Development of unmanned centrifuges for submarine combat operations [Part 1]

Progress in the construction of the multitasking frigate The swordsmen are symbolic signs of long-awaited changes, which after years of stagnation carry the Polish Navy to its new chapter of actual development. With the acquisition of new capacities, however, the related needs and challenges must be addressed in order to make the most of the new potential.

New frigates, old restrictions. ZOP in the Swordfish Program

Program MIecznik It will introduce new capabilities to the Navy, because the leap in relation to the condition of the previous generation of individuals, in some areas, is so large that over the next years it is increasingly difficult to talk about any smooth transition to the next technological level or about sustaining experience. In the domain of the ZOP, on which this content focuses, we are dealing with several facts: reaching for the potential and capabilities of the next generation, of a different nature and selected ultimately for operational requirements.

Thus, the introduction of Swordfish to the service of ships, contrary to appearances, will not involve reaching for better instruments, but after those adapted to the operating conditions and the current specificity of the operation of the ZOP, which have evolved since the time when the Oliver Hazard Perry frigates entered the service. Towed station AN/SQR-19PG on frigates of the ORP "Gen. K. Pulaski" and ORP "Gen. T. Kościuszko" for now remains a passive sonar with the highest potential with which MW of the Republic of Poland has ever been in contact and there is no indication that this will change, even in the light of any of the current programs. However, this fact is not very relevant in relation to the current operational circumstances.

The full use of frigate Swordfish in the ZOP operations is closely linked to the interaction of ships with maritime aviation. The fact alone is nothing new, the air force has played and continues to play an important role in anti-submarine activities.

However, while the Swordfish itself overcomes the next stages of the construction, the choice of its aviation component remains pending. The protracted lack of decision on this issue today indicates that the first ship will proceed to sea trials and likely enter service without a helicopter. This means limiting the capacity referred to as the "stand-off ASW", that is, the widely understood interaction with the detected submarine outside the zone of effective use of its main weaponry – heavy torpedoes (caliber 533mm and above).

The current situation of the Polish Armed Forces in the field described leaves much to be desired, which is the result of the problem of the lack of successive replacement of equipment. After the recent withdrawal of deployed SH-2G deck helicopters and Mi-14PŁ land base, the ZOP aircraft consists of four AW-101 notabene Mi-14 successors. In addition to the loss of on-board aviation, the main source of the problem is the number of units that translate severely into their operational availability.

From the point of view of the current situation, with reference only to its own resources, it is important to consider the very limited support of ship forces operating in the Baltic Sea (not only in the activities of the ZOP) and the lack of organic component during the activities of Polish frigates outside the mother water. Partial solutions to this situation are unmanned systems, which are increasingly successfully introduced to the naval forces and aboard warships.

Unmanned on-board pay

The involvement of pilotless aircraft in maritime activities is one of the leading initiatives to expand maritime aviation forces worldwide. Airless pilotless systems have reached operational maturity, mainly in tasks related to the identification of the water situation. The scale of tasks to which they are engaged expands and the fight against submarines (ZOP) is another, now very dynamic direction of their development. At the same time, in recent years, the scale of mission modules solutions to allow adaptation to these activities of platforms of different sizes is growing. The challenge is the nature of ZOP operations, which are characterised primarily by long-termity.

Unmanned Aerial System (RUAS)-based unmanned systems enjoy a growing interest and a wide range of solutions based on different platform sizes. The number of programmes and the increasing popularity of this initiative stem, among other things, from their high technical maturity and relatively easy adaptation to operate on board vessels.

The adaptation of unmanned pilot-in-command to shipboard operations, with even minimal aviation infrastructure, e.g. the landing ground itself without hangar, is still a relatively small undertaking. Admission to the RUAS does not involve extensive work to adapt the ship's design to:

• interference with the design of the carrier (referring to units already holding a helicopter landing ground),
• installation of special reception equipment (e.g. RAST, etc.)

These points are, of course, simplification, because they do not take into account the need to prohibit technical equipment for maintenance and adaptation to tasks (task modules), nor do they relate to possible integration into the ship's combat system. No less, taking each RUAS on board, e.g. a frigate or a patrol vessel with the ability to base an on-board helicopter does not entail the need to adapt the design of the potential carrier.

Unmanned pilots can be put into service without much effort from lighter and older units. In the photo of the frigate USS McInerney (FFG 8) during air operations with MQ-8B (2009).

Today, there is no one universal standard for the classification of pilotless pilots. Various users, institutions, and armed forces operate according to their own doctrines, often using a classification of an evolving character. However, it is possible to attempt to group these platforms, based on the RUAS systems currently being implemented for maritime activities worldwide.

