WesWorld

Not the best design ever, but I'll still like to know how people think about her. She's a bit short legged and has bad sea keeping in excahnge for high speed.


Enter ship name, Siam Destroyer laid down 1938

Displacement:
1,886 t light; 2,000 t standard; 2,220 t normal; 2,395 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(420.27 ft / 403.48 ft) x 36.68 ft x (13.12 / 13.77 ft)
(128.10 m / 122.98 m) x 11.18 m x (4.00 / 4.20 m)

Armament:
6 - 4.92" / 125 mm 50.0 cal guns - 55.12lbs / 25.00kg shells, 250 per gun
Dual purpose guns in deck and hoist mounts, 1938 Model
2 x Twin mounts on centreline, forward deck forward
1 raised mount - superfiring
1 x Twin mount on centreline, aft deck aft
6 - 2.17" / 55.0 mm 55.0 cal guns - 5.51lbs / 2.50kg shells, 1,000 per gun
Anti-air guns in deck mounts, 1938 Model
3 x Twin mounts on centreline, evenly spread
3 raised mounts
12 - 0.98" / 25.0 mm 75.0 cal guns - 0.55lbs / 0.25kg shells, 1,500 per gun
Anti-air guns in deck mounts, 1938 Model
6 x Twin mounts on sides, evenly spread
4 raised mounts
Weight of broadside 370 lbs / 168 kg
Main Torpedoes
8 - 23.6" / 600 mm, 29.53 ft / 9.00 m torpedoes - 2.402 t each, 19.214 t total
In 2 sets of deck mounted carriage/fixed tubes
Main DC/AS Mortars
50 - 440.92 lbs / 200.00 kg Depth Charges + 2 reloads - 10.236 t total
in Stern depth charge racks

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.98" / 25 mm - -
2nd: 0.79" / 20 mm - -
3rd: 0.39" / 10 mm - -

- Conning towers: Forward 0.98" / 25 mm, Aft 0.00" / 0 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 50,689 shp / 37,814 Kw = 36.00 kts
Range 2,210nm at 20.00 kts
Bunker at max displacement = 396 tons

Complement:
161 - 210

Cost:
£1.503 million / $6.012 million

Distribution of weights at normal displacement:
Armament: 143 tons, 6.4%
- Guns: 106 tons, 4.8%
- Weapons: 37 tons, 1.7%
Armour: 15 tons, 0.7%
- Armament: 12 tons, 0.5%
- Conning Tower: 4 tons, 0.2%
Machinery: 1,124 tons, 50.6%
Hull, fittings & equipment: 563 tons, 25.4%
Fuel, ammunition & stores: 334 tons, 15.0%
Miscellaneous weights: 40 tons, 1.8%
- On freeboard deck: 20 tons
- Above deck: 20 tons

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
497 lbs / 226 Kg = 8.3 x 4.9 " / 125 mm shells or 0.2 torpedoes
Stability (Unstable if below 1.00): 1.21
Metacentric height 1.6 ft / 0.5 m
Roll period: 12.2 seconds
Steadiness - As gun platform (Average = 50 %): 50 %
- Recoil effect (Restricted arc if above 1.00): 0.42
Seaboat quality (Average = 1.00): 0.78

Hull form characteristics:
Hull has rise forward of midbreak,
a normal bow and large transom stern
Block coefficient (normal/deep): 0.400 / 0.411
Length to Beam Ratio: 11.00 : 1
'Natural speed' for length: 23.05 kts
Power going to wave formation at top speed: 66 %
Trim (Max stability = 0, Max steadiness = 100): 64
Bow angle (Positive = bow angles forward): 30.00 degrees
Stern overhang: 1.64 ft / 0.50 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 20.00%, 26.25 ft / 8.00 m, 18.86 ft / 5.75 m
- Forward deck: 20.00%, 18.86 ft / 5.75 m, 18.86 ft / 5.75 m
- Aft deck: 45.00%, 9.84 ft / 3.00 m, 9.84 ft / 3.00 m
- Quarter deck: 15.00%, 9.84 ft / 3.00 m, 9.84 ft / 3.00 m
- Average freeboard: 14.04 ft / 4.28 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 182.9%
- Above water (accommodation/working, high = better): 134.2%
Waterplane Area: 9,454 Square feet or 878 Square metres
Displacement factor (Displacement / loading): 68%
Structure weight / hull surface area: 37 lbs/sq ft or 181 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 1.10
- Overall: 0.54
Cramped machinery, storage, compartmentation space
Excellent accommodation and workspace room
Poor seaboat, wet and uncomfortable, reduced performance in heavy weather

0.78 is pretty bad, probably worth backing off a half-knot or so.

The 55mm AA battery is going to be fairly problematic, since it wasn't until after WWII that automatic guns in that size were perfected. A clip-fed automatic, like a big version of the 40mm Bofors, is possible, but difficult because of the increasing weight of clips.

