WesWorld

Otta class CVX (0 units) - 1911/20 (now repair ship)

Palk Bay class CVS (0 units) - 1921

Urumi class CV (2 units) - 1924/1939 + 1927/1941-42

Gaudhi Sagar class CVS (2 units) - 1929-30

Lathi class CVT (0 unit) - 1921/31, to China 1945

Talwar class CV (2 units) - 1929-30

Aruval class CVE (0 unit) - 1931/1937

Vel class CVE (1 training unit) - 1929/1938

Katar class CVE (0 unit) - 1930/1938

Khanda class CV (0 unit) - 1941

Bagh Nakh class CV (1 unit) - 1940/42

[SIZE=3]Otta Class Aircraft Carrier[/SIZE]

Note: formerly the collier Bhima. She was taken in hand for conversion in 1920, when it was decided that possessing an "experimental carrier" under the looming Cleito Treaty, which could be replaced by 1925, was more desirable than being stuck with whatever the first purpose-built attempt turned out like, for up to twenty years.

Deleted from service in early 1927, and rebuilt as a repair ship.



Otta, CV-1, laid down 1911, converted 1920

(Note: not re-engined)

Length, 142.7 m x Beam, 19.8 m x Depth, 5.5 m
9387 tonnes normal displacement (8268 tonnes standard)

Airgroup: 40 max; typically 8 fighters, 12 bombers, 4 trainers

Main battery: 4 x 10.5-cm
Secondary battery: 8 x 3.5-cm
QF battery: 8 x 1.5-cm

Weight of broadside: 69 kg

Armor deck, average 2.5 cm
Conning tower, 2.5 cm

Battery armor:
Main, 5.0 cm shields / secondary, 2.0 cm
QF, 2.0 cm shields

Maximum speed for 3996 shaft kw = 15.00 knots
Approximate cruising radius, 10000 nm / 10 knots

Typical complement: 477-620


Estimated cost, $1.327 million (£332,000)

Remarks:

Ship has slow, easy roll; a good, steady gun platform.

Excellent seaboat; comfortable and able to fight her guns
in the heaviest weather.

Magazines and engineering spaces are roomy, with superior
watertight subdivision.

Ship is roomy, with superior accommodation and working space.

Main deck secondary guns subject to being washed down
in a seaway.


Distribution of weights:
Percent
normal
displacement:

Armament ......................... 19 tonnes = 0 pct
Armor, total ..................... 418 tonnes = 4 pct

Deck 393 tonnes = 4 pct
C.T. 9 tonnes = 0 pct
Armament 15 tonnes = 0 pct

Machinery ........................ 239 tonnes = 3 pct
Hull and fittings; equipment ..... 5392 tonnes = 57 pct
Fuel, ammunition, stores ......... 1319 tonnes = 14 pct
Miscellaneous weights ............ 2000 tonnes = 21 pct
-----
9387 tonnes = 100 pct

Estimated metacentric height, 1.0 m

Displacement summary:

Light ship: 8068 tonnes
Standard displacement: 8268 tonnes
Normal service: 9387 tonnes
Full load: 10244 tonnes

Loading submergence 2025 tonnes/metre

+++++++++++++++++++++++++


Estimated overall survivability and seakeeping ability:

Relative margin of stability: 1.12

Shellfire needed to sink: 13203 kg = 822.4 x 10.5-cm shells
(Approximates weight of penetrating
shell hits needed to sink ship,
not counting critical hits)

Torpedoes needed to sink: 5.5
(Approximates number of 'typical'
torpedo hits needed to sink ship)

Relative steadiness as gun platform, 76 percent
(50 percent is 'average')

Relative rocking effect from firing to beam, 0.01

Relative quality as a seaboat: 1.53

+++++++++++++++++++++++++


Hull form characteristics:

Block coefficient: 0.60
Sharpness coefficient: 0.40
Hull speed coefficient 'M' = 6.78
'Natural speed' for length = 21.6 knots
Power going to wave formation
at top speed: 30 percent


Estimated hull characteristics and strength:

Relative underwater volume absorbed by
magazines and engineering spaces: 34 percent

Relative accommodation and working space: 133 percent


Displacement factor: 308 percent
(Displacement relative to loading factors)


Relative cross-sectional hull strength: 2.22
(Structure weight per square
metre of hull surface: 863 kg)

Relative longitudinal hull strength: 2.48
(for 4.70 m average freeboard;
freeboard adjustment +0.14 m)

Relative composite hull strength: 2.24

+++++++++++++++++++++++++


[Machine-readable parameters: Spring Style v. 1.2.1]

468.00 x 65.00 x 18.00; 15.42 -- Dimensions
0.60 -- Block coefficient
1911 -- Year laid down
15.00 / 10000 / 10.00; Turbine, coal fired -- Speed / radius / cruise
2000 tons -- Miscellaneous weights
++++++++++
4 x 4.13; 0 -- Main battery; turrets
Central positioning of guns
Gun-shields
:
8 x 1.38; 0 -- Secondary battery; turrets
Main deck battery
:
8 x 0.59 -- Tertiary (QF/AA) battery
Gun-shields
:
0 -- No fourth (light) battery
0 -- No torpedo armament
++++++++++
0.00 -- No belt armor
0.98 / 0.98 -- Deck / CT
1.97 / 0.79 / 0.79 / 0.00 -- Battery armor


(Note: For portability, values are stored in Anglo-American units)


+++++++++++++++++++++++++++++++++++++++++++++++++++++++

[SIZE=3]Palk Bay Class Seaplane Tender/Survey Ship[/SIZE]



Palk Bay, CVS-2, laid down 1921, to China 1939

Length, 152.4 m x Beam, 19.8 m x Depth, 4.9 m
7874 tonnes normal displacement (6819 tonnes standard)

Airgroup: typically 10 floatplanes

Main battery: 4 x 10.5-cm
Secondary battery: 8 x 3.5-cm
AA battery: 6 x 1.5-cm

Weight of broadside: 69 kg

Hull unarmored

Battery armor:
Main, 5.0 cm shields / secondary, 2.0 cm shields
AA, 2.0 cm shields

Maximum speed for 8999 shaft kw = 19.53 knots
Approximate cruising radius, 14000 nm / 12 knots

Typical complement: 418-543


Estimated cost, $3.124 million (£781,000)

Remarks:

Ship has slow, easy roll; a good, steady gun platform.

Excellent seaboat; comfortable and able to fight her guns
in the heaviest weather.

Magazines and engineering spaces are roomy, with superior
watertight subdivision.

Ship is roomy, with superior accommodation and working space.

Ship includes extensive working space for scientific and surveying missions.


Distribution of weights:
Percent
normal
displacement:

Armament ......................... 19 tonnes = 0 pct
Armor, total ..................... 15 tonnes = 0 pct

Armament 15 tonnes = 0 pct

Machinery ........................ 415 tonnes = 5 pct
Hull and fittings; equipment ..... 4199 tonnes = 53 pct
Fuel, ammunition, stores ......... 1226 tonnes = 16 pct
Miscellaneous weights ............ 2000 tonnes = 25 pct
-----
7874 tonnes = 100 pct

Estimated metacentric height, 0.9 m

Displacement summary:

Light ship: 6649 tonnes
Standard displacement: 6819 tonnes
Normal service: 7874 tonnes
Full load: 8687 tonnes

Loading submergence 1990 tonnes/metre

+++++++++++++++++++++++++


Estimated overall survivability and seakeeping ability:

Relative margin of stability: 1.07

Shellfire needed to sink: 9838 kg = 612.7 x 10.5-cm shells
(Approximates weight of penetrating
shell hits needed to sink ship,
not counting critical hits)

Torpedoes needed to sink: 3.8
(Approximates number of 'typical'
torpedo hits needed to sink ship)

Relative steadiness as gun platform, 91 percent
(50 percent is 'average')

Relative rocking effect from firing to beam, 0.02

Relative quality as a seaboat: 1.82

+++++++++++++++++++++++++


Hull form characteristics:

Block coefficient: 0.53
Sharpness coefficient: 0.37
Hull speed coefficient 'M' = 7.69
'Natural speed' for length = 22.4 knots
Power going to wave formation
at top speed: 38 percent


Estimated hull characteristics and strength:

