How do I set the Reference point for the positional information aboard the vessel?

The area occupied by the vessel is provided with reference to the Inland AIS device’s GPS antenna, which is the point for the positional information aboard the vessel. The values A, B, C and D provides the distance from the GPS antenna to the bow (A), the stern (B), the port side (C) and the starboard side (D) of the vessel.

However, the boatmaster must ensure that the approved specialised firm enters the data correctly.

Input of Values A, B, C and D during installation

The values A, B, C and D are entered with an accuracy of 1 m during the installation of the Inland AIS device by the approved specialised firm. The overall length and beam of the vessel is input with an accuracy of 0.1 m.

In cases where the vessel is not a convoy those values do not change. No further action by the boatmaster is required.

Figure A: The position of the GPS antenna on the vessel is input during installation (values A, B, D, C refers from the GPS antenna to the outline of the vessel)

Input of Values A, B, C and D in case of a convoy

In case of a convoy the values A, B, C and D needs to be changed when the setting of the convoy is changed. The A, B, C and D value always represents the overall area occupied by the vessel which includes the pusher and all connected barges.

The boatmaster needs to amend the A, B, C, D values accordingly in the Inland AIS device when the outline of the convoy is changed.

There are two different procedures to change those values depending on the age of the Inland AIS device.

Input of Values A, B, C and D in Inland AIS devices installed before december 1st 2015

For Inland AIS devices which are installed before December 1st 2015 (type approval number R-4-200 to R-4-222) the boatmaster needs to change the A, B, C, D values according the outline of the convoy with an accuracy of 1 m. The overall length and beam need to be input with the accuracy of 0,1 m.

Admittedly this is a kind of cumbersome for which reason some Inland ECDIS devices offer a special configuration menu to support the input of those data.

Figure B1 : The A, B, C, D value representing the position of the GPS antenna on the convoy needs to be amended by the boatmaster whenever the setting of the convoy is changed to reflect the overall contour of the convoy (values A, B, D, C refers from the GPS antenna to the outline of the vessel).

This applies to Inland AIS devices which are installed before December 1st 2015 (type approval number R-4-200 to R-4-222).

Input of Values A, B, C and D in Inland AIS device installed after December 1st 2015

All Inland AIS devices which are installed after December 1st 2015 (type approval number R-4-300 to R-4-3xx) the boatmaster does not needs to change the A, B, C, D values directly according the change of the outline of the convoy. Instead, the values for the extension to the push tow caused by the barges shall be input.

These values in metre with an accuracy of 0.1m are shown in figure B2:

  • EA: the extension in front of the of the push tow or tug,

  • EB: the extension at the rear,

  • EC: the extension at the port side,

  • ED: The extension at the starboard side.

The overall length and beam are calculated automatically accordingly and transmitted by the Inland AIS device.

Here as well some Inland ECDIS devices offer a special configuration menu to support the input of those data.

Those values must be input by the boatmaster whenever the convoy is changed. This applies to Inland AIS device which are installed after December 1st 2015 (type approval number R-4-300 to R-4-3xx).

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