Germans were first to demonstrate the revolutionary capability of submarines in World War I, by both sinking enemy combatants and interdicting commerce. Modern Submarines have become one of the deadliest weapons which are hardest to detect. They are literally a pile of submerged nuclear weapons ready to unleash widespread destruction with single command. In case of a nuclear war, the stealthy submarines have a greater chance of surviving the first strike. Once on high alert, the boats can leave their bases and stay undetected for months and can carry and fire missiles that could sink even the sturdiest ship and flatten entire cities.
Also worthy of note in this context is the coupling of two formerly disruptive technologies – nuclear propulsion and missiles – to provide the Submarine Force with two of our most unique capabilities today: submarine-launched ballistic missiles and no-notice land attack using Tomahawk.
However, submarines still face many challenges: Building a hull strong enough to withstand the water pressure while keeping atmospheric pressure inside. Not just the hull itself, but any windows, hatches, electrical fittings, levers etc. Military submarines which can travel a large distance cannot dive very deep, while the deep-diving submersibles are small and cannot go very fast or carry supplies (air, food, water, fuel) to go very far. It’s easier and cheaper to send robot vessels.
Emerging quantum technologies are another threat for submarines. Quantum gravimeters and magnetometers would enable long range standoff detection of military targets based on their magnetic or gravitational signatures. Massive constructions or vehicles generate a unique gravitational signature depending on the mass and magnetic signature based on metallic composition which can be detected. Quantum gravimeters based on atom interferometry could enable airborne detection and localization of underground structures, nuclear stockpiles, and nuclear submarines.
A quantum magnetometer such as superconducting quantum interference device (SQUID) promises ultra-sensitivity and large area search in the oceans. Scientists at the Chinese National Academy of Science claimed to have developed SQUID that can detect a submarine from six kilometers away. It is also developing an airborne version, the “Submarine Star of Death,” Which may cause increased vulnerability of US submarines.
Combat Power, Access, and Knowledge Superiority
RADM Malcolm Fages, USN stressed the importance of innovation in maintaining the relevance of the Submarine Force in the 21st century. He stressed three factors: Combat Power, Access, and Knowledge Superiority.
“Combat power emphasizes payload, but even with superior payload capabilities, employing submarines for maximum benefit is critically dependent on access and knowledge superiority. Without the ability to get within range of the target – achieving access – combat power is valueless. And without knowledge superiority, combat power cannot be applied in a timely and coherent fashion for maximum effect.”
Access has two components: Physical access and Electronic access. Submarine is most effective means of enabling assured physical access to a denied area. A well-operated nuclear-powered submarine is invulnerable to coastal cruise missiles, tactical ballistic missiles, and the biological and chemical weapons of mass destruction that are likely to pose growing problems to non-stealthy forces.
The “physical access” our submarines can achieve stem from our acoustic and non-acoustic stealth, and the quality of our sonar and mine reconnaissance equipment – areas of sustained investment by the Submarine Force, but also areas in which we are looking at leading-edge opportunities. And in the future, that access will likely depend increasingly on advanced sensors and payloads. For example, leave-behind sensors, submerged weapon pods that fire when signaled, or submarine launched unmanned aerial vehicles (UAVs) are all plausible means for expanding physical access and for leveraging force structure
Electronic access depends on ACINT and SIGINT capabilities, and is more than just the ability to put submarine sensors into an area where collection is required. The leap forward in onboard submarine processing capabilities – made possible largely by new computer technologies and programs like ARCI – has enabled a paradigm shift in how we collect and process intelligence
We are making similar progress in our SIGINT superiority initiative – combining the enhanced wideband capability of the Type 18I periscope with the “Classic Troll” exploitation suite. Just getting a 3 dB improvement in sensitivity with the Type 18I makes an extraordinary difference in the standoff range available to the submarine in ISR missions.
New Concepts and technologies
Researchers are developing new concepts and technologies for submarines from sonar absorbent composites, advanced propulsion systems like AIP and nuclear, mind-controlled, ultrafast, laser-based communications to launching UUVs and UAVs. They will also benefit from Virtual Reality or holographic displays of the 3D battlespace in which they are operating. Command centers may look more like Star Trek with more space and physically slimmer equipment. And much of the AI, navigation and communications may leverage quantum computing.
