*Article published in CRANE BRASIL Ed. 84
The main feature of fixed platforms is the direct connection with the seabed through rigid or semi-rigid structures, which can be jackets, tubes or gravity structures, such as concrete columns.
These structures tend to have the smallest possible plan dimensions, for reasons of cost, lifting and assembly, which results in the various decks being stacked vertically, preventing cranes from reaching the lower decks.
This fact limits lifts to only the upper decks and the small forward areas on the sides, called “laydown areas”, generally used for routine lifting.
When the destination or origin of the load is the decks not reached by the cranes, and when the loads to be lifted are larger or heavier, or the cargo areas are far from the final or initial position, there are at least three solutions:
- Use of hoists supported by eyebolts welded to the platform’s edge beams, performing the horizontal movement with crane support. It involves the greatest risk of all, as the greatest number of climbers working over the sea is required;
- Construction of a monorail projecting out from the platform. The crane transfers the load to the hoists and the horizontal movement is done by trolleys. Safer, it involves one or two climbers, only in the transition operation of the load from the crane to the hoist;
- Construction of a temporary platform, on the edge of the platform and trolley resting on the deck. It is the safest, fastest and most effective of all, requiring no climbers. The load is supported on the trolley directly using the crane and moved inland with the trolley supported on rails or directly on the deck.
With the need to modernize several platforms in Brazil, there will be an increasing need to remove and place equipment under decks, challenging Brazilian lifting engineering, which increasingly responds with qualified people, effective lifting projects and safe supervision.
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