Intermodal container including double lap shear joints

A vehicle body, such as an intermodal shipping container, including upper and lower rail assemblies at the longitudinal corners of the body. The lower rail assemblies interconnect the side walls of the container with the bottom wall of the container, and the lower rail assemblies each sandwich and are adhesively bonded to the walls they interconnect to form double lap shear joints that secure the walls together without the use of fasteners and that provide double adhesive seals to make the container weathertight.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention relates generally to vehicle bodies, such as intermodal 
shipping containers for example, and more particularly to vehicle bodies 
made substantially of non-metallic materials and to joints for joining the 
walls of such vehicle bodies. 
2. Reference to Prior Art 
Intermodal shipping containers are widely used in the freight transport 
industry where different modes of transport (e.g., sea, rail and roadway) 
are used to ship the containers from one destination to another. 
Intermodal containers constructed using metal components are well known. 
One known container construction includes top, side and bottom walls 
joined by metal upper and lower rails that are attached to the walls with 
fasteners. The joints between the side walls and the bottom wall at the 
lower rails are subjected to particularly high loads during use of the 
container. Those joints also include seams and fastener holes that present 
potential leak sites that make the container susceptible to water (and 
air) leakage which can seriously damage the freight inside the container. 
That potential is heightened by the failure or loosening of fasteners and 
by possible corrosion of metal parts which can be particularly damaging in 
the harsh and varied environments in which intermodal containers are 
expected to perform. Additionally, the use of metal increases the tare of 
the containers to thereby reduce payload capacity. 
In response to problems associated with intermodal containers (and other 
vehicle bodies such as trailers and truck bodies, for example) made of 
metallic materials, the assignee of the present invention (hereinafter 
"Assignee") has undertaken the development of vehicle body structures 
which are made substantially entirely of lightweight, corrosion resistent, 
fiber-reinforced plastic composite material. Examples of containers 
produced using such non-metallic material are provided in U.S. Pat. No. 
5,178,292 issued Jan. 12, 1993 and U.S. Pat. No. 5,255,806 issued Oct. 26, 
1993, both of which have been assigned to the Assignee. Those containers 
include composite skin members which are adhesively bonded to one another. 
The skin members also overlap and are adhesively bonded to container frame 
components. 
The Assignee has also developed refrigerated or insulated intermodal 
containers (ISO and domestic) including walls constructed of interfitting 
modular panels. The panels each include spaced apart skin members, one 
side of each of which is adhesively bonded to the upper and/or lower rails 
of the container. Such a container is illustrated in U.S. patent 
application Ser. No. 08/065,925, filed May 21, 1993. 
The Assignee's above-mentioned intermodal containers are lightweight and 
weathertight when compared to standard intermodal containers made 
substantially of metal, and Assignee's intermodal containers are 
structurally capable of withstanding the loads encountered during service. 
Additionally, the degree of weathertightness achieved by the use of 
adhesive material seals and joints makes those containers substantially 
airtight. This is especially desirable for shippers that fill containers 
with inert gas, to stop the ripening process of produce, for example. 
SUMMARY OF THE INVENTION 
The invention provides a lightweight, noncorrosive vehicle body 
construction having an improved arrangement for interconnecting the walls 
thereof to provide a structurally sound and sealed body construction. In 
its continuing efforts to improve its products, Assignee has replaced 
single lap joints between some of the frame components (i.e., the lower 
rails) and the walls (i.e., the side and bottom walls) with "double lap 
shear joints". The double lap shear joints provide improved load carrying 
and safety factors (especially in the highly loaded areas of the lower 
rails) relative to single lap joints as used in prior art containers made 
of non-metallic materials, and it is believed that the double lap shear 
joints will permit greater load-carrying capacity due to the greater 
inherent strength of those joints. Applicants also believe that the double 
lap joints increase resistance to loads tending to peel the joints apart, 
thereby providing even better structural characteristics that increase the 
durability and life of the vehicle body. Additionally, the double lap 
shear joints provide positive adhesive seals at the wall interfaces. 
