Note: Descriptions are shown in the official language in which they were submitted.
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CENTER BEAM CAR WITH DEPRESSED CARGO-CARRYING AREA
BACKGROUND OF THE INVENTION
The present invention relates to freight-carrying railroad cars of the type
known as center beam or center partition bulkhead flat cars, and in particular
relates
a center beam for a center beam car providing enhanced protection for the
car's
cargo.
Center partition bulkhead flat cars, commonly known as center beam cars,
have been known for over 30 years and are depicted, for example, in Taylor
U.S.
1o Patent No. 3,244,120, Wagner IJ.S. Patent No. 3,734,031, Baker U.S. Patent
No.
4,543,887, and Saxton U.S. Patent No. 5,758,584. Evolving design of such
railroad cars has been directed generally toward cars with ample strength but
of
lighter tare weight in comparison to their cargo-carrying capacity.
Construction of
center beam cars of lighter weight with load-carrying floors located at a
uniform
height along the length of the car body leaves their load capacity limited by
the
available space.
Dominguez, et al., U.S. Patent 4,951,575 discloses a center beam car in
which a longitudinally intermediate portion of the load-carrying floor on
either side
of the center beam is located at a lower height than the load-carrying floors
located
2 o in end portions of the car above the trucks on which the car body is
carried. In the
intermediate portion of such a car, crossbearers extend between lowered
portions of
the side sills of the car body and are supported beneath the center sill.
The car disclosed by Dominguez, however, has a conventional box-beam
center sill structure, and the crossbearers of the car are attached to the
center sill by
hanger plates attached to the opposite sides of the center sill and extending
downward to support an upper flange portion of each of the crossbearers. The
structure of the car shown in the Dominguez et al. patent is thus
unnecessarily
heavy, making such cars expensive to build and operate.
In most previously available center beam cars the center of gravity has been
3 o relatively high because the entire load has been carried above the height
of the
trucks, but also at least partly as a result of the height of the center
partition
extending as high as the bulkheads on the ends of the car.
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The space above the floor on each side of the center beam forms a bunk
upon which bundles of cargo, typically wood products, can be stacked. When the
bundles are stacked, they are typically secured by cables or straps that
extend from
a winch device mounted on the periphery of the floor to a top fitting on the
center
beam. When the cable or strap is tightened it exerts a force inwardly and
downwardly so that the stack leans toward the longitudinal centerline of the
car and
is pulled tight against the center beam.
The bundles are often wrapped in a plastic sheet to protect the goods from
rain and snow, and to discourage embedment of abrasive materials such as sand
in
1o valuable goods, such as wood. The plastic sheet typically comprises
polyethylene,
but may comprise another plastic material.
In previously known center beam cars, various components of the center
beam are interconnected in such a manner as to present edges or fastening
devices
which could rub on the cargo. In addition, when the cables or straps are
tightened,
the innermost, uppermost elements of the topmost bundle bear against the top
chord
of the center beam. As the car moves, vibration and inertia cause the stacked
cargo
to move relative to the center beam. Exposed edges or fastening devices in the
center beam structure often abrade, tear, or damage the protective plastic
sheeting.
Portions of the cargo bearing against the center beam can be physically
damaged as
2 o a result of contact with exposed edges or projections. Moreover, damaged
sheeting
may permit entry and collection of moisture and dirt leading to discoloration
and the
growth of mold on wood products. The resulting loss of value for the cargo can
be
substantial.
Forbes, U.S. Patent No. 6,237,506, discloses a smooth, non-consumable
2 5 panel facing for a portion of the posts of a center beam. The smooth
facing protects
the plastic sheeting from tearing by reducing exposure to projections and
sharp
edges on the posts. However, a facing applied to the posts of the center beam
does
not protect the portion of the sheeting in contact with the top chord of the
center
beam. Abrasion induced by friction and relative movement of the cargo and the
top
3 o chord can cause rapid failure of the plastic sheeting exposing the goods
to a hostile
environment.
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What is desired, then, is a center beam or center partition bulkhead flat car
defining greater useable cargo-carrying volume and having ample strength yet
having lighter tare weight than previously available cars of the type, and in
particular including improved center sill and crossbearer structures. What is
further
desired is a center beam car in which the center beam is constructed so as to
be
substantially free of edges and projections that can damage the cargo or its
containers or coverings and in which the top chord is constructed so as to
reduce
damage resulting from relative movement of the car and its cargo.
