Saab A26 unveiled what it claims is the world's most advanced stealth submarine.

The A26 sub is 207 feet long, and features a 'ghost mode' to make it virtually undetectable when underwater. It also features a unique pod that allows special forces divers to enter and exit the sub while it is underwater.  

It can also 'play dead' at the bottom of the sea to remain unfound - while divers can still exit to lay mines

By Mark Prigg For Dailymail.com

The firm has already signed a $1 billion deal to build two of the new submarines for the Swedish Navy.

'Extreme stealth is at the heart of the Kockums A26 submarine,' the firm said.

'Sweden is unleashing its GHOST (Genuine HOlistic STealth) technology, thus making the Kockums A26 submarine effectively invisible.'

Type A26 submarines are nearly 207 feet in length, 21 feet in the beam.

The have an endurance of 45 days or 18 days underwater.

They have a test depth of about 658 feet. 

They will be conventional diesel-electric submarines equipped with the Kockums Stirling AIP (air-independent propulsion) system for enhanced stealth.

The order, with a value of about $1.04 billion, is for construction of two Type A26 submarines and conducting mid-life upgrades to two Gotland-class submarines.

Work on the two A26s is to be completed by 2024.

'Sweden has long experience in designing very silent submarines,' the firm says.

'In the Kockums A26 submarine, an extremely resilient platform technique incorporating extensive rubber mountings and baffles is used to minimise noise from operating machines and transient noise, as well as absorbing shocks. 

To further reduce emitted noise, the space between the frames is equipped with acoustic damping plates.

Video : Saab unveils 'world's most advanced' submarine

 

 

 

 

Hull shape and fins designed to make it appear almost invisible 

'Intelligence gathering, surveillance and sea denial along coastlines are becoming increasingly important, ' Saab said. 

'Operations in shallow water enable submarines to carry out covert monitoring of targets on land or sea using a range of electro-optical and electromagnetic sensors. 

'Moreover, the ability of a submarine to lie motionless on the ocean floor, or 'bottom out', makes it almost impossible to find.'

HOW GHOST MODE WORKS 

Extreme stealth is at the heart of the Kockums A26 submarine, and it depends on good design right from the very beginning, Saab claims.

'Sweden has long experience in designing very silent submarines,' it says.

'In the Kockums A26 submarine, an extremely resilient platform technique incorporating extensive rubber mountings and baffles is used to minimise noise from operating machines and transient noise, as well as absorbing shocks. 

Saab's A26 design includes a Multi-mission Portal flexible payload capability with a lock system in addition to its conventional torpedo tubes.

To further reduce emitted noise, the space between the frames is equipped with acoustic damping plates.

This approach is used in combination with, for example, encapsulated Stirling and diesel engine modules; flexible hoses and compensators; and specifying maximum flow speed in air ducts, minimum bending radius on cables and pipes, and the design of out-board holes and cavities. 

To become invisible, further ways of keeping silent are exploited by the Kockums A26 submarine:

The target strength of the Kockums A26 submarine is minimal because of the vessel's unique hull shape, the unique fin design, sonar and equipment accommodation, and a new type of surface acoustic absorption or reflection coatings. 

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.

This highly optimised design also cuts the hydrodynamic signatures and flow noise around the submarine, both in deep water and near the surface.

The magnetic signature is suppressed by an advanced degaussing system that is controlled by external sensors to facilitate compensation in all geographical locations and headings. 

Galvanic signatures, primarily electrical but including secondary magnetic signatures are reduced by a specially designed cathodic protection system and careful material selection that minimise electrical signatures without compromising the corrosion protection of the submarine.

The two vessels will be delivered to Sweden's Defense Materiel Organization in late 2018 and late 2019, respectively.

'Saab will deliver world-class submarines to Sweden,' said Hakan Buskhe, president and chief executive officer of Saab. 'Our ability to work closely with customers, to meet their needs with modern manufacturing and products, is one of Saab's greatest skills.

'Saab is also exploring export opportunities to provide complete submarine systems to a select number of countries, plus sub-systems across the wider market.'

The two vessels will be delivered to Sweden's Defense Materiel Organization in late 2018 and late 2019, respectively.

Added Gunilla Fransson, head of Saab's Security and Defense Solutions business area: 'The A26 will be a unique and high-tech submarine with proven modular design, which gives the platform a high level of availability at a low life-cycle cost. 

'The submarine will have long-endurance submerged performance and excellent maneuverability in all waters.

'Safety is paramount and A26 will be highly survivable thanks to modern underwater stealth technology and a unique heritage of shock resistant design.'