If depth of system is the key to a useful TDS, does a heavy cruiser with a maximum beam of ~21 - 22 metres have enough space to trade away for the purpose? Or does it just produce an ineffective waste of space while scrunching everything else into a tighter arrangement?
1. No 2. Yes
A beam of 21-22m is insufficient to have a fully functionning TDS. There isn't enough space for the force of the explosion to disappate. However having the longitudinal bulkhead present would be better than not having it. The better subdivision is probably useful. Everything else is really crammed in with the main belt having to be very long. Having a TDS of 30mm thick or so allows for 2 layers, a 10mm thick bulkhead + 20mm splinter bulkhead inboard.
The system should be 4-5m deep at minimum.
22m beam - 4x2 =14 m for mounting your magazine and machinery.
However; The real killer thing is the hullform of cruisers. It gets very narrow out towards the ends, i.e. where the turrets are, and there would be nowhere near enough beam available.
A very old design on file below;
Italian ACR laid down 1931
Displacement:
12,936 t light; 13,496 t standard; 15,454 t normal; 17,020 t full load
Dimensions: Length overall / water x beam x draught
625.46 ft / 610.24 ft x 74.02 ft x 23.95 ft (normal load)
190.64 m / 186.00 m x 22.56 m x 7.30 m
Armament:
9 - 7.99" / 203 mm guns (3x3 guns), 255.24lbs / 115.78kg shells, 1931 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, majority forward, 1 raised mount - superfiring
16 - 3.94" / 100 mm guns (4x4 guns), 33.07lbs / 15.00kg shells, 1931 Model
Anti-aircraft guns in deck mounts with hoists
on side, all amidships
16 - 1.46" / 37.0 mm guns (4x4 guns), 1.83lbs / 0.83kg shells, 1931 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
Weight of broadside 2,856 lbs / 1,295 kg
Shells per gun, main battery: 150
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 5.12" / 130 mm 479.00 ft / 146.00 m 10.33 ft / 3.15 m
Ends: Unarmoured
Main Belt covers 121 % of normal length
- Torpedo Bulkhead:
1.18" / 30 mm 479.00 ft / 146.00 m 21.06 ft / 6.42 m
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 5.91" / 150 mm 3.94" / 100 mm 5.51" / 140 mm
2nd: 1.18" / 30 mm 0.79" / 20 mm -
3rd: 0.39" / 10 mm 0.39" / 10 mm -
- Armour deck: 1.97" / 50 mm, Conning tower: 5.91" / 150 mm
Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 110,000 shp / 82,060 Kw = 31.85 kts
Range 6,000nm at 20.00 kts
Bunker at max displacement = 3,524 tons
Complement:
692 - 900
Cost:
£5.273 million / $21.091 million
Distribution of weights at normal displacement:
Armament: 351 tons, 2.3 %
Armour: 3,282 tons, 21.2 %
- Belts: 1,037 tons, 6.7 %
- Torpedo bulkhead: 441 tons, 2.9 %
- Armament: 629 tons, 4.1 %
- Armour Deck: 1,096 tons, 7.1 %
- Conning Tower: 79 tons, 0.5 %
Machinery: 3,289 tons, 21.3 %
Hull, fittings & equipment: 5,913 tons, 38.3 %
Fuel, ammunition & stores: 2,518 tons, 16.3 %
Miscellaneous weights: 100 tons, 0.6 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
22,477 lbs / 10,196 Kg = 88.1 x 8.0 " / 203 mm shells or 3.1 torpedoes
Stability (Unstable if below 1.00): 1.26
Metacentric height 4.9 ft / 1.5 m
Roll period: 14.1 seconds
Steadiness - As gun platform (Average = 50 %): 50 %
- Recoil effect (Restricted arc if above 1.00): 0.35
Seaboat quality (Average = 1.00): 1.05
Hull form characteristics:
Hull has low quarterdeck
Block coefficient: 0.500
Length to Beam Ratio: 8.24 : 1
'Natural speed' for length: 24.70 kts
Power going to wave formation at top speed: 58 %
Trim (Max stability = 0, Max steadiness = 100): 48
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 3.28 ft / 1.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 32.81 ft / 10.00 m
- Forecastle (20 %): 22.97 ft / 7.00 m
- Mid (50 %): 22.97 ft / 7.00 m
- Quarterdeck (23 %): 13.12 ft / 4.00 m (22.97 ft / 7.00 m before break)
- Stern: 13.12 ft / 4.00 m
- Average freeboard: 21.49 ft / 6.55 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 120.5 %
- Above water (accommodation/working, high = better): 190.2 %
Waterplane Area: 30,094 Square feet or 2,796 Square metres
Displacement factor (Displacement / loading): 121 %
Structure weight / hull surface area: 128 lbs/sq ft or 623 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.95
- Longitudinal: 1.53
- Overall: 1.00
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is excellent
Quoted
If depth of system is the key to a useful TDS, does a heavy cruiser with a maximum beam of ~21 - 22 metres have enough space to trade away for the purpose? Or does it just produce an ineffective waste of space while scrunching everything else into a tighter arrangement?
Friday, April 19th 2024, 9:28am
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