WesWorld

this is what happens when I am on a plane with springsharp and Conways...

First up, a folow-on to the Dolphin class submarines currently under constuction.

Dolphin II, Thai Submarine laid down 1941

Displacement:
600 t light; 618 t standard; 665 t normal; 702 t full load

Dimensions: Length overall / water x beam x draught
209.97 ft / 209.97 ft x 19.03 ft x 14.44 ft (normal load)
64.00 m / 64.00 m x 5.80 m x 4.40 m

Armament:
1 - 3.94" / 100 mm guns in single mounts, 30.86lbs / 14.00kg shells, 1941 Model
Quick firing gun in deck mount
on centreline amidships
1 - 1.46" / 37.0 mm guns in single mounts, 1.55lbs / 0.70kg shells, 1941 Model
Dual purpose gun in deck mount
on centreline amidships
2 - 0.79" / 20.0 mm guns (1x2 guns), 0.24lbs / 0.11kg shells, 1941 Model
Machine guns in deck mount
on centreline amidships, all raised guns - superfiring
Weight of broadside 33 lbs / 15 kg
Shells per gun, main battery: 250
5 - 21.0" / 533.4 mm submerged torpedo tubes

Machinery:
Diesel Internal combustion generators plus batteries,
Electric motors, 2 shafts, 1,533 shp / 1,144 Kw = 16.00 kts
Range 7,500nm at 8.00 kts
Bunker at max displacement = 84 tons

Complement:
65 - 85

Cost:
£0.186 million / $0.744 million

Distribution of weights at normal displacement:
Armament: 4 tons, 0.6 %
Machinery: 41 tons, 6.1 %
Hull, fittings & equipment: 423 tons, 63.6 %
Fuel, ammunition & stores: 65 tons, 9.7 %
Miscellaneous weights: 133 tons, 20.0 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
326 lbs / 148 Kg = 10.7 x 3.9 " / 100 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.00
Metacentric height 0.4 ft / 0.1 m
Roll period: 12.4 seconds
Steadiness - As gun platform (Average = 50 %): 0 %
- Recoil effect (Restricted arc if above 1.00): 0.00
Seaboat quality (Average = 1.00): 0.00

Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.404
Length to Beam Ratio: 11.03 : 1
'Natural speed' for length: 14.49 kts
Power going to wave formation at top speed: 39 %
Trim (Max stability = 0, Max steadiness = 100): 50
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: 0.00 ft / 0.00 m
- Forecastle (20 %): 0.00 ft / 0.00 m
- Mid (50 %): 0.00 ft / 0.00 m
- Quarterdeck (15 %): 0.00 ft / 0.00 m
- Stern: 0.00 ft / 0.00 m
- Average freeboard: 0.00 ft / 0.00 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 100.7 %
- Above water (accommodation/working, high = better): 0.0 %
Waterplane Area: 2,465 Square feet or 229 Square metres
Displacement factor (Displacement / loading): 270 %
Structure weight / hull surface area: 103 lbs/sq ft or 501 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 3.54
- Longitudinal: 2.54
- Overall: 2.76
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is extremely poor
Ship has quick, lively roll, not a steady gun platform
Caution: Lacks seaworthiness - very limited seakeeping ability

Operational Depth: 82.8m
Emergenty Diving Depth: 132.48m
Crush Depth: 207m
Actual Crew: 32-42

As the first submarines constucted in Thailand were being layed down in the middle of 1940, the Thai navy was already looking to build bigger boats. At almost double the size of the original Dolphin I design, the Dolphin II class subs bring the Thai navy to the ranks of nations with cabable domestic submairne programs. Equiped with five 21" torpedo tubes and a 100mm gun, these subs have a considerable ammament. A 37mm dual purpace anti-aircarft gun supliments both the antiship battery and aids the 20mm guns in fending off aircraft. With over 1.5 times the range of the Dolphin I class, the Dolphin IIs alow for a much greater projection of the Thai Navy's power. The dolphin II class brings both the abilties of the Thai Navy and the domestic shipyards up to producing subs that can compaire with modern types in servace the world over.

And next, a corvette of sorts

Monarch, Thai Escort/Patrol Corvette laid down 1941

Displacement:
750 t light; 785 t standard; 895 t normal; 984 t full load

Dimensions: Length overall / water x beam x draught
206.69 ft / 196.85 ft x 31.17 ft x 9.84 ft (normal load)
63.00 m / 60.00 m x 9.50 m x 3.00 m

Armament:
1 - 3.94" / 100 mm guns in single mounts, 30.86lbs / 14.00kg shells, 1941 Model
Dual purpose gun in a deck mount with hoist
on centreline forward
6 - 2.24" / 57.0 mm guns (3x2 guns), 5.65lbs / 2.56kg shells, 1941 Model
Dual purpose guns in deck mounts with hoists
on centreline, all amidships, 1 raised mount - superfiring
8 - 0.79" / 20.0 mm guns (4x2 guns), 0.24lbs / 0.11kg shells, 1941 Model
Machine guns in deck mounts
on side, all amidships
Weight of broadside 67 lbs / 30 kg
Shells per gun, main battery: 350