1o SUMMARY OF THE INVENTION
The present invention responds to some of the aforementioned needs by
providing a modified center partition bulkhead flatcar including a center sill
extending longitudinally along the car's body, a center beam extending along
the
center sill with a top chord of the center beam spaced upwardly above the
center sill
and connected to it by upright members, and including crossbearers each
attached to
and extending transversely beneath the center sill and supporting a floor on
each
side of the car body, and wherein in an intermediate portion of the center
sill
located between the opposite ends of the car body, a bottom plate of the
center sill
extends laterally outward beyond the side plates of the center sill and acts
as an
2 o inboard portion of the floor structure.
In one aspect of the invention the center beam includes upright members
which extend from the center sill to the top chord and which are attached in
such a
manner that the surfaces presented to cargo are coplanar and free of
projections that
could damage the cargo.
2 5 In another aspect of the invention, the top chord of the center beam
comprises a selectively affixable, lateral face arranged to contact and resist
lateral
displacement of the cargo while facilitating movement of the cargo in
directions
generally parallel to the lateral face.
The foregoing and other objectives, features, and advantages of the invention
3 o will be more readily understood upon consideration of the following
detailed
description of the invention, taken in conjunction with the accompanying
drawings.
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BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is an isometric view of a center beam railroad freight car embodying
the present invention and including a car body in which a longitudinally
intermediate portion includes cargo-carrying floors located at a lower height
than
cargo-carrying floors in the respective end portions of the car body.
FIG. 2 is an end elevational view of the center beam railroad car shown in
FIG. 1.
FIG. 3 is a side elevational view of the center beam railroad car shown in
FIGS. 1 and 2.
to FIG. 4 is a top plan view of a portion of the center beam railroad car
shown
in FIG. 3.
FIG. 5 is a bottom plan view of the portion of the center beam railroad car
shown in FIG. 4.
FIG. 6 is a sectional view of a portion of the railroad car shown in FIG. 4,
taken along line 6-b.
FIG. 7 is an isometric view of a portion of the center sill and floor
structure
of the center beam railroad car shown in FIGS. 1-6, taken from the underside
of the
intermediate portion thereof.
FIG. 8 is a partially cutaway sectional view of the center beam railroad car
2o shown in FIG. 4, taken along line 8-8.
FIG. 9 is a sectional view of the center beam railroad car shown in FIG. 4,
taken along line 9-9.
FIG. 10 is a sectional view of the center beam railroad car shown in FIG. 4,
taken along line 10-10.
FIG. 11 is a side elevational view showing the manner in which a column is
interconnected with the center sill and the top chord in the intermediate
portion of
the center beam railroad car shown in FIG. 3, at an enlarged scale.
FIG. 12 is a sectional view, taken along line 12-12 of FIG. 11 at an enlarged
scale, showing the interconnection of the vertical column with the center sill
and the
3 o top chord tube.
FIG. 13 is a sectional view of the center beam railroad car shown in FIG. 4,
taken along line 9-9 and illustrating placement of cargo on the car.
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FIG. 14 is a sectional view of the top chord of the center beam of the
railroad car shown in FIG. 4, taken along 9-9.
FIG. 15 is a perspective view of a portion of the center beam top chord
illustrated in FIG. 14.
5 FIG. 16 is a perspective view of a top chord and another embodiment of a
top chord cover.
FIG. 17 is a sectional view taken along 9-9 of the top chord of a center
beam of the railroad car and a top chord cover of still another embodiment.
FIG. 18 is a perspective view of the top chord and the embodiment of the
1o top chord cover illustrated in FIG. 17.
FIG. 19 is an isometric view of a center beam railroad freight car which is
another embodiment of the present invention and includes a car body in which a
longitudinally intermediate portion includes cargo-carrying floors located at
a lower
height than cargo-carrying floors in the respective end portions of the car
body and
in which the top chord of the center beam is at a height proximate the tops of
the
bulkheads.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings which form a part of the disclosure herein, as may
2o be seen in FIG. l, a center beam car 10 embodying the present invention has
a car
body 12 of welded steel construction carried on a pair of wheeled trucks 14
located
at respective opposite ends 16 and 18 of the car body 12.
Bulkheads 20, 22 are located at the opposite ends 16 and 18, and a center
beam 24 extends longitudinally of the car body 12 between the bulkheads 20 and
2 5 22 .
