Lightweight marine barge cover

An oceangoing barge cover is provided, which is made from lightweight structural fabric but enjoys the strength and stiffness of heavier steel covers and meets the requirements of the American Bureau of Shipping. The cover is comprised of a series of units, each of which in crosssection, is in the form of a series of concave quaternary curves, to the underside of which are fixed structural beams of fiberglass encasing rebar for support. Further support is provided by pipes of a structural fabric running perpendicular to the structural beams. A hatch can be optionally provided. Weathersealing and barge affixing means are also disclosed. In a preferred embodiment, the structural elements of the cover are comprised of fiberglass or fiberglass laminate.

BACKGROUND OF THE INVENTION 
This invention relates to hatch covers for oceangoing barges. As the cost 
of transportation has become an increasingly large part of the cost of 
material goods, transportation of materials in the holds of oceangoing 
barges has become increasing popular. This invention relates to an 
improved cover for the hatches or holds of such oceangoing barges. 
PRIOR ART 
Hatch covers have long been used on ships of various kinds. The present 
invention relates primarily to the hatch covers specially adapted to cover 
the hatches of oceangoing barges. Barge covers may be further 
distinguished in that some are roll-top covers, while others are lift-off 
covers. The present invention relates to a lift-off barge cover for an 
oceangoing vessel. 
Various governmental agencies regulate the merchant marine fleet, including 
oceangoing barges. An oceangoing barge must not only meet the desired 
performance specifications of its owner, it must also meet the 
seaworthiness requirements of the various regulatory bodies. In 
particular, hatch cover regulatory requirements specify characteristics, 
such as, the strength of the cover, the deflection of any particular span 
across the cover, the thickness of the cover, and the mechanism for 
securing watertightness between the cover and the hatchway. 
Among the most important of regulatory agencies and regulations is the 
American Bureau of Shipping and the Rules for Building and Classing Steel 
Vessels, as well as the American Bureau of Shipping's other regulations, 
including Rules for Building and Classing Plastic Vessels. The 
reguirements included in these Regulations have become increasingly 
stringent in the recent past, and are keyed to the strength 
characteristics of steel. Accordingly, the barge covers of the present 
invention must, in effect, meet the strength and stiffness requirements of 
steel. The present invention is a particular advance over the state of the 
art in that, rather than the comparatively heavy material of steel or 
traditional steel substitutes, a lightweight structural fabric is employed 
in the construction of the barge cover, thereby dramatically reducing the 
overall weight of the barge cover and the barge itself. 
It will be recognized that, as the cost of fuel increases, the importance 
of weight reductions in transportation vehicles becomes correspondingly 
more important. Additionally, as the amount of tonnage a particular barge 
can carry is determined, in part, by displacement and draft, the lighter 
weight structural fabric results in less initial displacement, therefore 
allowing a greater load to be carried, and reducing the cost per pound of 
materials transported. Thus, the hatch cover for oceangoing barges 
disclosed and claimed herein is a significant advance over the current 
state of the art. 
SUMMARY OF THE INVENTION 
As indicated, one object of this invention is to provide an oceangoing 
barge cover which is substantially lighter in weight than the steel and 
metal covers of the prior art. 
Another object of this invention is the provision of a cover constructed of 
structural fabric which meets the minimum requirements of the American 
Bureau of Shipping and other regulatory agencies, and has strength 
characteristics that resemble those of steel barge covers of the prior 
art, as is shown in U.S. Pat. No. 3,785,322. 
Yet a further object is to provide a lightweight oceangoing barge hatch 
cover which has a relatively simple construction but easily can be made 
watertight. 
The inventor has suprisingly discovered that, by providing a structural 
fabric cover, preferably of fiberglass, that is, in cross-section of a 
shape corresponding to a repeating series of concave caternary curves, 
there is a significant increase in strength in the cover. The strength of 
the cover is further increased by providing support beams on the underside 
of the cover, also preferably made of fiberglass or similar structural 
fabrics, which, by the use of reinforcing bars (rebar), are made 
relatively short and lightweight, yet strong. Further reinforcement is 
provided by the use of fiberglass pipes running perpendicular to, and 
through, the structural support beams. 
In an effort to provide still further strength and stiffness, a reinforced 
layer of structural fabric, preferably some form of fiberglass, is 
provided, at the point of attachment of the support beams to the cover 
member itself; this selective reinforcement increases strength and 
stiffness surprisingly, while keeping weight increase at a minimum. 
In a further preferred embodiment, in order to provide further strength, 
where a fiberglass fabric is employed in the practice of this invention, 
the fabric may be included in a laminate structure comprised of repeating 
alternating layers of woven fiberglass, uniglass or other structural 
material, and fiberglass chopped filler. This particular laminate, 
although lightweight, provides surprising strength. 
