In order to consider the possible evolution of submarine and antisubmarine warfare into the twenty first century, the focus of any analysis should be on some narrow regime of warfare. In this case the regime would be warfare between attack submarines and between SSNs and SSBNs.
Both attack submarines and strategic submarines have continuously grown in size and complexity. But there must be a limit to the growth of the size of submarines and it is a valid question as to whether or not there is an optimum size for attack submarines which designers should aim for in the near future. This size should be at least partly determined by scientific, engineering, and technological advances now available or expected soon.
An alternate way of viewing the question of size would be to select a size that would be in accord with a selected set of tactics — then optimizing the attack submarine’s capabilities in accord with that size and that set of tactics.
The technology to be examined with regard to the production of the next generation of attack submarine and its associated tactics should encompass the efforts of the Strategic Defense Initiative (SDI). From the SDI are coming new and modifications of old concepts, techniques, and hardware in the realms of battle management, computers, artificial intelligence, materials, and propulsion to emphasize only a few aspects of this project.
By using SDI advances, it becomes plausible to arrive at a scenario Cor future underwater combat wherein attack submarines — substantially smaller than submarines of the present generation are used in coordinated groups.
As the size of an attack submarine is decreased, the feasibility of maneuver warfare for the underwater domain is increased.
Although maneuver warfare has always applied in some sense to submarines, the execution of this type of warfare has been limited by a number of factors. These factors include hull strength, size, and propulsive power.
The three-dimensional reality of the oceanic environment however, can be exploited Cor the purposes of maneuver warfare by a generation of attack submarines that is radically different from that which now exists.
By decreasing bull size the potential is raised for quieter running with less volume being present to generate sound, and less surface being available to radiate sound and vibration into the enveloping ocean. The realization of this potential depends, as in all of the aspects of the design of this new attack submarine, upon the application of the appropriate technology. Although research submarines have been the only submarines to reach great depths, the smaller size of a new generation attack submarine, combined with advanced high-strength structural materials should allow a far greater depth capability to be achieved in SSNs. Some of the materials to be considered include metal matrix composites, plastic matrix composites, and rapid solidification processed metals, with alloys of iron and of aluminum as possibilities. Such new materials combined with new nuclear power technology would still yield a submarine volume sufficient for personnel and equipment to successfully fulfill required missions.
The topography of the oceanic environment can thus be more readily utilized for concealment and for tactical advantage by smaller submarines. The hills, mountains, valleys, and canyons of the sea bed and the ice structures lying below the surface of the sea can enhance the security of a small attack submarine while providing a magnified threat to enemy submersibles. A group of convolutions on the sea bed might be too large to be of benefit to a large submarine, while a small submarine could immerse itself among those folds. By being able to penetrate the convolutions, the small submarine could gain more sound and vibration propagation damping and muffling and perhaps better execute an attack upon the enemy with an increment of the surprise element.
The power plant and propulsion system driving a small attack submarine would necessarily have to differ substantially from what is currently available. This increase could be attained through manipulation of the nuclear reactor core geometry and the utilization of more efficient neutron reflectors.Improved shielding would provide a sufficient safety margin. An increase in the heat transfer efficiency could be obtained through modification of the working fluid circulation geometry to magnify the transfer area. The experience of the United States with the development of nuclear fission reactor rocket engines would be pertinent to the procurement of the small attack submarine reactor.
Non-propeller propulsion systems in the form of jet propulsion might be considered for utilization on this submarine. With proper design, the potential exists for a faster submersible generating less noise than would be expected from present designs. The electric motor-generator set driving a propeller mounted on a shaft would be eliminated along with this source of vibration and sound. Pumps and compressors could be driven by direct energy conversion devices that, in the case of thermoelectricity, would transform the reactor beat into electricity. Although the flow of the sea water which acts as the reaction mass through the submarine might be a source of noise, manipulation of the boundary-layers involved and attention to the maintenance of laminar flow could minimize noise generation making it less than the noise produced by an equivalent propeller drive.
If a propeller drive, however, should be deemed to be the appropriate system, direct energy conversion devices could be scaled up in power level to at least eliminate the generator part or the generator-motor set. Also, a means of genera-ting electricity through the exploitation of superconductivity and using it to drive a coupled motor via the utilization or direct current homopolar machines based upon the use or superconducting magnet coils, now has an enhanced attractiveness.
