The Most Advanced Nuclear Submarine (Not Made In The US)

The United States fields a formidable fleet of both attack and missile submarines that represent the pinnacle of stealth and cutting-edge technology. However, other developed nations have also invested in acquiring and developing a submarine force with advanced underwater capabilities. Take the Astute-class submarine, for example, which was developed by the United Kingdom for its Royal Navy. It is not as well known as its American counterparts, such as the Virginia-class attack submarines. However, this U.K. nuclear-powered attack submarine is rightfully ranked among some of the most advanced underwater military vessels patrolling the oceans today.

The Astute-class forms the backbone of the Royal Navy's current fleet of attack submarines. Designed by BAE Systems Maritime, the attack sub is the first nuclear submarine to be designed entirely using 3D modeling and integrated virtual reality systems. This technique helped accelerate the design and construction process. It also lacks traditional optical periscopes, relying instead on high-specification video technology and non-hull-penetrating optronic masts to scan the horizon. Designed around a Rolls-Royce PWR nuclear reactor, the submarine has a top speed of 30 knots (56 kph). The attack sub can operate for up to 25 years without refueling, allowing it to patrol for extended periods of time without port visits. This makes its location harder for the enemy to detect. 

The Astute-class submarine is also known for its ability to glide silently under the waves, able to circumnavigate the globe without surfacing. It is widely regarded as one of the quietest submarines ever made, thanks to an advanced system of more than 39,000 anti-acoustic tiles around the hull. There's also a secondary propulsion system informally known as the "egg whisk." It is an electrically operated thruster that can be used for low-speed navigation over short distances if the main propulsion is compromised.

With its designation as an attack submarine, the Astute-class is tasked with missions that include hunting and sinking other submarines, combat ships, merchant ships, and land targets. They can also be deployed on reconnaissance and intelligence-gathering missions. These are all missions that the Astute submarine is well-equipped to undertake. Its stealthy capabilities give it an edge when faced with enemy sonar tracking systems. It can also unleash a slew of deadly weapons in full attack mode. 

The Astute-class submarine can carry up to 38 weapons fired through six 21-inch torpedo tubes. The weapons load-out could be Spearfish heavyweight torpedoes or Tomahawk Block IV missiles. The Spearfish is the U.K. Royal Navy's main anti-submarine and anti-surface torpedo. At its full speed of 80 knots, the guided weapon can engage weapons at a range of 14 miles (23 km). That range can extend outward to 30 miles (48 km), with the Spearfish traveling at lower speeds.

The Tomahawk Block IV is a land-attack cruise missile equipped with a two-way satellite link that allows it to adapt to changing battlefield conditions en route to its target. The Tomahawk cruise missile can decimate targets 1,000 miles (1,609 km) away, further elevating the status of the Astute-class submarine as a deadly offensive weapon.

The first Astute-class submarine, the HMS Astute, was commissioned in August 2010, but did not become fully operational until May 2014. Its builder, BAE Systems, described it as "the largest and most advanced attack submarine ever built for the Royal Navy." The submarine stretches for 97 meters and weighs about 7,400 tonnes. HMS Astute (S119) has since been joined by four others – HMS Ambush (S120), HMS Artful (S121), HMS Audacious (S122) and HMS Anson (S123). The Royal Navy plans to eventually own seven Astute-class submarines, with HMS Agamemnon (S124) and HMS Achilles (S125) still under construction.

The Astute Submarines have seen barely any combat compared to their predecessors, say, during World War II. However, this is down to the evolving nature of warfare rather than the capabilities of the submarine itself. However, its role as a frontline deterrent cannot be over-emphasized, given its strengths, including the ability to patrol the seas at all times, ready to respond to threats against the United Kingdom or its allies.

The submarines remain in active service with the Royal Navy. However, plans are already underway for a replacement in future. According to a recent BBC report, the U.K. government will build up to 12 attack submarines as part of the AUKUS program, a trilateral security arrangement between the United States, the United Kingdom and Australia. These nuclear-powered submarines will eventually replace the Astute-class submarines in the late 2030s.