One feature that all oceangoing barge covers must be able to exhibit is one 
or more means for keeping the hold itself watertight, and preventing 
weather or ocean elements from entering and fouling the cargo. Although 
preferred means are disclosed herein, alternative means are also known in 
the art. 
It will, therefore, be recognized that the cover disclosed and claimed 
herein achieves the objects discussed above, and has the further advantage 
that it is much less expensive and much lighter in weight than prior art 
steel covers. Furthermore, maintenance and repair are more easily 
accomplished and thus less expensive. Rust, barnacles and other problems 
encountered with metal parts are not a problem with parts made from the 
structural fabric of this invention. 
Furthermore, the present invention is easily handled; at ports having 
cranes with weight restrictions, barge covers of the present construction 
are easily lifted, while prior art steel covers must sometimes include 
means for separating the cover units into multiple, discrete parts to 
permit handling by low capacity cranes. 
The advantages and other objects obtained by the use of oceangoing barge 
cover of this invention may be better understood by reference to the 
drawings which form a further part hereof, and to the accompanying 
descriptive matter in which there is illustrated and described a preferred 
embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION 
With reference to the drawings, applicant's invention will be described in 
detail. 
As is shown in the side view of FIG. 9, the barge cover of this invention 
is composed of a series of several sections, each section being 
substantially similar to the others. One such section is pictured in plan 
view in FIG. 1. Each section is comprised of lateral end panels 1, 1a and 
longitudinal end panels 2, 2a both made in similar fashion. Both lateral 
and longitudinal end panels extend integrally downward from cover member 
3. As can be seen in FIG. 2, cover member 3 is, in cross section, a series 
of concave caternary curves 4, each joined to the next at the peak 5 of 
each curve, which peak is reinforced, as can be seen in FIG. 5. It should 
be understood that the entire cover member 3, including sides 1, 1a and 2, 
2a is a single structural piece, and reference is made to repeated curves 
and joining merely for sake of descriptive clarity. 
Cover member 3 is supported by a plurality of support beams 8 affixed to 
the underside thereof, extending perpendicularly to the longitudinal 
centerline of the barge. Each support beam resembles in configuration a U, 
with the walls or legs of the U extending upwardly and slightly outward. 
Near the top of each leg, there is a first, substantially horizontal, 
flange 7, in which is encased rebar which lends support and stiffness to 
the supporting beam. Although, as will be recognized by one of skill in 
the art, the nature of the rebar will be determined by the structural 
needs of the barge cover to be constructed, in a preferred embodiment, the 
rebar employed is No. 8 rebar of grade 60. The leg or wall of the support 
beam continues substantially vertically beyond horizontal flange 7, until 
a second substantially horizontal flange 6 is encountered, which second 
flange also encases rebar 15, grade and quality similar to that encased by 
flange 7. Beyond substantially horizontal flange 6, the leg or wall of the 
support beam continues vertically upward until it joins cover member 3. 
At the junction of the leg or wall of each support beam 8 with cover member 
3, there is a reinforced section formed integrally with cover member 3. 
This section is illustrated in FIG. 5. Although this reinforced section 
can be made of any suitable structural fabric, in a preferred embodiment, 
it is composed of a coated layer of uni-glass, an industrial glass fabric 
wherein the glass strands comprising the fabric are of uniform 
orientation. It is again re-emphasized that, although for clarity of 
description, the configuration and structure of cover member 3 and support 
beams 8 have been described in discrete sections, each cover member, and 
each support beam, is an integral solitary structure. 
As can be seen most clearly in FIG. 3, each support beam 8 encases two 
reinforcement rebars 14 and 15 in each leg or wall. This method of 
encasement is most clearly shown in FIG. 4, which illustrates that rebar 
14 is completely enclosed within horizontal flange 7 and the vertical wall 
17 of support beam 8. It will therefore be recognized that, wherever rebar 
is to be enclosed, the wall or base of support beam 8 will in fact be a 
multilayered wall or base of at least two layers, an outer layer 18 and an 
inner layer 19. Additionally, the base of each support beam 8 encases at 
least nine, and preferably twelve, rebar reinforcements 36, of similar 
grade and quality as those employed in the leg or wall of each support 
beam. 
As further support for cover member 3 and the structural beams 8 attached 
thereto, running throughout support beams 8, and parallel to the 
longitudinal centerline of the barge to which the cover is attached, are a 
plurality of reinforcement pipes 10. These pipes can be constructed out of 
a suitable lightweight structural fabric, although in a preferred 
embodiment they are constructed of fiberglass reinforced plastic. 
Each intermediate cover section of the barge cover of this invention has a 
weather seal element or flange 9 affixed at either longitudinal end panel. 