Magnetic propulsion is another option that might be investigated as a non-propeller mode in which the field is generated by superconducting magnets. This option could be impractical if the required magnetic fields could not be confined to the immediate vicinity of the submarine. This situation would yield a non-acceptable magnetic signature which could be detected by enemy vessels.
Reduction of the size of the submarine implies a similar reduction in the size of the crew. The crew reduction could occur through the utilization of artificial intelligence and automation — and other expert systems to maximize the efficiency with which sophisticated weaponry and other offensive and defensive systems are employed and deployed . Such equipment would allow the performance of intricate maneuvers in the benthic layer along the bottom of the ocean, with its complex topography. This could not be performed by unaided crew personnel safely or not at all in some cases.
Also, the implementation of more complete four dimensional space-time tactics become practical. It makes practical the replacement of solitary actions by an individual attack submarine with group actions of three or more submarines linked together by their command, control, and communications systems — in a three-dimensional volume bounded by the sea surface and the ocean floor.
Group combat operations require close-knit communications but the oceanic environment presents a chronic problem for communication between submarines. A feasible solution is to use lasers tuned to regions of the electromagnetic spectrum at which ocean water is reasonably non- attenuating. The SDI program has been prominent in laser research and the proper laser may already exist. Although the laser itself is restricted to line-of-sight usage, it might be possible to develop a laser communications system that could utilize radiation scattered from the ocean surface and the sea floor. Such a scattering approach is not totally secure, but a reasonable level of security could be maintained through the use of coding and the restriction of scattering mode transmission to situations wherein eavesdropping is not a severe detriment relative to the benefits to be accrued by such transmissions.
Group operations have advantages over lone wolf operations in terms of concentrated firepower and mutual defense. With close enough spacing, the respective spheres of influence overlap so as to enhance the intensity of firepower being focussed on the enemy in an offensive situation context with similar enhancement for the mutual defense situation.
Coordinated group action should take less time for the applied firepower to be effective. Time is always a critical factor in submarine operations and this is especially important in the event of the action of a group of American attack submarines against an enemy strategic nuclear submarine within the context of the initiation of a global nuclear conflict. group of three small American attack sub-marines could more efficiently neutralize an enemy SSBN than would be the case of a one on one attack by a single attack submarine. Neutralization could entail diversion of the enemy SSBN from its route to its launch point, or the prevention of a launch of its missiles.
Group tactics can likewise be used against enemy attack submarines whether or not the enemy itself is grouped or is operating individually. For attack against SSNs, moreover, the time required for neutralization of the enemy is not so critical a factor.
By utilizing the small size, speed, and maneuverability of small nuclear submarines, a submarine battle group could use tactics akin to those usually associated with aerial warfare– resulting in concentrated weapon power, mutual protection, surprise, deception and confusion for the enemy.
However, there are limits as to how undetectable a submarine can be rendered — whether the detectable characteristics be acoustic or non-acoustic, still the contemplated size reduction of new SSN should enhance its non-detectability means of obfuscation of its strategic and tactical modes of operation.This should additionally enhance the submarine’s survivability.
Decoy countermeasures and platforms could be deployed under attack conditions. A decoy plat-form unlike many countermeasures would have no propulsive system of its own and depend solely upon the ocean currents for its motion — broad-casting taped submarine noises or wide band noise to confound the enemy’s sensors. As with the design of a small attack submarine system, advanced micro-miniaturization is essential throughout the design or the electronic and non-electronic components of countermeasures.
The countermeasures would fulfill a range of objectives. A sufficiently high noise level in terms of amplitude and variety could overload enemy identification and tracking capabilities. It should be possible to make a battle group of three subs seem to be a single submersible. An entire panoply of electronic warfare measures should be assisted in its development by the adoption of some of the on-going research and development of the SDI program.
The SDI program could also prove useful in providing new offensive and defensive weapons for the next-generation attack submarine. Kinetic-kill torpedoes with a solid non-explosive warhead of high strength and great hardness and loaded with depleted uranium for inertial mass could be rocket boosted before impact to provide maximum velocity at the surface or the enemy submersible. Other non-explosive devices could be constructed that would be oriented toward crippling the enemy’s maneuvering and steering mechanisms.
New American attack submarines and submarine tactics of the twenty first century should be radically different from what is now the case. The decision must be made in the not too distant future as to the character of a next generation submarine to counter the ever-growing threat posed by the Soviet’s greatly improved submarine force.