Super Stealthy Saab Submarines
Submarines remain the ultimate maritime insurance policy, which is why so many countries treat the ability to build or design them as a strategic capability. The Swedish Government has approved initiation of the design phase for a new generation submarines for the Royal Swedish Navy. The new generation, called the A26, will be designed for both littoral operations and ocean-going capabilities.
The A26 will be a 62m boat with about 1,800t displacement when surfaced, and more when fully submerged. It is designed to excel in littoral operations, while remaining a capable ocean-going vessel. As a point of comparison, that size is a bit larger than the German U212A/214, and about the same as the Scorpene AM-2000 AIP, all of which are ocean-going boats.
It will be powered by a conventional diesel-electric propulsion machinery, and equipped with Stirling AIP system (air-independent propulsion). The Stirling system, together with a set of balanced underwater signature reduction techniques, will make the Saab A26 submarine very stealthy and difficult to detect. It will also be highly resistant to underwater explosions through verified shock resistance technology.
Saab's A26 design includes a new innovative 6m x 1.5m Multimission Portal flexible payload capability with a lock system in addition to its conventional torpedo tubes. The lock system makes it easy for commandos to enter and exit the boat, and is large enough to allow the launch and retrieval of Unmanned Underwater Vehicles. UUVs are expected to play a larger role in future submarine warfare. They can already provide advance surveying and sensing capabilities, and their modification toward a combat role is a certainty. This will likely begin with coordinated decoying tactics, but UUVs are expected to graduate to active combat capabilities before the A26 leaves service.
Air Independent Propulsion
The A26 will be equipped with an air-independent propulsion (AIP) supplement to its diesel-electric systems, which is intended to allow it to remain underwater for up to 18 days at relatively slow speeds before its AIP fuel is exhausted. That avoids the need to surface and suck air for the diesel engines to recharge its batteries, a vulnerable time that was the absolute bane of conventional submarine operations until the USA introduced nuclear-powered boats. The A26’s AIP system will be the Saab Kockums’ Stirling, which also equips Sweden’s 3 Gotland and 2 Sodermanland Class submarines, Singapore’s Archer Class Sodermanlund variant, and Japan’s Soryu Class.
The submarine will also be prepared for network connectivity. A highly modular design facilitates efficient through-life upgrades and adaptations.