Divinus class SSK, Diesel-Electric boat!

Divinus class SSK

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STATS:

Surface Displacement: 2,450 tonnes
Submerged Displacement: 2,800 tonnes
Length: 67.73 m
Beam: 8.4 m
Draught: 6.6 m
Hull Construction: HY-100 steel
Propulsion:
-3x SEMPA-01 V-12 Diesel engines (4.63 MW)
-1x Duro electric motor (5.1 MW)
-2x Stirling Air Independent Propulsion Units (150 kW)
-420x Lead-Acid Batteries (11,750 Ah each)
-1x seven-bladed Pump-Jet Propulsor
Velocity (Surfaced): 13 knots
Velocity (Submerged): 21 knots
Maximum Depth: 400 m
Range: 18,520 km at 9 knots
Periscope:
-KAS-300 Optronic Mast
Armament:
-6x 533 mm torpedo tubes
-24x Mk-20 Mothra torpedoes or Sub-Harpoon AShM
-8x Umkhonto-IR SAM
Countermeasures:
-KAS-200 electronic support measures system
-KAS-100 Acoustic Device Countermeasure
Sensor Equipment:
-Bow Cylindrical SONAR Array
-Flank SONAR Array
-Distributed Array
-Mine Avoidance SONAR
-Active SONAR
-Self-Noise Monitoring Hydrophones
-Fully Reelable Towed Array Sonar
-KAS-400 Multi-Function RADAR (X band)
Communications:
-KAS-600 Multi-Frequency (UHF SATCOM, UHF LOS, VHF, HF) transmit/receive antenna buoy
-KAS-1400 ELF receive antenna
-KAS-2200 Underwater Telephone
-KAS-3000 Accoustic transmit/receive system
Crew Compliment: 8 officers, 27 enlisted
Cost Per Unit: 710,000,000 standard dollars

WRITE-UP:

Inspired by the Barbel and Walrus class of submarines, the Divinus was seen as the Lamonian entry into the submarine export business. The range, weapons, and most especially quietness of the design turn the Divinus into a capable opponent, costing less than nuclear submarines for the capabilities delivered.

Armament

The Divinus features six 533 mm torpedo tubes, capable of firing any five hundred thirty three millimeter diameter torpedoes, though the default torpedo type is LAIX ARMS' Mk-20 Mothra. The Mothra has a maximum range of 55 kilometers, and a maximum speed of seventy knots. Also capable of firing the Harpoon anti-shipping missile from the torpedo tubes, the Divinus can carry a total of twenty-four total weapons.

The Divinus also has VLS launch capability for eight Umkhonto-IR SAMs. The VLS cells are built into the ballast tanks in order to create the smallest possible space encroachment in the interior of the submarine, while allowing the Divinus to deal with aerial threats when the submarine is close to the surface. Provided with targeting data before launch, the missile is fitted into a launch canister, which allows the missile to reach the surface for launch (at a maximum launch depth of up to fifty meters) without the missile's electronics being affected by saltwater. As the missile is provided with targeting data before launch, it uses the IR seeker for final target acquisition. The missile has a range of fifteen kilometers, and can be fed data from either the KAS-400 radar, or from the Tergus sonar system. Bearing and estimated range are the important information to ensure that the aerial target is destroyed. Care must be used when firing SAMs from a submarine, as it gives anyone with a radar the ability to know where you launched from. Thus, it is only reccomended to use this system in emergency situations, when there is no other option open.

Umkhonto-IR SAM

Length: 3,320 mm
Diameter: 180 mm
Weight: 130 kg
Warhead: 23 kg HE blast-frag
Speed: Mach 2.5
Ceiling: 10,000 m
Range: 15 km
Maximum Launch Depth: 50 m

Propulsion

The Divinus is powered by three SEMPA-01 V-12 Diesel engines, giving a total power rating of 4.63 MW. The diesel engines feed their power to the Duro electric motor, providing 5.1 MW of power with which to turn the shaft. Since the diesels cannot run while underwater (without a snorkel), the batteries are the primary source of propulsive and electrical power while the submarine is underwater. This allows the ship to attain a top submerged speed of 21 knots, which drains the batteries faster. A snorkel has been fitted to the Divinus, allowing the main diesel engines to be run while underwater, in order to charge the batteries.

As a means of allowing the submarine to stay underwater for longer, the Divinus utilizes two Sterling engines, which provide a total combined power rating of 150 kW. The Sterling engines combine liquid Oxygen with number two diesel, in order to provide power which can be used to turn the main shaft, as well as recharging the batteries while underwater. A Sterling engine is a heat engine operating by cyclic compression and expansion of air or other gas, the working fluid, at different temperature levels such that there is a net conversion of heat energy to mechanical work. This mechanical energy is then transferred to a generator, where it can be used. Since the Sterling process is done at 90 MPa, the exhaust can be released into the surrounding ocean directly, instead of needing to be pressurized again.