Referring also to FIGS. 2 and 3, the car body 12 includes a center sill 26
that extends from the first end 16 to the other end 18. The center sill 26
acts as part
of the bottom chord or flange of the center beam 24. A top chord 28 of the
center
beam extends longitudinally along the car body 12 a distance above and
parallel
3 o with the center sill 26 from the bulkhead 20 to the bulkhead 22, and is
attached
structurally to each of the bulkheads 20 and 22. While the top of the center
beam
24 is shown as having a height less than that of the tops of the bulkheads 20
and 22,
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the car 10 could also be constructed with a center beam 24 of greater height,
at least
up to nearly as high as the tops of the bulkheads 20 and 22, as illustrated in
FIG.
19.
Vertical columns 30, 32 and 34 in the form of fabricated I-beams extend
upward from the center sill 26 to the top chord 28 as the web of the center
beam 24.
The top chord 28 may, for example, comprise 10" x 10" square tubing 29 of 1 /2-
inch wall thickness. The lower ends of the columns 30 are flared outward to be
broader than the upper portions of the columns, and to match the width of the
center
sill 26 at the location where each is attached to the center sill 26. The
upper
to portions of the columns 30, 32, and 34 are, for example, of welded steel
plate.
The vertical columns 30, 32 and 34 are attached to the center sill 26 with
ample strength and in such a way that the surfaces presented to the cargo
where they
are attached are smooth and free of edges or projections that could damage
cargo, as
will be explained in greater detail presently.
Square tubular diagonal members 36 are somewhat smaller than the columns
30, 32, and 34 and are attached to respective ones of the columns and to the
center
sill 26 and top chord tube 29 by upper end gusset plates 38 and lower end
gusset
plates 40 welded into place on each side of each diagonal member 36. The
gusset
plates 38 and 40 are welded to the transverse web plates of the respective
columns,
2 o as well as to the top of the center silt and the underside of the top
chord tube 29.
Each of a pair of end portions 42 of the car body 12 includes the respective
bulkhead 20 or 22 and extending beyond the respective truck 14. A generally
horizontal upper level cargo floor 44 is located alongside the respective
columns 30
on each lateral side of the center beam 24 in each end portion 42. The floor
44 in
2 5 each end portion 42 includes a floor sheet 46 on each of the laterally
opposite sides
of the center beam 24. Each floor sheet 46 extends along and is attached to a
respective end portion side sill 48, as will be explained more fully below.
An intermediate portion 50 of the car is located between the two end
portions 42. The intermediate portion 50 includes a depressed cargo-carrying
floor
3 0 located on each lateral side of the center beam 24 at a significantly
lower height
than that of the upper level cargo floors 44 in each of the end portions 42.
Whereas
the floor sheets 46 are located at a height above the top of the center sill
26, floor
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sheets 54 of the depressed floor extend in substantially coplanar alignment
with a
bottom plate 56 of the center silt 26, as is shown most clearly in FIG. 6, so
that
cargo carried in the intermediate portion 50 can be placed alongside and in
contact
with the center sill 26.
An outboard margin of each floor sheet 54 is attached to and supported by a
respective intermediate portion side sill 58, which may be a channel with
unequal
flanges of bent plate construction, as is seen best in FIG. 6. Preferably, the
side sill
58 channel is formed of 5/16 inch steel plate, and has its flanges facing
outboard to
provide a protected location for cargo tie-down strap spools 60 in the
intermediate
1 o portion 50 of the car body 12.
A height difference 62 between the floors 44 and the floor sheets 54, shown
in FIGS. 1 and 3, is preferably equal to or a multiple of the usual height of
a
package of goods, for example a bundle of plywood, intended to be carried on
the
center beam car 10. For example, the height difference 62 may preferably be
about
33 inches, equal to the height of a bundle of plywood including its packaging
and
leaving room for stickers providing clearance beneath the plywood for the
forks of a
forklift truck or other cargo-handling equipment.
A floor support transition portion of the car body 12 includes diagonal
structural members 64, which may be channels, and a shear plate 66 located on
each
2 o side of the center sill 26 and supported by stiffening channel structures
68, 70 and
72. Reinforcing angles 73 seen in FIGS. 6 and 8 assist in reinforcing the
shear
plates 66 and connecting the shear plates 66 with the side plates 76 of the
center sill
26. Transitional side posts 74 on each side of the car body interconnect the
upper,
or end portion side sills 48 with the intermediate portion side sill 58.
