Satorp’s Package 1 reached another milestone when the last of the super heavy equipment was erected in October 2011 of both the Vacuum (VDU) and Crude (CDU) Columns in Train 2 - Unit 012. Previously in June, two columns were delivered and erected for Train 1 - Unit 011. The following month, Train 2 columns were delivered to site and put on pedestals. Because the large LIEBHERR crane, LR11350, the only one of its sort in the Kingdom, was also contracted by both Packages 2A and 4, their planned heavy lift erection date was re-scheduled for October and the two enormous columns were parked near the East Gate of Plot 9.

The Crude Column 011/012-C0002, manufactured by MIS Arabia, which comprises three zones, Zone A; Zone B; and Zone C, has a height of 74.350m which includes its skirt of 11.200m and weighs a total of 520.3 tons. As for the Vacuum Column 001/012-C-0003, manufactured by BILFAL, which comprises four zones, Zone A; Zone B; Zone D; and Zone C, weighs a total of 504 tons and has a height of 54.365m. Its skirt is separate and made of concrete which is 25.850m from the ground which then the Vacuum Column sits on when erected. Both columns are made of carbon steel.

For the transporting and erection of these columns, accuracy and careful planning is required by all parties concerned, including the relevant Packages, the manufacturer, the erection company; in this case Mammoet, local authorities, royal commission, Satorp security and transportation contractor. After a study, a transportation simulation report was submitted to Package 1 EPCC, Tecnicas Reunidas, for approval, and to Satorp security to verify that the transportation plan is in compliance with the traffic plan procedure for the project. Then the necessary arrangements and preparation work started.

The Self Propelled Modular Trailer (SPMT) of 6-axle module was used to transport each column moving at a speed which doesn’t exceed 5km/h. The travelling distance for the columns was 20-30 km and one can only imagine how long it would take. But even when you’ve done all the preparations something still could possibly go wrong. It would take hours a day just to secure the column’s transport from one spot to another. There are times when you miss a light pole by a couple of millimeters.

Before the arrival of the columns, Mammoet’s construction manager and his staff had to go out to the site location to inspect and check the space required around where the column will be erected and prepare a Groundwork Plan and drawing. The Groundwork Plan indicates where the ground has to be prepared for the crane. It also indicates the required ground bearing pressure it has to take (Number is taken from the lifting drawing.) All groundwork underneath the crane has to be level for the crane, to allow the capacities indicated on the applicable crane load-chart. The Lifting Plan (Drawing) is the basis of the lift planning. The plan will determine how the lift will be executed. No deviation is allowed from this plan and Satorp’s PMT require at least a minimum of 10 days prior to the actual lift for the approval signatures of the Safety Manager and Mechanical Superintendent responsible for the heavy lifts.

Two cranes were then considered; the large Liebherr LR11350 crane was chosen as the main crane and the Demag CC2800 crane as the tailing crane. Before the columns arrive, the main crane will have to be mobilized, erected and commissioned; the weight and position of the Centre of Gravity (CoG) of the lifted item is to be confirmed; and the design of the lift prepared and checked. All of these operations will have been conducted in accordance with separate procedures. The appropriate check-lists completed and signed off. Also of importance to the lifting is the weather condition which needs to comply with minimum requirement to safely execute the works. The Heavy Lift Contractor Site Supervisor is the ultimate arbiter of what is or is not acceptable for lifting.

Once the lift has been completed, the main crane will still hold the column in its erected position from its trunnion supports and is only released, once final verticality has been signed off by the Satorp QA/QC department. Thereafter the cranes will be removed from the lifting area and transported or crawled to the following unit or area where the next heavy lift has been planned for; and once again the groundwork will be leveled to the original levels prior to the lift, once the crane mats have been transported away.

The crude and distillation units will process 400,000 BPSD of Arabian Heavy crude and the wild naphtha produced by the low and high pressure HDS Units. The crude will be processed into two parallel and identical trains of Atmospheric and Vacuum Distillation Units (Units 011 & 012). As such each CDU unit is designed to process a net throughput of 200 000 BPSD of crude.

The CDU & VDU unit will process crude from storage and will provide feeds to various units. Each CDU will be integrated with one VDU processing its entire atmospheric residue. The required turn-down of each of the CDU and VDU train will be 60%.

One can now see why the heavy lifts are seen by Satorp management as priority number 1 over all other scheduled activities on the construction site, because much work, labor and activities are required to make a successful lift.

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