BrightMariner
MEO Class II: MEKG MEKM MEP MET SC&S SSEP 📊 Trends
Q9 (10 Marks) General 🔥 Repeated 4x in exams
SSEP • Written Exam

Briefly discuss the following with respect to safety of navigation:

(a) Bridge Navigational Watchkeeping Alarm System (BNWAS).

(b) Long range identification and tracking of ships (LRIT)

(c) Voyage simplified voyage recorder (VDR/S-VDR).

Appeared In: Jul 2024Apr 2024Aug 2023Dec 2019

✓ Verified Model Answer (Text Solution)

Structured for DG Shipping MEO Class II examination scoring criteria.

Exam Ready

Briefly discuss the following with respect to safety of navigation:

Part (a)

BNWAS (Bridge Navigation Watchkeeping Alarm System)

Part (b)

LRIT (Long Range Identification and Tracking of ships)

Part (c)

VDR/S-VDR (Voyage Data Recorder / Simplified Voyage Data Recorder)

Part (d)

AIS-SART

Part (a)

BNWAS: The Bridge Navigational Watchkeeping Alarm System (BNWAS) monitors the bridge continuously and alerts the watch officers if the bridge watch becomes unattended or the OOW is incapacitated. It is fitted on SOLAS ships (300 GT and above, on new ships from 2010, retrofitted on existing by defined dates) to reduce the risk of the ship operating with an unattended or fatigued bridge. The system has three stages of alarm: (1) first alarm (visual/audible) at the bridge after a set timed interval (the "no-activity" period, typically 3-12 minutes, adjustable 1-12 min); (2) if not acknowledged, a second (remote) alarm in the quarters of the officers; (3) if still unanswered, a third (remote) alarm to all officers and/or to all stations (e.g. to the master and general). The BNWAS resets via pressing a reset/alarm acceptance button; a foolproof signal/config is set so the OOW must touch it periodically, and if there is no response through the stages, the system indicates (via silence in a "trick" test) that the bridge is unattended - it also has a "call all" indicating an unattended bridge. It comprises sensors (reset buttons/radar/conso), a processor, and alarm sounders and indicators.

Part (b)

LRIT: The Long Range Identification and Tracking of Ships system provides global tracking of ships. It transmits (via satellite) data on the ship's identity, position and time to the ship's flag Administration (and to search-and-rescue entities) at least every 6 hours (LRIT standards require position reports at intervals, and in emergencies more frequently). It is required for SOLAS ships (passenger ships, cargo ships of 300 GT and above and mobile offshore drilling units) engaged on international voyages (with some exemptions). LRIT differs from AIS in being global (long-range, satellite, beyond VHF). It enables flag States to identify and track their ships anywhere, support SAR and security, and monitor the movement/position; data is shared with maritime administrations and SAR; it is central to the global tracking and security framework.

Part (c)

VDR/S-VDR: The Voyage Data Recorder (VDR) continuously records data (bridge audio, electronic data, radar, GPS, speed/heading, alarms, communications) required for the reconstruction/analysis of an incident. The S-VDR is a simplified version (for existing ships/ smaller vessels) with a reduced data set and a simpler recording unit. Both use a tamper-evident protective capsule (a bright orange beacon) housing the recorded media which survives the sinking so the data can be recovered; the recorded data (12+ hours in protected capsules, stored overwriteable) is used to determine the cause of the casualty, support investigations and improve safety. SOLAS Ch. V requires VDR on passenger and cargo ships (new and by retrofit); the S-VDR is allowed for certain existing cargo ships. Data records are analysed after a casualty.

Part (d)

AIS-SART (AIS Search and Rescue Transmitter): An AIS-SART is a search and rescue locating device which transmits a distress signal on the AIS (Automatic Identification System) frequency (VHF 161.975/162.025 MHz using the AIS message 1 / special distress message). When activated (often manually or on immersion), it repeatedly transmits its position (via its built-in GPS) and identity over AIS, which is received by ships with AIS onboard and by SAR, giving a precise, dedicated distress location - an improvement over the older Racon-based SART which only blips on radar. AIS-SART is replacing (or supplementing) the radar SART in the lifeboat/life raft/EPIRB requirements (approved under SOLAS Ch. IV/III and the GMDSS). It is activated in an emergency, eg when the survival craft is deployed, enabling rescuers to home in accurately. It is an alternative to the radar SART where the configuration is approved.

← Back to SSEP Question Bank Upload Recent Question Paper →