleet the obsolence is pretty clear. Gorgon was laid down in 1913 and belongs to a different era. General Crawford and Sir John Moore are both 1915 ships but are armed with turrets from the Majestic class battleships and date from 1894! Rebuilding these ships with modern guns and engines would be a waste of resources so all three will be replaced.
The DNC was aksed to come up with a new design and he came up with a modified General Class gunboat design. The hull is much fatter and there are several changes;
The main 9.2in guns now have 200 rpg
4in twins replaced by 4.5in twins
2pdr qauds and HMG mounts replaced by four twin 2pdr L/70 mounts
Belt is 0.5in thicker and 2ft higher
Machinery has been replaced with a new 4x 1000hp diesel layout
Speed is now 4kts faster
Two ships have been authorised for construction in 1942.
General Class Gunboat, Great Britain Gunboat laid down 1942
Displacement:
3,719 t light; 4,081 t standard; 4,213 t normal; 4,319 t full load
Dimensions: Length overall / water x beam x draught
364.29 ft / 360.00 ft x 55.00 ft x 14.00 ft (normal load)
111.03 m / 109.73 m x 16.76 m x 4.27 m
Armament:
4 - 9.20" / 234 mm guns (2x2 guns), 510.00lbs / 231.33kg shells, 1936 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, evenly spread, 1 raised mount
8 - 4.50" / 114 mm guns (4x2 guns), 45.00lbs / 20.41kg shells, 1936 Model
Dual purpose guns in deck mounts with hoists
on side, all amidships
8 - 1.57" / 40.0 mm guns (4x2 guns), 2.00lbs / 0.91kg shells, 1941 Model
Anti-aircraft guns in deck mounts
on side ends, evenly spread, 2 raised mounts - superfiring
Weight of broadside 2,416 lbs / 1,096 kg
Shells per gun, main battery: 200
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 3.00" / 76 mm 250.00 ft / 76.20 m 9.00 ft / 2.74 m
Ends: Unarmoured
Main Belt covers 107 % of normal length
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 5.00" / 127 mm 2.00" / 51 mm 4.00" / 102 mm
2nd: 2.00" / 51 mm 1.00" / 25 mm 2.00" / 51 mm
3rd: 0.50" / 13 mm - -
- Armour deck: 2.00" / 51 mm, Conning tower: 3.00" / 76 mm
Machinery:
Diesel Internal combustion motors,
Geared drive, 2 shafts, 4,000 shp / 2,984 Kw = 16.21 kts
Range 4,500nm at 10.00 kts
Bunker at max displacement = 238 tons
Complement:
260 - 339
Cost:
£2.216 million / $8.864 million
Distribution of weights at normal displacement:
Armament: 242 tons, 5.7 %
Armour: 1,054 tons, 25.0 %
- Belts: 289 tons, 6.9 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 225 tons, 5.3 %
- Armour Deck: 523 tons, 12.4 %
- Conning Tower: 17 tons, 0.4 %
Machinery: 104 tons, 2.5 %
Hull, fittings & equipment: 2,218 tons, 52.6 %
Fuel, ammunition & stores: 495 tons, 11.7 %
Miscellaneous weights: 100 tons, 2.4 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
9,140 lbs / 4,146 Kg = 23.5 x 9.2 " / 234 mm shells or 2.2 torpedoes
Stability (Unstable if below 1.00): 1.14
Metacentric height 2.6 ft / 0.8 m
Roll period: 14.3 seconds
Steadiness - As gun platform (Average = 50 %): 71 %
- Recoil effect (Restricted arc if above 1.00): 0.94
Seaboat quality (Average = 1.00): 1.57
Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.532
Length to Beam Ratio: 6.55 : 1
'Natural speed' for length: 22.36 kts
Power going to wave formation at top speed: 39 %
Trim (Max stability = 0, Max steadiness = 100): 45
Bow angle (Positive = bow angles forward): 15.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 16.00 ft / 4.88 m
- Forecastle (15 %): 16.00 ft / 4.88 m
- Mid (65 %): 16.00 ft / 4.88 m (10.00 ft / 3.05 m aft of break)
- Quarterdeck (18 %): 10.00 ft / 3.05 m
- Stern: 10.00 ft / 3.05 m
- Average freeboard: 13.90 ft / 4.24 m
Ship tends to be wet forward
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 58.7 %
- Above water (accommodation/working, high = better): 150.0 %
Waterplane Area: 14,140 Square feet or 1,314 Square metres
Displacement factor (Displacement / loading): 128 %
Structure weight / hull surface area: 115 lbs/sq ft or 561 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.91
- Longitudinal: 2.31
- Overall: 1.00
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather
Class Names: Crawford, Sir John Moore
Equipment List:
Gunnery Director Type 284 on main director
Gunnery Director Type 282M on both HACS
Air Search Radar Type 271M
Surface Search Radar Type 274Q