WesWorld

Might be jumping the gun here, but what the heck.

Three classes (again) to show y'all. Another job, the Goa rebuilds, is not technically new, and I'm still working on the picture. So that will come later.

First: the L-1 class anti-submarine launch. Intended for coastal ASW, rescue, and patrol work, twelve will be built in a Type 0 slip using the small craft rules.

Second: the M-1 class coastal minelayer. Although aft superstructure is different and the hull flares out more, the resemblance to the T-19 class torpedoboat should be evident. Two of these guys are being laid down this year.

Third: the light cruiser Agra. This four ship class is evolved from the Trincomalee class (pictured above Agra for comparison). Improvements include better protection, a heavier AA suite, a floatplane, and for the first time, just two funnels in an Indian cruiser. This class is expected to see service in the independent cruiser squadrons when completed, while the Trincomalees take on carrier escort and the older, small cruisers escort the battleships or serve in quieter areas.

L-1 ASW Launch, laid down 1926

Length, 40.0 m x Beam, 5.8 m x Depth, 2.0 m
220 tonnes normal displacement (201 tonnes standard)

Main battery: 1 x 10.5-cm
Secondary battery: 1 x 3.5-cm
AA battery: 2 x 1.5-cm

Weight of broadside: 17 kg

Hull unarmored

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

Maximum speed for 1800 shaft kw = 19.95 knots
Approximate cruising radius, 2000 nm / 12 knots

Typical complement: 29-37


Estimated cost, $296,000 (£74,000)

Remarks:

Magazines and engineering spaces are cramped, with poor
watertight subdivision.


Distribution of weights:
Percent
normal
displacement:

Armament ......................... 5 tonnes = 2 pct
Armor, total ..................... 2 tonnes = 1 pct

Armament 2 tonnes = 1 pct

Machinery ........................ 77 tonnes = 35 pct
Hull and fittings; equipment ..... 93 tonnes = 42 pct
Fuel, ammunition, stores ......... 27 tonnes = 12 pct
Miscellaneous weights ............ 16 tonnes = 7 pct
-----
220 tonnes = 100 pct

Estimated metacentric height, 0.1 m

Displacement summary:

Light ship: 193 tonnes
Standard displacement: 201 tonnes
Normal service: 220 tonnes
Full load: 234 tonnes

Loading submergence 141 tonnes/metre

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


Estimated overall survivability and seakeeping ability:

Relative margin of stability: 1.07

Shellfire needed to sink: 78 kg = 4.9 x 10.5-cm shells
(Approximates weight of penetrating
shell hits needed to sink ship,
not counting critical hits)

Torpedoes needed to sink: 0.2
(Approximates number of 'typical'
torpedo hits needed to sink ship)

Relative steadiness as gun platform, 54 percent
(50 percent is 'average')

Relative rocking effect from firing to beam, 0.26

Relative quality as a seaboat: 1.09

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


Hull form characteristics:

Block coefficient: 0.47
Sharpness coefficient: 0.36
Hull speed coefficient 'M' = 6.64
'Natural speed' for length = 11.5 knots
Power going to wave formation
at top speed: 72 percent


Estimated hull characteristics and strength:

Relative underwater volume absorbed by
magazines and engineering spaces: 138 percent

Relative accommodation and working space: 96 percent


Displacement factor: 105 percent
(Displacement relative to loading factors)


Relative cross-sectional hull strength: 0.84
(Structure weight per square
metre of hull surface: 154 kg)

Relative longitudinal hull strength: 5.04
(for 2.90 m average freeboard;
freeboard adjustment +0.75 m)

Relative composite hull strength: 1.00

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


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

131.20 x 19.02 x 6.56; 9.51 -- Dimensions
0.47 -- Block coefficient
1926 -- Year laid down
19.95 / 2000 / 12.00; Oil-fired turbine or equivalent -- Speed / radius / cruise
16 tons -- Miscellaneous weights
++++++++++
1 x 4.13; 0 -- Main battery; turrets
Central positioning of guns
Gun-shields
:
1 x 1.38; 0 -- Secondary battery; turrets
Gun-shields
:
2 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)


