Abstract:
A freight hauling vessel ( 10 ) has a deck ( 12 ) with sets of railroad tracks ( 14 ) for rail cars ( 64 ), enabling rail cars to &gt;be rolled onto and off of the deck. Upright rows of stanchions ( 18 ) support standardized freight containers ( 63 ) spanning between the rows and over the rail cars.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to the general field of freight hauling, and particularly to vessels adapted to transport roll-on, roll-off cargo such as rail cars.  
       BACKGROUND OF THE INVENTION  
       [0002]     One known freight hauling system uses a barge having a flat deck and standard railroad tracks extending lengthwise of the deck. Rail cars are loaded onto and off of the barge at the origin and destination docks by ramps, usually connected to the stern. Depending on the number of rail cars to be carried, other wheeled or non-wheeled cargo can be placed on the deck.  
       SUMMARY OF THE INVENTION  
       [0003]     The present invention uses a freight-hauling vessel having a deck adapted for wheeled cargo to be rolled on and rolled off the deck. More specifically, in a preferred embodiment, the deck of a barge has longitudinally extending railroad tracks for side-by-side rows of rail cars. The tracks can extend essentially the full length of the freight-carrying deck of the barge.  
         [0004]     In accordance with the present invention, the barge is provided with a “rack” system for supporting standard freight containers above the rail cars. The rack system includes at least two longitudinally extending rows of stanchions straddling at least one, preferably two or three, sets of tracks with the space between the stanchion rows being open and unobstructed at the top. The upper ends of the stanchions carry foundation blocks spaced apart transversely and longitudinally of the vessel at the standard distances between fittings (usually corner fittings) of known freight containers. Stacking cones or twist locks are used to connect freight containers to the stanchions, and to connect upper tiers of freight containers stacked on lower tiers.  
         [0005]     In a preferred embodiment, the rack system includes a row of stanchions along each outboard side of the vessel, and two inboard rows of stanchions toward the central portion of the vessel. The inboard stanchions are connected by cross-beams. A center grating walkway is supported on the cross-beams. The four rows divide the vessel into three side-by-side freight-hauling areas or zones. These zones include two outboard zones that are open and unobstructed at the top and an inboard “tunnel” zone having the central grating walkway at the top. Standard freight containers can be loaded so as to bridge across the outboard freight-hauling zones, with the lengths of the containers extending transversely of the vessel across multiple sets of tracks for rail cars. After placement of the containers, rolling stock, preferably rail cars, can be loaded underneath the containers in the outer zones and under the central grating in the center zone. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]     The foregoing and additional aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:  
         [0007]      FIG. 1  is a diagrammatic top perspective of a barge construction in accordance with the present invention, with some detail of the construction deleted,  FIG. 2  is a diagrammatic top plan thereof, and  FIG. 3  is a diagrammatic side elevation thereof.  
         [0008]      FIG. 4  is an enlarged, fragmentary top perspective of a barge construction in accordance with the present invention.  
         [0009]      FIG. 5  is a further enlarged, fragmentary end elevation of a central part of a barge construction in accordance with the present invention, showing additional detail,  FIG. 6  is a fragmentary side elevation of the central part shown in  FIG. 5 ,  FIG. 7  is a fragmentary top plan thereof,  FIG. 8  is an enlarged, diagrammatic, fragmentary section along line  8 - 8  of  FIG. 5 , and  FIG. 9  is a further enlarged, diagrammatic, fragmentary top perspective of such central part, showing additional detail.  
         [0010]      FIG. 10  is a diagrammatic top perspective of a barge construction in accordance with the present invention illustrating loading of freight onto a barge, and  FIG. 11  is an enlarged, diagrammatic, fragmentary top perspective illustrating additional detail in the freight-loading process. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0011]     The present invention provides a freight-hauling vessel having a deck adapted for wheeled cargo to be rolled on and rolled off the deck, and a permanent rack system incorporated in the vessel for carrying non-wheeled freight above the wheeled cargo. In the preferred embodiment the wheeled cargo includes rail cars and the non-wheeled freight includes standard freight containers supported by the rack system above the rail cars.  
         [0012]     With reference to  FIGS. 1-4 , barge  10  has a freight-carrying deck  12  with longitudinally sets of railroad tracks  14  that extend essentially the full length of the deck. As described in more detail below with reference to  FIG. 10 , rail cars can be loaded onto the deck from the stern  16  by an end ramp from a loading dock. The end ramp may have one or more sets of tracks, and the barge may be shifted transversely to provide access to its many sets of tracks.  
