Image Number 4 for United States Patent #4119145.
The invention concerns the handling of appliances on the seabed, particularly for handling and maintaining well-heads and corresponding installations. For handling the well-heads, trolleys are mounted for travel along a column which is articulated to a base constructed on the seabed over a number of drilling wells. The trolleys are movable between the upper structure of the columns and the lower body part of the column coupled to the base, and carry well-heads or other devices between the upper structure and the base and release the same upon reaching the lower part of the column at a position above corresponding well orifices. Elongate vertical members or posts of the column have lateral walls constituting guide rails for the trolleys.