Vessel adapted to perform subsea wellbore related operations including module handling and laying flexible pipeline, e.g. wellbore intervention, said vessel comprising: - a hull with a main deck; - a moonpool having a moonpool wall extending through the hull; - a stationary drilling mast having a closed contour mounted on the hull adjacent said moonpool, wherein the mast has a front side facing the moonpool; - one or more vertical trolley rails provided at the front side of the drilling mast, extending into the moonpool and along a mast side moonpool wall part; - a module handling trolley which is - during module handling - movable along the vertical trolley rails in a vertical trolley path into the moonpool; - a hoisting device being adapted - during module handling - to lower and raise the module; - a module handling device adapted to - during module handling - transfer modules to the module handling trolley, comprising skid rails on the main deck extending towards the moonpool wall, wherein - during module handling - an unobstructed module handling area is provided above the skid rails and the moonpool; - one or more tensioners (30; 31), each tensioner comprising a tensioner frame (30f, 30f'; 31f) supported by the by the drilling mast and multiple tracks (30t; 31t) supported by said tensioner frame, said tracks being adapted to - in a pipeline laying configuration during laying flexible pipeline - engage the flexible pipeline and to support at least part of the weight of a launched pipeline in a firing line which extends on the outside of and adjacent to the front side of the drilling mast and through the moonpool; wherein at least the tensioner frame of a lower tensioner is mounted pivotably about a vertical pivot axis (PA; PA') to the drilling mast, such that the tensioner frame is pivotable between the pipeline laying configuration wherein the lower tensioner is provided in the module handling area and an open configuration wherein the module handling area and at least part of the vertical trolley path is unobstructed to allow module handling. - a hull with a main deck; - a moonpool having a moonpool wall extending through the hull; - a stationary drilling mast having a closed contour mounted on the hull adjacent said moonpool, wherein the mast has a front side facing the moonpool; - one or more vertical trolley rails provided at the front side of the drilling mast, extending into the moonpool and along a mast side moonpool wall part; - a module handling trolley which is - during module handling - movable along the vertical trolley rails in a vertical trolley path into the moonpool; - a hoisting device being adapted - during module handling - to lower and raise the module; - a module handling device adapted to - during module handling - transfer modules to the module handling trolley, comprising skid rails on the main deck extending towards the moonpool wall, wherein - during module handling - an unobstructed module handling area is provided above the skid rails and the moonpool; - one or more tensioners (30; 31), each tensioner comprising a tensioner frame (30f, 30f'; 31f) supported by the by the drilling mast and multiple tracks (30t; 31t) supported by said tensioner frame, said tracks being adapted to - in a pipeline laying configuration during laying flexible pipeline - engage the flexible pipeline and to support at least part of the weight of a launched pipeline in a firing line which extends on the outside of and adjacent to the front side of the drilling mast and through the moonpool;