         [0013]     In a representative construction, the barge may be approximately 420 feet (128 meters) long by 100 feet (30.5 meters) wide, equipped with 8 sets of tracks to provide approximately 3,200 feet (975 meters) of track on the deck. The maximum number of rail cars in a load will vary based on car length. For example, rail cars can be about 40 feet (12.2 meters) to 90 feet (27.4 meters) long. In known rail car barges, the number of cars accommodated also depends on the extent to which deck space is used or reserved for other cargo. The barge has a sturdy understructure of steel frame construction to support the sizable load carried by the deck. Preferably, all materials and workmanship conform to standards of the American Bureau of Shipping (ABS).  
         [0014]     In accordance with the present invention, a permanent rack structure is incorporated in the barge to enable more cargo, and different types, to be hauled. Still referring to  FIGS. 1-4 , the rack system of the present invention includes a plurality of longitudinally extending, transversely spaced rows of stanchions  18 . In the preferred embodiment, four rows of nearly identical stanchions are permanently affixed to and supported by the deck understructure which is reinforced to safely carry the considerable weight of the rack structure and the cargo it will support. One row of stanchions extends along one outboard side  20  of the barge, and another row extends along the other outboard side  22  of the barge. Two inboard rows of stanchions are provided, equidistant from the barge centerline. The stanchions of each of the four rows are aligned transversely of the barge with stanchions of each of the other rows. For example, in the illustrated embodiment, each row includes 23 stanchions spaced substantially uniformly lengthwise of the barge. Since the aft-most stanchions are aligned transversely of the barge, all other stanchions of each row are aligned with corresponding stanchions of the other rows. In the illustrated embodiment, the length of the rack structure is slightly less than one-half the length of the entire barge, with the rack structure being offset aftward from the center. The aft end of the rack structure is approximately aligned with the leading end of the barge stern rake  24 .  
         [0015]     Each row of stanchions  18  is of steel beam and girder construction, with the bottom end of each stanchion welded to the barge understructure and any necessary reinforcement. For installation of the outboard stanchion rows, the barge bulwarks  26  are cut away, and bulwark plates  28  reinstalled between adjacent stanchions, except in the areas where the plates would interfere with standard deck fittings, vents, and so on. Limber holes or passages are provided as necessary. It is important that the spacing of the upper ends of the stanchions be precise. For this purpose, the upper end of each forward stanchion is connected to the lower end of the next aftward stanchion by a diagonal brace  30 . The top of the aft-most stanchion, and every second stanchion forward therefrom, is connected to an adjacent stanchion by a longitudinally extending top beam  32 .  
         [0016]     Essentially the same construction is used for the inboard rows of stanchions. Diagonal braces  30  and longitudinal top beams  32  are provided at corresponding locations. In addition, for the two inboard rows, the upper portion of each stanchion is connected to the corresponding stanchion of the other inboard row by a transverse beam  34 , and these beams support a center walkway of steel gratings  36 , described below in more detail with reference to  FIG. 9 . The gratings are permanent, such that the two inboard rows of stanchions form a covered “tunnel” center zone which is not completely open at the top.  
         [0017]     With reference to  FIG. 2 , the spacing from each outboard row of stanchions to the adjacent inboard row is the same at both sides of the vessel and, in the preferred embodiment, sufficient to accommodate three sets of railroad tracks therebetween. The inboard rows of stanchions are closer together, sufficient to accommodate two rows of rail cars in the center tunnel zone.  
         [0018]     Access to the center grating walkway is provided at each corner of the tunnel zone, as shown in  FIGS. 5-7  (these features are not shown in  FIGS. 1-4 ).  FIGS. 5-7  show the aft end, but the construction at the forward end is the same. An access ladder  40  with safety cage  42  is provided on each corner stanchion  18 , with a cantilever end walkway  44  in the form of a steel grating supported from the end crossbeam  34  (the walkway  44  is also seen in the sectional view of  FIG. 8 ). As also seen in  FIG. 5 , the bottom portions of the stanchions  18  can be supported by angle flanges  46  if necessary to spread the load more evenly to the deck understructure  47 .  
         [0019]     Additional details of the center walkway gratings  36  are best seen in  FIG. 9 . The transverse beams  34  are of I cross-section with bottom flanges  48 . T-shaped support brackets  50  are welded to the upper surfaces of the bottom flanges  48  and the center vertical webs  52  at equally spaced locations along each beam  34 . An angle iron  54  extends lengthwise of the beam, approximately midway between its top and bottom flanges, and is welded to the brackets  50 . Elongated steel gratings  36  are fitted side-by-side with their opposite end portions on the shoulders formed by the angle irons  54 . Preferably the T-brackets  50  are aligned with the joints between adjacent gratings, and all components are welded in position. As also seen in  FIG. 9 , a raised safety railing  56  can be provided along the centerline of the tunnel section.  
