In certain configurations, flexible risers or umbilicals need to be secured to the seabed. This is often achieved using steel tether clamps, tether systems, or seabed anchors. Njord TB (Tether Base) includes a clamp that is designed to withstand high differential axial loads, with a tether base at the bottom of the structure, securing the tether system to the seabed.

Njord TB connects to the pad eyes of the tether clamp, allowing connection and disconnection by ROV.

Often the anchors may comprise multiple units which can easily be lifted individually by the crane capacity available on offshore installation vessels. The multiple units are then designed to 'dock' together to provide a single structure with the required total weight in water.