Offshore Unit Dimensions

Introduction/Additional information:
  1. The purpose of this message is to supplement AIS message 5 (ITU-R M.1371-5, Annex 8, § 3.3.3) and AIS symbols (IMO SN/Circ.243 – True Scale Outline) related to offshore platforms or similar units.
  2. Offshore Support Vessels travel to offshore platforms, but must not touch them. The awareness  of the dimensions and facilities of platforms increases the platform and navigation safety.
  3. In order to support previous plan and real time approach, this message should be transmitted in the same rate of Message 5 of offshore unit and be displayed on ECDIS or ECS of support vessels.
  4. This content intends to represent features of the unit, like the edge, flare truss and auxiliary circles, besides cranes range and facilities points, to aid the approach of navigational watches.
  5. The Restiction Area is the circle where the navigation should be avoided. Auxiliary Circle could represent a rounded unit, the helideck, the mooring turret, the unit ramble around the turret or other feature.
  6. The Approaching Aid Points could be used to represent unit facilities to improve the approach safety. Its use increase  the message size from 2 AIS slots to 3 (up to 16 points) or 4 (up to 32 points) slots.
  7. ECDIS or ECS of support vessels should have the ability to use VRM (Variable Range Marker) and EBL (Electronic Bearing Line) dynamically to approaching aid points, according to IEC 62288.
  8. The display of this message on ECDIS or ECS of support vessels should be as the following:

8.1. The IMO SN/Circ.243 symbol of unit (AIS Target – True Scale Outline) should be superseded to this content. The AIS triangle symbol should be added at the reference point to clarify the true heading.
8.2. The offsets of edge unit and others features should be located relative to reported position of AIS Message 1. The unit edge and features should be oriented along the true heading of AIS Message 1.
8.3. The offshore unit representation on ECDIS or ECS of support vessels should be refreshed and redisplayed at the same rate as AIS Message 1 reporting intervals.
8.4. The colors, styles, weights and labels of the unit outline should be equivalent to IEC 62288. The display should not confuse with others standard symbols. Circles and polygons should be hollow.
8.5. The Restriction Area should be represented in all scales as a circle or a point. The offshore unit edge, flare truss and auxiliary circle should be represented on scales up to 1:12000.
8.6. The Flare truss could represent the horizontal projection of flare truss or the derrick base of an drilling unit. The derrick base should be represented as a square with diagonals (as an gray “X”).
8.7. The crane circle could represent the operational range of the crane on scales up to 1:4000. It should be represented as a gray circle (lighter than others lines) and its center as a gray point.
8.8. The Approaching Aid Points should be represented on scales up to 1:4000. They should be seen even if they overlap the lines (edges, circles and flare truss).
8.9. The origin of Set approaching aid points should not be displayed. If Transverse distance = Longitudinal distance = 0 of an specific approaching aid point, do not display the specific point.
8.10. The Label of Approaching Aid Points should be represented on scales up to 1:4000. The ECDIS / ECS of support vessels should have the ability to display or hide all labels by using a unique command.
8.11. The font of Approaching Aid Points labels should not be larger than the AIS default label font (MMSI, vessel name). The label of a specific point should be placed in order to avoid conflicts.

 

Registrant:
PETROBRAS
Message number:
8
DAC:
710
FI:
11
State:
draft
Used by:
PETROBAS
Number of slots (max):
4
Technical point of contact:

Filipe Modesto da Rocha fmodesto@petrobras.com.br(link sends e-mail)

Details:

 

Table 1 – Offshore Unit Dimensions – Main Message
Parameter # of bits Description
Message ID Repeat Indicator Source ID

Spare

 6

2

30

2

 Identifier for Message 8; always 8.

See ITU-R M.1371-5, Annex 2, § 4.6.1.; 0 = default; 3 = do not repeat any more. MMSI number of source station. This varies according to the transmitter ID.

Not used. Set to zero.
Designated Area Code

Function Identifier

 10

6

 DAC = 710

FI = 11
Origin of Edge – Transversal distance Origin of Edge – Transversal orientation Origin of Edge – Longitudinal distance

Origin of Edge – Longitudinal orientation

Direction of Edge 1

Length of Edge 1

Direction of Edge 2

Length of Edge 2

Direction of Edge n (Edge 3 to Edge 20) Length of Edge n (Edge 3 to Edge 20)

 6

1

6

1

3

6

3

6

54

108

 Distance from unit reference point (ITU-R M.1371-5, Annex 8, § 3.3.3) to origin of unit edge, releted to transversal axis. Metre units. 0 = default. Orientation of transverse  axis. 0 = From reference point to Portside; 1 = From reference point to Starboard = default

Distance from unit reference point (ITU-R M.1371-5, Annex 8, § 3.3.3) to origin of unit edge, releted to longitudinal axis. Metre units. 0 = default. Orientation of longitudinal axis. 0 = From reference point to Stern; 1 = From reference point to Bow = default

Angle clockwise between Heading and first side. 0 = 60°; 1 = 90°; 2 = 108°; 3 = 135°; 4 = 180°; 5 = 225°; 6 = 270°. 7: reserved for future use. 1 = default. Dimension, in metre steps, of unit side. 0 = default (no side).