Relative underwater volume absorbed by
magazines and engineering spaces: 48 percent

Relative accommodation and working space: 194 percent


Displacement factor: 263 percent
(Displacement relative to loading factors)


Relative cross-sectional hull strength: 1.56
(Structure weight per square
metre of hull surface: 639 kg)

Relative longitudinal hull strength: 2.34
(for 6.10 m average freeboard;
freeboard adjustment +1.70 m)

Relative composite hull strength: 1.63

+++++++++++++++++++++++++


[Machine-readable parameters: Spring Style v. 1.2.1]

500.00 x 65.00 x 16.00; 20.01 -- Dimensions
0.53 -- Block coefficient
1921 -- Year laid down
19.53 / 14000 / 12.00; Oil-fired turbine or equivalent -- Speed / radius / cruise
2000 tons -- Miscellaneous weights
++++++++++
4 x 4.13; 0 -- Main battery; turrets
Central positioning of guns
Gun-shields
:
8 x 1.38; 0 -- Secondary battery; turrets
Gun-shields
:
6 x 0.59 -- Tertiary (QF/AA) battery
Gun-shields
:
0 -- No fourth (light) battery
0 -- No torpedo armament
++++++++++
0.00 -- No belt armor
0.00 / 0.00 -- Deck / CT
1.97 / 0.79 / 0.79 / 0.00 -- Battery armor


(Note: For portability, values are stored in Anglo-American units)


+++++++++++++++++++++++++++++++++++++++++++++++++++++++

[SIZE=3]Urumi Class Aircraft Carrier[/SIZE]

Urumi, CV-3, laid down 1925, refit 1939
Bichawa (ex-Sulu), CV-13, laid down 1927, acquired 1941, refit 1942

These ships were originally built as near-sisters for different navies. As early carriers, they were built to survive action against enemy scouting forces - hence carried a heavy gun armament and torpedos aft.

Urumi was Bharat's first carrier, and received a refit that extended her hanger and flight deck aft at the expense of the anti-surface battery.

Bichawa was laid down for the Philippines as Sulu and served until deemed surplus in 1941. The BNS acquired her and is undertaking a refit that will see her emerge functionally identical to Urumi. See the Filipino encyclopedia for details on her original configuration.

As Built...

As Refitted (both ships)

Displacement:
12,699 t light; 13,140 t standard; 14,625 t normal; 15,813 t full load

Dimensions: Length overall / water x beam x draught
676.04 ft / 665.85 ft x 74.11 ft x 20.34 ft (normal load)
206.06 m / 202.95 m x 22.59 m x 6.20 m

Armament:
20 - 4.13" / 105 mm guns (10x2 guns), 35.32lbs / 16.02kg shells, 1939 Model
Dual purpose guns in deck mounts with hoists
on centreline ends, evenly spread, all raised mounts - superfiring
6 - 1.38" / 35.0 mm guns (3x2 guns), 1.31lbs / 0.59kg shells, 1939 Model
Anti-aircraft guns in deck mounts
on side, all amidships, all raised mounts - superfiring
18 - 1.38" / 35.0 mm guns (6x3 guns), 1.31lbs / 0.59kg shells, 1939 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
8 - 0.59" / 15.0 mm guns (2x4 guns), 0.10lbs / 0.05kg shells, 1939 Model
Machine guns in deck mounts
on side, evenly spread
8 - 0.59" / 15.0 mm guns (6 mounts), 0.10lbs / 0.05kg shells, 1939 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 739 lbs / 335 kg
Shells per gun, main battery: 350

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 3.15" / 80 mm 419.95 ft / 128.00 m 10.66 ft / 3.25 m
Ends: Unarmoured
Upper: 1.97" / 50 mm 492.13 ft / 150.00 m 17.22 ft / 5.25 m
Main Belt covers 97% of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.18" / 30 mm 0.59" / 15 mm 0.98" / 25 mm
2nd: 0.98" / 25 mm - -
3rd: 0.59" / 15 mm - -
4th: 0.59" / 15 mm - -

- Armour deck: 1.57" / 40 mm, Conning tower: 3.15" / 80 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 107,539 shp / 80,224 Kw = 32.25 kts
Range 15,750nm at 12.00 kts
Bunker at max displacement = 2,673 tons

Complement:
664 - 864

Cost:
£5.124 million / $20.496 million

Distribution of weights at normal displacement:
Armament: 92 tons, 0.6%
Armour: 2,340 tons, 16.0%
- Belts: 1,283 tons, 8.8%
- Torpedo bulkhead: 0 tons, 0.0%
- Armament: 51 tons, 0.3%
- Armour Deck: 967 tons, 6.6%
- Conning Tower: 41 tons, 0.3%
Machinery: 2,981 tons, 20.4%
Hull, fittings & equipment: 4,886 tons, 33.4%
Fuel, ammunition & stores: 1,926 tons, 13.2%
Miscellaneous weights: 2,400 tons, 16.4%

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
19,138 lbs / 8,681 Kg = 541.8 x 4.1 " / 105 mm shells or 2.2 torpedoes
Stability (Unstable if below 1.00): 1.21
Metacentric height 4.5 ft / 1.4 m
Roll period: 14.7 seconds
Steadiness - As gun platform (Average = 50 %): 54 %
- Recoil effect (Restricted arc if above 1.00): 0.09
Seaboat quality (Average = 1.00): 1.09

Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.510
Length to Beam Ratio: 8.98 : 1
'Natural speed' for length: 25.80 kts
Power going to wave formation at top speed: 55 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 1.00 ft / 0.30 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 25.26 ft / 7.70 m
- Forecastle (27%): 22.74 ft / 6.93 m
- Mid (87%): 15.16 ft / 4.62 m
- Quarterdeck (10%): 15.16 ft / 4.62 m
- Stern: 15.16 ft / 4.62 m
- Average freeboard: 19.75 ft / 6.02 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 92.7%
- Above water (accommodation/working, high = better): 178.7%
Waterplane Area: 33,180 Square feet or 3,083 Square metres
Displacement factor (Displacement / loading): 128%
Structure weight / hull surface area: 102 lbs/sq ft or 496 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.00
- Longitudinal: 1.00
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent

2025 tons = 45 planes
375 tons = Radar, Sonar, misc. stuff

As Built - Urumi

Urumi, CV-3, laid down 1925

Length, 203.0 m x Beam, 22.6 m x Depth, 6.2 m
14629 tonnes normal displacement (13030 tonnes standard)

Airgroup: 40 max; typically 16 fighters, 16 scout-bombers, 4 trainers

Main battery: 6 x 15.0-cm (2 x 3; 1 superfiring)
Secondary battery: 8 x 10.5-cm
AA battery: 8 x 3.5-cm
Light battery: 4 x 1.5-cm

Weight of broadside: 415 kg

4 TT, 50.0 cm (submerged, aft)

Main belt, 8.0 cm; ends unarmored
Upper belt, 8.0 cm (hanger sides)
Armor deck, average 5.0 cm
Conning tower, 8.0 cm

Battery armor:
Main, 10.0 cm / secondary, 5.0 cm shields
AA, 2.0 cm shields / light guns, 2.0 cm shields

Maximum speed for 78005 shaft kw = 32.01 knots
Approximate cruising radius, 15000 nm / 12 knots

Typical complement: 665-865


Estimated cost, $13.275 million (£3.319 million)

Remarks:

Superfiring turret is aft.

Main turrets are grouped together.

Relative extent of belt armor, 98 percent of 'typical' coverage.

Ship has slow, easy roll; a good, steady gun platform.

Ship is roomy, with superior accommodation and working space.


