Vessel Dimensions

Menu path
→ → Ownship → Dimensions

Vessel dimensions must be configured. Based on the configured vessel dimensions, charted hazard monitoring is performed both during voyage planning and track plotting.

Important

At each ECDIS startup, a settings check is performed: vessel dimensions and safety contour values. If any of these settings have not been configured by the navigator, ECDIS will display a warning: “Dimensions not set. Safety contour and/or vessel height, water level not established.”

Vessel structural dimensions

No.	Parameter	Description
1	Privileges	Obtain elevated privileges to edit vessel dimensions
2	Vessel diagram	Visual representation of the vessel and input parameters
3	CWL (Constr WL)	Construction waterline on the vessel diagram
4**	Actual air draught	Calculated vessel height accounting for water level excess; used during transit monitoring and route safety assessment
5	Under-keel clearance	Minimum under-keel clearance
6	Draught current	Current vessel draft
7	CWL (Construction waterline draft)	Draft at the construction waterline
8	Maximum draft (static)	Draft at full load
9	Height from construction waterline	Height of the highest point of the hull or cargo from the CWL
10	A and B	CCRP offset relative to the bow and stern of the vessel
11	C and D	CCRP offset relative to the vessel’s sides
12	Default data	Default values used during route creation and navigational safety zone calculation
13	Anchor hawse-hole	Position of the anchor hawse-hole in vessel coordinates. Required for correct calculation and monitoring of anchor watch
14	Barge dimensions	Enables configuration of barge and combination dimensions

Note

Vessel dimensions are entered by specifying the position of the common reference point (CCRP). Changes to the values in fields A, B, C, and D shift the CCRP relative to the bow/stern and port/starboard sides. The sum of fields A and B equals the vessel’s length, and the sum of fields C and D equals the vessel’s beam.

Barge settings

No.	Parameter	Description
14	Barge dimensions	Enables configuration of barge and combination dimensions
15	Barge diagram	Visual representation of the barge and input parameters
16	CWL (WL)	Construction waterline on the barge diagram
17	Under-keel clearance	Minimum under-keel clearance for the barge
18	Draught	Current barge draft
19	Actual air draught	Calculated barge height accounting for water level excess; used during transit monitoring and route safety assessment
20	CWL (Construction waterline draft)	Barge draft at the construction waterline
21	Maximum draft (static)	Maximum barge draft
22	Height from construction waterline	Height of the highest structure or cargo on the barge from the CWL
23	Barge position	Formation of the combination

Caution

When entering the barge height, enter the height of the cargo, not the barge’s own height. Oversized structures carried on the barge may exceed the towing vessel in height. Failure to account for cargo height may result in an incorrect assessment of the combination’s clearance along the route.

Tug-barge combination configurations

Important

When forming a tug-barge combination, in accordance with IMO recommendations, the combination is treated as a single vessel. The outline is calculated as the addition of the barge to the vessel and is then used for both route safety verification and charted hazard monitoring.

Important

Fields E — Barge length and F — Barge beam.

Alongside towing, barge on the port side

Diagram	Outline

Alongside towing, barge on the starboard side

Diagram	Outline

Push towing, barge ahead of the vessel on rigid coupling

Diagram	Outline

Astern towing, barge behind the vessel on towline

Diagram	Outline

Note

When towing on a towline, the towline length should be added to the barge length. The current towing calculation model does not account for the free movement of the barge. The combination is treated as a rigid vessel hull.

Important

When vessel dimensions change, including when forming a tug-barge combination or changing the draft of the vessel or barge, verified routes will change their status to “Not verified”. Before activating a route, perform a route safety check with the new dimensions and, if necessary, adjust the route before the voyage.

Important

When forming a tug-barge combination, note that ECDIS calculates the safety contour relative to the object with the greatest draft, and vertical clearance monitoring is performed based on the greatest height.

Default data

Note

Default values are elements used for route construction. When creating a route, the entered values are applied to the new route. The navigator can change them later.

No.	Parameter	Description
1	Turning radius	For economic speed and a rudder angle of 15°
2	ECO speed	Economic speed of the vessel
3	Maximum drift angle	Maximum predicted drift of the vessel (combination) during the voyage
4	Deviation portside	XTD to the left of the route axis
5	Deviation starboard	XTD to the right of the route axis

Additional recommendations

Warning

The values of height, draft, and clearance affect alarm and warning generation and are also used for depth calculation in the echo sounder. Incorrect settings may cause false safety system activations.

Note

The values of height, draft, and clearance affect alarm and warning generation, as well as depth calculation (see **Echo sounder**).

Settings quality control

Tip

It is recommended to regularly verify the correctness of entered vessel dimensions when: changing cargo type, adjusting draft, and forming a tug-barge combination.

Warning

Incorrectly set vessel dimensions may lead to conditions contributing to accidents.

Important

It is recommended to regularly update the current vessel draft values.