Abstract: A subsea abandoned wellhead protection system which may be installed underwater without the need for underwater assistance from divers or the like, the system allowing full site preparation and installation from the surface. The present invention teaches a new and unique system for the lowering and centering of the shelter over the wellhead, as well as a new system for the preparation of the installation site, including the removal of debris from the site and excavation of the ground surface area about the abandoned wellhead via a remote, fluid actuated, integrated excavation system.

Abstract: A linear amplifier circuit includes input and output signal ports and a pair of signal amplifying circuits. Each signal amplifying circuit couples an input signal from the input signal port to the output signal port. A bias supply can be connected to the signal amplifying circuits for supplying bias currents thereto. The input and output signal ports are isolated from the bias supply without using capacitors or inductors.

Abstract: A monolithic integrated analog multiplier circuit includes a series aiding connection of semiconductor junctions, each junction being arranged for conducting an input current from one of plural sources of input currents and for producing a voltage proportional to a logarithm of the input current conducted therethrough. A pair of opposite conductivity type transistors have their base-emitter circuits arranged to respond to the voltages produced at opposite ends of the series aiding connection for converting the voltage produced across the connection into an output collector current proportional to the product of the input currents.

Abstract: For protecting cargo in a ship's hold an inverted hatch tent is mounted between a cargo hatch cover and the hatch coaming to thereby define a concave liner below the hatch cover. The inverted hatch tent accoding to the instant invention therefore protects cargo from inevitable water leakage even with the hatch cover in place. Th instant liner further accommodates various hatch opening sizes through a plurality of gripper lines on the underside of a single liner. A further advantageous feature on the instant invention is the provision of a drain line at the apex of the inverted cover to communicate with a drain line which is passed within the hatch along the side wall and down to the ship's bilge.