Abstract: A light weight, energy dissipation bumper system for protecting the columns of an offshore platform. A plurality of rows of crushable tubes are provided to dissipate collision energy through absorption without storing such energy. The tubes have a diameter to thickness ratio between 30 and 40 for mild steel providing neutral/positive buoyancy. The tubes may be easily replaced when their ability to protect the column to which they are attached to exhausted through flattening. The tubes may extend either axially along or radially outward from the column.

Abstract: The present invention provides a service buoy for performing direct wireline maintenance of a subsea well. The buoy is maintained in position over the well by a rigid riser kept under tension and which allows for the well re-entry. The primary buoyant body of the buoy is maintained permanently submerged and a truss structure presenting the minimum surface area to the action of wind and waves extends above the sea level to support a small deck from which the wireline work can be performed. The centers of gravity and buoyancy for the buoy are in close proximity so as to minimize lateral surge and sway motions of the installed buoy.