Referring now to FIGS. 4, 5, 6 and 7, in the intermediate portion 50 of the
car body 12, the center sill 26 is integrated with the structure of the floors
on either
side of the center sill. As shown best in FIG. 6, the center sill 26 in the
intermediate portion 50 of the car includes a pair of parallel upright side
plates 76
having a thickness 78 of, preferably, 5/16 inch plate, extending
longitudinally and
3 o spaced apart laterally by a distance 80 of, for example, 9-3/8 inches. A
top plate
82 spans the distance 80, for example, between the upright side plates 76 and
interconnects them near an upper margin of the center sill, as may be seen in
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FIG. 6. The top plate 82 has a thickness 84 that is greater than the thickness
78 of
each side plate 76. For example, the thickness 84 may be 3/8 inch.
The bottom plate 56 is welded to the bottom margins of the side plates 76
and extends horizontally outward beyond the side plates 76 by a distance 86
of, for
example, 16 inches, on each side of the center sill 26, so that the center
sill 26 in
the intermediate portion 50 of the car body 12 thus has the form of a closed
rectangular box with a laterally extending flange on each side of its bottom
face.
The bottom plate 56 preferably has a thickness 88 which is similar to the
thickness
78 of each side plate 76. For example, the thickness 88 is preferably 5/16
inch.
to The distance 86 should be at least half the distance 80 and is preferably
greater than
the distance 80, so that the bottom plate 56 includes ample material to carry
the
forces developed in the bottom of the center beam 24, although the weight of
the
bottom plate 56 is spread laterally. The bottom plate 56 thus is available to
act as a
portion of the cargo supporting door structure and to aid in providing
stiffness of
the center sill to resist lateral bending in the intermediate portion 50 of
the car I0.
As shown best in FIGS. 11 and 12, the columns 30, 32 and 34 extend
upward from the center sill 26 to the top chord 28. While only a single column
34
is shown in FIGS. 11 and 12, the interconnections of the columns 30 and 32
with
the top chord 28 and the center sill 26 are similar except at the bottom of
columns
30 (shown in FIGS. 9 and 10). The columns 32 and 34 each have a width 83 equal
to the width 85 of the center sill 26 in the intermediate portion SO of the
car 10, and
are constructed as fabricated I-beams each having a transverse web plate 87
fitting
between a pair of flange, or side, plates 89 extending vertically and
longitudinally
and aligned with the side plates 76 of the center sill 26. The upper end 91 of
each
z 5 of the columns is welded to the underside of the top chord tube 29, as
seen best in
FIG. 12, to present a continuous planar surface including one lateral face 93a
of the
top chord 28.
Each of the side plates 76 of the center sill 26 includes upwardly projecting
portions 95 whose lengths and locations along the center sill 26 correspond
with the
3 o bottom margins 97 of the flange plates 89 of the columns 30, 32, and 34,
as may be
seen in FIGS. 3 and 11. Each of the flange plates 89 of each column includes a
broad bottom margin 97 to provide ample material to be welded to the center
sill
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26. Above the bottom margin 97 each flange or side plate 89 is tapered to a
narrower width that continues for the majority of the length of each column.
Each
flange plate 89 is located above, and is aligned with, an upwardly projecting
portion
9S of a respective side plate 76 of the center sill 26 so that the respective
laterally
outer faces 93a, 93b, 93c and 93d of the top chord 28, the center sill 26, and
each
of the columns 32 and 34, are all coplanar with each other on each lateral
side of
the center beam 24 in the intermediate portion SO of the car 10. The lateral
faces
93e of the portions of each column 30 above the end portion floors 44 are
similarly
coplanar with the lateral faces of columns 32 and 34 and the top chord 28.
1o The lower end of each of the columns 32 and 34 is welded to the top of the
center sill 26 as shown in FIG. 12 to provide a connection with ample strength
and
a joint surface free from exposed edges or projections that might catch or
cause
wear on the surfaces of cargo or packaging. The lower end of the central web
plate
87 is welded to the top of the top plate 82 of the center sill 26, preferably
leaving a
small gap 99 between the bottom margin 97 of each flange plate 89 and the
adjacent
projecting portion 95 of the side plate 76. A portion of each side of the web
plate
87 is cut out as shown at 101, leaving room for a backing bar or doubter plate
I03
to be attached flush against the inner face of each flange plate 89 where the
bottom
margins 97 of the flange plates 89 face the projecting portions 95 of the side
plates
2 0 76.