The Divinus also makes use of a seven-bladed pump-jet propulsor, reducing the sonar footprint of the Divinus as it moves, thus helping to make the platform stealthier that it might otherwise be. The use of an X configuration of the rudders and diving planes allows greater maneuvering control, which enables the Divinus to move closer to shore than might otherwise be the case, as well as being able to hug close to the ocean floor in areas where it is within the submarine's crush depth.

Hull and Interior

The Divinus makes use of a single pressure hull, constructed out of HY-100 steel. This allows it to dive to depths of up to four-hundred meters, and is further divided into two water-tight compartments. Further, each water-tight compartment is divided into two floors. Previously seen on Swedish submarines, this floor plan allows for the maximum usage of the available space onboard the submarine. For example, the torpedo room is located on the bottom floor of the frontal compartment, while the engineering spaces are located on the bottom floor of the aft compartment.

The submarine's control room is located on the upper floor of the frontal compartment, which connects to the communications room. The helm is manned by one sailor, who also controls heading, depth, speed, and trim. To starboard of the helm is the navigation console, from where the navigation of the ship is accomplished. Behind the navigation console, are the three sonar consoles of the Divinus, with capabilities that will be discussed later. Aft of the helm console is the operations console, with it's assorted systems, followed by the weapons and engineering consoles.

The upper floor of the aft compartment contains the heads, showers, and sleeping quarters of the officers and crew of the submarine. The ship features bunks for all crew members, with the enlisted crewmembers being required to "hotbunk," or share their bunk with another crewmember when they are not using it. Officers are required to share their cabins in order to save space, while the ship's captain has his own small private room. Full head and shower facilities are available for both the officers and crew. The ship has a small library which the crew are permitted to use during their off-duty time.

There is also a small galley, in which two crewmembers at a time can prepare food for the entire ship's crew. All cooking is done using either electric stove burners, or via electric ovens. This reduces the risk of fire, which is an ever-present danger on submarines. In addition to freezer and sink space, the galley also features a dual coffee making unit, which can make either coffee or tea, according to national tastes.

One hundred twenty millimeter thick rubber anechoic tiles cover the exterior of the Divinus, which both reduces the range in which the submarine can be detected with active sonar, as well as further reducing "own noise," making it more difficult to detect the submarine on passive sonar. Of course, the anechoic tiles are no substitute for intelligent use of the submarine and it's capabilities.

A technique known as "rafting" is also employed with heavy or noisy pieces of shipboard equipment. Isolating said equipment from contact with the floor or hull of the submarine via rubber and steel "rafts," reduces the amount of noise transmitted to the surrounding ocean, and thus makes the submarine quieter.

Sonar

The Divinus makes use of the Tergus integrated sonar system. The Tergus system makes use of the following systems in order to supply the Divinus with a complete sonar picture.

-Bow Cylindrical SONAR Array
-Flank SONAR Array
-Distributed Array
-Mine Avoidance SONAR
-Active SONAR
-Self-Noise Monitoring Hydrophones
-Fully Reelable Towed Array Sonar

The Towed Array Sonar is a one kilometer long cable, with passive sonar hydrophones attached, allowing the submarine to detect long range targets, with a theoretical maximum range of five hundred kilometers. Further, the towed array can be reeled into a specialized tank when it is not needed, protecting the system from damage. The Tergus system is fully capable of active and passive sonar modes, using sound to detect any sonar contacts which might present themselves.

Communications and Electronics

Aside from an antenna for receiving ELF broadcasts, the Divinus sports a floating antenna buoy, which can receive and transmit in UHF SATCOM, UHF LOS, VHF, and HF. While the buoy can receive communications while it is underwater, the buoy must be above the surface in order to transmit, allowing the carrying submarine to remain beneath the waves. The fiber-optic cable between the submarine and the buoy ensures repeatable use of the buoy. An acoustic transmit/receive communications system is further augmented by an underwater telephone, though care must be taken in their use.

The KAS-300 Optronics Mast takes the place of the traditional periscopes. The design of the KAS-300 allows it to not pierce the hull, while providing EO and IIR images to the control room staff, which can be displayed on a widescreen television, even as the footage is being shot.

The KAS-400 X-band multi-function radar is placed on another non-hull penetrating mast, while displaying the requested information in a clear, easily understood format. Depending on the radar mode selected, the KAS-400 can display navigation, or target acquisition and tracking modes. The installed radar warning receiver is a KAS-200 electronic support measures system, scanning the 2 GHz to 18 GHz frequency bands, and able to pinpoint radar sites with an accuracy between 1.4 to 5 degrees of angle (depending on frequency).

The KAS-100 ADC (Acoustic Device Countermeasure) is a 7.62 centimeter diameter, expendable countermeasure device designed for launch from submarines to counter torpedo threats. The ADC hovers vertically at a pre-selected depth, emitting an acoustic signal. The vertical depth is set prior to launch and maintained by a pressure-controlled motor driving a small, shrouded propeller in the tail of the decoy. Power for the motor and electronics is provided by a thermal battery. In the electronics section mounted below the acoustic projector section, the signals are generated and amplified, while the uppermost acoustic projector section consists of ceramic transducers and impedance-matching networks.

