WesWorld

Considering laying this down in 1946Q4 as a platform for the development of a very early sub-launched cruise missile, probably about like the historical Loon missile or one of its followons.



K Class, Nordmark Submarine laid down 1946

Displacement:
4,800 t light; 4,912 t standard; 5,266 t normal; 5,550 t full load

Dimensions: Length overall / water x beam x draught
328.08 ft / 328.08 ft x 39.37 ft x 26.25 ft (normal load)
100.00 m / 100.00 m x 12.00 m x 8.00 m

Armament:
2 - 4.33" / 110 mm guns in single mounts, 40.61lbs / 18.42kg shells, 1946 Model
Quick firing guns in deck mounts
on centreline ends, evenly spread
Weight of broadside 81 lbs / 37 kg
Shells per gun, main battery: 150
8 - 24.0" / 610 mm submerged torpedo tubes

Machinery:
Diesel Internal combustion generators plus batteries,
Electric motors, 2 shafts, 4,933 shp / 3,680 Kw = 16.00 kts
Range 7,500nm at 12.00 kts
Bunker at max displacement = 638 tons

Complement:
308 - 401

Cost:
£1.374 million / $5.496 million

Distribution of weights at normal displacement:
Armament: 10 tons, 0.2 %
Machinery: 123 tons, 2.3 %
Hull, fittings & equipment: 3,466 tons, 65.8 %
Fuel, ammunition & stores: 466 tons, 8.9 %
Miscellaneous weights: 1,201 tons, 22.8 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
5,317 lbs / 2,412 Kg = 130.9 x 4.3 " / 110 mm shells or 1.9 torpedoes
Stability (Unstable if below 1.00): 1.03
Metacentric height 1.3 ft / 0.4 m
Roll period: 14.5 seconds
Steadiness - As gun platform (Average = 50 %): 0 %
- Recoil effect (Restricted arc if above 1.00): 0.00
Seaboat quality (Average = 1.00): 0.00

Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.544
Length to Beam Ratio: 8.33 : 1
'Natural speed' for length: 18.11 kts
Power going to wave formation at top speed: 39 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 0.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 0.00 ft / 0.00 m
- Forecastle (15 %): 0.00 ft / 0.00 m
- Mid (50 %): 0.00 ft / 0.00 m
- Quarterdeck (15 %): 0.00 ft / 0.00 m
- Stern: 0.00 ft / 0.00 m
- Average freeboard: 0.00 ft / 0.00 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 50.3 %
- Above water (accommodation/working, high = better): 0.0 %
Waterplane Area: 8,961 Square feet or 833 Square metres
Displacement factor (Displacement / loading): 345 %
Structure weight / hull surface area: 254 lbs/sq ft or 1,238 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 4.65
- Longitudinal: 3.58
- Overall: 3.82
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is extremely poor
Ship has quick, lively roll, not a steady gun platform
Caution: Lacks seaworthiness - very limited seakeeping ability

K-1, Experimental Large Submarine

6 fore torpedo tubes with a total of 24 torpedoes at 3 tons each, 72 tons
2 aft torpedo tubes with a total of 6 torpedoes at 3 tons each, 18 tons

900 tons ballast

2 tons navigational radar
9 tons sonar

100 tons portside secondary pressure hull
100 tons starboard secondary pressure hull

Operational Diving Depth: 115 meters nominal, 100 meters reccomended

Effective construction cost: 9,600 tons, 1,371 tons/quarter

Can you explain how you arrived at the "effective construction cost"?

Navalism's x2 submarine cost perhaps?


If it is used "as a platform for the development of a very early sub-launched cruise missile", why isn't there any miscellaneous weights assigned to any such weapon? Right now its only weapons are the torpedoes and deck guns. Also wouldn't the deck guns interfere with the available space for any Loon-like launch system and watertight storage container?

What about the "100 tons portside secondary pressure hull" and "100 tons starboard secondary pressure hull"? Personally, I feel that using belt armor or torpedo bulkhead to calculate the weight of any kind of additions to the pressure hull to be more proper.

Quoted from "Rooijen10"

Navalism's x2 submarine cost perhaps?


If it is used "as a platform for the development of a very early sub-launched cruise missile", why isn't there any miscellaneous weights assigned to any such weapon? Right now its only weapons are the torpedoes and deck guns. Also wouldn't the deck guns interfere with the available space for any Loon-like launch system and watertight storage container?

What about the "100 tons portside secondary pressure hull" and "100 tons starboard secondary pressure hull"? Personally, I feel that using belt armor or torpedo bulkhead to calculate the weight of any kind of additions to the pressure hull to be more proper.

...Wesworld doesn't do the doubled-cost thing? Huh. You learn something new every day. I thought I'd just missed it when I looked up subs.

Anyway. The intent of the design is that it's got a smaller version of the I-400's dry hanger on either side of the main hull, including outsized access hatches. Since the missiles for it to testfire don't exist yet and will start development around the same time the keel is laid down, those two hundred tons of space are 'generic' rather than laid out as specific fittings - they'll be easily refitted to hold anything the developers come up with. As hollow structures in their own right, they're certainly not armor.