Submarine-launched UAVs and UUVs
One of the trends is to make them more lethal by integrating more weapons as well as autonomous underwater vehicles (AUVs, aka UUVs or simply ‘drones’). US navy’s recent Virginia-class attack submarines provide the Navy with the capabilities required to maintain the nation’s undersea supremacy well into the 21st century. It has Virginia Payload Modules whose real strength lies in the ability of these tubes to hold other payloads. Alternative payload modules, both in development today and in the future, can replace the standard Tomahawk compartment. Sensor payloads under development include a submerged launched Unmanned Aerial Vehicle (UAV) and a remotely launched Unmanned Underwater Vehicle (UUV).
On the other end, their usage is also being enhanced by integrating more lightweight weapons such as Swedish lightweight torpedoes which are loaded two to a tube. Or the Very Lightweight Torpedo (VLWT) that Northrop Grumman is working on. These can be used against lower-value targets, which are currently a problem for submarines armed only with very expensive torpedoes. And they can be used to intercept incoming enemy torpedoes.
India to develop Submarine launched UAVs reported in May 2022
Larsen & Toubro (L&T) has signed a memorandum of understanding (MoU) with NewSpace Research & Technologies (NRT), a start-up based in Bangalore, India, to develop a new range of submarine-launched uncrewed aerial vehicles (UAVs), reported Economic Times in May 2022.
“Globally, the US has deployed this capability on their submarines to close a viable ‘kill chain’ for their underwater launched weapons to target surface and land targets.” Earlier Defence Research and Development Organisation’s (DRDO) Technology Development Fund (TDF) floated a requirement on behalf of the Indian Navy to develop UAV systems.
According to TDF, the submarine-launched uncrewed aerial system (SLUAS) project is expected to meet the tactical needs of the submarines by providing intelligence, surveillance and reconnaissance (ISR) as well as maritime domain awareness (MDA) to the Indian Navy.
Royal Navy project shows how underwater warfare could look in 50 years’ time
The UK’s brightest and most talented young engineers and scientists came up with the designs after being challenged by the Royal Navy to imagine what a future submarine would look like and how it would be used to keep Britain safe in decades to come.
The concepts unveiled include a crewed mother ship shaped like a manta ray. This mothership would be capable of launching unmanned underwater vehicles shaped like eels, which carry pods packed with sensors for different missions. These pods can damage an enemy vessel, or dissolve on demand at the end of an operation to evade detection. The mother ship shall launch fish-shaped torpedoes to swarm against enemy targets would be crewed by only 20 people, who would use their minds to control the ship.
The whale shark/manta ray-shaped mothership would be built from super-strong alloys and acrylics, with surfaces which can morph in shape. With hybrid algae-electric cruising power and propulsion technologies including tunnel drives which work similarly to a Dyson bladeless fan, the submarine could travel at unprecedented speeds of up to 150 knots.
Unlike the submarines of today, which perform multiple roles in one hull, it is envisaged that the Royal Navy of the future would operate a family of submarines of various shapes and sizes, both manned and unmanned, to fulfill a variety of tasks.
Commander Peter Pipkin, the Royal Navy’s Fleet Robotics Officer, said: “With more than 70 per cent of the planet’s surface covered by water, the oceans remain one of the world’s great mysteries and untapped resources. “It’s predicted that in 50 years’ time there will be more competition between nations to live and work at sea or under it. So it’s with this in mind that the Royal Navy is looking at its future role, and how it will be best equipped to protect Brit
Russian submarines to receive new sonar absorbent composites
Russia’s Krylov State Research Center (KSRC) has developed innovative new technologies, which will reduce the ability of sonar to detect Russian submarines, according to Valeriy Shaposhnikov, chief of KSRC’s endurance and shipping hull construction unit.
“We have developed the appropriate technologies and constructions made of composites,” Shaposhnikov said. These new multilayer composites the company is using have a structure and consistency that absorb sonar signals, thereby preventing the detection of a submarine via hydroacoustics. “Such effect is provided by the extremely complex inner structure of the composite developed by KSRC,” he added. According to Shaposhnikov, the control surfaces of a submarine like rudder blades can be made from the new composites.