Distribution of weights:
Percent
normal
displacement:

Armament ......................... 114 tonnes = 1 pct
Armor, total ..................... 2438 tonnes = 17 pct

Belt 1015 tonnes = 7 pct
Deck 1145 tonnes = 8 pct
C.T. 41 tonnes = 0 pct
Armament 238 tonnes = 2 pct

Machinery ........................ 3394 tonnes = 23 pct
Hull and fittings; equipment ..... 5091 tonnes = 35 pct
Fuel, ammunition, stores ......... 1967 tonnes = 13 pct
Miscellaneous weights ............ 1625 tonnes = 11 pct
-----
14629 tonnes = 100 pct

Estimated metacentric height, 1.2 m

Displacement summary:

Light ship: 12662 tonnes
Standard displacement: 13030 tonnes
Normal service: 14629 tonnes
Full load: 15849 tonnes

Loading submergence 2946 tonnes/metre

+++++++++++++++++++++++++


Estimated overall survivability and seakeeping ability:

Relative margin of stability: 1.14

Shellfire needed to sink: 8089 kg = 172.4 x 15.0-cm shells
(Approximates weight of penetrating
shell hits needed to sink ship,
not counting critical hits)

Torpedoes needed to sink: 2.0
(Approximates number of 'typical'
torpedo hits needed to sink ship)

Relative steadiness as gun platform, 70 percent
(50 percent is 'average')

Relative rocking effect from firing to beam, 0.12

Relative quality as a seaboat: 1.09

+++++++++++++++++++++++++


Hull form characteristics:

Block coefficient: 0.51
Sharpness coefficient: 0.35
Hull speed coefficient 'M' = 8.33
'Natural speed' for length = 25.8 knots
Power going to wave formation
at top speed: 54 percent


Estimated hull characteristics and strength:

Relative underwater volume absorbed by
magazines and engineering spaces: 97 percent

Relative accommodation and working space: 177 percent


Displacement factor: 125 percent
(Displacement relative to loading factors)


Relative cross-sectional hull strength: 1.00
(Structure weight per square
metre of hull surface: 528 kg)

Relative longitudinal hull strength: 1.03
(for 6.00 m average freeboard;
freeboard adjustment +1.02 m)

Relative composite hull strength: 1.01

+++++++++++++++++++++++++


[Machine-readable parameters: Spring Style v. 1.2.1]

665.84 x 74.13 x 20.34; 19.68 -- Dimensions
0.51 -- Block coefficient
1925 -- Year laid down
32.01 / 15000 / 12.00; Oil-fired turbine or equivalent -- Speed / radius / cruise
1625 tons -- Miscellaneous weights
++++++++++
6 x 5.91; 2; 1 -- Main battery; turrets; superfiring
Central positioning of guns
Superfiring turret aft only
:
8 x 4.13; 0 -- Secondary battery; turrets
Gun-shields
:
8 x 1.38 -- Tertiary (QF/AA) battery
Gun-shields
:
4 x 0.59 -- Fourth (light) battery
4 / 4 / 19.69 -- TT / submerged / size
++++++++++
3.15 / 0.00 / 3.15 / 0.00; 98 -- Belt armor; relative extent
1.97 / 3.15 -- Deck / CT
3.94 / 1.97 / 0.79 / 0.79 -- Battery armor


(Note: For portability, values are stored in Anglo-American units)


+++++++++++++++++++++++++++++++++++++++++++++++++++++++

[SIZE=3]Gaudhi Sagar Class Seaplane Carrier[/SIZE]

The Gaudhi Sagar class (named after lakes, if you were wondering...) is equipped to eighteen seaplanes, though she will normally only embark ten. In addition to flag facilities, the class is equipped to resupply warships (particularly escorts) that she may be operating with. This includes sixteen hundred tonnes of fuel oil and a lesser amount of non-ordnance stores. In theory, the ship should be able to function as the centrepiece of an escort group shepparding convoys.

There are two catapults, each serviced by a crane on a tower amidships. Tracks allow movement of aircraft to and from the aft workshop, within which is an elevator. The tracks also allow positioning of up to five aircraft aft of the catapults for rapid movement on to the catapults. At the stern, a second pair of cranes and tracks are located to embark landed seaplanes.



Gaudhi Sagar, CVS-4, laid down 1929
Nizam Sagar, CVS-5, laid down 1930

Length, 140.0 m x Beam, 19.0 m x Depth, 5.0 m
6705 tonnes normal displacement (5470 tonnes standard)

Main battery: 4 x 12.5-cm (2 x 2; 1 superfiring)
Secondary battery: 4 x 7.5-cm (2 x 2)
AA battery: 8 x 3.5-cm (4 x 2)
Light battery: 8 x 1.5-cm (2 x 4)

Weight of broadside: 137 kg

Miscellaneous Weight:

450 t: Facilities for 18 aircraft (10 typically embarked)
25 t: Flag facilities
125 t: Stores
1,600 t: Fuel
80 t: Weight Reserve


Hull unarmored

Battery armor:
Main, 4.0 cm / secondary, 2.0 cm shields
AA, 2.0 cm shields / light guns, 2.0 cm shields

Maximum speed for 9992 shaft kw = 20.59 knots
Approximate cruising radius, 20000 nm / 12 knots

Typical complement: 370-482


Estimated cost, $4.401 million (£1.100 million)

Remarks:

Main turrets are grouped together.

Ship has slow, easy roll; a good, steady gun platform.

Excellent seaboat; comfortable and able to fight her guns
in the heaviest weather.

Magazines and engineering spaces are roomy, with superior
watertight subdivision.

Ship is roomy, with superior accommodation and working space.


Distribution of weights:
Percent
normal
displacement:

Armament ......................... 38 tonnes = 1 pct
Armor, total ..................... 66 tonnes = 1 pct

Armament 66 tonnes = 1 pct

Machinery ........................ 411 tonnes = 6 pct
Hull and fittings; equipment ..... 2417 tonnes = 36 pct
Fuel, ammunition, stores ......... 1394 tonnes = 21 pct
Miscellaneous weights ............ 2380 tonnes = 35 pct
-----
6705 tonnes = 100 pct

Estimated metacentric height, 0.9 m

Displacement summary:

Light ship: 5311 tonnes
Standard displacement: 5470 tonnes
Normal service: 6705 tonnes
Full load: 7665 tonnes

Loading submergence 1686 tonnes/metre

+++++++++++++++++++++++++


Estimated overall survivability and seakeeping ability:

Relative margin of stability: 1.07

Shellfire needed to sink: 6715 kg = 247.9 x 12.5-cm shells
(Approximates weight of penetrating
shell hits needed to sink ship,
not counting critical hits)

Torpedoes needed to sink: 2.5
(Approximates number of 'typical'
torpedo hits needed to sink ship)

Relative steadiness as gun platform, 80 percent
(50 percent is 'average')

Relative rocking effect from firing to beam, 0.11

Relative quality as a seaboat: 2.00

+++++++++++++++++++++++++


Hull form characteristics:

Block coefficient: 0.50
Sharpness coefficient: 0.37
Hull speed coefficient 'M' = 7.45
'Natural speed' for length = 21.4 knots
Power going to wave formation
at top speed: 43 percent


Estimated hull characteristics and strength:

Relative underwater volume absorbed by
magazines and engineering spaces: 64 percent

Relative accommodation and working space: 206 percent


Displacement factor: 188 percent
(Displacement relative to loading factors)


Relative cross-sectional hull strength: 0.92
(Structure weight per square
metre of hull surface: 404 kg)

Relative longitudinal hull strength: 2.14
(for 6.80 m average freeboard;
freeboard adjustment +2.54 m)

Relative composite hull strength: 1.00

+++++++++++++++++++++++++


[Machine-readable parameters: Spring Style v. 1.2.1]

459.20 x 62.32 x 16.40; 22.30 -- Dimensions
0.50 -- Block coefficient
1929 -- Year laid down
20.59 / 20000 / 12.00; Oil-fired turbine or equivalent -- Speed / radius / cruise
2380 tons -- Miscellaneous weights
++++++++++
4 x 4.92; 2; 1 -- Main battery; turrets; superfiring
Central positioning of guns
:
4 x 2.95; 0 -- Secondary battery; turrets
Gun-shields
:
8 x 1.38 -- Tertiary (QF/AA) battery
Gun-shields
:
8 x 0.59 -- Fourth (light) battery
0 -- No torpedo armament
++++++++++
0.00 -- No belt armor
0.00 / 0.00 -- Deck / CT
1.57 / 0.79 / 0.79 / 0.79 -- Battery armor


(Note: For portability, values are stored in Anglo-American units)


+++++++++++++++++++++++++++++++++++++++++++++++++++++++

[SIZE=3]Lathi Class Aircraft Carrier (Training)[/SIZE]

The passenger liner Coromandel was built by Bengali Steamship Lines in 1921-22 to serve the "Bengal Loop" (Trincomalee - Chennai - Vishakhapatnam - Dhaka - Sittwe - Port Blair - Trincomalee). In 1924, the ship was added to the list of civilian vessels the Navy could call up for military use during emergencies.