More particularly, the invention provides a vehicle body, such as an 
intermodal container for example, having double lap shear joints formed at 
selected locations between the walls and the frame component(s) of the 
vehicle body. The walls include panel or skin members that are sandwiched 
by the frame component to facilitate adhesively bonding both sides of the 
skin members to the frame component, thereby providing a double lap bond 
and double seal. In one embodiment, the side walls of the vehicle body are 
constructed of one or more skin members that are joined to the lower rails 
with double lap shear joints. The lower rails include rail sections that 
sandwich the skin member(s) and that are bonded to the opposite sides of 
the skin member(s) to form the double lap shear joints. The use of double 
lap shear joints may also be employed at other locations in the vehicle 
body, such as, for example, at the joints between the top wall and the 
upper rails and at the joints between composite lower crossmembers in the 
bottom wall and the lower rails. 
In another embodiment the invention provides an insulated or refrigerated 
intermodal container (or other vehicle body) including side walls having 
interior and exterior skin members separated by an insulating space. Each 
side wall is connected to one of the lower rails with a double lap shear 
joint formed by bonding separate inner and outer lower rail sections to 
respective inwardly and outwardly facing surfaces of the interior skin 
member. The interior skin member is thus sandwiched between the rail 
sections. The outer rail section doglegs between the interior and exterior 
skin members to conveniently seal off the lower end of the side wall 
(i.e., the insulating space) against moisture or other foreign matter. 
The intermodal container also includes floor crossmembers that form part of 
a bottom wall of the vehicle body and that are also connected to the lower 
rail to transfer loads from the floor to the side wall. Such loads are 
then transmitted, at least in part, to an upper rail via the interior and 
exterior skin members of the wall. In particular, in one embodiment the 
side wall is connected to the upper rail by a single lap joint between the 
upper rail and the exterior skin member. Loads are therefore transferred 
from the interior skin member to the exterior skin member before being 
transferred to the upper rail. The load transference between the interior 
and exterior skin members occurs along the height of the side wall and the 
loads are transferred by integral webs interconnecting those skin members 
and by an insulating core, if any, provided between the skin members. 
Thus, any damage to the exterior skin member that might result from normal 
use of the container (i.e., such as might occur from bumping the container 
with other containers or striking the container with rocks or other 
foreign objects) will only delay the load transition between interior and 
exterior skin members or redistribute the load transition. Therefore the 
effect of such damage on the structural integrity of the container is 
minimized. The inner skin member(s) (i.e., the primary load carrying 
member(s)) is also inherently protected from damage by virtue of its 
unexposed position on the interior of the container. Additionally, the 
outer rail section inherently increases the amount of material at the 
double lap shear joint and therefore provides additional protection at the 
lower portion of the side wall. 
Various other features and advantages of the invention will become apparent 
to those skilled in the art upon review of the following detailed 
description, claims and drawings.

Before one embodiment of the invention is explained in detail, it is to be 
understood that the invention is not limited in its application to the 
details of construction and the arrangement of components set forth in the 
following description or illustrated in the drawings. The invention is 
capable of other embodiments and of being practiced or being carried out 
in various ways. Also, it is to be understood that the phraseology and 
terminology used herein is for the purpose of description and should not 
be regarded as limiting. 
DESCRIPTION OF PREFERRED EMBODIMENTS 
Illustrated in FIG. 1 is a freight hauling vehicle or container body 10 
embodying the invention. While the container body 10 can be integrated 
into a variety of freight hauling vehicles, such as to serve as a rail 
car, a trailer or truck body or a freight shipping container, in the 
illustrated embodiment the container body 10 is an intermodal shipping 
container. More particularly, the container 10 is a refrigerated domestic 
intermodal container (i.e., RDC container) having a length of about 48 
feet. However, as will be apparent to those skilled in the art upon review 
of the following, the invention is applicable to vehicle or container 
bodies of various sizes and lengths (including ISO and Domestic intermodal 
containers and variously sized trailer and truck bodies) used in various 
applications (including refrigerated, insulated or dry applications). 