Torpedo mounts should not be fixed tubes.

You probably don't need 50 depth charges in stern racks + reloads.

Quoted

Originally posted by Hrolf Hakonson
0.78 is pretty bad, probably worth backing off a half-knot or so.

Probably even worth a full knot.

Quoted

Originally posted by Hrolf Hakonson
The 55mm AA battery is going to be fairly problematic, since it wasn't until after WWII that automatic guns in that size were perfected. A clip-fed automatic, like a big version of the 40mm Bofors, is possible, but difficult because of the increasing weight of clips.

The Italians seems to be planning to mount 65mm AAs for their Rosolino Pilo class DDs if the guns successfully complete trials. I don't see then why it is bad to propose a new 55mm gun then.

Quoted

Originally posted by Hrolf Hakonson
Torpedo mounts should not be fixed tubes.

Ooops

Quoted

Originally posted by Hrolf Hakonson
You probably don't need 50 depth charges in stern racks + reloads.

why?

Quoted

The Italians seems to be planning to mount 65mm AAs for their Rosolino Pilo class DDs if the guns successfully complete trials. I don't see then why it is bad to propose a new 55mm gun then.

I should probably change that to the actual 37mm quadruple battery. The 65/64 automatic has been developed over the 1930s but doesn't really work that well. Italy decided it wanted a larger calibre for better surface capability and moved to a 76/62. This is just coming into service in manually loaded form - but enclosed mountings with RPC. Probably worth 3-4 40mm Bofors. Trials are still ongoing with the automatic version. Probably be introduced in the early 1940s with around 30rpm and then progressively raised in blocks (to the current 120).

There are a few other countries with AA guns larger than 40mm. Italy has a 47mm which is basically a 3pdr pompom and muzzle velocity and rate of fire a bit low. Japan has a 50mm with unknown charateristics. Mexico has a 47mm from somewhere. The UK has a new 6pdr/57mm but semi-auto with probably around 25rpm (the UK did build a fully automatic 6pdr in the period but it didn't work). Iberia has been playing around with various 57mm guns. Currently has an automatic with rof of 60+, that's probably the best choice for Siam.

Quoted

You probably don't need 50 depth charges in stern racks + reloads.

A destroyer isn't a great anti-submarine platform. Most likely just to carry one or two patterns to force submarines to keep their heads down.

Otherwise looks pretty good for Siam I think.

Quoted

Originally posted by Red Admiral
Italy decided it wanted a larger calibre for better surface capability and moved to a 76/62.

I'd seriously mulled acquiring or attempting to develop my own 57mm AA gun, but ended up doing much the same thing. Mostly because I had an existing 3" DP gun that gets put on minesweepers, and I hate introducing new calibers...

A revised version with decreased speed but improved sea keeping and range:


Enter ship name, Siam Destroyer laid down 1938

Displacement:
1,884 t light; 2,000 t standard; 2,308 t normal; 2,554 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(428.21 ft / 411.42 ft) x 37.40 ft x (13.12 / 14.00 ft)
(130.52 m / 125.40 m) x 11.40 m x (4.00 / 4.27 m)

Armament:
6 - 4.92" / 125 mm 50.0 cal guns - 55.12lbs / 25.00kg shells, 250 per gun
Dual purpose guns in deck and hoist mounts, 1938 Model
2 x Twin mounts on centreline, forward deck forward
1 raised mount - superfiring
1 x Twin mount on centreline, aft deck aft
6 - 2.17" / 55.0 mm 55.0 cal guns - 5.51lbs / 2.50kg shells, 1,000 per gun
Anti-air guns in deck mounts, 1938 Model
3 x Twin mounts on centreline, evenly spread
3 raised mounts
12 - 0.98" / 25.0 mm 75.0 cal guns - 0.55lbs / 0.25kg shells, 1,500 per gun
Anti-air guns in deck mounts, 1938 Model
6 x Twin mounts on sides, evenly spread
4 raised mounts
Weight of broadside 370 lbs / 168 kg
Main Torpedoes
8 - 23.6" / 600 mm, 29.53 ft / 9.00 m torpedoes - 2.402 t each, 19.214 t total
In 2 sets of deck mounted centre rotating tubes

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.98" / 25 mm - -
2nd: 0.79" / 20 mm - -
3rd: 0.39" / 10 mm - -

- Conning towers: Forward 0.98" / 25 mm, Aft 0.00" / 0 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 45,850 shp / 34,204 Kw = 35.00 kts
Range 3,075nm at 20.00 kts
Bunker at max displacement = 554 tons

