Message to the United States

[Logan]

Transmitted By the Authority of Vincenzo Navarro, Re D'Italia and Duca D'Este

Classified/Encrypted Level IV




​

Sir or Madame,

My R&D Center would like to request assistance in developing a highly technologically advanced hunter-killer SSN, which we are developing for the Italian Navy, primarily to fill the roles of long-range maritime surveillance and attack, Special Operations Forces (SOF) Deployment, and ELINT/SIGINT Gathering. Attached are the details of the project which I have been charged with leading. My nation will ensure that your government will be reimbursed for the assistance rendered. If a reply can be forthcoming, that would be preferable, as the project is preparing to enter the development phase.

God's Peace be Upon You,

Santina Drago
Director, Naval Systems Design
Marconi National Ressearch and Development Center
Regno d'Italia

highly encrypted attachment

Basic Information:

• Hull Designation: SSN
• Displacement: 14,750 tonnes surfaced, 16,500 tonnes submerged
• Complement: 15 officers, 120 enlisted
• Length: 140.5 m
• Beam: 13.5 m
• Draught: 10.5 m

Propulsion:

• 1x 90 MWe (250 MWt) Advanced High-Temperature Pebble-Bed Reactor (AHTPBR)
• 2x Helium/nitrogen closed-cycle gas turbine generators, 45,000 kW each
• 2x diesel generators, 1,800 kW each
• 1x High-temperature superconducting integrated motor/propulsor, 34 MW (45,594.75 shp)
• 2x Low-Noise Pump Jets (driven by above HTS Motor)
• 4x Retractable auxiliary maneuvering thrusters, 625 kW (830 hp) each

Performance:

• Speed:
  • Surfaced: 20 knots
  • Submerged (silent): 25 knots
  • Submerged (max): 35 knots
• Test Depth:
  • Design: 500 m
  • Crush: 700 m
• Range: crew endurance (210 days supplies)

Sensors & Processing Systems:

• Submarine Tactical Combat System
• Conformal Acoustic Velocity SONAR (CAVES) Integrated Bow Array
• Conformal Acoustic Velocity SONAR (CAVES) Wide Aperture Flank Array
• Fiber-optic thin-line towed-array SONAR
• Ultra-high frequency phased array antenna system
• Multifunction Towed Communications Buoy
• X band phased array surface search/navigation radar
• Tethered Multispectral Photonics Mast System

Electronic Warfare & Countermeasures:

• Tactical ESM System
• Acoustic interception and countermeasures system
• Own-Noise Monitoring System
• Electromagnetic Signature Suppression System
• 3 inch (76mm) Internal Countermeasure Launchers
• 6.5 inch (16cm) External Countermeasure Launchers

Armament & Payload:

• 8x Bow-facing 533 mm torpedo tubes, 40x 533mm torpedoes or missiles or 120 mines

The Neptune class SSN is an advanced nuclear-powered hunter-killer submarine designed by the Marconi National R&D Center, with the primary missions of hunting down and destroying high performance deep-diving submarines, and large surface warship groups. Secondary missions include undersea reconnaissance, mine warfare, SIGINT and ELINT, and deployment of special operations forces. The Neptune uses a conventional single-hull configuration with a pressure hull with an added bow and stern hydrodynamic fairings. The pressure hull is constructed from high tensile strength maraging steel while the outer light hull employs a low-drag axisymmetric teardrop shape and is constructed entirely from composite materials. The pressure hull is constructed from five modular hull sections (weapons module, habitability module, payload module, engine room module, and Auxiliary Machine Room (AMR module) which are welded together to form the final pressure hull. The large internal decks in each hull module are fabricated and inserted into the hull as individual Modular Isolated Deck Sections (MIDS) onto cushioned and vibration isolated supports before the separate hull modules are welded together.

Designed to operate autonomously against the most capable submarine and surface threats the Neptune features a variety of stealth systems designed to drastically reduce the detectability of the Submarine to both acoustic and electromagnetic sensor systems. The acoustic signature is monitored in real time by an Own-Noise Monitoring System (ONMS) which employs a series of self-noise hydrophones (SNHs) mounted outside of the pressure along with hull and machinery mounted accelerators connected to a centralized processing system and a display/interface inside the submarine. The ONMS monitors both acoustic noise and vibration inside the submarine for radiated noise self-estimation and source localization as well as machinery and hull health monitoring. The OMNS can detect propulsor cavitation, flow-induced structural resonation, and any odd noises emanating from the machinery or propulsion plants or due to loose objects inside of the submarine. The Neptune is also fitted with a Closed Loop Degaussing system, designed to take noise picked up by the ONMS and provide cancellation of those noises, in real time. Combined with the tight tolerances used in the construction of the vessels, the Neptune is designed to have a "silent-running" acoustic signature between that of the Russian Yasen-class (NATO Reporting Name: Severodvinsk) and that of the American SSN-21-class (Seawolf)

The primary undersea sensing system of the Neptune-class SSN is a water-backed Conformal Acoustic Velocity SONAR (CAVES) bow array which combines medium/high frequency transducers and low-frequency passive hydrophones in an array mounted conformally to the bow of the submarine. The curved array allows detection angles of +/-120 degrees in the horizontal and +/-30 degrees vertically off the centerline axis of the submarine. The Bow array has multiple functions which include active detection and identification of threat objects such as submarines and mines as well a long ranged passive detection and tracking of both surface and subsurface contacts. To eliminate the deleterious effect of self-noise on the CAVES array the entire array is attached to a an active noise-canceling composite layer connects the CAVES array to the hull of the submarine and consists of two layers of thin film polyvinylidine fluoride (PVF2) polymer transducers separated by a neoprene acoustic insulator layer connected to the submarine's hydrodynamic hull with a 25 mm thick layer of versathane adhesive. The detected acoustic signals from both the outer and inner PVF2 transducers are fed into an electronic control circuit which subtracts the signal of the inner sensor from the signal of the outer sensor to effectively cancel out the noise emanating from the array itself and from the submarine, allowing the primary transducer and hydrophone array to listen solely to sound external to the submarine. The submarine is also equipped with two towed arrays: a thin line towed array and a thick line towed array.

Furthermore, the Neptune is outfitted with an advanced SIGINT/ELINT and Communications Array, not only capable of intercepting (and receiving from friendly sources) ELF, VLF, and Acoustic communication, but also, while surfaced, picking up, intercepting, and tracking other electronic systems that emit large amounts of EM Radiation, such as (commercial and military) maritime radar systems, communications arrays (obviously), and the like.

@John