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

M-1, laid down 1926

Length, 86.0 m x Beam, 7.2 m x Depth, 2.7 m
691 tonnes normal displacement (625 tonnes standard)

Main battery: 1 x 10.5-cm
Secondary battery: 2 x 3.5-cm
AA battery: 2 x 1.5-cm
Weight of broadside: 17 kg

2 TT, 50.0 cm

Mines: Max. 75 Indian 600 kg type

Hull unarmored

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

Maximum speed for 15003 shaft kw = 31.61 knots
Approximate cruising radius, 4000 nm / 12 knots

Typical complement: 67-88


Estimated cost, $1.036 million (£259,000)

Remarks:

Caution: Hull structure is subject to strain in open-sea
conditions.

Magazines and engineering spaces are cramped, with poor
watertight subdivision.


Distribution of weights:
Percent
normal
displacement:

Armament ......................... 5 tonnes = 1 pct
Armor, total ..................... 3 tonnes = 0 pct

Armament 3 tonnes = 0 pct

Machinery ........................ 355 tonnes = 51 pct
Hull and fittings; equipment ..... 195 tonnes = 28 pct
Fuel, ammunition, stores ......... 83 tonnes = 12 pct
Miscellaneous weights ............ 50 tonnes = 7 pct
-----
691 tonnes = 100 pct

Estimated metacentric height, 0.3 m

Displacement summary:

Light ship: 608 tonnes
Standard displacement: 625 tonnes
Normal service: 691 tonnes
Full load: 741 tonnes

Loading submergence 344 tonnes/metre

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


Estimated overall survivability and seakeeping ability:

Relative margin of stability: 1.27

Shellfire needed to sink: 86 kg = 5.3 x 10.5-cm shells
(Approximates weight of penetrating
shell hits needed to sink ship,
not counting critical hits)

Torpedoes needed to sink: 0.2
(Approximates number of 'typical'
torpedo hits needed to sink ship)

Relative steadiness as gun platform, 55 percent
(50 percent is 'average')

Relative rocking effect from firing to beam, 0.10

Relative quality as a seaboat: 1.10

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


Hull form characteristics:

Block coefficient: 0.41
Sharpness coefficient: 0.28
Hull speed coefficient 'M' = 9.75
'Natural speed' for length = 16.8 knots
Power going to wave formation
at top speed: 67 percent


Estimated hull characteristics and strength:

Relative underwater volume absorbed by
magazines and engineering spaces: 179 percent

Relative accommodation and working space: 100 percent


Displacement factor: 50 percent
(Displacement relative to loading factors)


Relative cross-sectional hull strength: 0.51
(Structure weight per square
metre of hull surface: 124 kg)

Relative longitudinal hull strength: 1.25
(for 3.60 m average freeboard;
freeboard adjustment +0.89 m)

Relative composite hull strength: 0.56

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


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

282.08 x 23.62 x 8.86; 11.81 -- Dimensions
0.41 -- Block coefficient
1926 -- Year laid down
31.61 / 4000 / 12.00; Oil-fired turbine or equivalent -- Speed / radius / cruise
50 tons -- Miscellaneous weights
++++++++++
1 x 4.13; 0 -- Main battery; turrets
Central positioning of guns
Gun-shields
:
2 x 1.38; 0 -- Secondary battery; turrets
Gun-shields
:
2 x 0.59 -- Tertiary (QF/AA) battery
Gun-shields
:
0 -- No fourth (light) battery
2 / 0 / 19.69 -- TT / submerged / size
++++++++++
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)


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

Trincomalee pic for comparison...



And Agra...



