This data category is used to input the description of the mooring line/hawser attachment points/cable configurations. The types of mooring lines available at present include both linear and nonlinear cables. The linear cables are made up of linear elastic cables, winch cables and 'constant force' cables. The nonlinear cables are made up of catenary cables, steel wire cables and cables described by a polynomial of up to fifth order.

Up to a maximum of 100 mooring lines may be input, by specifying the structure number and node number (see Node Number and Coordinates (Data Category 1)) of the attachment points at each end of the mooring line, together with their physical characteristics.

Enter NONE for the data category keyword if no mooring lines are present (see Compulsory Data Category Keyword).

Attachment Positions of Mooring Lines

One end of all mooring lines must be attached to a point on a floating (or sinking!) structure. The other end of the mooring line may be attached to either another structure or a fixed point (e.g. the sea bed) with the following exceptions.

The FORC cable is inherently a constant force vector and cannot be attached between two structures. Although presented as a type of cable, this facility is used in practice to represent any external force acting at a point on a structure whose magnitude and direction are constant.

Input of Mooring Lines with Nonlinear Properties

It should be noted that the input format for nonlinear mooring lines is not the same as that for linear mooring lines. Linear mooring lines are input by specifying both the physical properties and the attachment points on one data record. Nonlinear mooring lines are input by specifying the physical properties on one data record followed by one or more data records, each representing a mooring line with the previously defined physical properties.

The maximum number of different types of nonlinear properties accepted by the program is 1000.