The doubter or backing bar 103 is ideally of bar stock whose thickness is
similar to that of each of the side plates 76. Each backing bar or doubter
plate 103
has a chamfered bottom surface that bridges the gap 99 and accounts for the
difference in thickness between side plates 76 of the center sill 26 and the
thinner
2 5 flange plates 89 of the column 32 or 34. The backing bar 103 thus supports
and
adds strength to the welded connection between the bottom margins 97 of the
flange
plates 89 and the side plates 76, while permitting the outer surface of the
interconnecting weld to be smooth and coplanar with laterally outer faces of
the side
plate 76 and the flange plate 89.
3 o In order to support the cargo-carrying floor in the intermediate portion
SO of
the car at the relatively low height of the bottom plate S6, lower than the
height of
the tops of the wheels of the trucks 14, several crossbearers 90 extend
transversely
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beneath and are attached to the center sill 26. Each of the opposite ends 92
of each
crossbearer 90 is welded to the respective side sill 58. Each crossbearer 90
includes
an upstanding web member 94 and a horizontal bottom chord or flange of which a
central portion 96 is of relatively thick steel plate, having a thickness 98
of, for
example, 5/8 inch. Outboard portions 100 of the flange of the crossbearer 90
are
preferably of thinner material such as steel plate 5/16 inch thick, which is
amply
strong for the loads imposed, while the greater thickness 98 of the central
portion
96 of the flange is desirable to carry the compressive loads imposed by the
weight
of the lading carried on the car 10.
1o The web 94, like the outboard portions 100, is similarly of thinner
material
such as sheet or plate material 1/4 inch thick, and the upper margin 104 of
the web
94 is welded to the underside of the bottom plate 56.
A pair of stringers 102 extend longitudinally along the underside of the
laterally extending, or outboard, portions of the bottom plate 56 of the
center sill
26, providing stiffening support and helping to stabilize the interconnection
of the
webs 94 of the crossbearers 90 with the bottom plate 56.
Each floor sheet 54 overlaps the respective longitudinally extending side
margin 106 of the bottom plate 56 by a small distance and is welded to it. The
floor sheet 54 extends outboard and has its outboard margin welded to the side
sill
2 0 58, whose upper flange forms the outboard-most portion of the cargo-
carrying
surface of the floor in the intermediate portion 50 of the car 10.
At each end of the intermediate portion 50 of the car body 12 an extension
plate 110 extends laterally beneath the door sheet 54, from the outward margin
of
the bottom plate 56 to the side sill 58, as may be seen in FIGS. 4, 5 and 8.
The
2 5 web 94 of the crossbearer 90 at each end of the intermediate portion 50 of
the car is
thus attached to the underside of each of the plates 110, as shown in FIG. 8.
Extending parallel with the stringers 102 are stringers 112 attached to the
underside of the floor sheets 54 and to the webs 94 of the crossbearers 90.
The
floor sheets 54 are preferably of material significantly thinner than the
material of
3 o the bottom plate 56 of the center sill. For example, the floor sheets 54
may be of
I 1 gauge sheet steel, l. e. , 0. I 196 inch in thickness, but they are
supported by the
bottom plate 56, the side sills 58, the webs 94 of the crossbearers 90, and
the
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stringers 112, and thus provide ample strength to support the types of lading
for
which the car 10 is intended.
In addition to having their webs 94 welded to the underside of the bottom
plate 56 of the center sill 26, the crossbearers 90 are connected with the
center sill
26 through gussets 114 which are in the form of tapered, hollow semicylinders,
or
half pipes. As shown best in FIG. 7, a pair of parallel upper margins 116 of
each
gusset 114 are welded to the underside of the bottom plate S6 of the center
sill 26,
aligned opposite the side plates 76 of the center sill. A semicircular end
face 118 of
each gusset I 14 is welded to the web 94 of a crossbearer 90. Each gusset 114
is
1 o tapered to a shorter length further from the bottom plate 56, near the
central portion
96 of the crossbearer 90, while the upper margins 116 are longer, to
distribute loads
from the crossbearer 90 over a significant length of the center sill 26. The
gussets
114 may be formed of steel 5/16 inch thick, for example.