Hmm. I have to wonder about the time frame for development of your missile - which of course we haven't see much of. A span of 15 months is rather short for designing and developing any sort of cruise missile - IMHO - given the complexity of the weapons system. Powerplant, launch mechanisms, guidance systems - there are quite a lot of variables. I do not believe that any other WW nation has developed cruise missiles yet - Germany has deliberately eschewed the FZG-76 so that cannot be the takeoff point for any Nordish developments. I just think you will need more time.

I do not think that they will be build with the missiles as part of the weaponry from the start. The "they'll be easily refitted to hold anything the developers come up with" would suggest that the missiles will be added after the completion of the submarine with a refit.

Japan has the MXY7 that could probably be used with some minor modifications... but a cruise missile it is not.

Quoted from "Rooijen10"

I do not think that they will be build with the missiles as part of the weaponry from the start. The "they'll be easily refitted to hold anything the developers come up with" would suggest that the missiles will be added after the completion of the submarine with a refit.

Japan has the MXY7 that could probably be used with some minor modifications... but a cruise missile it is not.

Perhaps that interpretation is valid, but I do not recall seeing any details - yet - of the missile project itself.

I must renew my subscriptions to the Stockholm Times.
:D

Quoted from "BruceDuncan"

Hmm. I have to wonder about the time frame for development of your missile - which of course we haven't see much of. A span of 15 months is rather short for designing and developing any sort of cruise missile - IMHO - given the complexity of the weapons system. Powerplant, launch mechanisms, guidance systems - there are quite a lot of variables. I do not believe that any other WW nation has developed cruise missiles yet - Germany has deliberately eschewed the FZG-76 so that cannot be the takeoff point for any Nordish developments. I just think you will need more time.

As Rooijen guessed, I'd anticipate somewhere between 36 and 48 months for a useful operational version. 12-18 months would be the point at which there'd be enough design and planning and calculation work done to start putting together handbuilt prototypes and playing with them to see what goes Kerbally wrong, and iterating that data into the next phases of development, so having the project start around the same time the boat's keel is laid should have the latter shaken down and ready for use around the time it's needed.

Speaking as another nation developing missiles, Atlantis hasn't gotten to weaponizing its missiles yet and that's after years of testing alongside Argentinian developers as well. I've chosen to take a long methodical development process so as to avoid any power gaming or unusually/unrealistically quick development of a "super weapon". Given the lack of any war I haven't seen the need to rapidly develop such weapons let alone mate them with a submarine design capable of mounting them.

I don't think any cruise missiles exist in WW.
Longer-range rockets like the V-2 do, but not in any military form. Rudimentary SAMs exist in experimental form. Mexico did some work on pulsejets but that seems to have stalled/ been abandoned.

I would design and build the missile before the sub, especially if you haven't considered size, weight, layout etc. which may change during testing.

Quoted

Speaking as another nation developing missiles, Atlantis hasn't gotten to weaponizing its missiles yet and that's after years of testing alongside Argentinian developers as well. I've chosen to take a long methodical development process so as to avoid any power gaming or unusually/unrealistically quick development of a "super weapon". Given the lack of any war I haven't seen the need to rapidly develop such weapons let alone mate them with a submarine design capable of mounting them.

By looking at the news, I feel that it is mainly an Argentinian effort and that Atlantis is just a fifth wheel.

Just put a small canister containing chlorine gas in the nosecone of the rocket and you got yourself a chemical weapon even if it is ineffective. It does not have to be a 1000 kg explosive warhead to weaponize a missile.

The Japanese scientists put a canister with Pasteurella Pestis on one of its rocket in order to shoot life into space, but by doing so they turned it into a biological weapon.

Quoted

I don't think any cruise missiles exist in WW.

Not yet but how far removed are we from it? Looking at the Valka website at the various project models of the MXY7, they have a much greater range so that one could easily be developed into a cruise missile, though I would probably have to do something about the guidance system of the weapon for the longer ranges.

Quoted

Mexico did some work on pulsejets but that seems to have stalled/ been abandoned.

IIRC abandoned because the mods did not like it.

Quoted from "Rooijen10"

Not yet but how far removed are we from it? Looking at the Valka website at the various project models of the MXY7, they have a much greater range so that one could easily be developed into a cruise missile, though I would probably have to do something about the guidance system of the weapon for the longer ranges.

My intention is that, circa 1950 or so, Nordmark will have access to a missile that can ride a single guidance beam to a surface target, with one capable of finding its own way to within two or three kilometers of its target following a couple years after that.

The planned mission profile for the earlier type is 'Surface outside of gun range but close enough that your missile's flight time is shorter than the scramble time of any fighters sent after you, flush the missile with its low-volatility fuel and solid rocket boosters, guide it in with prayer and puckered bottom - then dive and scram the instant it hits'.

Sub commanders interviewed about this plan have been dubious about its practicality, and very enthusiastic about the idea of a self-guiding missile that won't get them stuck on the surface like that.

Quoted

My intention is that, circa 1950 or so, Nordmark will have access to a missile that can ride a single guidance beam to a surface target]

How do you expect to monitor the distance to the target?

