Abstract:
For fabricating a double-hulled tanker, or a major component of one including at least part of longitudinal midbody, a floating drydock is used which has two independently elevatable-depressible sections. The midbody part is made of individual modules, each of which is fabricated in an upended orientation. The upended modules are successively floated onto a tilting assembly on one drydock section, tilted over and serially added to a growing midbody on the other drydock section. The two drydock sections are pumped out and flooded as the process progresses for shifting the positioning of the growing midbody and modules. Other parts, including a bow and stern are added, to provide a complete vessel.
Abstract:
Shrouded towers for supporting adjustably cantilevered work platforms for performing external surface work on ship hulls (such as abrading and painting) are modularized for sake of economy and efficient utilization, including shifting of modules using techniques and equipment currently used for shifting shipping containers. Supply and recovery line connections between support barge-mounted equipment, floating drydock and work platform-mounted work applicators is facilitated by fixed installation of some portions and the provision of flexible connectors between these portions. Alternative adjustable cantilevering structures are disclosed for mounting the work platforms to the vertically movable trolleys. Preferably, rotating wheels rather than compressed air, are used to propel the abrasive grit against the hull surface, and abrasive supply systems having degrees of automated recovery of spent grit are disclosed.
Abstract:
For coating the exterior of a ship hull while the ship is in drydock or afloat, creating a sizable chamber with comprehensive staging access for all required work, sealing off that chamber to contain environmentally unacceptable byproducts of the coating process, to keep storm water runoff from passing through spent abrasive and paint overspray on the deck of the drydock or barge and to keep out weather conditions which could delay and deteriorate the quality of this coating process, ventilating and evacuating the chamber maintaining an atmosphere inside the chamber which is conducive to worker safety and high coating quality and maintaining an atmosphere outside the chamber which is conducive to meeting requirements for the clean air and clean water laws and regulations, and at the same time reducing the overall cost of coating.
Abstract:
Dry, particulate abrasive for use in abrasive blast cleaning of a ship hull is supplied to blasting pots from abrasive supply hopper assemblies lifted into place from a recycling station. Spent abrasive, with debris, is collected and placed on a conveyor belt extending parallel to the keel blocks, for conveying the collected material to the recycling station. There, the collected material is processed to remove undersized and foreign material from the reuseable abrasive grit. The latter is loaded into supply hopper assemblies, which are crane-lifted back into supplying relation with respective blasting pots. By preference, the abrasive blasting work takes place from elevatable, curtain-enclosed platforms supported on a drydock floor, the blasting pots are located on the drydock wing wall, the abrasive grit is ferromagnetic and recovered from the drydock floor partly with the aid of a magnetic abrasive pick-up unit, and the recycling station is located on a barge moored at an end of the drydock.
Abstract:
For cleaning and/or painting the exterior of a ship hull while the ship is in dry dock, one or more staging devices are provided. Each includes a metal framework tower supporting a vertically movable elevator assembly that comprises a trolley, from which a variably laterally projecting platform is supported on articulated, cantilevered arms. Adjustable, non-porous shrouds enclose a volume of space between the outside of the tower and an increment of one side of the exterior of the ship hull, from above, fore, aft and outside. Cleaning and painting operations are conducted from the platform on the hull increment, and debris is removed from the dry-dock deck area enclosed by the shroud, after which the device is moved by crane, typically twenty feet (6.1 m), towards the ship's bow or stern. The shrouds are then adjusted so that a further hull increment can be worked on. The trolley and extension-retraction of the platform support arms are operated by electrohydraulic winch and hydraulic cylinders, respectively. The margins of the shroud may be fastened by magnets to the hull. Air drawn through the enclosed volume from above, is drawn out near the dry-dock deck for processing to remove dust and appropriately treat VOCs, if present.
