New functions introduced for radar data processing help masters to avoid adverse ocean conditions
Radar is a key tool for tugboat operators to avoid hazards and can now identify large waves that could disrupt cargo and vessel towage.
Oceangoing tugs would ideally avoid adverse weather and potentially hazardous waves during towage duties; however, detecting and analysing waves would be useful in mitigating risk to tugs and their tow. Manufacturers have developed software that analyses radar returns at different radio frequencies to detect potentially damaging waves.
Japan Radio Co (JRC) has developed radar functionality to detect these waves, helping tug masters minimise destabilising vessel motions.
JRC says its navigational radar JMR-7200/9200 can be upgraded with software for wave analysis. This comes as more ships and tugs lose cargo in adverse weather and sea conditions.
In the past 12 months, there have been several incidents of containers falling overboard from container ships operated by Ocean Network Express, Maersk Line, Evergreen Marine, APL and MSC in heavy weather during ocean voyages.
At least one tug operator has suffered a similar issue. In June 2020, Young Brothers lost at least 21 containers in Hilo Bay, Hawaii off barge Ho Omaka Hou, which was being towed by 1991-built tug Hoku Loa, while sailing from Honolulu. The US Coast Guard is still investigating the incident but suspects this tow may have been adversely affected by wave action.
Heavy rolling and pitching can cause containers to lose their stability and fall overboard. These incidents could have been prevented by using weather routeing and wave analysis radar.
JRC says its radar Wave Analysis function can help operators deviate away from potentially damaging waves. Radar can measure wave height, direction and length to support masters’ decisions so navigators steer vessels on the safest course and speed to reduce rolling and pitching.
JRC radar’s signal processor Blizzard accurately measures waves and detects vessel movements simultaneously through scan correlation and pulse-length adjustment. Blizzard can analyse waves ahead in the range of 1.5-2 nautical miles (nm) in a 4 km2 zone, while JRC’s navigation radar continues to detect ships up to 12 nm away to prevent collisions.
The wave analysis function is integrated in the JRC JMR-7200 and 9200 IMO radar as a software licence function, with no additional hardware. To display both wave and navigation information, a window can be included on the IMO radar screen to indicate wave height, length, period and direction in values, or displayed in a spectrum chart for easy and fast interpretation.
Alternatively, wave analysis functions can work in combination with a JRC dynamic sensor, JLR-21, to measure the motion of the vessel around three axes. Wave data can be recorded and shared with shore-based managers, ship design institutes and weather data companies for research and to improve calculation models.
“By analysing and measuring the waves, and presenting clear decision-making information to the crew, we can prevent containers from falling over or rolling dangerously,” JRC says.
In Canada, Rutter Inc launched an advanced radar processing system for its Sigma S6 line. WaveSignal uses X-band radar and predictive analytics to determine when quiet periods in wave action will occur.
This information can be used to improve mariner safety while conducting on-deck operations, carrying out cargo or personnel transfers and offshore activities.
WaveSignal provides a high-definition display of approaching wave fields and combines this with a timer to predict the next change. Operators can use this to assess risks and identify safe periods for on-deck operations.
Rutter says an operator can input specific wave height thresholds as determined by the nature of the work and acceptable conditions. When these thresholds are exceeded, a red signal light is activated on the bridge display and on a deck signal panel. Quiet periods are identified with a green signal light, indicating it is safe to proceed.
Rutter chief executive Blair Wheaton says WaveSignal was developed during 12 years of research following German-based OceanWaveS’ acquisition in 2008. “It has been very challenging bringing this breakthrough product to market,” he says.
“Because only now, some 12 years after the idea first germinated, has computing power and high-definition imaging been up to the task of dealing with the complexities of real-time wave prediction,” says Mr Wheaton.
There are times when captains do not need to detect waves and would benefit from suppression of this clutter. JRC and Alphatron Marine introduced a new river radar with wave suppression technology in August 2020. JMR-611 is the first river radar to meet the stricter requirements for maximum reflection from radar monitors. JRC says it is the first river radar to have calculation technology to minimise signals from waves on open water, which disrupt hazard and ship detection. With this sea-state function, buoys and other small hazard echoes will remain clearly visible.
Broadband pulse-compression radar, such as Navico’s HALO20+ and HALO20 radars provide hazard detection in short range and long range for tracking objects with small footprints and low profiles.
Navico says these can be used in crowded waterways and in poor visibility to provide navigators with a clear, current picture of their surroundings. HALO20 can detect hazards up to 24 nm away. Masters can monitor selected collision hazards with mini-automatic radar plotting aid target detection to track up to 10 targets. It requires 18 W of power and has 24 rpm.
HALO20+ has VelocityTrack for dual-range operations and can detect targets from a greater distance than HALO20. This radar comes in a compact dome antenna (50.8 cm diameter) and delivers high-quality short-, mid- and long-range detection, with full 360° sweep, up to 36 nm. HALO20+ consumes 29 W of power and requires 10.5-31.2 V direct current. It weighs 5.9 kg, has a minimum range of 50 m and an operating temperature range of -25°C to + 55°C.
Furuno Electric gained certification from Lloyd’s Register in December 2020 for its HermAce digital health manager tool. This uses a virtual replica of wheelhouse equipment, including radar workstations, based on data streamed directly from the vessel and offers live identification and diagnosis of problems. It enables managers to remotely monitor, maintain and test the onboard equipment, reducing costs and need for engineer-vessel visits.
Miros is working with BW Group to use radar for vessel performance optimisation. The two companies expect this to provide reliable information in actual operating conditions, such as a tug’s speed and performance during different weather and sea states.
Riviera Maritime Media will provide free technical and operational webinars in 2021. Sign up to attend on our events page