In 1928, she was indeed called up for service as a troop transport, and was torpedoed by a Filipino Revolutionary MAS boat on 16 February 1929 off Dagupan. The ship returned to Kaoshiun, Formosa for repairs, which were completed in July 1929.

Unfortunately for Bengali Steamship Lines, their insurance company had issues with the fact that the work was done outside India - thus permiums have more than doubled, rendering the ship's continued use as a passenger ship uneconomic. Frustrated, BSL turned the ship over to the Government in November 1929, in return for taxation credits. The Government then assigned the ship to the Navy.

The navy considered several options for her use - troop transport, tender, etc - but decided that she would be employed as a training aircraft carrier due to her high speed and potentially large flight deck.

Such a vessel is deemed essential, as the Filipino Revolution demonstrated a need for a cadre of trained pilots in addition to those actually deployed. A training carrier will allow a "reserve" cadre to be built up for Urumi without imposing on Urumi's actual use, and will also train the pilots to be deployed on the additional carriers India expects to lay down in the next few years.

The conversion will be fairly simple - some superstructure will be razed, some cabin-class accommodation will be gutted and replaced with a small workshop/hanger, and a teak deck will be installed. The teak deck is fairly heavy, and while not "armor", should protect the below-decks areas from rough landings. As most of the ship's passenger spaces will remain intact, the ship be able to double as a transport of aircraft and their personnel to more remote locations such as Diego Garcia or Asir.

Note that the ship will be used to test alternate exhaust venting systems. The stack is actually angled out around twenty degrees to starboard. Below this is a downward-venting funnel through which the exhaust can be vented as an alternative.

The platforms are intended for the use of landing- and launch-control operations, except for some on the aft starboard side, which are sited to test the effects of exhaust coming out of the downward-venting funnel.




Lathi [Truncheon], ex-Coromandel, CVT-6, laid down 1921, refitted to service 1931, to China 1945

Length, 155.0 m x Beam, 23.0 m x Depth, 5.4 m
11063 tonnes normal displacement (10233 tonnes standard)

Main battery: 1 x 1.5-cm

Weight of broadside: 0 kg

Armor deck, average 2.5 cm (20 cm teak beams)
Conning tower, 5.0 cm

Maximum speed for 7994 shaft kw = 17.76 knots
Approximate cruising radius, 9000 nm / 12 knots

Typical complement: 539-701

Miscellaneous Weight (as built)
-1600 t: cargo
-1600 t: cabin-class accommodation for 200
-2400 t: steerage-class accommodation for 800

Miscellaneous weight (as refitted)
-1600 t: cargo
-1400 t: cabin-class accomodation for 175
-2400 t: steerage-class passengers for 800
-200 t: Workshop, hanger, bunkerage, elevator


Estimated cost, $4.094 million (£1.023 million)

Remarks:

Ship has slow, easy roll; a good, steady gun platform.

Excellent seaboat; comfortable and able to fight her guns
in the heaviest weather.

Magazines and engineering spaces are roomy, with superior
watertight subdivision.

Ship is roomy, with superior accommodation and working space.


Distribution of weights:
Percent
normal
displacement:

Armor, total ..................... 500 tonnes = 5 pct

Deck 479 tonnes = 4 pct
C.T. 21 tonnes = 0 pct

Machinery ........................ 369 tonnes = 3 pct
Hull and fittings; equipment ..... 3543 tonnes = 32 pct
Fuel, ammunition, stores ......... 1051 tonnes = 10 pct
Miscellaneous weights ............ 5600 tonnes = 51 pct
-----
11063 tonnes = 100 pct

Estimated metacentric height, 1.2 m

Displacement summary:

Light ship: 10012 tonnes
Standard displacement: 10233 tonnes
Normal service: 11063 tonnes
Full load: 11683 tonnes

Loading submergence 2466 tonnes/metre

+++++++++++++++++++++++++


Estimated overall survivability and seakeeping ability:

Relative margin of stability: 1.08

Shellfire needed to sink: 10138 kg = 216580.5 x 1.5-cm shells
(Approximates weight of penetrating
shell hits needed to sink ship,
not counting critical hits)

Torpedoes needed to sink: 3.0
(Approximates number of 'typical'
torpedo hits needed to sink ship)

Relative steadiness as gun platform, 70 percent
(50 percent is 'average')

Relative rocking effect from firing to beam, 0.00

Relative quality as a seaboat: 2.00

+++++++++++++++++++++++++


Hull form characteristics:

Block coefficient: 0.57
Sharpness coefficient: 0.40
Hull speed coefficient 'M' = 6.98
'Natural speed' for length = 22.5 knots
Power going to wave formation
at top speed: 35 percent


Estimated hull characteristics and strength:

Relative underwater volume absorbed by
magazines and engineering spaces: 67 percent

Relative accommodation and working space: 216 percent


Displacement factor: 162 percent
(Displacement relative to loading factors)


Relative cross-sectional hull strength: 0.97
(Structure weight per square
metre of hull surface: 446 kg)

Relative longitudinal hull strength: 1.77
(for 7.10 m average freeboard;
freeboard adjustment +2.39 m)

Relative composite hull strength: 1.03

+++++++++++++++++++++++++


[Machine-readable parameters: Spring Style v. 1.2.1]

508.40 x 75.44 x 17.71; 23.29 -- Dimensions
0.57 -- Block coefficient
1921 -- Year laid down
17.76 / 9000 / 12.00; Oil-fired turbine or equivalent -- Speed / radius / cruise
5600 tons -- Miscellaneous weights
++++++++++
1 x 0.59; 0 -- Main battery; turrets
Central positioning of guns
:
0 -- No secondary battery
0 -- No tertiary (QF/AA) battery
0 -- No fourth (light) battery
0 -- No torpedo armament
++++++++++
0.00 -- No belt armor
0.98 / 1.97 -- Deck / CT
0.00 -- No battery armor


(Note: For portability, values are stored in Anglo-American units)


+++++++++++++++++++++++++++++++++++++++++++++++++++++++

[size=3]Talwar Class Aircraft Carrier[/size]

India’s first effort at a purpose-built aircraft carrier, Urumi, was completed in mid-1927. The ship was intended to cooperate with the battle squadron, providing air defence, scouting, and a light strike capability. Whereas some other nations rushed ahead to build up their carrier force as quickly as possible, India instead filled out its battleline while gathering some operational experience with Urumi. During this time, the carrier was involved in several naval exercises and the Filipino Revolution. The Revolution saw her provide air defence to Indian naval forces, strike at Revolutionary light naval forces, and conduct ground attack and recce missions over land in support of the SATSUMA campaign to liberate Luzon in particular.

The Revolution demonstrated in particular a clear need to generate larger and more effective attacks against naval targets, and a more sustained ability to conduct operations supporting ground forces. Urumi’s small airgroup had constrained her in both regards; her limited flight deck space also made it difficult to spot a large attack force or operate torpedo-carrying aircraft. This confirmed the need to build a larger carrier than Urumi (which was important as there had been some consideration towards India building three additional small carriers). Talwar’s large size allows her to include two hangers plus a workshop forward of the upper hanger deck (in the drawing the area forward of the leading elevator). She is capable of taking on sixty aircraft, with an expectation of 24 fighters and 36 strike aircraft, including both Toofani scout-bombers and an as-yet unselected torpedo aircraft. Three elevators are provided, all offset from the centreline.

India expects the new carrier to operate primarily in the Indian Ocean, deploying elsewhere as requirements dictate. Two expected consequences - the low likelihood of a surface encounter, and the generally good weather - have driven the design of the ship's armor scheme and armament.

As Talwar can generally keep pace with most current heavy cruisers, any encounter with an enemy CA would likely take place at longer range - therefore, a thick armor deck is provided to protect against plunging 21 cm fire. The belt is thinner, and protects the ship's machinery and magazines from destroyer-calibre fire. There was little doubt that a torpedo bulkhead would be fitted to a ship of this size.