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.79" / 20 mm 0.20" / 5 mm 0.79" / 20 mm
2nd: 0.39" / 10 mm - 0.79" / 20 mm
3rd: 0.20" / 5 mm - -

- Conning tower: 1.18" / 30 mm

Machinery:
Oil fired boilers, complex reciprocating steam engines,
Direct drive, 2 shafts, 3,201 ihp / 2,388 Kw = 18.06 kts
Range 5,000nm at 12.00 kts
Bunker at max displacement = 199 tons

Complement:
81 - 106

Cost:
£0.358 million / $1.431 million

Distribution of weights at normal displacement:
Armament: 8 tons, 0.9 %
Armour: 6 tons, 0.7 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 4 tons, 0.4 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 2 tons, 0.3 %
Machinery: 176 tons, 19.6 %
Hull, fittings & equipment: 295 tons, 33.0 %
Fuel, ammunition & stores: 145 tons, 16.2 %
Miscellaneous weights: 265 tons, 29.6 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
1,085 lbs / 492 Kg = 35.6 x 3.9 " / 100 mm shells or 0.5 torpedoes
Stability (Unstable if below 1.00): 1.10
Metacentric height 1.0 ft / 0.3 m
Roll period: 12.8 seconds
Steadiness - As gun platform (Average = 50 %): 50 %
- Recoil effect (Restricted arc if above 1.00): 0.16
Seaboat quality (Average = 1.00): 1.26

Hull form characteristics:
Hull has low quarterdeck
Block coefficient: 0.519
Length to Beam Ratio: 6.32 : 1
'Natural speed' for length: 14.03 kts
Power going to wave formation at top speed: 60 %
Trim (Max stability = 0, Max steadiness = 100): 39
Bow angle (Positive = bow angles forward): 30.00 degrees
Stern overhang: 2.26 ft / 0.69 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 13.12 ft / 4.00 m
- Forecastle (20 %): 11.48 ft / 3.50 m
- Mid (50 %): 11.48 ft / 3.50 m
- Quarterdeck (15 %): 6.56 ft / 2.00 m (11.48 ft / 3.50 m before break)
- Stern: 6.56 ft / 2.00 m
- Average freeboard: 10.88 ft / 3.32 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 104.5 %
- Above water (accommodation/working, high = better): 112.3 %
Waterplane Area: 4,160 Square feet or 386 Square metres
Displacement factor (Displacement / loading): 130 %
Structure weight / hull surface area: 44 lbs/sq ft or 214 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.88
- Longitudinal: 3.18
- Overall: 1.01
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is adequate
Good seaboat, rides out heavy weather easily

After the defence review conduted in late 1940, one thing became clear to the Thai Navy. During wartime and peacetime, there was a sever lack of light craft. With the needs of escorting the two new aircraft carriers purchaced from Italy predicted to take up most of the small flotilla of destoyers at any time, and the inabiltiy of domestic Thai yards to build modern types in any signifigent number, a different soultion was needed. Due to the demands that this new ship would have to fufill, it was quickly apparent that the high speed that was inherent of modern Destoryers was uneeded. Subhunting was considered to be the primary role along with patrol and other coast guard like duties, none of which requier high speed. With this in mind, Thai designers chose to look at the carateristcs that defined the emergency escort vessles built during the Great War. The Monarch class embodies all of the roles that the ships need to handle. One 100mm gun is adiquit for all patrol and coastguard duties, while still being powerful for taking on surfaced submarines. Many depthcharges are caired for causeing havoc to submerged submarines as well. A heavy 57mm dual purpace anti-aircraft battery is also caried to aid in the neuturalzation of surface threats and to provide defence against aircraft along with 20mm cannon. The Monarchs are also equiped with many advanced fetures, and the abilty to take on more grear then is currently avalible. While they may not be a match for a true desotyer, the Monarch class corvettes alow the Thai navy the flexibilty with how it deploys its destoyers wile still providing esential duties that are invauble in times of peace and war.

Thoughts on these?

Yeah. Oil fired complex reciprocating engines?

Good catch!

historic Flower class corvettes used them according to conways. that was what I based this design on.

If I recall correctly, at around eighteen knots and under, complex reciprocating is more reliable and fuel-efficient than turbines. Diesels are slightly better, though.

Snip - one of your closest allies, Denmark, happens to have one of the world's leading maritime diesel makers: Bumeister & Wain. I'd suggest talking with B&W as a fallback position.

always an alternative. problem is it makes getting acquit stability a bit harder, and I need the hull to be this size for being able to fit all the equipment on there. but something to keep in mind for later

Quoted

Originally posted by Brockpaine
If I recall correctly, at around eighteen knots and under, complex reciprocating is more reliable and fuel-efficient than turbines. Diesels are slightly better, though.

I'm not sure I'd agree with more reliable or fuel efficient for reciprocating engines. Maybe for direct drive turbines (i.e. large diameter and low pressure) but not for modern geared drives. However, it's probably appropriate that Thailand doesn't have an industry capable of manufacturing large quantities of turbine blades or gear cutting. The reciprocating option is indigenous, and likely cheaper.

Diesels are still a bit of an unknown quantity in this period. Italy has used the historical diesel-electric setup in the Gabbiano-Class corvettes (and scaled up as well) as I couldn't find any mentions of issues.