Complement:
166 - 216

Cost:
£1.479 million / $5.917 million

Distribution of weights at normal displacement:
Armament: 144 tons, 6.3%
- Guns: 106 tons, 4.6%
- Weapons: 38 tons, 1.7%
Armour: 15 tons, 0.7%
- Armament: 12 tons, 0.5%
- Conning Tower: 4 tons, 0.2%
Machinery: 1,094 tons, 47.4%
Hull, fittings & equipment: 590 tons, 25.6%
Fuel, ammunition & stores: 424 tons, 18.4%
Miscellaneous weights: 40 tons, 1.7%
- On freeboard deck: 20 tons
- Above deck: 20 tons

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
626 lbs / 284 Kg = 10.5 x 4.9 " / 125 mm shells or 0.2 torpedoes
Stability (Unstable if below 1.00): 1.30
Metacentric height 1.8 ft / 0.6 m
Roll period: 11.6 seconds
Steadiness - As gun platform (Average = 50 %): 50 %
- Recoil effect (Restricted arc if above 1.00): 0.38
Seaboat quality (Average = 1.00): 0.91

Hull form characteristics:
Hull has rise forward of midbreak,
a normal bow and large transom stern
Block coefficient (normal/deep): 0.400 / 0.415
Length to Beam Ratio: 11.00 : 1
'Natural speed' for length: 23.28 kts
Power going to wave formation at top speed: 64 %
Trim (Max stability = 0, Max steadiness = 100): 55
Bow angle (Positive = bow angles forward): 30.00 degrees
Stern overhang: 1.64 ft / 0.50 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 20.00%, 26.25 ft / 8.00 m, 18.70 ft / 5.70 m
- Forward deck: 20.00%, 18.70 ft / 5.70 m, 18.70 ft / 5.70 m
- Aft deck: 45.00%, 10.83 ft / 3.30 m, 10.83 ft / 3.30 m
- Quarter deck: 15.00%, 10.83 ft / 3.30 m, 10.83 ft / 3.30 m
- Average freeboard: 14.58 ft / 4.44 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 171.9%
- Above water (accommodation/working, high = better): 114.2%
Waterplane Area: 9,830 Square feet or 913 Square metres
Displacement factor (Displacement / loading): 77%
Structure weight / hull surface area: 37 lbs/sq ft or 180 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 1.15
- Overall: 0.54
Cramped machinery, storage, compartmentation space
Adequate accommodation and workspace room
Poor seaboat, wet and uncomfortable, reduced performance in heavy weather


-so probably going for a Siamese 55mm version of the Iberian 57mm?


On a side note, if I still want to stick to 36 knots:


Enter ship name, Siam Destroyer laid down 1938

Displacement:
1,886 t light; 2,000 t standard; 2,208 t normal; 2,374 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(418.53 ft / 402.40 ft) x 36.58 ft x (13.12 / 13.74 ft)
(127.57 m / 122.65 m) x 11.15 m x (4.00 / 4.19 m)

Armament:
6 - 4.92" / 125 mm 50.0 cal guns - 55.12lbs / 25.00kg shells, 250 per gun
Dual purpose guns in deck and hoist mounts, 1938 Model
2 x Twin mounts on centreline, forward deck forward
1 raised mount - superfiring
1 x Twin mount on centreline, aft deck aft
6 - 2.17" / 55.0 mm 55.0 cal guns - 5.51lbs / 2.50kg shells, 1,000 per gun
Anti-air guns in deck mounts, 1938 Model
3 x Twin mounts on centreline, evenly spread
3 raised mounts
12 - 0.98" / 25.0 mm 75.0 cal guns - 0.55lbs / 0.25kg shells, 1,500 per gun
Anti-air guns in deck mounts, 1938 Model
6 x Twin mounts on sides, evenly spread
4 raised mounts
Weight of broadside 370 lbs / 168 kg
Main Torpedoes
8 - 23.6" / 600 mm, 29.53 ft / 9.00 m torpedoes - 2.402 t each, 19.214 t total
In 2 sets of deck mounted centre rotating tubes

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.98" / 25 mm - -
2nd: 0.79" / 20 mm - -
3rd: 0.39" / 10 mm - -

- Conning towers: Forward 0.98" / 25 mm, Aft 0.00" / 0 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 50,585 shp / 37,736 Kw = 36.00 kts
Range 2,088nm at 20.00 kts
Bunker at max displacement = 374 tons

Complement:
160 - 209

Cost:
£1.499 million / $5.995 million

Distribution of weights at normal displacement:
Armament: 144 tons, 6.5%
- Guns: 106 tons, 4.8%
- Weapons: 38 tons, 1.7%
Armour: 15 tons, 0.7%
- Armament: 12 tons, 0.5%
- Conning Tower: 4 tons, 0.2%
Machinery: 1,118 tons, 50.7%
Hull, fittings & equipment: 568 tons, 25.7%
Fuel, ammunition & stores: 322 tons, 14.6%
Miscellaneous weights: 40 tons, 1.8%
- On freeboard deck: 20 tons
- Above deck: 20 tons