Export

These features make the Divinus into an effective diesel-electric powered submarine, ready and able to serve in the naval fleets of foreign powers. All of these great features can be yours for the price of 710,000,000 standard dollars per unit.

ELF is not really usable for submarine broadcast operations due to the extremely low Baud rate one can get from ELF, i.e. it takes an extremely long time to receive a single message using ELF, thus negating the point. It is most useful for receiving very simple condition messages ordering a sub up to a shallower depth, where you should use VLF to get the signals to the submarine.

Giving your crew the luxury of cabins seems to be an indulgence you can't really afford on a submarine, given the endemic lack of available space. I'd rather give the officers a dedicated sleeping mess with a number of bunks, similar to the enlisted, only that the officers most likely don't have to hot-bunk. Also, if your crew have to hot-bunk, you don't have enough bunks for everyone in the crew.

You're on a submarine, i.e. below the waves. How do you provide the SAMs targetting information without a dedicated air search radar? I'm genuinely curious, since you don't want to be shining any form of sensors that can trigger ESM receivers (which ASW helicopters/aircraft do have), and having a dedicated air search radar 1) takes up space, and 2) tells the world that you're out there somewhere when you have it turned on.

Whats the height of the pressure hull of your submarine, and the height from keel to casing? It seems somewhat overly ambitious to have two decks on a draught of 6.6 meters, considering that at least three of those meters will be taken up by 1) the pressure hull, 2) fuel, fresh water and battery tanks, just to mention a few, 3) intakes for the main ballast and trim tanks as well as the tanks themselves, 4) hydraulics, 5) moving equipment, 6) sensor package, et cetera. Also keep in mind that you'll want some leeway between the casing and the pressure hull, since the casing will be compressed somewhat by the water pressure as you go deep.

You don't have a dedicated weapons system console(s)? No engineering consoles/control section?

It should also be mentioned that fiberoptic cables are extremely fragile, and don't take well to being exposed to too much stress. They dislike being bent too, so coiling up the fiberoptic cables would result in them fracturing and the entire system becoming useless. I've personally tried it with milspec fiberoptic cables aboard a submarine and learned this the hard way.

Thats what I can see at first glance. There may be more to come when I get a chance to read this properly.

Hey, who here remembers the anti-helicopter mine?
-Can we encapsulate and navalize it as a fire&forget surprise?

Dipping sonar ops + Short-range Igla at point blank = lulz

Submarine-launched SAM do exist; I think they are intended to be launched against helicopters at very close range when the noise of the rotors can be detected. The missile probably has to acquire the target itself after exiting the water.

ELF is still useful for short, coded messages, which is still the primary means of contacting submerged SSBNs. Why couldn't you do the same for submarines which don't carry ballistic missiles?

Crew Bunks

Officer Bunks

As you can see, the crew don't get their own cabins, and there are only 14 crew bunks. Only the officers get their own cabins, and those are tiny. Four junior officers in one cabin, three senior officers in another, except for the Captain, who gets his own. These are not pleasure boats, and the conditions reflect it, to the point where any embarked special forces troops would require improvised bunks in the torpedo room, or crew's mess.

Sonar can pick up ASW helicopters and aircraft if you are close enough to the surface, this can give you bearing and range information. One can also use the optronic mast for bearing and range information. Feed the bearing and (estimated) range info into the missile, and fire. The advantage of the Umkhonto is that the missile can use it's own IR seeker to lock on to and attack the target at Mach 2.5, which is much faster than any ASW helicopter or ASW aircraft will be doing.

Older Umkhonto data sheet

http://en.wikipedia.org/wiki/Umkhonto_(missile)

I've also noted that it is wiser not to use the missiles if you don't have to do so, and that missiles are there for emergency situations. However, it does give the submarine a way to penetrate LOL ASW HELO screens.

As for the optronic mast itself, this is what it is based on:

http://www.sagem-ds.com/IMG/pdf/D1432E_SERIES_30.pdf

http://www.kockums.se/ImageVault/Images/id...ultHandler.aspx

http://t2.gstatic.com/images?q=tbn:ANd9GcR...KYGd2b9Z5fGBy-S

I see two decks. One for equipment, and one for the crew. That's on a Swedish submarine, with a smaller draught (5.6 m).

Here again, is the same thing on a British made Upholder class submarine:

http://t3.gstatic.com/images?q=tbn:ANd9GcQ...7qtZjv59XDqxZ4w

All i'm doing is following the same idea.

I can fix that, there's still room in the control center.

Hmmm... old style copper wires for transmission between the buoy and submarine then? Because the Germans have managed a similar system IRL, which i've based this off of.

http://maschinenbau.gabler-luebeck.de/en/e...kationssysteme/