The RDC container 10 as well as other embodiments discussed below are 
preferably made substantially entirely of non-metallic materials. In 
particular, in preferred embodiments many of the components of the 
containers in accordance with the present invention are made with 
fiber-reinforced plastic material and are preferably formed via 
pultrusion. Pultrusion apparatus and methods known in the art are 
disclosed in U.S. Pat. No. 3,769,127 issued Oct. 30, 1973 to Goldsworthy 
et. al., and in U.S. Pat. No. 3,556,888 issued Jan. 19, 1971, and U.S. 
Pat. No. 2,871,911 issued Feb. 3, 1959, both to Goldsworthy, all of which 
are incorporated herein by reference. Briefly, the pultrusion process 
involves passing fibrous material through a resin bath and pulling the 
resulting composite through a die wherein the material is formed into the 
desired shape and cured. 
The composite material used to produce the pultruded components includes a 
resin binder material, such as polyester resin which is sold by 
Owens-Corning as Model No. E606-6-12. Other suitable resins include, for 
example, various polyesters, polypropylenes, phenolics, epoxies, and 
polycarbonites. The composite material also preferably includes a 
multi-directional array of filamentary material dispersed throughout the 
cross-section of the pultrusion. A suitable filamentary material is known 
in the industry as 113E-glass roving. Possible filamentary material 
substitutes include, for example, glass fibers known in the industry as 
E-, S-, S2- and A-glass fibers, as well as carbon, graphite, boron, and 
aramid fibers. If desired, the different filamentary materials can be 
mixed in the same part to customize the structural characteristics of that 
part to its particular application. 
The RDC container 10 includes opposite side walls 12 and 14 that are mirror 
images of each other. Hence, only side wall 12 is discussed in detail. As 
shown in FIGS. 1 and 2, side wall 12 includes interfitting modular side 
panels 16 that are preferably adhesively bonded to one another with a 
structural adhesive material A. An example of a suitable adhesive material 
is a methacrylate adhesive sold by ITW Adhesive Systems of Farmington 
Hills, Mich. under the model designation AO420. 
As shown in FIG. 2, each of the side panels 16 includes a hollow panel 
member 18 that is preferably pultruded of fiber-reinforced plastic 
composite material. The interior space within the panel member 18 is open 
at the bottom (see FIGS. 5 and 6) and at the top (see FIG. 8) and is 
filled with a suitable insulation such as foam insulation 20. The panel 
member 18 includes laterally spaced apart interior and exterior sheet-like 
panels or skin members 22 and 24, respectively, interconnected by integral 
webs 26. The interior and exterior skin members 22 and 24 each include 
inwardly and outwardly facing surfaces 28 and 30, respectively. For 
reasons more fully explained below, the interior skin member 22 of each 
side panel 16 (see FIGS. 5 and 6) extends below the exterior skin member 
24. Otherwise, the side panels 16 are substantially as shown and described 
in aforementioned patent application Ser. No. 08/066,391 which is herein 
incorporated by reference. 
To join the side walls 12 and 14 with a top wall 31 (partially shown in 
FIG. 8) each of the side walls 12 and 14 is provided with an upper rail 
assembly 32 (only one of which is shown). While the upper rail assemblies 
32 can have other configurations, in the illustrated embodiment the upper 
rail assemblies 32 (and the top wall) are as described in aforementioned 
patent application Ser. No. 08/066,391. As shown in FIG. 8, each upper 
rail assembly 32 includes a hollow upper rail 33 filled with the 
insulation 20 and a pultruded angle member 33a bonded with adhesive 
material A to the upper rail 33 and the interior wall skin 22. The upper 
rail 33 includes a flange 33b that is bonded with adhesive material A to 
the exterior wall skin 24. Thus, angle member 33a and the flange 33b 
sandwich one of the side panels 16. 
