Abstract: A movable ocean launching apparatus includes a semi-submersible ocean launcher for space rockets and a carrier for carrying it while holding the upper supporting deck thereof. This arragement makes it possible to inexpensively realize the transporation of the ocean launcher, preparation for ocean-based launching and the like and also to reduce the total construction costs of the launching base.

Abstract: An ocean launching apparatus of space rockets comprises a launch pad platform having a floating-island structure and a semi-submersible hull for loading and transporting the launch pad platform. When the apparatus reaches an intended ocean area, a rocket set on the launch pad platform is floated from the hull in a semi-submersing state on the ocean together with the launch pad platform and moved to a launching site. In this way, it is possible to provide an ideal launching site of space rockets, increase an economical efficiency of launching of space rockets, and guarantee the safety if an accident should occur.

Abstract: A method of installing an offshore platform. The superstructure is assembled and completed in advance in a fabrication yard. The superstructure with a floating body attached thereto is transported to the area of the sea where a jacket of the platform has been erected by towing the superstructure while floating on the sea. It is made to sink by pouring sea water into the floating body and installed on the top portion of the jacket which is situated under the sea level. An extension is attached to the jacket in advance such as to project above the sea level during the piling operation and thereafter it is removed such that the top portion of the jacket is brought to a position below the sea level.