Company Announcement - Johnson Crane Hire’s ability to successfully develop and deliver a specialised alternative lifting solution is showcased in the heavy lift recently undertaken by the company at Sasol. According to James Robinson, heavy lift manager for crawler cranes and projects at Johnson Crane Hire, extensive years of collaborative experience, coupled with a solid track record, allowed the company to safely deliver a project nine days ahead of schedule to the project’s EPCM contractor Fluor.

“Extensive time was spent on evaluating the site conditions and Johnson Crane Hire considered the customer’s needs when putting the proposed solution into place. We were fully aware of the urgency of the project and knew that we needed to provide value to the customer in terms of completing the lift as quickly as possible. This was underlined by the necessity to allow the other contractors to start on their portions of the shutdown work,” Robinson explains. The lift had to be conducted during shutdown of this plant, which obviously had strict time constraints so it was necessary to provide an efficient lifting solution that would remove the vessels in the shortest possible time without compromising safety. The scope of the project entailed the removal of three vessels for the GHHER (Gas Heated Heat Exchanger Reformer) project on the Gas Reforming plant at Sasol Secunda. All three vessels were housed within the plant structure which is also fitted with cabling, racking, pipework and ancillary equipment.

Two identical waste heat boilers measured 17 metres in length and 2 metres in diameter, with a mass of 60 tons each, while the third vessel had a length of 8 metres and a diameter 2.5 metres. This vessel was mounted on concrete plinths standing 3.5 metres high. Previous attempts at removing these vessels during a prior shutdown had proved very costly due to valuable time being wasted. As with any shutdown, Johnson Crane Hire was aware that once access was granted, the site would quickly become congested with numerous contractors, erecting items such as scaffolding. This prompted the company to leverage its previous experience on challenging lifts to provide an alternative lifting solution.

Robinson explains that this solution viewed the smaller vessel and its two concrete plinths as a single unit. Johnson Crane Hire designed, engineered and manufactured a steel bracing system which would allow the steam drum and its concrete plinths to be removed in one piece. The bracing system was assembled around the vessel and plinths to provide the necessary stability. Once this was accomplished, a demolition contractor was deployed to cut the plinths at their bases. At this point the base was jacked to provide sufficient clearance for the vessel and its plinths to readily pass the existing concrete structure on the plant floor.

“The weight was transferred onto the sliding rails using jacks and then the combined unit of vessel/concrete plinth was slid out of the plant to a position where crane access was possible. The vessel and concrete plinths were then lifted out of the plant using a JCH 550-ton mobile crane,” he continues. The remaining two vessels were removed from the steel plinths on which they were mounted, and removed from the plant using the same sliding system. Once overhead clearance was available, these vessels were lifted using the Johnson Crane Hire mobile crane. Each individual lift was completed within a day.

Robinson points out that careful attention to detail and planning was necessary to ensure that the sliding system could be assembled inside this constrained work area within the available timeframe. In addition to the severe time constraints, the project called for careful attention to uncompromising safety levels and adherence to the necessary legislation. “In order to achieve a careful balance between all these elements, the time spent in preparation was considered critical to the success of the lift. To the untrained eye, lifts of this nature appear effortless but people are often not aware of the intricate planning that a lift entails. It is merely the mechanics of the lift that happens on the day; the actual theory of the lift is actually completed in advance of the physical lift,” Robinson says.

“Although three vessels were removed during this lift, it was the lifting solution applied to the lighter of the three which allowed Johnson Crane Hire to provide the greatest value to the customer in terms of time saved. We have undertaken numerous lifts for Sasol on shutdowns and our understanding of the organisation made it easier for our engineers to plan the various activities within the available windows of opportunity. The final result was a cost and time saving on a lift that was expedited in a safe and efficient manner,” he concludes.