         [0020]     With reference to  FIG. 4  and  FIG. 9 , freight container foundation blocks  58  are welded to the inboard and outboard stanchion structures at precise locations corresponding to uniform distances between lifting and stacking fittings of standard freight containers. A representative foundation is a model “TF-11” MacGregor Conver foundation available from Pacific Marine and Industrial of Novato, Calif. For example, stacking and lifting fittings on standard 40 foot (12.2 meter) containers and freight platforms (“flats”) are corner inserts having downward opening sockets at the bottom corners and upward opening sockets at the top corners, spaced 40 feet (12.2 meters) apart lengthwise of the container and 8 feet, 7 inches (2.6 meters) apart transversely of the container. Longer containers, such as 53 foot (16.2 meter) containers, have stacking and lifting fittings at the same uniform locations, although not at the corners. The foundations  58  used in the present invention have upward opening sockets positioned to register with the sockets of the standard freight containers and freight platforms. Thus, the distance between the foundation  58  mounted on an aft, outboard stanchion and the corresponding inboard foundation is 40 feet (12.2 meters), with sufficient room being provided in the inboard tunnel structure for an overhang of a longer container. At the outboard side, a longer container will simply overhang the outboard side of the barge.  
         [0021]     With reference to  FIG. 10  and  FIG. 11 , the present invention allows great flexibility in the cargo to be transported by the barge, and convenience in loading and unloading the cargo. In most cases, the combination will include cargo in standard freight containers  63  or on freight platforms of 40 feet (12.2 meters) or longer. The containers can be loaded in the transversely extending orientation by a conventional forklift  60  using the same end ramp  62  that normally is used for loading rail cars  64 . The forklift can travel lengthwise along one of the outboard loading zones to the far end of the rack structure, after raising the container to clear the highest parts of the rack structure, namely, the end walkways from the inboard corner ladders. The first such container can be placed at the forwardmost location. Preferably, semiautomatic twist locks are used for the outboard foundations such that the outboard corners of the container are automatically lashed by placement over the foundations and transverse shifting. The inboard foundations and twist locks  66  or cones are accessible to a worker standing on the center gratings. Suitable outboard twist locks are model “AFC-1L” and suitable inboard twist locks are model “CV-20/DUAL/2” twist locks, both available from Pacific Marine and Industrial of Novato, Calif.  
         [0022]     Working from the forward end of an outboard loading zone, containers can be placed across the zone and also can be stacked in tiers, using the same latching mechanism, namely, semiautomatic twist locks on the outboard ends and dual twist locks on the inboard ends. Standardized freight platforms (“flats”) can be used on the top tier. The particular twist locks used may allow the containers to be loaded and lashed without other lashing apparatus, eliminating the need for catwalks or other manners of end access at the outboard side. In the rack construction having 23 stanchions in each row, 22 container locations are provided at each side, as indicated diagrammatically in broken lines in  FIGS. 2 and 3 . As represented in  FIG. 3 , containers can be stacked at each location. Only a single loading ramp is required, with no dockside or onboard lifting or hoisting apparatus such as container cranes.  
         [0023]     When the desired containers have been mounted in one of the outboard zones, the rail cars for that zone can be loaded. Containers at the other outboard loading zone are positioned and lashed by the twist lock and stacking mechanism prior to loading rail cars in that zone.  
         [0024]     Cargo too wide to fit between the outboard loading zones of the rack structure can be carried on the forward or aft area of the deck. Tall cargo can be carried at the same areas, or in one of the outboard loading zones, either between containers on the rack system or in an outboard zone that does not have any overhead containers. Tall cargo also can be loaded by movement through an outboard zone prior to loading of containers.  
         [0025]     Occasionally difficulties may arise in mounting or, particularly, uncoupling or unlashing a container. The open construction of the rack structure permits access to the underside of the lowest tier of containers at both the outboard and inboard ends. As seen in  FIG. 11 , preferably the center walkway gratings  36  are spaced inward from the foundation blocks  58  slightly, and the inboard blocks  58  are mounted on the crossbeams  34  at locations spaced inward from the adjacent stanchions  18 . Thus, there is open access to the inboard end portion of the bottom tier of containers as well as to the outboard end portions from below. Since the gratings  36  are lowered relative to the top flanges of the crossbeams  34 , there also is some room for a worker to access a twist lock or cone, for example, by lying on the grating and reaching under a container.  
         [0026]     While the preferred embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.