Angle clockwise between prior side and next side. 0 = 60°; 1 = 90°; 2 = 108°; 3 = 135°; 4 = 180°; 5 = 225°; 6 = 270°. 7: reserved for future use. 1 = default. Dimension, in metre steps, of unit side. 0 = default (no side).

Same as Direction of Edge 2

Same as Length of Edge 2
Flare Truss – Transverse distance Flare Truss – Transverse orientation Flare Truss – Longitudinal distance Flare Truss – Longitudinal orientation Flare Truss – Horizontal length

Flare Truss – Direction

 7

1

9

1

6

3

 Distance from reference point (ITU-R M.1371-5, Annex 8, § 3.3.3) to Flare Truss base, related to transverse axis. Metre units. 0 = default. Orientation of Flare Truss base at Transverse dimension. 0 = From reference point to Portside; 1 = From reference point to Starboard = default Distance from reference point (ITU-R M.1371-5, Annex 8, § 3.3.3) to Flare Truss base, related to longitudinal axis. Metre units. 0 = default. Orientation of Flare Truss base at Longitudinal dimension. 0 = From reference point to Stern; 1 = From reference point to Bow = default

Horizontal projection of Flare Truss, in metre units. 63: Vertical flare or derrick base (Always represented as a square with 15 m of side). 0 = default.

Angle clockwise between Heading and Flare  (or Derrick base square). 0 = 0° = default; 1 = 45°; 2 = 90°; 3 = 135°; 4 = 180°; 5 = 225°; 6 = 270°; 7 = 315°.
Restriction Area – Radius

Restriction Area – Scale Factor

 4

2

 This is the radius of raund Restriction Area, from unit reference point (ITU-R M.1371-5, Annex 8, § 3.3.3), in metre units. 5 = default.

This is the multiplier for the Restriction Area radius. 0 = maintain radius; 1 = 10 x radius; 2 = 100 x radius; 3 = 1000 x radius. 2 = default.
Auxiliary Circle – Transverse distance Auxiliary Circle – Transverse orientation Auxiliary Circle – Longitudinal distance Auxiliary Circle – Longitudinal orientation

Auxiliary Circle Radius

 7

1

9

1

6

 Distance from reference point (ITU-R M.1371-5, Annex 8, § 3.3.3) to Auxiliary Circle centre, related to transverse axis. Metre units. 0 = default. Orientation of Auxiliary Circle centre at Transverse dimension. 0 = From reference point to Portside; 1 = From reference point to Starboard = default Distance from reference point (ITU-R M.1371-5, Annex 8, § 3.3.3) to Auxiliary Circle centre, related to longitudinal axis. Metre units. 0 = default. Orientation of Auxiliary Circle centre at Longitudinal dimension. 0 = From reference point to Stern; 1 = From reference point to Bow = default

Radius of Auriliary Circle, in metre units. 0 = default.
Crane 1 24 Same as Auxiliary Circle.
Crane 2 24 Same as Auxiliary Circle.
Expand Message

Spare

 2

3

 Expand message to display Approaching Aid Points. 0 = No expand = default; 1 = Expanded message (Table 2); 2 = Full message (Tables 2 and 3).

Not used. Set to zero.
Total of slots 360 40 bits header + DAC-FI + Application data. If Expand Message = 0: 2 slots; If Expand Message = 1: 3 slots; If Expand Message = 2: 4 slots.