Based on the maximum starting mass parameter of MTOW (Maximum Take-Off Weight) of systems currently in place or already in operation, pilot-free rotors can be divided into 3 groups. The proposed division may be changed as a result of many new structures being created in the world and that work on many projects is interrupted, completed or undergoing profound modifications.

Development of an unmanned ZOP helicopter

The use of unmanned rotors in the operation of the ZOP is not a new initiative, but a reintroduction in a new form, shaped by current technological capabilities. The first, operated against the RUAS submarines, was the American Gyrodyne QH-50 DASH (Drone Anti-Submarine Helicopter), introduced into service in 1963. The helicopter operated from the deck of ships and was capable of carrying and dropping on a tracked target deep-sea bombs or light torpedoes of the Mk-43 type (Mk-44 in the later variant), which was a direct response to the entry into service of the next generation of post-war sonars, which significantly increased the detection range, while failing to fire the target beyond the range of its own ship effects. At that time, the technology did not allow this helicopter to be adapted to a role other than the weapons carrier in the activities of the ZOP. The DASH system proved to be defective (about half of the 746 systems were lost) and difficult to operate, resulting in it being withdrawn after only a few years of service.

Despite the fact that the first step of the adaptation of RUAS to the ZOP was an arms carrier (DASH), current efforts are however far more focused on search capabilities than damage. The main task element of most of the current programs is the adaptation of sensors or/and retranslation systems (signal transmission).

Division ZOP abilities includes two main columns: the effector and the sensor (scheme below) which are divided into a number of technical solutions to them – task modules. The launch mass is the main determining factor which modules (and on what scale) can be integrated into the host. In the case of lighter platforms, there are significant compromises to which the following breakdown refers. In practice, this may mean sharing missions/capacity into separate RUAS units, in two complementary configurations of task modules.

Acoustic sensors

As with the Maritime Patrol Aircraft, such as the General Atomics MQ-9B Sea Guardian, the area of joint development of most unmanned aviation programs of the ZOP, independent of the platform's launch mass, is the ability to operate with radio-hydroacoustic buoys (PRHA). The choice of this direction was obvious for many reasons due to the availability and relatively low mass of the buoys themselves and the associated elements.

Schiebel S-100 with four PRHA G-size discharges (on the sides) and a single A-size (under the fuselage) against the background of both sizes (REPMUS 2024)

The PRHA of the size groups "A" and "G-size" are now the basic buoys used by NATO's naval aviation forces. In view of very light unmanned platforms, work was also undertaken on an even more scaled-down variant of the miniature PRHA of the size "F-size", which probably covers the same range of functionality as "G-size".

The ability to operate with PRHA of the size group "A-size" is associated with a significant increase in surveillance capacity for solutions based only on the family "G-size". The reduction of dimensions and masses allowed to take or simply increase PRHA's numbers on board light aircraft. Miniaturisation also has limitations and, for some solutions, reducing elements has serious potential implications. As a result, the "G-size" family now only includes passive buoys.

However, new technologies have made significant progress in this area too. The next generation of PRHA developed by Ultra Marine will expand the "G-size" group by two new buoys, developed for bi/multi-static activities. This new product is also aimed at unmanned systems, which is due not only to the size group itself, but to the functionality of: the active element SSQ-92X (only source of impulses) not available in the group, and remote programming of the settings.

These functionalities significantly increase the real capabilities and flexibility of the unmanned aviation ZOP. In the case of classic, manned helicopters and marine patrol aircraft, the described increase takes a lower scale, mainly due to the range represented by the entire "A-size" group together with the so-called "high potential" buoys.

Sound data from PRHA shall be transmitted via radio or satellite to the command and guidance station. This also means that sound surveillance capacity depends, inter alia, on the capacity of the communication system. In the event of loss, loss of transmission capacity, the acoustic data may be recorded in the memory of the on-board system and analysed upon completion of the mission.

The efficiency of the analysis of acoustic data has been and is still dependent on the involvement of experienced personnel. The drive to automate this process is one of the priority efforts, driven, inter alia, by the development of autonomy for underwater unmanned vehicles. The problem is the complexity of this process, especially in passive detection (shu-trace). It should be added that the difficult hydroacoustic operating environment, combined with the low noise of the next generation of submarines, further complicates and slows down the progress of automation.

Sound spectrum analysis system

The tools currently available for the analysis of sound spectrum (LOFAR) have powerful capabilities that face the growing challenges of search conditions. As a result, the development of autonomy in this area, despite all modern tools, remains a process of slow evolution, setting real limits on the effectiveness of passive sound surveillance.