A system (1) for attaching a plurality of seismic nodes (110, 110a) along a main carrier rope (101). The main carrier rope is made of steel or synthetic fibre, and comprises no power or communication lines. The system has a length measuring device (210) for providing a measured length (Lm) of deployed main carrier rope (101); a data source (220, 230, 240) for providing positioning data affecting the rope position of each seismic node (110, 110a) on the main carrier rope (101); a control unit (200) for providing an attachment command whenever the measured length (Lm) corresponds to a rope position of a seismic node (110, 110a) computed from the positioning data; and a node attaching unit (100) for attaching a seismic node (110, 110a) to the main carrier rope (101) in response to the attachment command. The system is capable of attaching nodes (110) with different node spacing between some or all nodes along the main carrier rope (101). As the rope positions are determined by the measured length (Lm), the system automatically compensates for creep or stretch in the main carrier rope (101). Attaching a seismic node (110) to the main carrier rope (101) at any rope position by means of a clamping device, a suspension device and a fly line is also disclosed.