Author: KRP

Long range identification and tracking Requirement, Transmission, obtain LRIT data

LRIT
Long range identification and tracking.
Global identification and tracking using satellite.

LRIT Requirement / regulation
SOLAS chapter 5 regulation 19.1
Passenger ship including high speed craft
Cargo ship 300 grt and above including high speed craft
Mobile offshore drilling unit
Report position to flag at least four times a day.

LRIT Transmission
Report position to flag at least four times a day or at an interval of every 6 hours.
Also, when required, at an interval of every 15 minutes.
LRIT data – Ship’s ID, position, time and date.

LRIT working concept / content
Shipborne transmitter
Communication service provider
Application service provider
Data centre
Data distribution plan
International data exchange

Ship to satellite
Satellite to CSP
CSP to ASP
ASP to DC
DC to IDE, after receiving feedback from DDP

Criteria to obtain LRIT data
Flag state: flag state have full access to ship under it’s flag.
Port state: port state can poll and track ship which is bound to it’s port.
Coastal state: coastal state can poll and track ship within 1000 NM of it’s coast.
SAR: SAR services can request LRIT data for any particular SAR area.
Contracting Governments can receive LRIT information, upon request.

Rate of Turn Indicator Advantage, SOLAS requirement

To ensure that the ship turns at a steady rate.
To ensure the number of degrees the ship will turn in a fixed period.
ROTI is a free gyro with only two degrees of freedom. Freedom to spin and tilt.
Formula, rate of turn= V/R * 57.3/60

SOLAS requirement
For ship 50000 gt and above.
Dial should be marked 0-60 degrees per minute on either side.
Dial should not be marked less than 0-30 degrees per minute on either side.

Use of ROTI
It can be used,
To ensure that the ship turns at a steady rate.
To ensure the number of degrees the ship will turn in a fixed period.

Incorporate with gyro
ROTI is a free gyro with only two degrees of freedom. Freedom to spin and tilt.
To turn a ship, ROTI is a very useful equipment.

Advantage
Ensure that the ship turns at a steady rate.
Easy to measure.
Effective in pilotage.
Help helmsman to steer.

Precautions
Is it operational
Are you going to monitor

Constant radius turn
Let Ship will go from A to B
Total course change= @°
Total distance AB= R@/57.3 mile
We know, distance= V * T
So, V T = R@/57.3
Or, T = R@/57.3V (time to cover the distance)
So, rate of turn @/T = 57.3V/R
Rate of turn= V/R
Therefore, for constant radius, relationship between V and ROT is established.

LRIT vs AIS

AIS is a broadcast system and data is available to all receiver within range whereas LRIT is available only to the authorized person.
AIS works on the very high frequency, whereas LRIT is based on the satellite
system.
AIS range is limited to the VHF range but LRIT range is worldwide.
AIS DATA İs not stored by any organization whereas LRIT data is stored and available on denmand.
There is display for AIS on board but there is no display for LRIT on board.

Difference between VDR and SVDR, SOLAS requirement, VDR advantage

SOLAS requirement / carriage requirement
SVDR
Cargo ships of 3,000 gt and above, international voyage.
VDR
All passenger ships constructed on or after 1 July 2002.
Ships other than passenger ships of 3,000 gt and above constructed on or after 1 July 2002.

Difference between VDR and SVDR
SVDR
Cargo ships of 3,000 gt and above, international voyage.
Capsule: fixed or float free.
Mandatory data: GPS – date, time, position, speed, heading, Audio – bridge audio, VHF audio, RADAR data, ECDIS data.
AIS: if Radar image not available.
Radar image: Not mandatory
VDR
All passenger ships constructed on or after 1 July 2002. Ships other than passenger ships of 3,000 gt and above constructed on or after 1 July 2002.
Capsule: fixed
Mandatory data: SVDR data+ Echo Sounder, Alarms, Wind speed-direction, Watertightness-fire door, Hull opening, Hull stress.
AIS: not required because Radar image is available.
Radar image: mandatory

VDR microphone
Conning position
Near Radar
Chart room
Radio room
Bridge wing

VDR advantage
Accident investigation.
Insurance cost reduction.
Heavy weather damage analysis.
Accident analysis.
Training.
Monitor performance, safe practice.
Assessment.

VDR disadvantage
Required maintenance.
Required Constant power supply.
Chances of error.

Recommendation of ECDIS with VDR
Msc resolution 333(90)
Required Electronic signal of ECDIS
Required ECDIS playback mode
Required Chart data

Advantage
Accident investigation
Insurance cost reduction
Heavy weather damage analysis
Accident analysis
Training
Monitor performance, safe practice
Assessment

Disadvantage
Required more input
Required maintenance
Required Constant power supply
Chances of error

Voyage Data recorder operation, VDR capsule, Data recorded

VDR
Data recording system.
Collect data from various sensors.
Store the collected data in an externally mounted unit. (Capsule)
Capsule is tamper proof – fire, explosion, collision, sinkage.

SVDR
Simplified voyage data recorder.
Collect normal ship data.
Lower Cost.

VDR capsule
Capsule is tamper proof – fire, explosion, collision, sinkage.
Storage unit.
Fixed or float free unit.
Retrievable.
Store data for at least 12 hours.

VDR operation or principle
Two unit: Data collection unit, Data recorder unit.
DCU: Collect data from various sensors.
DRU: Store the collected data in an externally mounted unit. (Capsule). Capsule is tamper proof – fire, explosion, collision, sinkage. Fitted at monkey island.
The battery power supply to the DCU for at least 2 hours in case of power failure.

What are the Data recorded
GPS – date, time, position, speed, heading
Audio – bridge audio, VHF audio
RADAR data
ECDIS data
AIS data
Echo Sounder
Alarms
Wind speed, direction
Watertightness, fire door
Hull opening
Hull stress