Laser-based Submarine communications
Submarine communications have always been a challenge because radio waves can’t penetrate seawater. Ultra-low frequency electromagnetic waves have been used but are a slow method of communicating. Submarines are completely reliant on satellites for communications and orders from their commanders ashore. However, Satellite communications require submarines to briefly surface and the use of towed antennae compromises the ability of the vessel to remain stealthy. A command and control denied environment (C2DE) is an area in which communications are jammed or degraded. There is no technology currently available that allows submarines to conduct communications in a C2DE.
Blue-green lasers is a potential technique for high bandwidth underwater wireless communication because of its high data transfer rate, reasonably large range, small size, low power consumption, immunity to interference and jamming and covertness of transmission. The laser works in much the same way as a fiber optic cable, with the medium for data transfer being the air instead of the cable. Blue and blue-green laser wavelengths can penetrate sea water so offer the potential of improved submarine communications. Blue and blue-green laser wavelengths can penetrate sea water so offer the potential of improved submarine communications.
With new secure, discrete, underwater communications technologies, drones and submarines will operate together as part of a network. Today submarines are generally lone wolfs because of the difficulty of identifying whether a target is friend or foe.
The Submarine Force can achieve knowledge superiority through network-centric operations, where enormous tactical synergy comes not only from developing, but also sharing, knowledge across the force.
High data rate antenna that will provide data rates in the EHF spectrum up to 256 Kbps, as well as provide access to SHF and GBS communications shall lead to new disruptive capabilities is in covert communications.
High-data rate, covert communications will not only bring extraordinary advantages in warfighting, but will also enable telemedicine, or real-time consultations with technical experts to solve maintenance problems that might otherwise force a ship off station. We might even be on the threshold of having loved ones back home able to send video family-grams to our deployed sailors!
Covert, precision strike from a submarine operating in denied areas in the early stages of a conflict will have a profound impact in future engagements. Whether for destroying enemy air defenses, hitting command and control complexes, or neutralizing other key nodes, our ability to strike with surprise from close in will play a disproportionate role in achieving final success. In Afghanistan, our Navy conducted its first attack on targets within a landlocked nation. Significantly, we chose a submarine attack to achieve maximum surprise against Bin Laden’s terrorist camps and thus inflict greater damage. Submarine-launched missiles are particularly potent for other reasons: Tomahawk attrition is reduced, and fired close to shore, they have sufficient range to attack enemy weapon launchers from widely separated azimuths, thus boosting chances of success.
While fixed targets can be hit with GPS, Capability to attack mobile targets, like missile batteries requires real-time intelligence with the reduced flight time of close-in, submarine-launched missiles. Many target sets can be destroyed before they have time to move, and with enemy defenses neutralized at the outset, our strikers can focus on power projection without needing to devote scarce resources to defense suppression. In flight guidance of missiles shall allow striking mobile targets, this requires feedback link from the missile and a floating-wire UHF antenna with both transmit and receive capability
Lithium-ion batteries and the latest Air Independent Power (AIP), particularly fuel cells, are making larger non-nuclear submarines more capable. These will transform non-nuclear countries’ navies.
These future capabilities will be greatly facilitated by the “all-electric” submarine. Rather than harnessing most of the nuclear reactor’s output power directly to the propulsion turbines, it will be converted to electric power on a common bus. When there is a high propulsion demand, power can be allocated to the propulsion train. But when propulsion demand is low, as is frequently the case, the Commanding Officer will be able to allocate power from the common bus to a host of functions, including High endurance UUVs, UAVs, and directed energy weapons systems.
3D printing for submarine
Submarines are still large steel tubes today largely because of limitations in how they are manufactured. The ongoing 3D printing revolution can make new things possible. If 3D printing of hulls becomes possible then odd shapes might become more popular.
Navies are planning 3D printing submarine parts today. However, putting printed parts on a submarine is as risky a proposition as putting them on aircraft, with both communities having strict standards to keep sailors safe in the air and under the ocean.
US Navy will start using 3D printed parts on in-service submarines in 2022. In a statement at an event for the American Society of Naval Engineers, Matt Sermon, executive director of Program Executive Office Strategic Submarines, said, “[AM] gives you a better material, a better steel, than [working with raw materials]. It is complicated, and microstructures…are complicated and do change some fundamental concerns of ours. We will have to change how we do nondestructive testing in many cases — not because it’s bad, but because it’s different, and we have to understand that.”