Shifting “bullets” The recent move of giant LPG storage tanks from northern Spain presented a tricky challenge for Braemar SA.

Braemar (Incorporating The Salvage Association), “Braemar SA”, was recently appointed by project owners Royal Vopak N.V. to provide risk management consultancy services for the heavy lift, marine transportation and installation of the six supersized mounded Liquefied Petroleum Gas (LPG) storage vessels or “bullets” as part of the Vopak Presto Project.

Fluor provided the engineering, procurement and construction management services for the project. The design and fabrication of the six bullets was undertaken by Felguera Calderería Pesada S.A. at their Felguera facility in Gijon, Northern Spain. Sarens Nederland B.V. were subcontracted to provide heavy lift and marine transport services for moving the six bullets from the fabrication sheds at Gijon to the sand mounds at Vopak Terminal, Vlissingen-Oost.

Vopak Terminal Vlissingen B.V 3Naval Architects & Master Mariners based in Braemar SA’s London head office undertook a thorough review of the various calculations, drawings, method statements, towage manuals and risk assessments. Experienced Surveyors from Braemar SA’s London and Rotterdam offices attended at Gijon, Spain, and at Vlissingen, The Netherlands, to monitor each stage of the transportation process, working alongside the Marine Warranty Surveyors appointed by the project’s insurers and providing hands-on advice and guidance to the various contractors.

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The transport of the six bullets was a complex matter which presented the heavy lift contractors with a number of challenges. Due to tidal limitations and draft restrictions at the fabricators quayside facility in Felguera, it was necessary to load-out each bullet in turn onto a small barge, tow the barge to the adjacent deep water Port of Gijon and then tranship each bullet onto a larger barge. The lifting and moving of the bullets was undertaken using two clusters of self propelled modular transports (SPMTs), each of which was fitted with a turntable attached to the transport saddles on the bullets.

The first three load-outs were undertaken using the Cadans Shipping 70m x 22m pontoon barge ‘CS1’. The remaining load-outs were undertaken using the Sarens 61.5m by 22.84m twin barge ‘KAREL-VICTOR’. After each load-out at Felguera and tow to the Port of Gijon, the bullets were transhipped from the small barges onto the Sarens 100m by 33m pontoon barge ‘JAN’, again using the self propelled modular transporters. The barge “JAN” was capable of carrying three bullets at a time. Seafastenings for the sea passage between Spain and The Netherlands comprised on a specially designed grillage which was fitted to the barge before being towed to Spain.

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Internal brackets in the main support beams were not fitted in order to allow clearance for the SMPTs and bullets during movement along the deck of the barge ’JAN’. With three bullets transhipped onto the larger barge the task of welding and testing of the seafastening grillage was completed. To avoid stressing of the shell of the bullets during the sea passage, the seafastening grillage featured a sliding connection which prevented uplift whilst allowing the barge to flex independently of the bullets.

On completion of the seafastening grillage, the barge ‘JAN’ and the three bullets were towed from Gijon to Vlissingen-Oost by Multraship’s 72 ton bollard pull tug ‘MULTRATUG 20’. On arrival at Vlissingen-Oost, the barge ‘JAN’ was moored up to a specially constructed ramp and each bullet was off-loaded in turn and moved to the installation site using SMPTs.

To install the bullets into the partially completed sand mounds, the SPMTs were reconfigured with substantial support beams arranged to pick up on the transport saddles, each bullet was jacked up and the weight transferred to the SPMTs. The SPMTs were then driven into the sand mounds and manoeuvred to accurately position each bullet which was then jacked down onto the sand mound. This entire process was then successfully repeated for the remaining three bullets.

 


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