In offshore cable and umbilical installation, the hang-off is the structure that secures and transfers the load of the subsea cable/umbilical from the installation vessel to the fixed offshore structure (such as a jacket platform, monopile, or topside deck). It essentially “hangs off” the cable in position and provides both mechanical support and sealing (if required).
Installation location
The hang-off assembly is typically installed at the top of the J-tube or I-tube exit on the offshore structure.
It can be either a temporary hang-off (during cable installation) or a permanent hang-off (long-term fixation of the cable).
Links above and below
Above the hang-off
The subsea power cable or umbilical continues upward inside the J-tube/I-tube until it reaches the deck or transition piece.
Above the hang-off point, the cable is usually terminated, connected to a junction box, switchgear, or other topside equipment.
Below the hang-off
The cable or umbilical runs down through the J-tube/I-tube into the subsea environment.
Additional protection systems are often installed below, such as:
Bend restrictors or bend stiffeners (to prevent over-bending at the J-tube exit).
Centralizers (to maintain spacing inside the J-tube).
Cable protection sleeves or ducts (for abrasion and impact protection).
Major features
• Continuos or split design
• Clamp on cable outer body
• DNV Norway approved
Technical specifications
Riser Size (mm) | ≤508 mm |
Pipeline sizes | 4x 8" NS up to 12x 18" NS |
Axial loads | ≤200t |
Design pressures | ≤350 bar |
Material | Carbon Steel, Stainless Steel, SuperDuplex (NORSOK Coated) |
Fasteners | Carbon Steel, Stainless Steel, Super Duplex |
Contact Philson to provide solutions to your subsea riser umbilical hang-off needs.