The side walls 12 and 14 are also provided with (FIG. 3) lower rail 
assemblies 34 for joining the side walls and a bottom wall, as is further 
explained below. The components of the lower rail assemblies 34 are 
preferably also pultrusions made of fiber-reinforced plastic composite 
material, and each lower rail assembly 34 is assembled on one of the side 
walls 12 and 14 as an integral part thereof, preferably without the use of 
fasteners. In particular, as shown in FIGS. 5 and 6, each lower rail 
assembly 34 includes a plate-like first or inner rail section 36 bonded 
with adhesive material A to the inwardly facing surfaces 28 of the 
interior skin members 22. Each lower rail assembly 34 also includes a 
second or outer rail section 38 that is generally doglegged (or S-shaped) 
and that fits over the exposed lower end portions of the side panels 16 to 
seal the bottoms of the side walls 12 and 14. The outer rail section 38 
includes an outer leg 40 bonded with adhesive material A to the outwardly 
facing surfaces 30 of the exterior skin members 22 and an inner leg 42 
bonded with adhesive material A to the outwardly facing surfaces 30 of the 
interior skin members 22. A third or middle portion 44 extends between the 
outer and inner legs 40 and 42 to close the bottoms of the side panels 16. 
The joint thus formed between each lower rail assembly 34 and the 
corresponding one of the side walls 12 and 14 includes a double lap shear 
joint 46 in which the interior skin members 22 of the side wall are 
sandwiched between and fixed via adhesive bonds to the inner and outer 
rail sections 36 and 38. 
The RDC container 10 also includes a bottom wall 48 which in the 
illustrated embodiment is provided with (FIG. 3) a tunnel section 50 at 
its front end to accommodate a chassis (not shown) to permit the RDC 
container 10 to be transported over the road in a manner known in the art. 
The bottom wall 48 also includes (FIGS. 3 and 4) laterally extending 
I-shaped crossmembers 52 spaced at regular intervals along the length of 
the RDC container 10. The crossmembers 52 can be made of metal or can also 
be pultruded of composite material. 
Means are provided for attaching the crossmembers 52 to the lower rail 
assemblies 34 to interconnect the side walls 12 and 14 and the bottom wall 
48. In the illustrated arrangement, the means for attaching includes 
(FIGS. 5 and 6) T-shaped clips 54 (only one is shown) attached to the 
opposite ends of the crossmembers 52 via suitable mechanical means such as 
adhesive material and/or fasteners 56. The T-shaped clips 54 or angles are 
also fixed to the lower rail assemblies 34 via adhesive material and/or 
additional fasteners 56 extending through the double lap shear joints 46. 
In the embodiment illustrated in FIGS. 1-6, loads exerted on the bottom 
wall 48 are transmitted to the side walls 12 and 14 through the double lap 
shear joints 46 such that the primary loads are transferred substantially 
entirely to the interior skin members 22. The primary loads, at least in 
part, are then transferred to the exterior skin members 24 by the webs 26 
of the panel members 18 (and also to a lesser degree by the core of 
insulation 20). That load transference takes place over the height of the 
panel members 18 and therefore localized damage to the exterior skin 
members 24 (or the interior skin members 22) will result in delay or 
redistribution of the load transition between interior and exterior skin 
members 22 and 24. Therefore, such damage has minimal effect on the 
structural integrity of the RDC container 10. Additionally, since the 
inner skin members 22 are on the inside of the container 10 they are 
inherently protected from damage. 
The bottom wall 48 also includes a floor section 58 that is supported on 
the crossmembers 52. The floor section 58 includes (FIG. 4) spacer tubes 
or stringers 60 which are preferably pultruded of fiber-reinforced plastic 
composite material and which are positioned on top of the crossmembers 52. 
The floor section 58 also includes a suitable floor 62, such as the 
inverted composite T-duct floor, for example, which is explained 
hereinafter, supported on top of the stringers 60. Foam insulation 64 is 
provided in the spaces between the stringers 60, and a subpan 66 is 
provided between the floor section 58 and the crossmembers 52 to protect 
the insulation 64. The subpan 66 is preferably made of a non-metallic 
material. An example of a suitable material is sold under the name 
KEMLITE. 
To seal the joints between the bottom wall 48, and particularly the floor 
section 58, and the side walls 12 and 14, each of the lower rail 
assemblies 34 is provided with means for interfacing with the floor 
section 58. In the illustrated arrangement each of the interfacing means 
includes a flexible sealing member 68 that is movable between flexed and 
unflexed positions and that is preferably made of thermoplastic polymer 
material. As shown in FIG. 7, the sealing member 68 includes a 
wedge-shaped upper flange 70 and a lower flange 72 that (FIGS. 5 and 6) 
fit over the crossmembers 52 in the area above the clips 54. The subpan 66 
overlaps and is adhesively bonded to the upper flange 70. The sealing 
member 68 also includes an upper portion 74 which (FIG. 7) is angled when 
in the unflexed state. 
