The invention relates to a Device (10) for separating a tubular web (11) in two flat webs (12, 13) with an adjustable blade (20) for cutting the tubular web (11) and with a pulling device (30) which impinges the blade (20) with a tensile force (K) on a folding edge (14) of the tubular web (11) wherein the pulling device (30) is configured in a way that the tensile force (K) is adjustable depending on the tubular properties of the tubular web (11) and that the tensile force (K) can be mainly kept constant with constant tubular properties independent from the tubular web (11).

An internal caisson/jacket leg cutter and method provides a frame having upper and lower end portions. The upper end portion has rigging that enables the frame to be lifted. Extensible arms are movably supported upon the frame. The arms extend and retract along generally radially extending lines. Extension of the arms enables them to contact the inside surface of a caisson/jacket leg and thus center and anchor the frame within the caisson/jacket leg interior. A cutting mechanism at the lower end portion of the frame includes one or more rotary cutters or milling devices that cut the caisson/jacket leg wall as these cutters traverse an arc shaped path, tracking the caisson/jacket leg wall.