Zycraft, a Singapore-based company specializing in the design and manufacture of automatic surface boats (ANC) for civil and military applications, continues to improve the Longrunner-class prototype of the ANC Independent Unmanned Surface Vessel (IUSV) Vigilant class by adding new capabilities.
In March, Zycraft installed a remote controlled fire nozzle and an electric fire pump along with ancillary hardware and software to test remote fire fighting concepts. Self-contained fire extinguishing equipment has demonstrated its ability to deliver water to a maximum distance of 40 meters, although the company plans to upgrade the system to increase the range.
According to Zycraft President James Sun, the crewless fire platform is one of several concepts being explored on the Longrunner platform. He added that other specialized options are at various stages of design or construction, for example: anti-submarine warfare, naval reconnaissance and surveillance, mine action and search and rescue.
“Smaller ANCs are dependent on the launch vehicle and appropriate launch and recovery methods, and as systems evolve, operational problems will persist, especially in high seas. In addition, increasing the range reduces the ANC's payload and increases the costs of the launch vehicle. When using the IUSV concept, fleets also do not need to build larger ships just to carry small ANCs, instead they can rely on the carrying capacity of the larger IUSV and its inherent long sailing time to carry the necessary target equipment … warships should focus on where they are enemy ships, and not be burdened by the management of a small ANC."
"Having left its base, IUSV can go to the area of operation and then remain there for a long time, needing only infrequent refueling in order to increase the duration of the stay at sea,"
he added.
Construction and power plant
According to Zycraft, the Vigilant IUSV was designed from the outset as an uninhabited platform, so that the final product could be easily optimized for various tasks, as opposed to the modification of traditional boats or ships. However, it can be optionally inhabited, the tandem wheelhouse can accommodate up to two operators, seated on shock-absorbing military-standard SHOXS suspension seats.
Construction began in early 2010 with the lead vessel Longrunner, launched in October 2011. The entire line is based on a lightweight hull 16.5 meters long and 3.6 meters wide, with an empty weight of about 8500 kg and a total displacement of 16000 kg, including a payload and 7000 kg of fuel.
The Longrunner body has a high elongation ratio, which reduces drag. It is made from Arovex's proprietary carbon nanotube-reinforced carbon fiber composite. According to Zycraft, the hull is 40% stronger and 75% lighter than a similar sized hull made of traditional marine grade aluminum or fiberglass, allowing ANC to reach high speeds without the need for large, heavy motors. The combination of a lightweight hull and low-displacement engines allows for more payload and fuel to be carried on board for increased cruising range and capabilities.
The Vigilant IUSV has a maximum speed of 40 knots and a sailing duration of over 30 days, according to the specification provided by the company, with a cruising range of up to 1,500 nautical miles in standard configuration at an economic speed of 12 knots.
“We believe that sailing duration is a key characteristic for ANC, as the vehicle must observe at low speeds for extended periods of time during deployment,” said Song. "A maximum speed of 40 knots is quite adequate for the ANC, since a vessel of this size with higher speeds cannot be used effectively with wave heights over a meter."
ANK is equipped with two turbocharged diesel engines Yanmar 6LY3-ETP with a volume of 5, 8 liters and a dry weight of 640 kg each, which generate a total power of 960 hp. The engines are coupled through a ZF Marine ZF 280-1 gearbox to Konrad Marine 680 stern drives with counter-rotating coaxial propellers, which have been specially selected for their ability to provide optimum efficiency over a speed range of up to 40 knots.
“We also have experience with the Arneson ASD10 direct drive system equipped with five-blade Rolla propellers in a boat with a similar hull shape,” explained Sun. “Both configurations provide good fuel efficiency, especially during low speed patrol operations, which are one of the ANC's primary missions.
With such a propulsion system, we have a fuel consumption of about 10-15 liters per hour at a speed of 6 knots in favorable conditions, that is, the duration of the voyage increases significantly with the existing volume of fuel tanks."
Equipment set
The Vigilant 1USV device is equipped with a sensor kit, which includes an automatic recognition system, a rooftop optoelectronic surveillance station Current Corporation Night Navigator 3 and a Simrad Broadband 4G mast radar with a declared detection range of 36 nautical miles, as well as stabilized all-round cameras.
The survey electro-optical station includes an uncooled high-resolution thermal imager with a matrix size of 640x480 and a double field of view of 20 ° and 6, 8 °, as well as 3x optical zoom and 12x digital continuous zoom; night image converter of high resolution with a field of view of 20 ° and continuous digital magnification 12x; daytime camera of high resolution with a resolution of 1080i / 720p and fields of view from 50 ° to 5.4 °, optical zoom 10x and digital zoom 12x.
Meanwhile, the 360 ° Surround System consists of six 4MP AXIS Communications Q16 low-light cameras with frame rates up to 120fps, networked together. The cameras are housed in a self-cleaning module that uses air jets to clean the lenses to ensure excellent visibility in all weather conditions, Sun said.
