Skip to content

Home > Model Components > Fairlead and hang-off points

Fairleads / Hang-off points

Fairleads / Hang-off points are special point that belong to a rigid body, floater, buoy or other equipment, and can be connected with primary nodes of lines or any other model component. These points can be defined within the Fairleads / Hang-off tab and are listed in the grid placed in the lower part of the tab.

You can create new fairleads by clicking the Add new... button. Points can be removed by clicking the Delete selected hanging point, which will delete the active row from the grid. Each hang-off point is defined by the following parameters :

  • Name: the name that will be used to refer to this point when connecting another model component.

  • Select coordinates system: this is used to select whether local coordinates of the fairlead / hang-off points are specified using a rectangular coordinates system or a cylindrical coordinates system.

  • Coordinates based on rectangular coordinates system: Enter the X, Y and Z coordinates of the fairlead / hang-off points. These coordinates are relative to the geometrical center of your model component, and expressed in the local coordinates system of the model component.

  • Coordinates based on cylindrical coordinates system: Enter the Center-X, Center-Y, radius (R), angle (theta) and Z coordinates of the fairlead / hang-off points. Center-X, Center-Y and Z coordinates are relative to the geometrical center of the model component, and expressed in the local coordinates system of the model component. The radius is the horizontal distance between the fairlead/hang-off point and the point defined with the Center-X, Center-Y and Z coordinates. Click here to see schematic illustrating cylindrical coordinates.

  • Built-in angle: the built-in angle defines a reference direction with respect to the model component local z-axis. The built-in angle is defined through the elevation and azimuth parameters which are detailed below. In case you connect a line end to this hang-off point using a pin connection, angular deflections could be output during post-processing. If the line is connected using a clamp, the direction of the line at the connection will always be the built-in angle. See more details...

    • Elevation (deg.): the direction in which the line or attached object will be pointing in the vertical plane.

    • Azimuth (deg.): the heading in which the line or attached object will be pointing in the horizontal plane.

Note

Built-in angles are defined by two parameters - Elevation and Azimuth.

  • Azimuth is the rotation angle around the local Z-axis, and is positive from local X-axis towards the local Y-axis.

  • Elevation denotes the rotation angle around the local Y-built-in axis. Elevation depends on the line orientation, as shown in the sketch below :

Hint

Use the pop-up menu that displays when right-clicking over the 3D View window and activate the Show local axes option to display the local axes corresponding to your built-in angles. The local Z-axis corresponds to the local orientation of the line. This way, you can easily check whether you have correctly defined your Elevation and Azimuth parameters.

  • Connected lines: Connected lines is not an input. It is automatically filled with the name of the line(s) or object(s) connected to the equipment at each fairlead.

  • Impose lines bending axes: By default, this option is not selected. Only the local vector Z is derived from the Azimuth and Elevation. This vector defines the reference axial direction of any lines connected to the fairlead. If the line is clamped to the fairlead, this axial direction is imposed to the line. If the line is pinned to the fairlead, the angle between this reference Z and the axis of the line corresponds to the so-called built-in angle. The two local bending axes (x,y) are automatically determined so that the local vector X is as close as possible to global X vector.

If the option "Also impose lines bending axis" is switched on, the two local bending axes (x,y) are derived from the fairlead Azimuth and Elevation and are imposed to any line clamped to this fairlead.

Warning

By default, it is recommended not to check the "Also impose bending axes" option when defining clamp connections.

Hint

You can copy/paste any part of the grid, which means for instance that you can import or export these data to Excel.