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
499 lbs / 226 Kg = 8.4 x 4.9 " / 125 mm shells or 0.2 torpedoes
Stability (Unstable if below 1.00): 1.21
Metacentric height 1.6 ft / 0.5 m
Roll period: 12.3 seconds
Steadiness - As gun platform (Average = 50 %): 50 %
- Recoil effect (Restricted arc if above 1.00): 0.43
Seaboat quality (Average = 1.00): 0.80

Hull form characteristics:
Hull has rise forward of midbreak,
a normal bow and large transom stern
Block coefficient (normal/deep): 0.400 / 0.411
Length to Beam Ratio: 11.00 : 1
'Natural speed' for length: 23.02 kts
Power going to wave formation at top speed: 66 %
Trim (Max stability = 0, Max steadiness = 100): 63
Bow angle (Positive = bow angles forward): 30.00 degrees
Stern overhang: 0.98 ft / 0.30 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 20.00%, 26.25 ft / 8.00 m, 19.36 ft / 5.90 m
- Forward deck: 20.00%, 19.36 ft / 5.90 m, 19.36 ft / 5.90 m
- Aft deck: 45.00%, 9.84 ft / 3.00 m, 9.84 ft / 3.00 m
- Quarter deck: 15.00%, 9.84 ft / 3.00 m, 9.84 ft / 3.00 m
- Average freeboard: 14.20 ft / 4.33 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 183.1%
- Above water (accommodation/working, high = better): 107.7%
Waterplane Area: 9,404 Square feet or 874 Square metres
Displacement factor (Displacement / loading): 68%
Structure weight / hull surface area: 37 lbs/sq ft or 181 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 1.15
- Overall: 0.54
Cramped machinery, storage, compartmentation space
Adequate accommodation and workspace room
Poor seaboat, wet and uncomfortable, reduced performance in heavy weather

Quoted

Originally posted by Brockpaine

Quoted

Originally posted by Red Admiral
Italy decided it wanted a larger calibre for better surface capability and moved to a 76/62.

I'd seriously mulled acquiring or attempting to develop my own 57mm AA gun, but ended up doing much the same thing. Mostly because I had an existing 3" DP gun that gets put on minesweepers, and I hate introducing new calibers...

Hmmm... thinking of having a combo of 100mm and 55mm instead of having the 76mm...

Quoted

Originally posted by gaiasabre11

Quoted

Originally posted by Brockpaine

Quoted

Originally posted by Red Admiral
Italy decided it wanted a larger calibre for better surface capability and moved to a 76/62.

I'd seriously mulled acquiring or attempting to develop my own 57mm AA gun, but ended up doing much the same thing. Mostly because I had an existing 3" DP gun that gets put on minesweepers, and I hate introducing new calibers...

Hmmm... thinking of having a combo of 100mm and 55mm instead of having the 76mm...

I gave that some consideration, yes. Starting off in Chile, I had a lot of calibers in the pot: 20mm, 37mm, 40mm, 48.3mm, 3", 100mm, 102mm, 105mm, 109mm, 110mm, 119mm, 127mm, 130mm, 140mm, and 150mm. Some of the guns in that spread were old, some rare, some not so rare.

The decision I finally made was that 130mm would be the main gun for destroyers, carriers, and capital ship secondaries; 20mm and 40mm would be the main AA guns; 110mm would go aboard auxiliaries and sea escorts (frigates); and 100mm is the deck gun for submarines. 3", despite the slower rate of fire, gets used as the primary AA battery aboard capital ships, but I don't have very many of those coming down the line. 3" also gets used aboard submarine chasers, minesweepers, and other assorted ships.

The Chileans mainly want the 3" HA/LA because it has good performance for shooting at high altitudes and angles (shooting at divebombers), good performance for shooting at submarines and MTBs, and good range to excel in both roles. 100mm might have done the trick, but I had a kissing cousin in the much more prolific and fairly modern 110mm. The 3" was in service and the Armada determined it worked better than a weapon in the 40mm-65mm range anyway. Why spend money to develop an inferior weapon?

In fact, I'm a greedy man. I want to have them all: 25mm, 55mm, 75mm, 100mm, and 125mm.

This is what I envision:

125mm would be the main gun for destroyers, carriers, and capital ship secondaries; 25mm and 55mm would be the main AA guns; 100mm would go aboard auxiliaries, sea escorts (frigates), and the deck gun for submarines. 75mm gets used aboard submarine chasers, minesweepers, and other assorted ships.

Perhaps the 75mms can be used in place of 55mm on board of larger ships, but they are heavier and requires more crew to handle than the 55mm, hence I prefer the 55mm in lighter AA applications. (Oh, and btw, I'm not really convinced that the 3" can work as a better AA weapon than a wepon in the 55~65mm range.)