Method and apparatus for conducting subaqueous operations in ice conditions

In an improved platform from which subaqueous operations are performed in ice conditions, the platform having an aperture therethrough through which the subaqueous operations are performed and having a substructure carried by the platform for supporting the equipment for performing subaqueous operations, said substructure being positioned such that it straddles the aperture and said substructure preferably remaining in a fixed lateral position with respect to the subaqueous operations being performed by the equipment supported by such substructure, an improved apparatus associated with the underside of the substructure for presenting relatively low lateral resistance to the movement of the platform horizontally beneath the fixed position substructure comprising:

• at least two first guide means carried by the platform in parallel relationship with each other, one of such first guide means being on each side of the aperture;
• at least two second guide means positioned in parallel relationship with each other, one of such second guide means being on either side of the aperture, said second guide means being positioned above the first guide means;
• at least two first wheeled traveling members secured to the underside of each of the second guide means, each of such first wheeled traveling members being positioned such that it is in contact with one of the first guide means and may move longitudinally along such first guide means;
• a drive motor associated with at least one of such first wheel traveling members and operatively coupled to the wheel portion thereof for generating motive forces to revolve such wheel in a selected direction;
• at least four second wheeled traveling members secured to the underside of the substructure, such second wheel traveling members being positioned such that at least two of such second wheeled traveling members are in contact with the upper surface of each of the second guide means and may move longitudinally along such second guide means;
• a drive motor associated with at least one of such second wheeled traveling members and operatively coupled to the wheel portion thereof for generating motive forces to revolve such wheel in a selected direction;
• the controlled operation of the drive motors and the associated wheeled traveling members providing relatively low lateral resistance to the movement of the platform as it moves horizontally underneath the positioned substructure responsive to the ice conditions.

In a platform from which subaqueous operations are performed in ice conditions, the platform having an aperture therethrough through which the subaqueous operations are performed and the platform carrying a substructure for supporting the equipment for performing the subaqueous operations, such substructure being positioned whereby it straddles the aperture and said substructure preferably remaining in a fixed lateral position with respect to the subaqueous operations being performed by the equipment supported by such substructure, the improved method of allowing the platform to move horizontally beneath the fixed position substructure responsive to the ice forces whereby the platform may move relative to the substructure and the substructure may remain in a fixed lateral position above the subaqueous operations being performed by the equipment carried by the substructure, including the steps of:

• positioning between the underside of the substructure and the platform:
• at least two first guide means in parallel relationship, one of such first guide means being positioned on either side of the aperture;
• at least two second guide means in parallel relationship with each other, one of such second guide means being positioned on either side of the aperture, said second guide means being positioned above the first guide means, first wheeled traveling members secured beneath each of the second guide means and in contact with one of the first guide means for longitudinal movement therealong;
• second wheeled traveling members secured beneath the underside of the substructure and in contact with the second guide members for longitudinal movement therealong;
• drive motors associated with the wheel traveling members and operatively coupled thereto for generating motor forces to revolve the wheeled portion thereof;
• and
• operating the drive motors whereby the traveling members move selected distances longitudinally along the first and second guide means and the platform is moved horizontally beneath the substructure responsive to ice conditions to maintain the substructure in a fixed position.