Hi-Res Image available for download/viewing
RESTRICTION LEVEL THREE
PRICE
- Unit Cost: $4.7bil NSD
- DPR: $62 Billion NSD
Legacy-class Strike Submarine
Length: 387ft
Width: 41ft
Speed: 33 knots (surfaced)(37 on LIHBS), 34knots (submerged)(39 on LIHBS)
Depth: 2,500 feet
Propulsion: (2) S10W2 Liquid Metal Cooled Thermal-Fission Reactor
Armament:
10 VLS Pods (4 ESSMs/3 Tomahawk missiles/3 Harpoon missiles, 12 Stinger missiles/ 1 UCAV)
6 Torpedo Tubes (Bow)
90 Anti-Torpedo active countermeasures/explosives (45 PORT/STBD)
16 (8 PORT/STBD) Passive Countermeasures
Complement:
116 Enlisted
14 Officers
Deployment:
2 ASDS (Internal Bay)
1 ASDS (External Mount)
†: Denotes ideal specification
Description
The primary purpose of the Legacy is to support and defend special forces troops in near-ocean waters. In addition to mission-modular VLS tubes, the Legacy sports a state-of-the-arts communication and reconnaissance suite, as well as the same dual-mini-sub bay and lockout chamber as the previous Halcyon Block III, as well as the external mounting capabilities, allowing for the deployment of three full squads as well as assisting in coordinating them with UAVs launched from the VLS tubes and its extensive electronic warfare capabilities.
The Legacy itself still maintains the ability to go toe-to-toe with other attack subs, priding itself in stealth and first-strike capability, and the agility and countermeasures to get out of trouble, if not the ability to match torpedo-for-torpedo with only six tubes.
Stealth, for the Legacy, is a three part system. Like all modern submarines, it uses sound isolation and shock mounts on all equipment. Foremost, the outer skin is relatively smooth, thanks to having a secondary skin covering up all equipment which would protrude, filled with a foam-gel mixture designed to absorb impact as well as assist in preventing the vessel from being crushed.
Second is the acoustic-feedback system, a multi-tiered system designed to both negate incoming sonar as well as emit ambient-like noises to mask itself.
Third, as well as least well known, is Bernoulli-hump negating. The skin of the Legacy, in combination with small pumps and tubes throughout the vessel, allows water to flow around the vessel with less of a pressure difference, negating the Bernoulli-hump caused by the ship's natural movement through water in coordination with its displacement.
When all else fails, the aft end of the Legacy's sail and midsection of the hull underneath it is detachable, ejecting itself as an escape pod, easily mannable by the forward end of the ship (the "Coners") via natural access routes, and for those in the propulsion spaces (the "Nukes") the Reactor Compartment overhead accessway and a torpedo scoot from the upper aft angled towards the torpedo bay. The pod, holding a decent amount of supplies, racks, and communications equipment of the ship, is barely large enough for all personnel, but is equipped with inflatable rafts and stabilizers for extended stay, as well as part of the boat's reverse osmosis desalinization plant, ensuring long term survival of the crew.
The S10W2 LCTR Reactor Plant is a signficant upgrade from the S10W LCTR on the Halcyon-class Block III submarine. While the core itself is similar - though a bit more reliable - the S10W2 involves all lessons learn from its predecessor. Virtually no support systems are used, and the reactor is cooled by conduction/convection heat transfer of seawater to the outside of the reactor vessel for emergency situations, but primarily by a vast number of high-efficiency thermocouples, rendering the entire steam-production aspect of all other reactor plants obsolete. Once heated to operating temperature, thermal driving head is maintained in order to keep the reactor plant itself entirely quiet; absolutely no sound is produced.
With the elimination of the Machinery Room and Engine Room of other submarines, a second S10W reactor plant was able to be installed, as well as expanded berthing compartments, supply, and the ability to house more special forces units, including an additional ASDS.
The propulsor set is made up of a series of internalized step-DC-powered pumps, both positive displacement and centrifugal, eliminating noise produced by traditional props, as well as allowing the submarine to go faster without cavitating.
Despite being able to have a SONAR view behind itself, as the lack of propeller and engine room now allow for such, it still maintains a pair of towed-sonar array/decoys for redundancy.
By far the craziest addition to the submarine - taken is the Liquid Hydrogen Booster System (LIHBS), which takes water from the two reactor's shield tank that has radiolidically decomposed and separates it out via centrifuge, sending oxygen into the machinery and conn spaces, and trapping hydrogen with a cooling tank, where it is cooled until a liquid, and further subcooled. During tactical situations, this liquid hydrogen is run through channels in and around the reactor, acting as a high-efficiency moderator, vastly increasing its capable output power, allowing for an "overdrive." The LIHBS system can only be maintained for a limited time to prevent damaging the core of the reactor itself.