“The video is stabilized by software algorithms so that the output image remains stable even when the IUSV is rolling. This makes it easier to detect objects. We use software to instantly enlarge the image of an object automatically in order to reduce the burden on the operator."
The power supply on board is provided by a 12 kW generator from Fischer Panda, while a 5 kW generator provides additional energy for functional systems and ensures continuous operation in the event of a main generator failure.
The IUSV is equipped with a Seakeeper Model 7000A gyroscopic stabilizer designed to stabilize ships with a total mass of 15 to 25 tons. According to the specification, the 7000 A model with dimensions 910x990x710 mm and weighing 455 kg can provide damping torque up to 15000 Nm and compensate for kinetic moment up to 7000 Nm / s. For its full promotion, 45 minutes are required (although it can reach operating modes approximately 20 minutes after switching on) and a power of 3000 W, in a stable mode, a power of 1500-2000 W and 8 l / min of seawater is required for cooling.
Song noted that such stabilization systems are typically used in crewed seagoing vessels to reduce roll amplitude and improve crew and passenger comfort, although they offer significant benefits for uninhabited platforms. For example, a stable ANC can help optimize the output and tracking performance of optocouplers and radars at higher sea levels.
“It actually removes roll, thereby significantly increasing the capabilities of the radar and optoelectronic devices at the expense of added stability,” he explained. “Since the ship is likely to use a satellite system for over-the-horizon communication, the Seakeeper damper also helps to improve the reliability of the connection by reducing the load on the stabilization subsystem of the satellite communication system.
In addition, any ANC carrying out submarine control or demining missions must necessarily move slowly and need good stabilization during the descent and return of the target load. The IUSV can now operate in significantly higher sea conditions. We found out that even a stationary IUSV behaves relatively calmly when hitting the side of a wave with a height of 1.5 meters, because it simply rises and falls smoothly, which would be impossible without the stabilization system."
Command and control
The Longrunner is typically operated from a dedicated command center located at Zycraft's facility in western Singapore. The IUSV can be operated using standard broadband radios or cellular modems, while the Cobham SAILOR500 FleetBroadBand500 (FBB500) L-band satellite communications system supports all-weather over-the-horizon operations.
“With a single antenna, all control and datasets are encrypted and passed between the ANC and the coast station,” Sun explained. "The bandwidth of the data transmission channel allows the transmission of the radar image, images from the optoelectronic station and all cameras, information of the automatic recognition system and the parameters of the boat itself without delay."
“Adaptive bandwidth throttling is used to control communications so that the connection remains reliable,” he added. "The current over-the-horizon vehicle control solution was tested in extended trials in 2013 and 2017, when the IUSV was deployed for 22 days for continuous unmanned operations."
The company has developed proprietary command and control software that is loaded onto the IUSV on-board computer. It uses built-in collision detection and avoidance algorithms to enable the vessel to navigate autonomously in ports and busy waterways.
Civilian computers and large displays were used to equip the command center. Three display screens display information from the radar, from the optoelectronic station and all-round cameras and ANC control operations.
“We have a high-quality radar image on our display, which also shows tracking information,” Sun continued. "We are proud of the radar image because it gives the operator a very good sense of the IUSV environment - the operator has an almost complete feeling that he is on board a real boat."
Meanwhile, the IUSV subsystems interact via a local network and are controlled by a host computer that exchanges information and sends data packets to the coast station via a radio or satellite link. Sun said the open architecture principle allows Zycraft to easily integrate and configure new capabilities into the vessel.
The host computer also offers a separate collision detection and avoidance function, receiving information from an automatic recognition system, lidar, radar and imaging devices and then analyzing it. In order to improve accuracy and reliability, the collision avoidance software was updated in 2013-2016.
“In the design of the collision avoidance program, most of the effort went into making the platform more adaptable to external conditions, which allows movement in high traffic areas as well as in open water without operator intervention. International rules for preventing collisions of ships at sea are used as a basis for decision-making, but the most important rule is self-preservation, he added. "The minimum safe distance determines the ANC's response even when it has priority of passage."
Ship development
Zycraft completed initial development of the Vigilant IUSV in September 2013, after which Longrunner completed 2,000 nautical miles in 24 months of sea trials in Singapore waters. According to Zycraft, the unit took part in a demonstration for an unnamed fleet, and also took part in several operations lasting more than 48 hours, including a sea test in May 2013 at a distance of 150 nautical miles.
The company has also undertaken a number of real-world marine assessments of the hull properties, focusing on sailing duration, range and seaworthiness of the hull design, using the Shomari-class long-range vessels, the crewed IUSV options that Zycraft offers to shipping companies in the region to combat pirates and material and technical supply.
Shomari ships have the same hull shape as the Vigilant IUSV, the same total displacement of 16 tons and similar balancing, which allows the company to use crew vessels as test platforms.