The hangers themselves are unprotected apart from internal fire screens (thick asbestos curtains) that can cut the hangers in three. The hangers are a light-weight structure above the armor deck, and can be opened to the outside via numerous shutters for dissapation of aircraft exhaust. In the minds of India's designers, this leaves the ship somewhat vulnerable to being "mission-killed", but allows for good performance in other areas of the design; besides which, the lightweight hangers should be amenable to rapid emergency repairs if the ship does survive the experience.

The armament is limited to 10.5 cm guns, sufficient to deal with enemy aircraft or lone destroyer-type ships that get in range. A large battery of light weapons is also included.

Talwar will be laid down in 1932; plans for a second unit have been deferred to 1934 as India evaluates the fate of the Cleito Treaty.

Thanks to Wes for the springsharp help; since the hull strength remains a bit higher than needed, the final design will likely add a bit of miscellaneous weight.

Thanks to Gavin for comments on hanger/elevator layout.



Talwar, CV-7, laid down 1932
Val, CV-8, laid down 1933

Displacement:
16,017 t light; 16,478 t standard; 18,657 t normal; 20,401 t full load

Dimensions: Length overall / water x beam x draught
695.37 ft / 684.38 ft x 81.69 ft x 23.36 ft (normal load)
211.95 m / 208.60 m x 24.90 m x 7.12 m

Armament:
16 - 4.13" / 105 mm guns (8x2 guns), 35.27lbs / 16.00kg shells, 1932 Model
Dual purpose guns in deck mounts with hoists
on centreline ends, evenly spread, all raised mounts - superfiring
28 - 1.38" / 35.0 mm guns (14x2 guns), 1.32lbs / 0.60kg shells, 1932 Model
Anti-aircraft guns in deck mounts
on side, all amidships, all raised mounts - superfiring
16 - 0.59" / 15.0 mm guns (8x2 guns), 0.10lbs / 0.05kg shells, 1932 Model
Machine guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 603 lbs / 273 kg
Shells per gun, main battery: 250

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 1.96" / 50 mm 467.00 ft / 142.34 m 9.85 ft / 3.00 m
Ends: Unarmoured
Main Belt covers 105 % of normal length

- Torpedo Bulkhead:
1.96" / 50 mm 467.00 ft / 142.34 m 9.85 ft / 3.00 m

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.18" / 30 mm - -
2nd: 0.78" / 20 mm - -
3rd: 0.78" / 20 mm - -

- Armour deck: 3.14" / 80 mm, Conning tower: 2.35" / 60 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 101,876 shp / 76,000 Kw = 31.87 kts
Range 20,000nm at 12.00 kts
Bunker at max displacement = 3,924 tons

Complement:
797 - 1,037

Cost:
£4.750 million / $18.998 million

Distribution of weights at normal displacement:
Armament: 75 tons, 0.4 %
Armour: 3,040 tons, 16.3 %
- Belts: 378 tons, 2.0 %
- Torpedo bulkhead: 334 tons, 1.8 %
- Armament: 42 tons, 0.2 %
- Armour Deck: 2,250 tons, 12.1 %
- Conning Tower: 36 tons, 0.2 %
Machinery: 3,007 tons, 16.1 %
Hull, fittings & equipment: 5,975 tons, 32.0 %
Fuel, ammunition & stores: 2,641 tons, 14.2 %
Miscellaneous weights: 3,920 tons, 21.0 %
-3,600 t: 60 aircraft
-25 t: command facilities
-175 t: seven crated spare aircraft
-120 t: weight reserve

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
27,770 lbs / 12,596 Kg = 786.2 x 4.1 " / 105 mm shells or 4.0 torpedoes
Stability (Unstable if below 1.00): 1.11
Metacentric height 4.5 ft / 1.4 m
Roll period: 16.1 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.07
Seaboat quality (Average = 1.00): 1.20

Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.500
Length to Beam Ratio: 8.38 : 1
'Natural speed' for length: 30.28 kts
Power going to wave formation at top speed: 54 %
Trim (Max stability = 0, Max steadiness = 100): 58
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 30.18 ft / 9.20 m
- Forecastle (20 %): 20.77 ft / 6.33 m
- Mid (50 %): 20.77 ft / 6.33 m
- Quarterdeck (15 %): 20.77 ft / 6.33 m
- Stern: 20.77 ft / 6.33 m
- Average freeboard: 21.52 ft / 6.56 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 104.8 %
- Above water (accommodation/working, high = better): 192.3 %
Waterplane Area: 38,738 Square feet or 3,599 Square metres
Displacement factor (Displacement / loading): 137 %
Structure weight / hull surface area: 109 lbs/sq ft or 530 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.99
- Longitudinal: 1.15
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform

Aruval Class

Notes: The passenger ship Indira was supposed to be the flagship of the Red Sea Steamship Line when construction started in 1931 but destiny got on the way. The company made their fortune in the transport of pilgrims to the Holy Cities in the Hedjaz during the 1920's and this ship was supposed to be their status symbol, being presented to the press with great fanfare in early 1931.

The war in Asir affected the flow of Bharat's Muslim pilgrims into Mecca and Medina, forcing many to use alternate routes to reach these cities instead of the more direct route by sea to Asir. By the end of 1932 the company began to lose money,the board of directors hiding this to the shareholders hoping to a fast resolution to the war. Construction continued in the ship, the honor of the company at stake plus the PR damage of cancelling the ship could be very damaging indeed. The Indira was completed around the same time as the war began to enter their final phase and hopes existed that the company could pull thru. Their hopes were dashed in February 1935 when tax fraud was discovered by the Imperial Revenue Service for the periods of 1932 to 1933, with expectations that indeed fraud existed for the year 1934 also. The shareholders were shocked and the board of directors was replaced but still the problem of the money owned to the government existed. The company agreed to pay the government under a payment plan plus their three newest ships of their fleet were accepted as part of their payments to the government in the middle of 1936.

The BNS was in a doubt of what to do with the three liners that fell on their laps, all three being used for the rest of 1936 as accomodation ships. Then the budget constrains of the 1937 Naval Plan forced the cancellation of the construction of a new small carrier, the decision being made instead to start the conversion of the Indira to be an escort carrier in May 1937.

The Indira entered the drydock on Jul 1937, the modifications of the CVT Lathi being used as the benchmark. A teak deck was installed after some superstructure was razed and some rooms were replaced with hangar space and workshops.

Strategic changes prompted the sale of this ship to China in 1942.

Aruval CV-9, ex- Indira, India Carrier laid down 1931, conversion 1937, to China 1942

Displacement:
11,648 t light; 11,961 t standard; 12,770 t normal; 13,417 t full load

Dimensions: Length overall / water x beam x draught
492.13 ft / 492.13 ft x 73.82 ft x 24.61 ft (normal load)
150.00 m / 150.00 m x 22.50 m x 7.50 m

Armament:
8 - 4.92" / 125 mm guns in single mounts, 59.59lbs / 27.03kg shells, 1931 Model
Dual purpose guns in deck mounts with hoists
on side, evenly spread
16 - 1.38" / 35.0 mm guns (4x4 guns), 1.31lbs / 0.59kg shells, 1931 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
16 - 0.59" / 15.0 mm guns (4x4 guns), 0.10lbs / 0.05kg shells, 1931 Model
Machine guns in deck mounts
on side, evenly spread, all raised mounts
8 - 0.59" / 15.0 mm guns (2x4 guns), 0.10lbs / 0.05kg shells, 1931 Model
Machine guns in deck mounts
on side ends, evenly spread
Weight of broadside 500 lbs / 227 kg
Shells per gun, main battery: 200

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.97" / 50 mm 0.79" / 20 mm 1.97" / 50 mm
2nd: 0.79" / 20 mm - -
3rd: 0.39" / 10 mm - -
4th: 0.39" / 10 mm - -

- Armour deck: 3.94" / 100 mm, Conning tower: 1.97" / 50 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 29,716 shp / 22,168 Kw = 23.00 kts
Range 9,000nm at 12.00 kts
Bunker at max displacement = 1,457 tons