In order to facilitate installation of the stringers 102 and 112 during
construction of the car, a short sleeve 120 fit around one end of each
stringer 102 or
112, which is somewhat shorter than the space between crossbearer webs 94
where
the stringer fits. The sleeves 120 are welded to the stringers, the underside
of the
floor plate 54 or bottom plate 56, and the adjacent web 94, while the
remainder of
each stringer 102 or 112 is welded in place tight against a web 94 at the
opposite
2 o end of the stringer.
The resulting floor in the intermediate portion 50 is a significantly
integrated
structure incorporating the stringers 102 and 112 and the crossbearers 90,
which, in
turn, are securely attached to the underside of the center sill 26, through
the web 94
and the gussets 114. The portions of the bottom plate 56 which extend
laterally
beyond the side plates 76 of the center sill are supported between the
crossbearers
90 by the attached stringers 102 and provide part of the cargo-carrying floor
surface. The center sill 26 is thus reinforced by the floor structure just
described,
which serves as part of a wide bottom chord of the center beam whose columns
30,
32 and 34 and diagonal members 36 extend upward to the top chord 28.
3 o The intermediate portion 50 of the car 10 preferably has a length 122,
established by the distance between the shear plates 66, that is related to a
multiple
of the usual length of packages of goods which the car 10 is intended to
carry. For
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example, the distance 122 may be 40 feet 6 inches, allowing five. bundles of
lumber
or sheet of plywood each 8 feet long and 4 feet wide to fit in the
intermediate
portion 50 of the car between the shear plates 66 and below the height of the
end
portion floors 44. The lading can thus be conveniently stacked on the
depressed
floor to a height equal to the height difference 62, above which the lading of
the car
can extend over a greater length established by the distance between the
bulkheads
20 and 22, which is also preferably related to the usual cargo package size.
In the intermediate portion 50 of the car 10, the depth 125 of the center sill
26, established by the vertical height of the side plates 76, is greater than
in the end
1 o portions 42 of the car 10. 'The center sill 26 is also narrower in the
intermediate
portion 50 than in the end portions 42. Because the floor 44 of each end
portion 42
is located above the stub end portions 124 of the center sill 26, and because
it is
desirable for the car to rest as low as practical on the trucks 14, in order
to
minimize the height of the center of gravity of the car 10, the stub end
portions 124
are wider but shallower, as may be seen clearly in FIGS. 3 and 5 and by
comparison between FIGS. 8 and 9.
A sloping portion 126 of the bottom plate of each stub end portion 124 of
the center sill 26 is welded to the bottom plate 56 beneath the reinforced
shear
plates 66, as shown best in FIG. 5. The sloping portion 126 and the horizontal
2 o portion 128 of the bottom plate of the stub end portions 124, shown also
in FIG. 9,
have a greater thickness than the bottom plate 56, and may be, for example,
3/4
inch thick. A top plate 129 of the stub end portions 124 of the center sill 26
is of
relatively thick plate, for example, 1 /2 inch thick.
Interconnected with the stub end portions 124 of the center sill 26 in each of
2 5 the end portions 42 is a respective body bolster 130 which rests atop the
wheeled
truck 14 that supports that end of the car body 12. As shown in FIG. 9, a
center
bearing 132 is associated with the bottom of the body bolster 130.
A pair of lateral arms 134 extend laterally outward and diagonally upward
from the stub end portion 124 of the center sill to the upper or end portion
side sills
30 48, and each is welded to the respective side sill 48. Each arm 134
includes a pair
of upright transverse plates, or side plates 136, tapered and extending
outwardly
from the center sill, parallel with each other and spaced apart from each
other in a
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direction parallel with the length of the car 10. The side plates 136 are
interconnected with each other by a bottom plate 138 and a top plate 140 that
extend
longitudinally of the car body 12 beyond each side plate 136 so that each arm
134
has the form of a tapered flanged box beam. The bottom plate 128 of the stub
end
portion 124 of the center sill 26 extends laterally outward beyond each of its
side
plates 142 for a distance of about one-half the width 144 of the stub end
portion
124, and so the bottom plate 138 of each arm 134 is welded to an adjacent
portion
of the lateral margin of the bottom plate 128 of the stub end portion 124.
