Ships – Mother ship – floating landing platform – and harbor – Vessel carrier
Reexamination Certificate
1999-08-16
2001-04-03
Avila, Stephen (Department: 3617)
Ships
Mother ship, floating landing platform, and harbor
Vessel carrier
C114S125000
Reexamination Certificate
active
06209474
ABSTRACT:
FIELD OF THE INVENTION
The invention concerns a transporter for heavy objects at sea, comprising an oblong structure with a U-shaped cross section and a prismatic enveloping surface, comprising two long sides, an intermediate underside, an opposite open top side and two short sides.
DESCRIPTION OF THE BACKGROUND ART
Heavy objects, such as platform decks, platform jackets and bridge elements are transported by sea on ships or barges. The object is transferred from and to the ship or the barge by hoisting cranes, the object being pushed or pulled, or by means of rolling transport where wheels or rollers are employed.
Another known method is to transfer objects by ballasting the ship or the barge and moving it into a passage under the object, whereupon the ship or the barge is deballasted, thus causing it to be raised and leaving the object lying on the ship or the barge. The object may be unloaded in a similar manner by deballasting the ship or the barge, thus causing it to be lowered, with the object supported by lower-lying supports on the side of the ship or the barge.
These known methods of transporting heavy objects at sea work well as long as the object does not require to be turned, and as long as the level differences which have to be obtained by the ballasting/deballasting are relatively small. When using a ship or a barge, however, it is not possible to turn an object, such as a mast or a platform jacket, which is so large that it has to be transported horizontally, but which has to be turned into a vertical position before being installed in position.
U.S. Pat. No. 5,111,764 describes a method for recovering the substructure of an offshore platform. A floating barge is used comprising a ballastable hull having a deck suitable for receiving the substructure in a substantially horizontal position and including ballastable floats disposed above the deck to right and to left of the intended location for the substructure. The hull and the floats are ballasted so that although it does not sink, the barge moves down into the water and tilts into a position where its deck can be moved against one of the faces of the substructure. The barge is fixed to the substructure, the substructure is disconnected from the sea bed, ballast is removed from the barge to return it to a position where it is floating and carrying the substructure, and the barge is moved to the desired location for unloading the substructure. The invention is applicable to recovering substructures of large dimensions. With the method and barge according to U.S. Pat. No. 5,111,764 it is thereby possible to a certain extent to transport heavy objects at sea, and to turn the object in the water. The degree of attachment and rotational movement which are achieved, however, are limited to the attachment and rotation.
SUMMARY OF THE INVENTION
The object of the invention is to provide a transporter which compared with known devices for transport of heavy objects at sea has greater possibilities for securing the object, and which also has greater possibilities for turning the object in the water.
The object is further to provide a transporter which will also be able to be used for installation or removal of a deck on and from a platform jacket respectively, and installation or removal of a platform jacket on and from the seabed respectively.
The latter object is achieved with a transporter of the type mentioned in the introduction, which, is also characterized by the features which are stated in the claims in the applicant's copending Norwegian patent applications Nos. 973561 and 973562.
The invention therefore includes in a transporter for heavy objects at sea, comprising an oblong structure with a U-shaped cross section and a prismatic enveloping surface, comprising two long sides, an intermediate underside, an opposite open top side and two short sides. In the invention ballasting chambers are arranged in each of the structure's 8 corners which are formed by the points of intersection between the long sides, the undersides, the open top side and the short sides, whereby the structure can be rotated by means of ballasting into a desired position in the water. Moreover, the transporter is provided with attachment means for securing objects which have to be transported.
The ballasting and deballasting are performed in the known manner by pumping water in and out of the ballasting chambers by means of pumps, piping and valves. When the structure is rotated, those ballasting chambers which have to be moved downwards during rotation and after rotation will be located at the bottom are ballasted, while at the same time those ballasting chambers which have to be moved upwards during rotation and after rotation will be located at the top are deballasted. A computer calculates which ballasting chambers have to be ballasted and deballasted in order to achieve the desired rotation and final position of the transporter in the water, while simultaneously calculating the metacentric height and monitoring the progress of the ballasting/deballasting and the rotation. The computer communicates with an operator, who in turn gives orders concerning the execution of the necessary ballasting and deballasting. In this context the information on the metacentric height is very important, since a stable rotation of the transporter, without sudden movements, is dependent on the maintenance of a constant positive metacentric height.
The actual movement of the transporter will be conducted by tugs.
The transporter's ballasting chambers are preferably provided in longitudinal pontoons in the corner areas between the transporter's underside and long sides, and at the top of the long sides. The result is a structure which offers little resistance to movement in the water, and which is consequently suited for transport.
In a preferred embodiment the transporter has attachment means for securing objects, for example in the form of brackets or beams attached to the pontoons.
The above and further preferred embodiments of the invention will be seen in the detailed description.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
REFERENCES:
patent: 2586966 (1952-02-01), Kuss et al.
patent: 3054267 (1962-09-01), Alcorn et al.
patent: 3633369 (1972-01-01), Lawrence
patent: 3859804 (1975-01-01), Koehler et al.
patent: 4280429 (1981-07-01), Wells
patent: 4927296 (1990-05-01), Kaldenbach
patent: 5111764 (1992-05-01), D'Ettorre
patent: 3219968 (1983-12-01), None
patent: 2005603 (1979-04-01), None
patent: 910358 (1991-05-01), None
patent: 9826978 (1998-06-01), None
patent: 9906270 (1999-02-01), None
Bull Haugsøen Per
Foss Gunnar
Avila Stephen
Birch & Stewart Kolasch & Birch, LLP
Offshore AS
LandOfFree
Transporter for heavy objects at sea does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Transporter for heavy objects at sea, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Transporter for heavy objects at sea will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2441280