Section 2.5 Navigational Equipment: ECDIS, Radar, AIS, GMDSS – Specifics for Large Vessels

The bridge of a modern bulk carrier is a sophisticated command center, equipped with an array of electronic navigational aids designed to ensure the safe passage of the vessel across the oceans and through confined waters. While the fundamental principles of navigation remain timeless, the tools available to the Master and navigating officers have evolved dramatically. Understanding the capabilities, limitations, proper use, and maintenance of this equipment is paramount for safe navigation, collision avoidance, and regulatory compliance. For large vessels like bulk carriers, with their considerable momentum and often restricted maneuverability, the effective use of this equipment takes on even greater significance.

1. Electronic Chart Display and Information System (ECDIS):

ECDIS has largely replaced paper charts as the primary means of navigation on SOLAS-compliant vessels, including all bulk carriers. It integrates electronic navigational charts (ENCs) with real-time positioning information (primarily from GPS/GNSS) and other sensor data.

1. Core Functionality:
   1. Displays Electronic Navigational Charts (ENCs): Official vector charts produced by hydrographic offices, containing detailed hydrographic and navigational information.
   2. Real-time Ship’s Position Plotting: Continuously displays the vessel’s position, course, and speed on the chart.
   3. Route Planning and Monitoring: Allows for detailed route planning, including waypoints, cross-track distance (XTD) limits, safety contours, and danger highlighting. During the voyage, it monitors the vessel’s progress along the planned route and provides alarms for deviations or approaching dangers.
   4. Information Overlay: Can display information from other sensors, such as Radar/ARPA targets, AIS targets, echo sounder depths, and Navtex warnings.
   5. Safety Parameter Settings: Allows the navigating officer to set safety parameters like safety depth, safety contour, and look-ahead distances for anti-grounding alarms.
   6. Automatic Chart Updates: Official ENCs are updated regularly (weekly) with corrections (Notices to Mariners). ECDIS facilitates the application of these updates.
   7. Logbook Functions: Many systems have features for automatic or manual logging of voyage data.
2. Regulatory Requirements (SOLAS Chapter V):
   1. Mandates carriage of ECDIS for most large vessels, including bulk carriers, using official ENCs.
   2. Requires a suitable backup arrangement if ECDIS is the primary means of navigation (e.g., a second type-approved ECDIS, or an appropriate portfolio of paper charts as a last resort, though the latter is becoming less common as primary backup).
   3. Requires type-approved equipment and approved training for operators (generic ECDIS training and type-specific familiarization).
3. Key Considerations for Use:
   1. ENC Data Quality and Availability: Ensure the vessel has up-to-date official ENCs for the intended voyage. Be aware of the CATZOC (Category Zone of Confidence) for different chart areas, which indicates the accuracy of the hydrographic data.
   2. System Setup and Configuration: Correctly setting safety parameters (safety contour, safety depth, look-ahead times/distances for alarms) is crucial. Improper settings can lead to nuisance alarms or, worse, failure to warn of genuine dangers.
   3. Over-reliance: ECDIS is a powerful tool, but over-reliance without cross-checking with other navigational aids (Radar, visual bearings, echo sounder) can be dangerous. Maintain good situational awareness.
   4. Alarm Management: ECDIS can generate numerous alarms. Officers must understand their significance and how to respond. “Alarm fatigue” from poorly configured systems can lead to genuine warnings being ignored.
   5. Sensor Inputs: The accuracy of ECDIS depends on the accuracy of its sensor inputs, primarily GNSS for position. Understand potential GNSS errors and have backup positioning methods in mind.
   6. Chart Symbology and Display Modes: Familiarity with IHO S-52 presentation library standards for symbols and display modes (e.g., base display, standard display, all display) is essential.
   7. Route Checking: Before finalizing a route, use the system’s route check functions to identify potential hazards along the planned track.
4. Maintenance:
   1. Regular software updates (as provided by the manufacturer).
   2. Ensuring ENC permits are current and updates are applied correctly.
   3. Calibration of display.
   4. Functional checks of alarms and sensor inputs.
   5. Keeping the system clean and ensuring adequate ventilation for the processing units.

2. Radio Detection and Ranging (RADAR) / Automatic Radar Plotting Aid (ARPA):

Radar remains a cornerstone of collision avoidance and coastal navigation, providing the ability to “see” other vessels, landmasses, and navigational marks in all weather conditions, day or night. ARPA automates the plotting of targets, providing information on their course, speed, closest point of approach (CPA), and time to closest point of approach (TCPA).