A tie plate 146 which may be 1/2 inch thick extends along a portion of each
1 o bottom plate 138 and the bottom plate 128, providing an additional
thickness of
material to carry the loads encountered where the arms 134 are interconnected
with
the stub end portion 124, and gussets 148 provide additional reinforcement
along
the margins of the bottom plate 128.
Mounted atop each of the arms 134 of the body bolster 130 is a floor support
s5 riser 150 in the form of a downwardly open U-shaped channel that provides a
flat
horizontal top face 152 and has sides aligned with the side plates 136.
A side bearing foundation 153 is integrated with the lower side of each arm
134, and extends downward beneath the bottom plate 138, as may be seen in
FIGS. 2, 5 and 9.
2 o A pair of longitudinally extending floor support stringers 154, preferably
in
the form of channels similar to the stringers 102 and 112, are mounted atop
the
horizontal top face 152, and are welded to the underside of the end portion
floor
sheet 46 on each lateral side of the car body 12. The stringers 154 extend
longitudinally from the reinforcement channel 68 supporting the shear plate 66
to
25 the end sill 156 located beneath the bulkhead 20, in order to provide
support for the
floor sheets 46, which are preferably of 11 gauge sheet steel (0.1196 inch
thick).
As shown in FIG. 10, the stringers 154 are also supported between the body
bolster 130 and the end sill 156 by a transversely extending support member
158,
preferably in the form of a channel of bent sheet steel thick and having
horizontal
3 o flanges and a vertical web. The support members 158 each extend from a
side sill
48 laterally inward to a support plate 160 welded to and extending upward from
a
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respective side plate 142 of the stub end portion 124 of the center sill 26,
as shown
in FIG. 10.
Each stub end portion 124 houses appropriate gear to support a conventional
coupler at each end 16 or 18 of the car body 12.
Each bulkhead 20 or 22 extends upwardly above the respective end sill 156,
and preferably includes a closed section central column 162 fabricated of a
pair of
channels connected by flat plates, and a pair of side columns 164 in the form
of
outwardly facing channels, with a pair of face plates 166 on each bulkhead 20
or 22
facing toward the opposite end 16 or 18 of the car body. Each face plate 166
is
to reinforced by horizontal channels 168 welded to the outboard side of each
bulkhead
20 and 22 between the central column 162 and each column 164, as shown in
FIG. 2.
Referring to FIGS. 13,14, and I5, the cargo 500 of the center beam railroad
car 10 is stacked on the floor 44 of the car on both sides of the center beam
24.
Additional bundles of cargo 501 may be stacked above the center beam 24. If a
plurality of bundles 501 are stacked across the car above the center beam 24,
the
bundles are typically stacked to abut along their inboard sides to aid in
stabilizing
the load. Straps or cables 502 run over the cargo to cargo tie-down strap
spools 60
at the periphery of either side of the car. When the straps or cables 502 are
2 o tightened, the stacked cargo 500 is pulled toward the center of the car 10
and the
upper inboard corner of the cargo stack comes into contact with the lateral
face 93a
of the top chord 28 of the center beam '24 which resists further lateral
displacement
of the cargo.
The internal structure of top chord 28 of the center beam 24 is typically a
hollow rectangular beam or tube 29, for example, a section of 10" x 10" square
steel tubing of 'h-inch wall thickness having a top wall 508, a bottom wall
510 and
lateral walls 512. The cargo is typically covered by a protective plastic
sheet 514
that becomes trapped between the goods 516 and the lateral face 93a of the top
chord 28 when the straps or cables binding the cargo are tightened. Typically,
3 o center beam rail cars are not enclosed and the plastic sheet 514 is
intended to protect
the goods 516 from exposure to moisture, dirt, and sand that is encountered
during
transit.
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When the car is in motion it vibrates and changes speed and direction and
the cargo moves relative to the car's structure. The upper corner of the
stacked
cargo 500 in contact with the lateral face 93a of the top chord 28 of the
center
beam 24 moves relative to the lateral face in directions generally parallel to
the
5 face. While the protective sheeting 514 can be damaged by sharp edges of
various
elements of the center beam structure, the present inventors concluded that
friction
between the protective sheeting 514 and the lateral face 93a of the top chord
28 can
cause the sheeting to be abraded, eventually exposing the goods 516 to the
elements. The goods 516 transported by center beam rail cars are often wood
10 products and the value of the cargo can be substantially reduced by the
presence of
dirt and sand embedded in the surface of the wood or by discoloration of the
wood
by mold or mildew following exposure to moisture.