Abstract:
The parallel midbody for the hull of a tanker is fabricated of modules, each made of double-walled longitudinal subassemblies welded to one another and to a bulkhead. The subassemblies are made of outer cylindrically curved plates welded edge to edge, and inner cylindrically curved plates welded edge to edge. Longitudinal rib plates are extended between and are welded into joints between curved plates in the inner and outer hulls. The curved plates are convex towards the exterior of the vessel. At respective transitions between the bottom and sides, the inner and outer hulls have bilge radii which approximate in size the radii of curvature of others of the plates including ones both adjacent to and remote from the bottom-to-side transitions. A fixture for facilitating welding of the T-joints of the subassemblies is provided. The subassemblies and modules are fabricated in an up-ended orientation. Each successively completed module is tilted-over and joined to the growing midbody with the aid of a variable buoyancy barge and a caisson pontoon.
Abstract:
Each of a plurality of cargo holds of a bulk carrier vessel has a self-contained staging system lowered into it, from the platform track of which workers operate semi-automatic blasting machines that are mounted onto the platform. The set-up for each vessel also includes, for each hold, a ventilation unit provided on a hatch plug, and a transporter for the staging system. Groups of staging systems are served by on-deck air compressors. Staging systems actually engaging in blasting are served by recycling shot blast units which recycle and supply steel shot. Following blast cleaning, the cleaned surfaces are painted from the platforms.
Abstract:
The self-contained device for cleaning and coating hold surfaces in a bulk carrier includes four major components, namely a horizontally mobile vertical tower (e.g., with walking beams for permitting the device to move into the four corners of the hold into which it has been lowered), a vertical trolley for permitting the workers to reach with their equipment all elevations within the hold, a horizontal trolley for permitting the workers to achieve optimum proximity to a wall surface, and cleaning and coating support equipment and systems. By preference, the device can be lifted into and out of the cargo hold altogether, or in a maximum of two sections, including a base section (which includes the base of the vertical tower, walking beams, all required systems for cleaning and coating, worker air supply and electrical power, as well as lower parts of distribution systems, with connectors), and an upper section (which includes a variable height upper vertical tower, vertical trolley, variable extension horizontal trolley, vertical trolley hoist mechanism, horizontal trolley extension mechanism, and upper parts of distribution systems, with connectors). The upper section is stackable on the base. The walkway on the horizontal trolley extends on all four sides, in order to permit working from at least two sides simultaneously for each of four positions of the base on the bottom of the hold.
Abstract:
The self-contained device for cleaning and coating hold surfaces in a bulk carrier includes four major components, namely a horizontally mobile vertical tower (e.g., with walking beams for permitting the device to move into the four corners of the hold into which it has been lowered), a vertical trolley for permitting the workers to reach with their equipment all elevations within the hold, a horizontal trolley for permitting the workers to achieve optimum proximity to a wall surface, and cleaning and coating support equipment and systems. By preference, the device can be lifted into and out of the cargo hold altogether, or in a maximum of two sections, including a base section (which includes the base of the vertical tower, walking beams, all required systems for cleaning and coating, worker air supply and electrical power, as well as lower parts of distribution systems, with connectors), and an upper section (which includes a variable height upper vertical tower, vertical trolley, variable extension horizontal trolley, vertical trolley hoist mechanism, horizontal trolley extension mechanism, and upper parts of distribution systems, with connectors). The upper section is stackable on the base. The walkway on the horizontal trolley extends on all four sides, in order to permit working from at least two sides simultaneously for each of four positions of the base on the bottom of the hold. For cleaning and coating, automated abrasive blasting equipment and automated coating spraying equipment is provided for horizontal travel along each of the four sides of the horizontal trolley, e.g., on the safety rail.
Abstract:
The fixtures in which curved and reinforced flat plates are held while being welded, cleaned, coated and cured include fixedly mounted exterior towers and interior towers removably mounted on rollable bogies (i.e., rail cars or carriages) for ease of transport through a succession of work stations. Subcomponents fabricated on respective bogies are weldingly joined to form module subassemblies after coupling and maneuvering the respective bogies to align the subcomponents (i.e., units). A transverse bulkhead is supported on fluid cushion pallets beside the bogie-supporting rails, so that the transverse bulkhead can be positioned for welding of each subassembly thereto, to provide each respective double-walled vessel hull midbody module.