Complement:
599 - 780

Cost:
£2.551 million / $10.204 million

Distribution of weights at normal displacement:
Armament: 63 tons, 0.5 %
Armour: 1,828 tons, 14.3 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 42 tons, 0.3 %
- Armour Deck: 1,763 tons, 13.8 %
- Conning Tower: 23 tons, 0.2 %
Machinery: 889 tons, 7.0 %
Hull, fittings & equipment: 6,869 tons, 53.8 %
Fuel, ammunition & stores: 1,122 tons, 8.8 %
Miscellaneous weights: 2,000 tons, 15.7 %
32 aircrafts (around 1,000 tons)
air fuel, equipment, room for growth (1,000)

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
32,252 lbs / 14,629 Kg = 541.2 x 4.9 " / 125 mm shells or 4.7 torpedoes
Stability (Unstable if below 1.00): 1.03
Metacentric height 3.4 ft / 1.0 m
Roll period: 16.8 seconds
Steadiness - As gun platform (Average = 50 %): 96 %
- Recoil effect (Restricted arc if above 1.00): 0.10
Seaboat quality (Average = 1.00): 1.91

Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.500
Length to Beam Ratio: 6.67 : 1
'Natural speed' for length: 22.18 kts
Power going to wave formation at top speed: 49 %
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: 27.23 ft / 8.30 m
- Forecastle (20 %): 22.64 ft / 6.90 m
- Mid (50 %): 22.64 ft / 6.90 m
- Quarterdeck (15 %): 22.64 ft / 6.90 m
- Stern: 22.64 ft / 6.90 m
- Average freeboard: 23.01 ft / 7.01 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 44.8 %
- Above water (accommodation/working, high = better): 174.2 %
Waterplane Area: 24,205 Square feet or 2,249 Square metres
Displacement factor (Displacement / loading): 209 %
Structure weight / hull surface area: 180 lbs/sq ft or 878 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.72
- Longitudinal: 4.25
- Overall: 1.88
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

Notes: One of the three ships accepted as payment from the Red Sea Steamship Line in 1936, the Mohinder Singh spent 1937 and the earlier part of 1938 as an accomodation ship. But in January 1938, with the Aruval(former Indira) already starting their conversion to CVE, the decision was made to rebuilt it and the other former liner into CVE's also.

While a smaller ship than the Indira, the Mohinder recieved a more extensive reconstruction, making possible to carry an aircraft complement very close to the one planned for the Aruval and increased the original speed of the ship by one knot. But the ship never carry that expected complement.

The ship entered service not as a escort carrier but as an aircraft maintenance ship when completed. She was then assigned to a supply and repair role with facilities to handle and repair any aircraft used by the BNS Air Arm, including seaplanes. There were workshops and necessary stores, including 36,000 gallons of aviation fuel.

Vel AV-10, ex-Mohinder Singh, India Aircraft Maintenance Ship laid down 1929, conversion 1938

Displacement:
7,377 t light; 7,607 t standard; 8,677 t normal; 9,532 t full load

Dimensions: Length overall / water x beam x draught
512.00 ft / 512.00 ft x 65.00 ft x 18.25 ft (normal load)
156.06 m / 156.06 m x 19.81 m x 5.56 m

Armament:
6 - 4.92" / 125 mm guns in single mounts, 59.59lbs / 27.03kg shells, 1929 Model
Dual purpose guns in deck mounts with hoists
on side, evenly spread
16 - 1.38" / 35.0 mm guns (4x4 guns), 1.31lbs / 0.59kg shells, 1929 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
32 - 0.59" / 15.0 mm guns (8x4 guns), 0.10lbs / 0.05kg shells, 1929 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 382 lbs / 173 kg
Shells per gun, main battery: 250

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 2.00" / 51 mm 1.00" / 25 mm -
2nd: 1.00" / 25 mm - -
3rd: 0.50" / 13 mm - -

- Armour deck: 4.00" / 102 mm, Conning tower: 2.00" / 51 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 26,996 shp / 20,139 Kw = 24.00 kts
Range 9,000nm at 15.00 kts
Bunker at max displacement = 1,926 tons

Complement:
449 - 584

Cost:
£1.657 million / $6.630 million

Distribution of weights at normal displacement:
Armament: 48 tons, 0.6%
Armour: 1,693 tons, 19.5%
- Belts: 0 tons, 0.0%
- Torpedo bulkhead: 0 tons, 0.0%
- Armament: 34 tons, 0.4%
- Armour Deck: 1,641 tons, 18.9%
- Conning Tower: 18 tons, 0.2%
Machinery: 829 tons, 9.6%
Hull, fittings & equipment: 3,007 tons, 34.7%
Fuel, ammunition & stores: 1,299 tons, 15.0%
Miscellaneous weights: 1,800 tons, 20.7%
28 aircrafts (around 800 tons)
aricraft spares, aviation fuel, equipment, radar, room for growth (1000 tons)

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
21,015 lbs / 9,532 Kg = 352.6 x 4.9 " / 125 mm shells or 3.0 torpedoes
Stability (Unstable if below 1.00): 1.20
Metacentric height 3.7 ft / 1.1 m
Roll period: 14.3 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.09
Seaboat quality (Average = 1.00): 2.00

Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.500
Length to Beam Ratio: 7.88 : 1
'Natural speed' for length: 22.63 kts
Power going to wave formation at top speed: 47 %
Trim (Max stability = 0, Max steadiness = 100): 35
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: 26.90 ft / 8.20 m
- Forecastle (20%): 22.15 ft / 6.75 m
- Mid (50%): 22.15 ft / 6.75 m
- Quarterdeck (15%): 22.15 ft / 6.75 m
- Stern: 22.15 ft / 6.75 m
- Average freeboard: 22.53 ft / 6.87 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 59.1%
- Above water (accommodation/working, high = better): 208.4%
Waterplane Area: 22,174 Square feet or 2,060 Square metres
Displacement factor (Displacement / loading): 157%
Structure weight / hull surface area: 86 lbs/sq ft or 418 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.93
- Longitudinal: 1.93
- 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

The Katar when finally completed entered the fleet as an experimental carrier; the expected complement of aircrafts instead being replaced by Japanese designed autogyros and German designed helicopters. The plan was utilize this ship as a test bench for future ASW operations but in case of need the ship could be utilized as an emergency carrier.

The ship was rendered redundant with the purchase of the Bichawa and was sold to China in 1942.

Katar CV-11, ex-Ranjic Singh, India Carrier laid down 1930, conversion 1938, to China 1942

Displacement:
9,114 t light; 9,381 t standard; 11,126 t normal; 12,522 t full load

Dimensions: Length overall / water x beam x draught
475.72 ft / 475.72 ft x 63.98 ft x 25.59 ft (normal load)
145.00 m / 145.00 m x 19.50 m x 7.80 m

Armament:
6 - 4.92" / 125 mm guns in single mounts, 59.59lbs / 27.03kg shells, 1930 Model
Dual purpose guns in deck mounts with hoists
on side, evenly spread
16 - 1.38" / 35.0 mm guns (4x4 guns), 1.31lbs / 0.59kg shells, 1930 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
24 - 0.59" / 15.0 mm guns (6x4 guns), 0.10lbs / 0.05kg shells, 1930 Model
Machine guns in deck mounts
on side, evenly spread, 4 raised mounts
Weight of broadside 381 lbs / 173 kg
Shells per gun, main battery: 200

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.97" / 50 mm 0.79" / 20 mm -
2nd: 0.79" / 20 mm - -
3rd: 0.39" / 10 mm - -

- Armour deck: 3.94" / 100 mm, Conning tower: 1.97" / 50 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 32,245 shp / 24,055 Kw = 24.00 kts
Range 13,000nm at 15.00 kts
Bunker at max displacement = 3,141 tons

Complement:
541 - 704

Cost:
£2.073 million / $8.293 million

Distribution of weights at normal displacement:
Armament: 48 tons, 0.4 %
Armour: 1,527 tons, 13.7 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 29 tons, 0.3 %
- Armour Deck: 1,477 tons, 13.3 %
- Conning Tower: 21 tons, 0.2 %
Machinery: 977 tons, 8.8 %
Hull, fittings & equipment: 4,562 tons, 41.0 %
Fuel, ammunition & stores: 2,012 tons, 18.1 %
Miscellaneous weights: 2,000 tons, 18.0 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
23,738 lbs / 10,767 Kg = 398.3 x 4.9 " / 125 mm shells or 3.5 torpedoes
Stability (Unstable if below 1.00): 1.06
Metacentric height 2.9 ft / 0.9 m
Roll period: 15.8 seconds
Steadiness - As gun platform (Average = 50 %): 80 %
- Recoil effect (Restricted arc if above 1.00): 0.11
Seaboat quality (Average = 1.00): 1.99

Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.500
Length to Beam Ratio: 7.44 : 1
'Natural speed' for length: 21.81 kts
Power going to wave formation at top speed: 51 %
Trim (Max stability = 0, Max steadiness = 100): 40
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: 27.56 ft / 8.40 m
- Forecastle (20 %): 22.64 ft / 6.90 m
- Mid (50 %): 22.64 ft / 6.90 m
- Quarterdeck (15 %): 22.64 ft / 6.90 m
- Stern: 22.64 ft / 6.90 m
- Average freeboard: 23.03 ft / 7.02 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 52.6 %
- Above water (accommodation/working, high = better): 161.6 %
Waterplane Area: 20,278 Square feet or 1,884 Square metres
Displacement factor (Displacement / loading): 190 %
Structure weight / hull surface area: 128 lbs/sq ft or 625 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.30
- Longitudinal: 3.90
- Overall: 1.45
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

Misc:
750t for 24 aircrafts and 6 spares
450t for aviation fuel and support equipment
100t for growth
400t for accomodation for 200 Naval Infantry
300t for support equipment

The cruiser Cuttack was laid down in 1941 but almost inmediatly the decision was made to instead use the hull for the construction of a light carrier as allowed by the ABUSE agreement. At the time the Aruval and the Katar were filling the niche of light carriers in the BNS but at best they were a weak compromise; with the Katar being used primary as an experimental carrier.

The ship was cancelled three months into construction when the drydock became urgently required for a spate of refits.

Thanks Brock for SIM

Khanda CV-12, laid down 1941, cancelled 1941

Khanda CV-12, Indian CV laid down 1941

Displacement:
13,112 t light; 13,518 t standard; 15,317 t normal; 16,756 t full load

Dimensions: Length overall / water x beam x draught
666.80 ft / 656.17 ft x 68.90 ft x 23.62 ft (normal load)
203.24 m / 200.00 m x 21.00 m x 7.20 m

Armament:
8 - 4.92" / 125 mm guns (4x2 guns), 59.59lbs / 27.03kg shells, 1941 Model
Dual purpose guns in deck mounts with hoists
on centreline ends, evenly spread, all raised mounts - superfiring
12 - 1.38" / 35.0 mm guns (6x2 guns), 1.31lbs / 0.59kg shells, 1941 Model
Anti-aircraft guns in deck mounts with hoists
on side, all amidships, all raised mounts - superfiring
24 - 0.59" / 15.0 mm guns (6x4 guns), 0.10lbs / 0.05kg shells, 1941 Model
Machine guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 495 lbs / 224 kg
Shells per gun, main battery: 350

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 0.79" / 20 mm 426.51 ft / 130.00 m 9.97 ft / 3.04 m
Ends: Unarmoured
Main Belt covers 100 % of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.57" / 40 mm 0.79" / 20 mm 1.18" / 30 mm
2nd: 0.79" / 20 mm - -
3rd: 0.79" / 20 mm - -

- Armour deck: 2.95" / 75 mm, Conning tower: 5.12" / 130 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 92,402 shp / 68,932 Kw = 32.00 kts
Range 20,000nm at 12.00 kts
Bunker at max displacement = 3,238 tons

Complement:
687 - 894

Cost:
£5.141 million / $20.563 million

Distribution of weights at normal displacement:
Armament: 62 tons, 0.4 %
Armour: 1,955 tons, 12.8 %
- Belts: 140 tons, 0.9 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 33 tons, 0.2 %
- Armour Deck: 1,714 tons, 11.2 %
- Conning Tower: 68 tons, 0.4 %
Machinery: 2,471 tons, 16.1 %
Hull, fittings & equipment: 4,875 tons, 31.8 %
Fuel, ammunition & stores: 2,205 tons, 14.4 %
Miscellaneous weights: 3,750 tons, 24.5 %
48 aircrafts: 2880 tons (60t each)
Radar and misc. equipment: 870 tons

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
21,328 lbs / 9,674 Kg = 357.9 x 4.9 " / 125 mm shells or 2.3 torpedoes
Stability (Unstable if below 1.00): 1.09
Metacentric height 3.4 ft / 1.0 m
Roll period: 15.7 seconds
Steadiness - As gun platform (Average = 50 %): 51 %
- Recoil effect (Restricted arc if above 1.00): 0.09
Seaboat quality (Average = 1.00): 1.22

Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.502
Length to Beam Ratio: 9.52 : 1
'Natural speed' for length: 29.34 kts
Power going to wave formation at top speed: 54 %
Trim (Max stability = 0, Max steadiness = 100): 42
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 29.20 ft / 8.90 m
- Forecastle (20 %): 21.33 ft / 6.50 m
- Mid (50 %): 20.51 ft / 6.25 m
- Quarterdeck (15 %): 20.51 ft / 6.25 m
- Stern: 20.51 ft / 6.25 m
- Average freeboard: 21.42 ft / 6.53 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 83.1 %
- Above water (accommodation/working, high = better): 180.1 %
Waterplane Area: 31,382 Square feet or 2,916 Square metres
Displacement factor (Displacement / loading): 137 %
Structure weight / hull surface area: 101 lbs/sq ft or 491 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.98
- Longitudinal: 1.25
- Overall: 1.00
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Good seaboat, rides out heavy weather easily

Bagh Nakh Class Aircraft Carrier

This is the former battleship Samanjir, which was halted when about 50% complete. The BNS had drawn up plans to either complete her as a battlecruiser or as an aircraft carrier, and following a delay in construction in 1941, the latter route was chosen.

As the hull did require a substantial refit to meet the new specifications, machinery and underwater protection were updated from the Samanjir design.

Bagh Nakh, CV-14, laid down 1940, rebuilt 1942




Enter ship name, Enter country Enter ship type laid down 1940 (Engine 1942)

Displacement:
27,353 t light; 28,180 t standard; 31,434 t normal; 34,038 t full load

Dimensions: Length overall / water x beam x draught
761.44 ft / 721.78 ft x 91.86 ft x 27.89 ft (normal load)
232.09 m / 220.00 m x 28.00 m x 8.50 m

Armament:
12 - 4.92" / 125 mm guns in single mounts, 59.59lbs / 27.03kg shells, 1940 Model
Dual purpose guns in deck mounts with hoists
on side, evenly spread
28 - 2.24" / 57.0 mm guns (14x2 guns), 5.65lbs / 2.56kg shells, 1940 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
8 - 2.24" / 57.0 mm guns (4x2 guns), 5.65lbs / 2.56kg shells, 1940 Model
Anti-aircraft guns in deck mounts
on side, all amidships, all raised mounts - superfiring
28 - 0.59" / 15.0 mm guns (7x4 guns), 0.10lbs / 0.05kg shells, 1940 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 921 lbs / 418 kg
Shells per gun, main battery: 350

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 3.94" / 100 mm 469.16 ft / 143.00 m 16.01 ft / 4.88 m
Ends: Unarmoured
Upper: 0.98" / 25 mm 567.59 ft / 173.00 m 18.04 ft / 5.50 m
Main Belt covers 100 % of normal length

- Torpedo Bulkhead:
2.95" / 75 mm 469.16 ft / 143.00 m 26.25 ft / 8.00 m

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.97" / 50 mm 0.79" / 20 mm 1.97" / 50 mm
2nd: 0.79" / 20 mm 0.39" / 10 mm -
3rd: 0.39" / 10 mm - -
4th: 0.39" / 10 mm - -

- Armour deck: 3.54" / 90 mm, Conning tower: 3.94" / 100 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 147,454 shp / 110,000 Kw = 32.03 kts
Range 15,000nm at 15.00 kts (Bunkerage = 5,858 tons)