To protect the sheeting 514 from wear and, thereby, to protect the
goods 516 from the elements, the lateral faces 93a of the top chord 28 of the
center
15 beam 24 comprise a material presenting a smooth surface and a low
coefficient of
friction to the protective sheeting 514 covering the goods S 16. The lateral
surface 93a of the top chord 28 may be constructed of any material exhibiting
a
relatively low coefficient of friction with the protective cargo sheeting
which
commonly comprises polyethylene but which may comprise another common
2 o plastic. One suitable material for the lateral face 93a of the top chord
is an ultra-
high molecular weight polyethylene.
In one embodiment, the lateral face 93a of the top chord 28 is an outer
surface of a top chord cover 520 that is interposed between the lateral wall
512 of
the top chord tube 29 and the plastic sheeting 514 covering the goods 516.
Lateral
displacement of the cargo 500 is resisted by the compression of the top
chord cover 520 between the cargo 500 and the lateral wall 512 of the top
chord
tube 29. The top chord cover 520 for the top chord 28 is selectively removable
to
permit the cover to be replaced when worn or damaged and to permit covers
comprising materials that are particularly suited to certain cargoes or cargo
3 o coverings to be installed when appropriate.
In a first embodiment, the top chord cover 520 comprises, generally, a
channel-shaped cross-section having a channel base 522 having one side that
forms
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the lateral face 93a and covering substantially all of the lateral wall 512 of
the top
chord tube 29. The top chord cover 520 also comprises a top leg 524 and a
bottom
leg 526 that fit over portions of the top 508 and bottom 510 walls of the top
chord
tube 29. The top chord cover 520 is selectively affixable to the top chord
tube 29
and clamped to the top chord tube by nuts 527 that engage studs 528 welded to
the
top wall 508 and bottom wall 510 of the tube. Clamping the top chord cover 520
to
the top wall 508 and bottom wall 510 of the top chord tube 29 presents a
smooth,
low friction, lateral face 93a of the top chord 28 for contact with the cargo
500.
Referring to FIG. 16, in another embodiment, a top chord cover 600 is
to adhered to a lateral wall 512 of the top chord tube 29 with an adhesive 602
compatible with the material of the top chord cover and the top chord tube.
The top
chord cover 600 may be selectively removed from the lateral wall 512 by
breaking
the adhesive joint.
Referring to FIGS. 17 and 18, in still another embodiment, the top chord
cover 650 comprises, generally, a channel of C-shaped cross-section with a
pair of
sides 652 each having one surface that forms the lateral face 93a and a second
surface supported by and substantially coextensive with the outer surface of
the
lateral wall 512 of the top chord tube 29. The top chord cover 650 also
comprises a
web 654 that connects the sides 652 and which extends substantially coplanar
to the
2 o top wall 508 of the top chord tube 29 when the cover is installed. A
bottom leg 656
extends laterally from each of the sides 652, fitting over the corner formed
by the
bottom surface and the lateral wall S 12 and extending over a portion of the
bottom
surface of the top chord tube 29 in an interfering relationship. The web 654
and the
sides 652 of the top chord cover 650 are sufficiently flexible to permit
installation
of the top chord cover 650 by separating the bottom legs 656 to create a gap
sufficiently wide to permit the width of the top chord tube 29 to pass between
the
ends of the legs. When released, the top chord cover 650 returns to its
original
shape substantially encircling the perimeter of the cross-section of the top
chord
tube 29. Additional security for the top chord cover 650 is provided by nuts
527
3 o engaging studs 528 welded to the bottom wall 510 and clamping the legs 656
to the
bottom of the top chord tube 29. The top chord cover 650 provides a smooth
upper
surface eliminating traps for dirt and moisture, reduces the number of parts
to
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simplify installation and repair, and presents a smooth, low friction, top
chord
lateral face 93a for contact with the cargo 500.
The railroad car 10 with the structure described above is amply strong yet
lighter in tare weight than previously known railroad freight cars of
depressed floor
center beam construction, and thus is potentially cheaper to construct and to
operate.
The terms and expressions which have been employed in the foregoing
specification are used therein as terms of description and not of limitation,
and there
is no intention, in the use of such terms and expressions, of excluding
equivalents of
1o the features shown and described or portions thereof, it being recognized
that the
scope of the invention is defined and limited only by the claims which follow.