VSMC Installation – Cable Pulling Frame, North Sea, Germany
ALE has successfully completed the engineering, fabrication, certification and installation of a replaceable cable pulling frame in the North Sea, Germany.
ALE was contracted to design and fabricate a cable pulling frame to pull-in four cables through J-tubes on top of an offshore jacket. Following each pull, the frame had to be moved to the next position on the jacket.
The cable pulling frame needed to have an 8t lifting capacity which increased to a work load limit of 10t with the weight of the Couperus winch. The frame was load tested onshore to 125% of its work load limit.
During the pull-in of the cables, the frame needed sufficient load-spreading to avoid damage to the fibreglass grating beneath. Additional steel plates and plywood were also used underneath the steel load-spreading frame.
The cable pulling frame had to be modular with each section weighing less than 750kg. As the installation and erection of the 5m pulling frame was to be done with a 2m high 1.2t capacity portal crane, provision for the erection and repositioning was included in the design of the cable pulling frame.
ALE used steel wire pullers, lashing chains, hydraulic hand pumps and caterpillar skates to erect and move the complete pulling frame. The offshore mobilisation, upending, and pulling of the four cables took one week during which the frame had to be re-positioned four times on the same jacket. The frame was also dismantled in the same week.