Agra, laid down 1926

Length, 174.0 m x Beam, 17.4 m x Depth, 5.6 m
8035 tonnes normal displacement (7233 tonnes standard)

Main battery: 9 x 15.0-cm (3 x 3; 1 superfiring)
Secondary battery: 10 x 10.5-cm
AA battery: 8 x 3.5-cm
Light battery: 6 x 1.5-cm

Weight of broadside: 587 kg

8 TT, 55.0 cm

Main belt, 8.0 cm; ends unarmored
Armor deck, average 4.0 cm
Conning tower, 8.0 cm

Battery armor:
Main, 8.0 cm / secondary, 4.0 cm shields
AA, 2.0 cm shields / light guns, 2.0 cm shields

Maximum speed for 52021 shaft kw = 31.54 knots
Approximate cruising radius, 11000 nm / 12 knots

Typical complement: 424-552


Estimated cost, $9.560 million (£2.390 million)

Remarks:

Relative extent of belt armor, 108 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 ......................... 162 tonnes = 2 pct
Armor, total ..................... 1320 tonnes = 16 pct

Belt 469 tonnes = 6 pct
Deck 570 tonnes = 7 pct
C.T. 27 tonnes = 0 pct
Armament 254 tonnes = 3 pct

Machinery ........................ 2231 tonnes = 28 pct
Hull and fittings; equipment ..... 3202 tonnes = 40 pct
Fuel, ammunition, stores ......... 1070 tonnes = 13 pct
Miscellaneous weights ............ 50 tonnes = 1 pct
-----
8035 tonnes = 100 pct

Estimated metacentric height, 0.8 m

Displacement summary:

Light ship: 6965 tonnes
Standard displacement: 7233 tonnes
Normal service: 8035 tonnes
Full load: 8644 tonnes

Loading submergence 1841 tonnes/metre

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


Estimated overall survivability and seakeeping ability:

Relative margin of stability: 1.12

Shellfire needed to sink: 3769 kg = 80.3 x 15.0-cm shells
(Approximates weight of penetrating
shell hits needed to sink ship,
not counting critical hits)

Torpedoes needed to sink: 1.3
(Approximates number of 'typical'
torpedo hits needed to sink ship)

Relative steadiness as gun platform, 71 percent
(50 percent is 'average')

Relative rocking effect from firing to beam, 0.40

Relative quality as a seaboat: 1.06

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


Hull form characteristics:

Block coefficient: 0.47
Sharpness coefficient: 0.32
Hull speed coefficient 'M' = 8.71
'Natural speed' for length = 23.9 knots
Power going to wave formation
at top speed: 55 percent


Estimated hull characteristics and strength:

Relative underwater volume absorbed by
magazines and engineering spaces: 107 percent

Relative accommodation and working space: 137 percent


Displacement factor: 113 percent
(Displacement relative to loading factors)


Relative cross-sectional hull strength: 0.99
(Structure weight per square
metre of hull surface: 484 kg)

Relative longitudinal hull strength: 1.18
(for 5.30 m average freeboard;
freeboard adjustment +0.88 m)

Relative composite hull strength: 1.01

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


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

570.72 x 57.07 x 18.37; 17.38 -- Dimensions
0.47 -- Block coefficient
1926 -- Year laid down
31.54 / 11000 / 12.00; Oil-fired turbine or equivalent -- Speed / radius / cruise
50 tons -- Miscellaneous weights
++++++++++
9 x 5.91; 3; 1 -- Main battery; turrets; superfiring
:
10 x 4.13; 0 -- Secondary battery; turrets
Gun-shields
:
8 x 1.38 -- Tertiary (QF/AA) battery
Gun-shields
:
6 x 0.59 -- Fourth (light) battery
8 / 0 / 21.65 -- TT / submerged / size
++++++++++
3.15 / 0.00 / 0.00 / 0.00; 108 -- Belt armor; relative extent
1.57 / 3.15 -- Deck / CT
3.15 / 1.57 / 0.79 / 0.79 -- Battery armor


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


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

AGRA´s a good design - a cruiser I´d like to have for the RSAN as well. Especially her low silhouette gives her a remarkable look and is useful for sneak attacks at night. She doesn´t offer that much of a visible target.

