Definition(s)
Top Tensioned Riser
Vertical or nearly vertical riser supported by top tension in combination with boundary conditions that allow for relative riser/vessel motions in vertical direction and constrained to follow the horizontal vessel motion at one or several locations.
Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global Standards