1. Core Functionality:
   1. Detection of Targets: Transmits radio pulses and detects echoes from objects.
   2. Range and Bearing: Provides the range and bearing of detected targets.
   3. Collision Avoidance: The primary tool for assessing risk of collision and determining appropriate avoidance maneuvers.
   4. Navigation: Used for position fixing (e.g., by ranges and bearings to charted objects), pilotage in confined waters, and landfall identification.
   5. ARPA Functions:
      1. Automatic target acquisition (or manual acquisition).
      2. Target tracking, providing course, speed, CPA, and TCPA.
      3. Trial maneuver function to assess the effect of proposed course/speed changes.
      4. Guard zones and target alarms.
2. Regulatory Requirements (SOLAS Chapter V):
   1. Mandates carriage of one or two Radars (depending on vessel size/type; bulk carriers typically require two, one of which must be an ARPA).
   2. Specifies performance standards for Radar and ARPA.
3. Key Considerations for Use:
   1. Proper Setup and Tuning: Gain, sea clutter, and rain clutter controls must be adjusted correctly for optimal performance in prevailing conditions.
   2. Range Scale Selection: Use appropriate range scales for the situation (long ranges for early detection, short ranges for collision avoidance and pilotage).
   3. Interpretation of Display: Understand the limitations (e.g., blind sectors, detection of small targets in clutter, indirect echoes, false echoes).
   4. ARPA Limitations: ARPA data is based on past tracking and predicts future movement assuming the target maintains course and speed. Be aware that targets can maneuver. Accuracy depends on smooth tracking.
   5. Integration with ECDIS/AIS: Radar/ARPA targets can often be overlaid on ECDIS, and AIS data can be correlated with Radar targets, enhancing situational awareness. However, be aware of potential data errors or miscorrelation.
   6. Parallel Indexing (PI): A powerful technique for continuously monitoring the vessel’s track and cross-track distance in pilotage waters.
4. Maintenance:
   1. Regular cleaning of the scanner unit (antenna).
   2. Checking the performance of the magnetron (transmitter tube) and replacing it as per its operational lifespan.
   3. Ensuring the display unit is functioning correctly.
   4. Routine performance checks and calibration as per manufacturer’s instructions.

3. Automatic Identification System (AIS):

AIS is a broadcast system that automatically transmits and receives vessel information, enhancing situational awareness and contributing to collision avoidance and vessel traffic services (VTS).

1. Core Functionality:
   1. Transmits Ship’s Own Data: Static data (MMSI, IMO number, call sign, name, type of ship, dimensions), dynamic data (position, course over ground – COG, speed over ground – SOG, heading, rate of turn, navigational status – e.g., “underway using engine,” “at anchor”), and voyage-related data (destination, ETA, draft).
   2. Receives Data from Other AIS-Equipped Vessels: Displays this information, often on Radar or ECDIS.
   3. Information Exchange: Can also transmit and receive short safety-related messages.
   4. Aids to Navigation (AtoN): Some physical aids to navigation (buoys, lighthouses) are being fitted with AIS transponders, broadcasting their position and status. Virtual AIS AtoNs can also be created.
2. Regulatory Requirements (SOLAS Chapter V):
   1. Mandates carriage of Class A AIS for most SOLAS vessels, including bulk carriers.
3. Key Considerations for Use:
   1. Data Accuracy: The accuracy of received AIS data depends on the correct input and functioning of the transmitting vessel’s AIS and sensors. Errors in transmitted position or dynamic data are possible.
   2. Not a Replacement for Radar: AIS relies on other vessels having operational transponders. Small craft or fishing boats may not be AIS-equipped or may have it switched off. Radar should always be the primary means of detecting all targets.
   3. Identification: AIS greatly aids in identifying Radar targets, facilitating VHF communication if necessary.
   4. Input of Own Data: Ensure the vessel’s own static, dynamic, and voyage-related data is correctly entered and updated as necessary (especially navigational status and voyage data).
   5. Information Overload: In busy waters, the AIS display can become cluttered. Effective filtering or display settings may be needed.
4. Maintenance:
   1. Ensure correct connection to positioning (GNSS) and heading sensors.
   2. Verify antenna and cabling are in good condition.
   3. Software updates as required.

4. Global Maritime Distress and Safety System (GMDSS):

GMDSS is an internationally agreed-upon set of safety procedures, equipment types, and communication protocols used to increase safety and make it easier to rescue distressed ships, boats, and aircraft. It is not solely for navigation but is a critical bridge system.