Not sure what to think of those minesweepers. They look as if you just re-named some TBs as MS. What does a minesweeper needs such a high speed for? Why torpedos? Wouldn´t a MS need a little bit more deckspace? RSAN experts would rate her as a fast minelayer meant for offensive minelaying in hostile waters....

Those L-1 launches on the other hand are quite interesting. Small, not too expensive but quite useful. I just think a 10,5cm gun is way too large and heavy for such a vessel and would have negative impact on their seakeeping. Even a 88mm gun would be too much, methinks. Given the designs task I doubt anything larger than light AA guns of 40mm and smaller are necessary. But that´s probably just me. Keep in mind you need at least 6-8 men to operate the 10,5cm gun plus some guys for ammo handling while a 4cm twin might be operated by 4-5 men plus two more for ammo handling. However, the latter will be easier for the smaller gun as more ammo ready for use can be stored nearby. Anyway, a good design and probably the RSAN will contact Indian yards to build some of the for South Africa too... (Any capacity left?)

Umm...the M-1 is a fast minelayer intended for offensive minelaying in hostile waters. The torpedoes are a defensive measure; I'm not sure it's a good idea, but the Indians seem to like to install them on unusual platforms (see Urumi). Later units of the type may replace them with additional light weapons.

I'd thought that a large gun on the launch might be needed if a surfaced sub was encountered. The alternative - two pairs of 35mm guns - can still be considered, if not for the lead group, then for the later units.

It appears that India has a Type 0 slipway - perfect for building the launches - sitting idle in 1926. No SATSUMA authorization is required for a unit this size, so all the SAE has to do is place the order and show me the rupees. I can sim up a version with 2x2 40mm guns for you easily enough.

Glad you like Agra. I'm happy with her appearance - seems to blend my cruiser evolution and the Akbar two-funnel look nicely.

Quoted

Originally posted by The Rock Doctor
The torpedoes are a defensive measure

Uh? Torpedos on a 31+kn craft are a defensive measure?!

Quoted

It appears that India has a Type 0 slipway - perfect for building the launches - sitting idle in 1926. No SATSUMA authorization is required for a unit this size, so all the SAE has to do is place the order and show me the rupees. I can sim up a version with 2x2 40mm guns for you easily enough.

IIRC no slip is necessary for small wooden crafts if they are not build faster than 1 craft per 3 factories per month. Could be wrong, though.

So propably it would be easier to build them in the SAE (more factories) under licence. There some minor tweaks I´d also like to incorporate and the vessel has to be simed in SSv2.1 with an armament of 1-2x 40mm (bow) and 2x 20mm (stern), probably 4x 20mm.

Drop me a PM and tell me what India wants to have for the rights to build a SAE version of said craft. Could be either material (ie. money) or something different. Should make for some interesting news as otherwise I could simply lay down my own class anyway... ;o)

Quoted

Glad you like Agra. I'm happy with her appearance - seems to blend my cruiser evolution and the Akbar two-funnel look nicely.

I indeed like her and the fact that she shows how indian naval design develops along a realistic path adds to that.

Quoted

Uh? Torpedos on a 31+kn craft are a defensive measure?!

A destroyer starts chasing the slower minelayer. The minelayer fires her two torps at the destroyer, maybe forcing the destroyer to turn away as the minelayer runs. By the time the destroyer has evaded the fish, the minelayer has disappeared into the night.

I dunno. These're my first minelayers, after all.

Quoted

IIRC no slip is necessary for small wooden crafts if they are not build faster than 1 craft per 3 factories per month. Could be wrong, though

Ah, but you see, I'm already building a dozen MTBs with that clause. That's why I have a Type 0 slip set aside for building these launches (I assume the build time is the same, just that I need a slip to accommodate them).