When the bottom wall 48 and the side walls 12 and 14 are drawn together 
during assembly, the upper portion 74 of each sealing member 68 is flexed 
toward a vertical position (see FIGS. 5 and 6). The ultimate orientation 
of the upper portion 74 depends on the fit-up tolerance between the 
corresponding one of the side walls 12 and 14 and the bottom wall 48. 
Adhesive material is preferably applied to the upper portion 74 of each 
sealing member 68 prior to fit-up to bond the sealing members 68 to the 
lower rail assemblies 34. The resulting joints between the side walls 12 
and 14 and the floor section 58 are substantially leakproof. If desired, a 
scuff plate 76 can be bonded to the lower part of each side wall 12 and 
14. 
The RDC container 10 also includes a frame structure which incorporates the 
upper and lower rail assemblies 32 and 34, as well as the crossmembers 52 
and the tunnel section 50. The frame structure also includes (FIG. 1) 
vertically extending posts 78 and (FIG. 3) horizontally extending beams 80 
interconnecting the upper and lower rail assemblies 32 and 34. To 
facilitate attachment of the RDC container 10 to other containers or to a 
support surface, such as the deck of a ship, a railroad well car or a 
trailer chassis, standard metallic lock-receiving fittings 82 are provided 
at standard locations on the frame structure. 
Illustrated in FIGS. 9 and 10 is a container 84 in accordance with a second 
embodiment of the invention. While the container 84, like the RDC 
container 10, can be a domestic container, an ISO container, or a 
container of any other desirable size, in the illustrated arrangement the 
container 84 is a 40' long ISO dry van container. 
The ISO container 84 includes (FIGS. 10 and 12) opposite side walls 86 and 
88 that are preferably mirror images of each other. The side walls 86 and 
88 are constructed of overlapping side skin members 90 (see FIG. 11) that 
are adhesively bonded to one another and that are preferably thicker than 
the skin members 22 and 24 of container 10. Each of the side skin members 
90 also includes inwardly and outwardly facing surfaces that respectively 
form portions of inwardly and outwardly facing surfaces 92 and 94 of the 
side walls 86 and 88. In a preferred embodiment, the side skin members 90 
are pultruded of fiber-reinforced plastic composite material, however, in 
other embodiments other materials could be used. 
Each of the side walls 86 and 88 also includes reinforcing ribs 96 
adhesively bonded to the side skin members 90 to reinforce those members. 
Each of the ribs 96 includes a rib section 98, which in the illustrated 
arrangement is made of a thermoplastic polymer material, and a pultruded 
composite insert 100. 
Each of the side walls 86 and 88 is preferably assembled as a subassembly 
including part of an upper rail assembly 102 which acts as a means for 
joining the corresponding one of the side walls 86 and 88 to a top wall, 
as is further explained below. As shown in FIG. 13, each upper rail 
assembly 102 includes a tubular upper rail section 104 having successive 
upper step portions 106 and 108 and a pair of inwardly extending and 
downwardly offset flanges 110 and 112. The upper rail section 104 also 
includes an inner surface having successive step portions 114 and 116. 
Step portion 116 is overlapped by side skin members 90 which are bonded 
thereto with adhesive material A. Each upper rail assembly 102 also 
includes a second rail section or lap plate 118 bonded with adhesive 
material A to the inwardly facing surface 92 of the corresponding side 
wall and to the step portion 114. The side skin members 90 are thus 
sandwiched by the upper rail assembly 102 to provide a double lap shear 
joint 120 between the upper rail assembly 102 and the corresponding one of 
the side walls 86 and 88. The components of each upper rail assembly 102 
(i.e., the upper rail section 104 and the lap plate 118) are preferably 
pultruded of fiber-reinforced plastic composite material. 