Since 2014, Shomari LRVs have undergone a series of endurance tests, including a seven-day sailing at a range of 1,100 nautical miles. LRV boats also passed stability tests at wave heights up to 4 meters, during which they reached a maximum speed of 34 knots under full load.
In the spring of 2017, the company tested the IUSV in the South China Sea, during which it sailed non-stop for 22 days at an average speed of 6 knots with periodic accelerations, eventually covering a total distance of 1,900 nautical miles. The vessel went out for trials with a little over 6,000 liters of diesel fuel and returned to port with 2,800 liters.
The IUSV was operated by two operators onshore, monitoring the vessel 24 hours a day, although the company also provided an escort boat to deal with any emerging issues.
It is understood that recent life tests have bolstered Zycraft's expectations for the fuel economy of the IUSV, the reliability of its electronics and mechanical systems. Song said that these endurance tests provided data on the performance of the sensor and navigation systems under real-world conditions.
“Since IUSV had the opportunity to observe sea traffic and other events for a long time during the tests, we were able to recognize clear shipping patterns and even witnessed several dangerous approaches of commercial vessels”, - shared Sung, but refused to provide details.
"There were some challenges, but we were able to find ways to overcome them and optimize the real-time capabilities of IUSV through software updates."
Future opportunities
The company pays great attention to expanding the range of tasks for the vessel by using its sealed modular compartment for a payload of 3x3x2 meters with a maximum capacity of 3 tons.
“This compartment is specifically designed to accommodate a payload that requires specialized handling equipment,” said Sung. “To support this target load, ancillary equipment, such as electronics cabinets, can be installed in the designated cargo hold.”
In the proposed low-cost anti-submarine defense concept, the IUSV will be equipped with a complete active / passive sonar supplied by one of Zycraft's technology partners. The boat will work as a replacement for the anti-submarine platform, allowing crewed combat vessels to avoid distraction and perform other tasks.
Zycraft has developed the YZDDS-920 DDS (diver detection sonar). The compact sonar system, 300 mm high and 425 mm in diameter, can be installed on board the Vigilant IUSV, other ANC and marine vessels, or used as a stationary device to protect ports or coastal infrastructure.
According to the company, the DDS is designed to detect open-loop scuba divers at distances of up to 600 meters and divers equipped with regenerative breathing apparatus at distances of up to 400 meters in all directions to a maximum depth of 50 meters. The system includes an antenna unit weighing 45 kg, a processing unit and a graphical user interface on a laptop. It can track up to 100 objects simultaneously and independently issue a warning signal when a threat is detected.
The company is currently looking for a partner to integrate the sonar system into the IUSV, with plans to conduct another long-term sailing test in the near future, focusing on underwater research and observation. Song noted that work on integrating sonar could open the way for the introduction of anti-submarine warfare technologies in the future. Zycraft also expects increased demand for search and rescue operations.
The company noted that the IUSV device, equipped with appropriate sensor systems and detectors for transmitting coordinates in emergency situations, could be an excellent choice for countries with long coastlines and vast sea areas.
The IUSV device, configured for search and rescue, during such operations can remain at sea for a long time, while a specially designed module allows the operator to remotely rescue survivors using a robotic arm and carry up to seven stretchers with the wounded.
Patient monitoring devices can be incorporated into equipment to monitor the psychological state of the victims and send information to the coastal service even before arriving ashore.
For reconnaissance and intelligence gathering, Zycraft is considering deploying off-board sensors such as tethered drones for long-term visual surveillance. However, custom payload modules can be deployed to meet specific customer requirements for both civil and military applications.
The company also wants to enter the training and simulation market, in connection with which they began development of a new project M75 Unmanned Target Boat. The AHK target weighing 0.9 tons has a total length of 5.8 meters, a width of 1.6 meters and a draft of 0.33 meters. The boat is equipped with a Yamaha F115 outboard motor, which allows you to reach a speed of 35 knots, a fuel tank with a capacity of 220 liters allows you to be at sea for up to 23 hours at a speed of 12 knots or 5 hours at stable maximum speeds.
ANK Vigilant IUSV is part of a small but expanding line of large-displacement, versatile uninhabited platforms under development in the Asia-Pacific region.
Among the countries with ANC platforms over 11 meters long, China and Singapore are especially notable, developing respectively the JARI multi-task boat weighing 20 tons (China Shipbuilding Industry Corporation) and the 22-ton boat Venus 16 (ST Engineering), optimized for mine action.
Large unmanned surface vessels offer several advantages to fleets. For example, larger hulls tend to have more payload volume as well as fuel capacity, giving operators more flexibility and control radius. Larger platforms can be optionally manageable for tasks that require better situational awareness and complex decision making.
However, due to their large size and displacement, large automatic ships, as a rule, operate from coastal bases, since for most ships, with the exception of universal amphibious ships, which have large landing docks, they are too cumbersome and heavy for launching and lifting. on Board.