I was thinking about that as well Bruce. To guide the weapon to its target, you would probably want to see the target. For a weapon launched from a plane at high altitude that is not really a problem (well maybe it is, especially when it is cloudy), for a weapon launched from a submarine close to the surface of the ocean that is going to be much more problematic.

Outside of gun range you are looking at a range of +40 kilometers. Assuming 50 kilometers, you need to be at a point of almost 200 meters above the sea level to be able to spot a target that far away to guide your weapon there. That is probably not going to do it with just the submarine. So you would either have to use a floatplane/helicopter/balloon to do the spotting and guiding meaning the sub has to stay at the surface for a longer time to recover the spotting platform or you are going to use a much less accurate fire-and-forget-and-submerge tactic using an autopilot system like the V-1.

Precisely - terminal guidance is going to be an issue if the weapons system is to be viable.

Germany's experience with the Hs293 glide bomb and the Fritz-X has made the Luftwaffe painfully aware of the limits of visual guidance. While some work on improvements is ongoing, there isn't any rush on its developments.

Quoted from "Rooijen10"

Quoted

By looking at the news, I feel that it is mainly an Argentinian effort and that Atlantis is just a fifth wheel.

Sadly your opinion doesn't really taken into account the heavy design influence, coin and lead scientists contributions to the project that could easily be rooted in Venezuela or Colombia but instead are rooted in Argentina with a close partner in the region as a colaberative and cost saving measure,

Quoted from "Rooijen10"

Quoted

Just put a small canister containing chlorine gas in the nosecone of the rocket and you got yourself a chemical weapon even if it is ineffective. It does not have to be a 1000 kg explosive warhead to weaponize a missile.

at this point it could be that easy and may yet be approved by the military, but for now Atlantis and Argentina have desided to further develop the technology by seting the goal of reaching space. I assume I don't need to suggest the side benefits of such a goal being achieved.

Quoted from "Rooijen10"

Quoted

Quoted

Mexico did some work on pulsejets but that seems to have stalled/ been abandoned.

IIRC abandoned because the mods did not like it.

Its more complicated than that but I don't think its appropriate for us to discuss that here, or to discuss it at all really because the same situation is not being played out here.

I don't see this as remotely practical at this stage without some form of terminal guidance and even then its more likely to miss than hit.
Also, the sub would need a long-range accurate detection system for cueing in the target parameters.

Quoted from "Hood"

I don't see this as remotely practical at this stage without some form of terminal guidance and even then its more likely to miss than hit.

+2

Quoted from "thesmilingassassin"

Quoted from "thesmilingassassin"

Quoted from "thesmilingassassin"

Quoted from "thesmilingassassin"

Quoted from "Rooijen10"

Quoted

By looking at the news, I feel that it is mainly an Argentinian effort and that Atlantis is just a fifth wheel.

Sadly your opinion doesn't really taken into account the heavy design influence, coin and lead scientists contributions to the project that could easily be rooted in Venezuela or Colombia but instead are rooted in Argentina with a close partner in the region as a colaberative and cost saving measure,

Quoted from "Rooijen10"

Quoted

Just put a small canister containing chlorine gas in the nosecone of the rocket and you got yourself a chemical weapon even if it is ineffective. It does not have to be a 1000 kg explosive warhead to weaponize a missile.

at this point it could be that easy and may yet be approved by the military, but for now Atlantis and Argentina have desided to further develop the technology by seting the goal of reaching space. I assume I don't need to suggest the side benefits of such a goal being achieved.

Quoted from "Rooijen10"

Quoted

Quoted

Mexico did some work on pulsejets but that seems to have stalled/ been abandoned.

IIRC abandoned because the mods did not like it.

Its more complicated than that but I don't think its appropriate for us to discuss that here, or to discuss it at all really because the same situation is not being played out here.

Your post is too hard to read, Wes.

Your post is too hard to read, Wes.

Your post is too hard to read, Wes.

Your post is too hard to read, Wes.

Your post is too hard to read, Wes.

Quoted

I don't see this as remotely practical at this stage without some form of terminal guidance and even then its more likely to miss than hit.

Well, it would depend on what you want, whether you want to be fairly precise to hit your target in a harbor or if you accept the fact that there is a fairly large chance that your missile will miss the harbor and end up blowing up the local pub in the city beyond the harbor.

Quoted from "BruceDuncan"

How do you expect to monitor the distance to the target?

With great crudity; probably dead reckoning of predicted flight speed vs flight time. Later on - and I have no idea when - there may be a variant that gives up one or two tons of warhead for an on-board radar set to allow autonomous seeking capability.

Keep in mind that, except under very specific circumstances, I don't anticipate this being what most people would consider a practical weapon's system. I'd estimate that a 'good' shot would be one that came within, say, 300 meters of the intended target.

Aiming it even that well - well, I admit that my first thought on the problem is to use a hydrogen-filled aerostat to lift the radar illuminator... and to power and control it by wire, so that once its job is done, you can just cut the wire and write off the set. Expensive way of doing business, but a lot cheaper than a new sub.