 

 

Table 2 – Offshore Unit Dimensions – Approaching Aid Points
Parameter # of bits Description
Origin of Set A – Transverse distance Origin of Set A – Transverse orientation Origin of Set A – Longitudinal distance Origin of Set A – Longitudinal orientation A1 – Transverse distance

A1 – Longitudinal distance

A1 – Label

A2 – Transverse distance A2 – Longitudinal distance A2 – Label

A3 – Transverse distance A3 – Longitudinal distance A3 – Label

A4 – Transverse distance

A4 – Longitudinal distance

A4 – Label

 4

1

5

1

4

4

3

4

4

3

4

4

3

4

4

3

 Distance from reference point (ITU-R M.1371-5, Annex 8, § 3.3.3) to Origin of Set, related to transverse axis. Unit multiple of 10 meters. 0 = default. Orientation of Set Transverse dimension. 0 = From Unit reference point to Portside; 1 = From Unit reference point to Starboard = default

Distance from reference point (ITU-R M.1371-5, Annex 8, § 3.3.3) to Origin of Set, related to longitudinal axis. Unit multiple of 10 meters. 0 = default. Orientation of Set Longitudinal dimension. 0 = From Unit reference point to Stern; 1 = From Unit reference point to Bow = default

Distance from Origin of Set to displayed Point, related to transverse axis to starboard. Metre units. 0 = default. Distance from Origin of Set to displayed Point, related to longitudinal axis to bow. Metre units. 0 = default. Label as defined in Table 4. 0 = No label = default

Distance from Origin of Set to displayed Point, related to transverse axis to starboard. Metre units. 0 = default. Distance from Origin of Set to displayed Point, related to longitudinal axis to bow. Metre units. 0 = default. Label as defined in Table 4. 0 = No label = default

Distance from Origin of Set to displayed Point, related to transverse axis to starboard. Metre units. 0 = default. Distance from Origin of Set to displayed Point, related to longitudinal axis to bow. Metre units. 0 = default. Label as defined in Table 4. 0 = No label = default

Distance from Origin of Set to displayed Point, related to transverse axis to starboard. Metre units. 0 = default. Distance from Origin of Set to displayed Point, related to longitudinal axis to bow. Metre units. 0 = default.

Label as defined in Table 4. 0 = No label = default
Set B 55 Same as Set A (Origin of Set A, A1, A2, A3 and A4)
Set C 55 Same as Set A (Origin of Set A, A1, A2, A3 and A4)
Set D 55 Same as Set A (Origin of Set A, A1, A2, A3 and A4)
Label Operational Mode

Spare

 2

2

 Label Operational Mode as defined in Table 4. 0 = Supply Mode; 1 = Engineering Mode; 2 = 3 = Reserved for future use. 0 = default.

Not used. Set to zero.
Total of slots 224  
 
Table 3 – Offshore Unit Dimensions – Supplemental Approaching Aid Points
Parameter # of bits Description
A5 – Transverse distance A5 – Longitudinal distance A5 – Label

A6 – Transverse distance A6 – Longitudinal distance A6 – Label

A7 – Transverse distance A7 – Longitudinal distance A7 – Label

A8 – Transverse distance

A8 – Longitudinal distance

A8 – Label

 5

5

3

5

5

3

5

5

3

6

6

3

 Distance from Origin of Set to displayed Point, related to transverse axis to starboard. Metre units. 0 to 31. 0 = dfault. Distance from Origin of Set to displayed Point, related to longitudinal axis to bow. Metre units. 0 to 31. 0 = default. Label as defined in Table 4. 0 = No label = default

Distance from Origin of Set to displayed Point, related to transverse axis to starboard. Metre units. 0 to 31. 0 = dfault. Distance from Origin of Set to displayed Point, related to longitudinal axis to bow. Metre units. 0 to 31. 0 = default. Label as defined in Table 4. 0 = No label = default

Distance from Origin of Set to displayed Point, related to transverse axis to starboard. Metre units. 0 to 31. 0 = dfault. Distance from Origin of Set to displayed Point, related to longitudinal axis to bow. Metre units. 0 to 31. 0 = default. Label as defined in Table 4. 0 = No label = default

Distance from Origin of Set to displayed Point, related to transverse axis to starboard. Metre units. 0 to 63. 0 = dfault. Distance from Origin of Set to displayed Point, related to longitudinal axis to bow. Metre units. 0 to 63. 0 = default.

Label as defined in Table 4. 0 = No label = default
Set B Supplemental Points 54 Same as Set A – Supplemental Points (A5, A6, A7 and A8)
Set C Supplemental Points 54 Same as Set A – Supplemental Points (A5, A6, A7 and A8)
Set D Supplemental Points 54 Same as Set A – Supplemental Points (A5, A6, A7 and A8)
Spare 8 Not used. Set to zero.
Total of slots 224  

 

Table 4 – Labels of Points
0 = Supply Mode
1 Water
2 Bulk
3 reserved for future use
4 Laser
5 Radascan
6 Radius
7 Other PRS
 
1 = Engineering Mode
1 Point ID (eg: C3, D7, …)
2 To do
3 In progress
4 Done
5 ID + to do (eg: C3 to do)
6 ID + in progress  (eg: D7 in progress)
7 ID + done (eg: A1 done)