1. Core Functionality:
   1. Distress Alerting: Provides multiple means of sending distress alerts (ship-to-shore and ship-to-ship) that will be received by search and rescue (SAR) authorities and other vessels. Key equipment includes:
      1. EPIRB (Emergency Position Indicating Radio Beacon): Automatically activates and transmits a distress signal (with position) when floating free or manually activated.
      2. DSC (Digital Selective Calling): Used on VHF, MF, and HF radios to send formatted distress alerts, urgency, safety, and routine calls.
      3. Inmarsat Satellite Terminals (e.g., Inmarsat-C): Provide distress alerting, two-way communication, and reception of Maritime Safety Information (MSI).
   2. Search and Rescue Communications: Facilitates on-scene communications during SAR operations (e.g., VHF radio, SART).
   3. Maritime Safety Information (MSI): Reception of navigational warnings, meteorological warnings and forecasts, and other urgent safety information via Navtex and Inmarsat SafetyNET.
   4. General Communications: Provides for ship-to-shore and ship-to-ship general communications.
2. Key GMDSS Equipment on Bulk Carriers (typically Sea Area A3):
   1. VHF Radio(s) with DSC
   2. MF/HF Radio Transceiver with DSC and Radiotelex (NBDP)
   3. Inmarsat Ship Earth Station (e.g., Inmarsat-C, and often FleetBroadband for voice/data)
   4. Navtex Receiver
   5. EPIRB (406 MHz)
   6. SART (Search and Rescue Transponder) / AIS-SART
   7. Portable GMDSS VHF Radios (for survival craft)
3. Maintenance and Testing:
   1. Daily, weekly, and monthly tests of GMDSS equipment are mandatory as per SOLAS and company procedures. These include testing DSC functions, battery conditions, and antenna integrity.
   2. Records of tests must be maintained in the GMDSS Logbook.
   3. Batteries for EPIRBs, SARTs, and portable VHFs have fixed expiry dates and must be replaced accordingly. Shore-Based Maintenance (SBM) agreements are often in place.

Specifics for sizes (Bulk Carriers):

The sheer size, draft, and handling characteristics of bulk carriers bring specific considerations to the use of navigational equipment:

1. Maneuverability and Momentum: Bulk carriers have large turning circles and long stopping distances, especially when laden. Early detection of developing situations (via Radar, AIS, visual) and timely decision-making are crucial. ECDIS route planning must account for these characteristics, allowing ample sea room.
2. Blind Sectors: The vessel’s own structure (masts, funnels, cranes) can create significant blind sectors for Radar scanners. Awareness of these and use of multiple Radars (if positioned differently) or careful maneuvering to clear blind sectors is important.
3. Squat and Interaction: In shallow waters, large vessels experience squat (reduction of under-keel clearance due to hydrodynamic effects), which must be factored into safety depth settings on ECDIS and UKC calculations. Interaction with banks or other vessels is also more pronounced.
4. Windage: Laden bulk carriers have less windage area, but large ballast bulk carriers present a significant area to the wind, affecting maneuvering, especially at slow speeds or when berthing/unberthing. This needs to be considered when interpreting vessel movement on ECDIS/Radar.
5. Rate of Turn: Large vessels have slower rates of turn. ARPA predictions and trial maneuvers must account for this.
6. Bridge Resource Management (BRM): Effective use of all available navigational equipment is a cornerstone of good BRM. This includes cross-checking information between different systems, clear communication within the bridge team, and a shared understanding of the navigational picture.
7. Sensor Placement: The placement of GPS/GNSS antennas for ECDIS and AIS is critical to ensure accurate position input. The conning position on a large bridge might be significantly offset from the GPS antenna position, which needs to be accounted for in precise pilotage (though modern systems often allow input of antenna offsets).
8. ECDIS Display Scale: Given the vessel’s speed and size, appropriate chart display scales on ECDIS are necessary to provide adequate look-ahead distance while retaining sufficient detail for safety.

Analysis for the Master (Navigational Equipment): The Master is ultimately responsible for the safe navigation of the vessel. This requires:

1. Ensuring Equipment Operability: Verifying that all navigational equipment is fully operational, properly maintained, and regularly tested. Any defects must be promptly addressed.
2. Crew Competency: Ensuring all navigating officers are competent and proficient in the use of all bridge equipment, including type-specific ECDIS familiarization. This involves ongoing training and assessment.
3. Adherence to Procedures: Implementing and enforcing standard bridge procedures, including passage planning, route monitoring, collision avoidance techniques, and GMDSS communication protocols.
4. Promoting Good BRM: Fostering a culture of effective teamwork, clear communication, and challenge/response on the bridge.
5. Maintaining Vigilance: Despite sophisticated automation, maintaining a proper visual lookout and a healthy skepticism towards electronic aids is essential. Over-reliance on a single system is a known cause of accidents.
6. Regulatory Compliance: Ensuring all equipment meets SOLAS requirements and that all necessary certifications and records (e.g., GMDSS Logbook, ECDIS training certificates) are in order.

The suite of navigational equipment on a modern bulk carrier provides an unprecedented level of information and automation. However, it is the skill, diligence, and sound judgment of the Master and navigating officers that transform this data into safe and efficient voyages.