As will be recognized, those sections that lie at either end of the barge 
will have means on the leading or trailing longitudinal end panel with 
which to engage the barge in place of a weather seal element. The 
interaction of corresponding weather seal means of each cover section is 
most clearly illustrated in FIG. 7, where a preferred embodiment is 
depicted. In this embodiment, two weather seal flanges 9 and 9a overlap. 
Affixed to longitudinal end panel 2a is a further weather seal flange 20, 
which abuts against a gasket 22 preferably made of EPDM rubber (a 
terpolymer of polypropylene, ethylene and butadiene). Directly below 
horizontal flange 20 is a second horizontal flange 21 extending from long 
wall 2, and abutting against corresponding gasket 23, also preferably 
constructed of EPDM rubber. It will be recognized that, the combination of 
weather seal unit 9, along with the two interior flange and gasket devices 
described above provides not only a fluid-tight seal, but provides 
channels for the run-off of any water or other fluid that does penetrate 
beyond weather seal elements 9 and 9a. A number of varieties of weather 
seal arrangements will occur to those skilled in the art. The arrangement 
illustrated in FIG. 7 and disclosed above is not intended to limit the 
barge cover of this invention, but rather merely to illustrate one 
alternative "gasket and seal" arrangement. 
Spaced along lateral end panel 1 and 1a of cover member 3 and longtiudinal 
end panels 2 and 2a of the leading and trailing cover sections of the 
barge are provided mechanisms for releasably engaging the barge on which 
the covers rest, thereby providing a means for preventing movement and 
slippage of the cover sections and sealing the barge hatches from water 
penetration. Although any releasable mechanism providing a suitable seal 
may be used, a preferred embodiment includes a U-shaped bracket 25, 
affixed to the barge by grommets 26, nuts 27a and bolts 28a. This bracket 
may be engaged by arm 27 which is mounted on cam member 28 which can be 
rotated about a pin. The pin and cam arrangement is secured to the outer 
wall of a cover section by being mounted on a plate 24 secured to the 
outer wall by nut and bolt arrangements 29. Thus, when cam 28 and arm 27 
are rotated downward, U-shaped bracket 25 is no longer engaged, and the 
cover section may be moved or lifted away. However, when arm 27 is rotated 
upward into a "closed" position, arm 27 engages bracket 25, preferably 
within a notch in bracket 25 (not illustrated) which thereby prevents 
movement of the cover section. To provide a watertight seal, a wear plate 
and gasket may be positioned between the barge and the cover section (not 
pictured). It will be recognized that enough of the illustrated and 
described securing means, or any other securing means found usable, will 
be provided about the cover sections to secure said cover sections against 
movement and water leakage. 
Each unit of the barge cover of this invention may be provided with one or 
more hatches through which cargo may be directly loaded, avoiding the 
necessity of lifting the cover unit. As is shown in FIG. 10, the cover 
consists simply of a hinged door 35 set into cover member 3, arranged so 
as to provide a watertight seal when in the closed position. Other 
hatches, such as those disclosed in U.S. Pat. No. 3,730,128, will occur to 
those of skill in the art. 
As noted above, except where employing gaskets or sealing members such as 
depicted in FIGS. 7 and 8, or rebar, such as depicted in FIG. 3, all the 
materials employed in the construction of this invention are preferably 
made of lightweight structural fabrics. In a further preferred embodiment, 
that structural fabric is a fiberglass laminate, as is illustrated in FIG. 
6. This preferred laminate is comprised of a first layer of woven 
fiberglass 30, of a type familiar to one of skill in the art. Underlying 
this layer is a layer of uniglass 31, and further underlying that layer is 
a layer of fiberglass chop filler 32. This series of layers can be 
repeated a number of times, until a sufficient strength is provided, but 
before the structural material becomes so heavy as to deprive the barge 
cover of the advantages and the objects described hereinabove. The layers 
can be secured, one to each other, by any of a number of methods commonly 
practiced in the art, including, but not limited to, application of 
adhesives between layers or resin encapsulation. 
As is shown in FIG. 9, in the practice of this invention, a barge 33 
supports a plurality of cover sections 34, as disclosed above. These cover 
sections, abutting and adjoining each other with weather seal means as 
described above or equivalent means, extend the entire length of the hatch 
opening of the barge, thereby providing a lightweight and watertight cover 
of surprising strength, which reduces the weight of the barge, increases 
carrying capacity, and reduces cost per ton of load. 
Although the barge cover of this invention has been described with 
particularity, it will be understood that the description provided is for 
illustration, and that the invention as claimed below contemplates all 
equivalents within the practice of this barge cover. Specifically, the 
nature, type and quality of the materials employed in constructing the 
cover will vary according to the understanding of one of ordinary skill in 
the art. Further, the emplacement of, and number of reinforcement rebars 
and fiberglass pipes may vary according to the particular needs of those 
of skill practicing the invention.