VDR & SVDR
VDR (Voyage Data Recorder) and SVDR (Simplified Voyage Data Recorder) are shipborne systems that continuously record navigational, audio, and sensor data to support accident investigation and safety analysis. As required by SOLAS Chapter V, Regulation 20 and IMO performance standards, these systems function as the ship’s “black box.”
Is VDR mandatory under SOLAS?
Yes. SOLAS Chapter V, Regulation 20 requires:
VDR for passenger ships and cargo ships ≥3,000 GT
SVDR for certain existing cargo ships, as permitted by flag states
What is the difference between VDR and SVDR?
VDR: Records comprehensive bridge audio, radar, ECDIS, alarms, and sensor data
SVDR: Records limited essential data, with reduced interface requirements
What data does a VDR record?
A VDR records:
Bridge audio
Radar and ECDIS data
Position, speed, and heading
AIS data
Alarms and communications
How long is VDR data stored?
IMO requires a minimum of 12 hours of recorded data, though modern systems often store more.
Where is the VDR capsule installed?
The float-free or fixed protective capsule is installed in a protected location to survive accidents.
Does VDR replace logbooks or bridge watchkeeping duties?
No. VDR is a recording and investigative tool and does not replace navigational responsibilities or logbooks.
How is VDR checked during PSC inspections?
Surveyors verify:
Operational status
Annual Performance Test (APT) certificate
Proper data recording
Backup power availability
Is an Annual Performance Test (APT) mandatory?
Yes. An IMO-approved APT must be carried out annually by an authorized service provider.
What happens if the VDR/SVDR fails?
The failure must be recorded, and repairs should be carried out as soon as practicable, in accordance with flag and class rules.
Can recorded VDR data be accessed by the crew?
Yes, but access is restricted and typically limited to the Master or authorized personnel.
Conclusion
VDR and SVDR are SOLAS-mandated safety systems that play a critical role in maritime accident investigation and safety improvement. When properly maintained, tested annually, and operated in compliance with IMO requirements, they provide reliable voyage data and support safer maritime operations.