This paper presents a comprehensive overview of various floatover technologies based on the latest advancements in offshore installation and decommissioning technology. Each floatover methodology is briefed and categorized into specifically defined divisions in a system of classification, including mechanical and non-mechanical schemes, single-barge, catamaran-barge and twin-barge schemes, etc. The presentation of these various floatover technologies will reveal the floatover history and evolution, the advantages and disadvantages of different methods, as well as the promising prospect of their wide applications in installation and decommissioning of integrated topsides onto and from various fixed and floating substructures.
Various floatover technologies have been developed and successfully applied to offshore installations of integrated topsides onto different fixed and floating platform substructures since the first floatover installation was successfully adapted for the production platform topsides of 18,600 tonnes on the Phillips Maureen Project in 1983. A string of offshore facilities using the floatover concept followed, including jackets, gravity base platforms, tension leg platforms, semisubmersible platforms, and even spars lately. The floatover technology is an offshore topsides installation method that lets large platform topsides be installed as a single integrated package without the use of a heavy lift crane vessel, i.e. modular lifting installation. For the past two decades, the floatover technology has advanced so much from the conventional "Hi-Deck" scheme with leg mating units to numerous floatover techniques with active/passive load transfer systems and different configuration of floatover barge(s), thus providing an installation solution that can accommodate a wide range of topsides sizes and seastate conditions.