A line shall be dropped to you...

Neither torpedos nor high speeds are important for an offensive minelayer, methinks.

Your best weapon is surprise. So you need a low profile (optically but propably also regarding noise) to stay "invisible" and a high constant speed (cruising speed) to arrive where nobody expects you.

Well, and a lot of room for many, many mines. If you take on the risk for such an operation it doesn´t make sense if you can drop just a handful of mines, right?

Like the cruiser, a lot. Also good to finally see a pic of Trincomalee.


As for the minelayer, tho...the fish are IMHO not a bad idea, however they run afoul of CT Part III, G, I (b):

Quoted

Naval surface combatant vessels exceeding 600 tons (610 metric tons)...provided they have none of the following characteristics:

(3) Are designed or fitted to launch torpedoes;

Nice little subchaser, tho.

I was guessing at 75 mines, based on misc. weight. Even 50 seems like a reasonable number for its size.

Stealth is certainly critical, and I'm thinking a vessel this size will do well in that regard. Nonetheless - somebody in the Design Bureau insisted on sticking torpedoes aboard. Maybe the thinking will be different when the cruiser-minelayers get built.

Once a couple of these ships are in service, I think I'll have to run an exercise or two to establish a doctrine for construction/operation.

Swampy: you're correct, but overlook the fact that India will likely officially list the class at 610 tonnes standard.

I had a drawing of Trincomalee that reflected a larger design I ended up trashing. I had to re-draw her, and it took some time to find an opportunity to do so.

Quoted

I just think a 10,5cm gun is way too large and heavy for such a vessel {L-1} and would have negative impact on their seakeeping. Even a 88mm gun would be too much, methinks. Given the designs task I doubt anything larger than light AA guns of 40mm and smaller are necessary.

The Filipino Ariete/Occidental-class minesweeper/minelayers, which are roughly the same size, have a single 40mm pompom forwards.


Y'know, I think this will be the first time we've had multiple ships building on the same slip, like the Italians did historically with some of their "colonial cruisers"...

Quoted

Maybe the thinking will be different when the cruiser-minelayers get built.

Hmmm. Got any tenative designs you could PM over?

Anything above 20mm should be suffice to scare submarines as their hulls can´t take penetrating hits...

So if your design is not meant to fight surface units there is little need for large weapons, methinks.

Ah, true. Well, I'll stick with the original design for the first batch, maybe have a change of heart later in the year.

Interesting drawing of Agra.

Any reason for preferring triple turrets instead of 4 duples? The duples would give more redundancy.

Not much space for the aircraft.

And I still think the 150mm guns should be 2 pixels thick.

Quoted

And I still think the 150mm guns should be 2 pixels thick.

Duly noted. But I still think they should be one pixel thick.

The cat probably has a sixty degree arc for launching on each beam. Perhaps it's not a lot but I thought it was sufficient. Unless you're referring to the hanger, which is large enough when the plane's wings are folded.

Triples are being used for weight savings, though twins did tempt me. I guess the navy was impressed with Trincomalee's shooting off Phuket and chose to stick with a winner.

Plus, you get one extra gun by going 3x3 instead of 4x2. ^_^

Agra is one cool looking ship ; )

You can always land the torpedo bank and take on more mines like the RN E&F class DD's did.

You're bothering with armour on a 200ton ship?


Cheers,

It's only 1% of the weight, and I'm satisfied with the launch's speed and armament otherwise. Besides, I like gun shields. The gun doesn't do much good if a machine gun can take out the crew.

Glad you like Agra. I think she's rather cool looking too.

Cheers,

Quoted

I like gun shields

I'm sure you do ; ) although 2" for a shield against MG fire is probably a tad excessive.

The first of the Hunt class DD's were supposed to have 3 twin 4" AA. When they were putting the 3rd turret on the first ship, she leaned over rested on the fitting out dock wall. They quickly took it off again and found out that there was a boo-boo with the calculations.

Cheers,