Port and shipyard cranes must meet stricter requirements than general construction cranes due to the need to operate them 24 hours a day in difficult conditions. Such requirements include protection against corrosion due to its proximity to the sea, total impermeability of all the crane´s components, facilitation of vehicle and people, LED lighting in the work area, and versatility to adapt to different projects.
When Aibel, a service provider to the oil, gas and offshore wind industries, required a bespoke craneage solution for construction of the 23,000-tonne Johan Sverdrup Phase 2 (JSP2) processing platform at the Haugesund yard in Norway close to the North Sea, the company turned to Comansa and its Norwegian distributor Rental Group Crane AS.
Comansa and Rental Group Crane customised a 50-tonne Comansa 21LC1050 flat-top tower crane with a reinforced portal and additional safety features. The modified 21LC1050 crane was designed to withstand wind pressure in accordance with European D25 standards, and its 80m boom length provided access to the entire platform, thus eliminating the need for another tower crane.
To meet the demands of the project, especially to withstand the 400 tonnes per corner that originate from a crane of more than 90 metres in a D25 wind zone, Rental Group Crane AS assembled a reinforced 10m portal built by Comansa. The portal could be used either with movement on rails or supported with levelling screws.
To protect the crane against inclement weather, Comansa used special protection elements and materials as well as 250-micron paint to prevent corrosion.
The tower crane was equipped with numerous safety features such as vision camera on the trolleys to view the loads and the environment more safely, alarm signals, high-luminosity LED lights on the boom for the area workstations with on/off from the ground, signalling lights pursuant to the EN14439 standard, counterweights protected with galvanised steel frames, stainless steel electrical cabinet and activation of the wind-release system from the base of the crane.
The crane’s flat-top design provided ease of assembly with a low space requirement, which simplified the logistics of erecting and operating the crane in a 600–700m2 area. The Aibel yard lent its facilities and helped pre-assemble the necessary parts which arrived in 32 trucks. For the assembly, a 500-tonne mobile crane with a height of 115m was used, and the heaviest piece assembled weighed 23 tonnes. Once the foundation was laid and the portal installed, the crane was assembled in two days in March 2021. Since then, the crane lifted very different loads, the heaviest being 20-tonne containers onto the platform. Aibel delivered the JSP2 processing platform to the Johan Sverdrup oil field in Q1 2022.