Complement:
1,179 - 1,534

Cost:
£9.560 million / $38.242 million

Distribution of weights at normal displacement:
Armament: 115 tons, 0.4 %
Armour: 6,497 tons, 20.7 %
- Belts: 1,682 tons, 5.3 %
- Torpedo bulkhead: 1,345 tons, 4.3 %
- Armament: 88 tons, 0.3 %
- Armour Deck: 3,297 tons, 10.5 %
- Conning Tower: 84 tons, 0.3 %
Machinery: 3,852 tons, 12.3 %
Hull, fittings & equipment: 9,341 tons, 29.7 %
Fuel, ammunition & stores: 4,081 tons, 13.0 %
Miscellaneous weights: 7,549 tons, 24.0 %
-7,056 t: Airgroup of 84 WW2 era aircraft
-100 t: Electronics, comms, and fire control
-100 t: Flight operations facilities
-100 t: Command facilities
-100 t: Enhanced damage control equipment
-93 t: Weight reserve

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
43,694 lbs / 19,819 Kg = 733.2 x 4.9 " / 125 mm shells or 5.7 torpedoes
Stability (Unstable if below 1.00): 1.10
Metacentric height 5.3 ft / 1.6 m
Roll period: 16.8 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.07
Seaboat quality (Average = 1.00): 1.52

Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.595
Length to Beam Ratio: 7.86 : 1
'Natural speed' for length: 30.93 kts
Power going to wave formation at top speed: 58 %
Trim (Max stability = 0, Max steadiness = 100): 46
Bow angle (Positive = bow angles forward): 25.00 degrees
Stern overhang: 16.40 ft / 5.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 49.87 ft / 15.20 m
- Forecastle (20 %): 30.18 ft / 9.20 m
- Mid (50 %): 30.18 ft / 9.20 m
- Quarterdeck (15 %): 30.18 ft / 9.20 m
- Stern: 30.18 ft / 9.20 m
- Average freeboard: 31.76 ft / 9.68 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 89.4 %
- Above water (accommodation/working, high = better): 245.3 %
Waterplane Area: 50,301 Square feet or 4,673 Square metres
Displacement factor (Displacement / loading): 139 %
Structure weight / hull surface area: 122 lbs/sq ft or 596 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.93
- Longitudinal: 1.78
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
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

Trishula Class Aircraft Carrier



A range of design options were considered while the previous carrier, Bagh Nakh, was under construction. This ranged from a duplicate of that carrier to something in the 45,000 t range. The duplicate option was discarded as the BNS began to develop niggling concerns about the limited length of Bagh Nakh's flight deck, and its implications for future aircraft operations. The full-sized option was discarded on account of cost.

What emerged was still a large warship (by Bharati standards), only just capable of fitting into the class four drydock where she will be built. It is hoped that the BNS will be able to maintain her as a capable warship for thirty years.

The ship is designed to operate 90 aircraft of WW2 size - only six more than the smaller Bagh Nakh. Seven full combat squadrons and one smaller utility squadron would nominally be embarked.

While the number of lifts has been kept at three, the disposition now sees the aft lift placed on the starboard deck-edge. Trishula's larger hull allows for a spacious 215 metre long, 6.5 metre high hanger. With the exception of the shuttering ventilation openings, the hanger sides are splinter-proofed.

Armament and protection follow the trends set by Bagh Nakh, with exceptions. One is heavier deck armor, for protection against bombs. Another is the heavier secondary and tertiary AA armament, both made possible by the larger hull. Four primary and eight secondary gun directors have been installed.

Considerable space has been set aside for command and air operations facilities, and nearly five hundred tonnes has been allocated as a weight reserve. This could include an additional dozen or more unassembled replacement aircraft.

Trishula's planned 1948 completion will have a significant impact on Bharati naval operations. It is anticipated that the utility carrier Vel will be retired at this point, with both of the Urumi class carriers being assigned to secondary duties such as training, aircraft transport, and ASW operations. An unspoken assumption is that the Urumi's battleship escorts, Akbar and Jahangir, will be retired at that time.

Trishula, CV-15, laid down 1945

Trishula (Trident), Bharati aircraft carrier, laid down 1945

Displacement:
36,715 t light; 37,896 t standard; 43,105 t normal; 47,272 t full load

Dimensions: Length overall / water x beam x draught
926.09 ft / 882.55 ft x 101.71 ft (Bulges 108.27 ft) x 28.71 ft (normal load)
282.27 m / 269.00 m x 31.00 m (Bulges 33.00 m) x 8.75 m

Armament:
12 - 4.92" / 125 mm guns in single mounts, 59.59lbs / 27.03kg shells, 1945 Model
Dual purpose guns in deck mounts with hoists
on side ends, evenly spread
8 - 2.24" / 57.0 mm guns (4x2 guns), 5.65lbs / 2.56kg shells, 1945 Model
Anti-aircraft guns in deck mounts
on side, all amidships, all raised mounts - superfiring
40 - 2.24" / 57.0 mm guns (20x2 guns), 5.65lbs / 2.56kg shells, 1945 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
40 - 0.98" / 25.0 mm guns (20x2 guns), 0.48lbs / 0.22kg shells, 1945 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 1,005 lbs / 456 kg
Shells per gun, main battery: 500

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 3.94" / 100 mm 518.37 ft / 158.00 m 16.01 ft / 4.88 m
Ends: Unarmoured
Upper: 0.98" / 25 mm 705.38 ft / 215.00 m 21.33 ft / 6.50 m
Main Belt covers 90 % of normal length

- Torpedo Bulkhead and Bulges:
2.95" / 75 mm 573.65 ft / 174.85 m 26.35 ft / 8.03 m

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.97" / 50 mm 0.79" / 20 mm 1.97" / 50 mm
2nd: 0.79" / 20 mm 0.39" / 10 mm -
3rd: 0.79" / 20 mm 0.39" / 10 mm -
4th: 0.39" / 10 mm - -

- Armour deck: 4.72" / 120 mm, Conning tower: 3.94" / 100 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 166,220 shp / 124,000 Kw = 32.05 kts
Range 20,000nm at 15.00 kts
Bunker at max displacement = 9,376 tons

Complement:
1,495 - 1,944

Cost:
£13.668 million / $54.672 million

Distribution of weights at normal displacement:
Armament: 126 tons, 0.3 %
Armour: 9,562 tons, 22.2 %
- Belts: 2,010 tons, 4.7 %
- Torpedo bulkhead: 1,651 tons, 3.8 %
- Armament: 96 tons, 0.2 %
- Armour Deck: 5,700 tons, 13.2 %
- Conning Tower: 104 tons, 0.2 %
Machinery: 4,197 tons, 9.7 %
Hull, fittings & equipment: 13,444 tons, 31.2 %
Fuel, ammunition & stores: 6,389 tons, 14.8 %
Miscellaneous weights: 9,386 tons, 21.8 %
-8,100 t: Airgroup of 90 WW2 era aircraft
-486 t: Weight reserve
-200 t: Electronics, fire control, and communications
-200 t: Command facilities
-200 t: Flight operations facilities
-200 t: Enhanced damage control equipment

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
94,527 lbs / 42,877 Kg = 1,586.2 x 4.9 " / 125 mm shells or 16.1 torpedoes
Stability (Unstable if below 1.00): 1.23
Metacentric height 7.5 ft / 2.3 m
Roll period: 16.6 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.04
Seaboat quality (Average = 1.00): 1.75

Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.550
Length to Beam Ratio: 8.15 : 1
'Natural speed' for length: 34.26 kts
Power going to wave formation at top speed: 50 %
Trim (Max stability = 0, Max steadiness = 100): 40
Bow angle (Positive = bow angles forward): 28.00 degrees
Stern overhang: 14.76 ft / 4.50 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 54.13 ft / 16.50 m
- Forecastle (20 %): 31.17 ft / 9.50 m
- Mid (50 %): 31.17 ft / 9.50 m
- Quarterdeck (15 %): 31.17 ft / 9.50 m
- Stern: 31.17 ft / 9.50 m
- Average freeboard: 33.01 ft / 10.06 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 73.6 %
- Above water (accommodation/working, high = better): 259.0 %
Waterplane Area: 65,217 Square feet or 6,059 Square metres
Displacement factor (Displacement / loading): 152 %
Structure weight / hull surface area: 137 lbs/sq ft or 671 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.97
- Longitudinal: 1.29
- 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