The subassembly of each of the side walls 86 and 88 also preferably 
includes part of a lower rail assembly 122, the lower rail assemblies 122 
acting as a means for joining the side walls 86 and 88 to a bottom wall 
124, as is further explained below. As shown in FIG. 13, each lower rail 
assembly 122 includes a main lower rail section 126 having a plate-like 
lower portion 128 and an upper portion 130. The upper portion 130 includes 
an outwardly projecting leg 132, a pair of opposed inwardly projecting 
flanges 134, and a recessed inwardly facing surface portion 136 bonded 
with adhesive material A to the outwardly facing surface 94 of the 
corresponding one of the side walls 86 and 88. Each lower rail assembly 
122 also includes an inner angled section 138 that is adhesively bonded 
over the inwardly facing surface 92 and to the upper portion 130. The side 
skin members 90 are thus sandwiched by the lower rail assembly 122 to 
provide a double lap shear joint 140 between the lower rail assembly 122 
and the corresponding one of the side walls 86 and 88. The components of 
each lower rail assembly 122 (i.e., the lower rail section 126 and the 
angled section 138) are also preferably pultruded of fiber-reinforced 
plastic composite material. 
The ISO container 84 also includes a top wall 142. In the illustrated 
arrangement, the top wall 142 includes (FIG. 9) longitudinally extending 
sheet-like top skin members 144 that can be pultruded of fiber-reinforced 
plastic composite material. In one embodiment, the top skin members 144 
overlap and are adhesively bonded to one another, however, in the 
illustrated arrangement the top skin members 144 are adhesively bonded to 
one another using a pultruded splice plate 145 as well as adhesive 
material. The top skin members 144 extend between the upper rail 
assemblies 102 and each overlaps and is bonded with adhesive material A to 
the step portion 108 (see FIG. 13) of one of the upper rail assemblies 
102. To provide a double lap shear joint 120 between each of the upper 
rail assemblies 102 and the top wall 142, each of the upper rail 
assemblies 102 includes a rail section in the form of a lap plate 149 that 
is preferably pultruded of fiber-reinforced plastic composite material. As 
shown in FIG. 13 the lap plate 149 is bonded to the step portion 106 and 
to one of the top skin members 144. The top wall 142 also includes 
laterally spaced apart roof bows 148 (one is partially shown in FIG. 13) 
supporting the top skin members 144. The roof bows 148 are supported on 
and adhesively bonded to the flange 112 of each upper rail assembly 102. 
The ISO container 84 also includes the aforementioned bottom wall 124. As 
shown in FIG. 10, the bottom wall 124 includes laterally extending 
I-shaped crossmembers 150 and means for attaching the crossmembers 150 to 
the lower rail assemblies 122. In the illustrated arrangement the 
attaching means includes L-shaped clips 152 each adhesively bonded between 
one of the crossmembers 150 and the inside of the lower portion 128 of one 
of the lower rail assemblies 122. Each crossmember 150 is preferably 
provided with a pair of clips 152 on each of its opposite ends to form a 
double lap shear joint with each lower rail assembly 122. The crossmembers 
150 are also preferably adhesively bonded to the lowermost flanges 134. 
Both the crossmembers 150 and the clips 152 are preferably pultruded of 
fiber-reinforced plastic composite material. 
The bottom wall 124 also includes a floor section 154 supported on the 
crossmembers 150. The floor section 154 includes (FIG. 12) floor panels 
156 which are preferably integrally pultruded of fiber-reinforced plastic 
composite material. Each floor panel 156 has a generally planar support 
skin or plate 158 that overlaps and is adhesively bonded to the support 
plate 158 of an adjoining floor panel. Each of the floor panels 156 also 
includes downwardly extending reinforcing members 160 each having an 
inverted "T" shape. The reinforcing members 160 can, if desired, be 
adhesively bonded to the tops of the crossmembers 150. 
To seal the interface between the bottom wall 124 and the side walls 86 and 
88, the support plates 158 of the outermost floor panels 156 (see FIG. 13) 
overlap and are bonded with adhesive material A to the uppermost flanges 
134. The angled rail sections 138 are also bonded with adhesive material A 
to the upper surfaces of the support plates 158 to sandwich the support 
plates 158 and to provide a double lap shear joint 162 between each of the 
lower rail assemblies 122 and the bottom wall 124. 
The ISO container 84 also includes a frame structure which incorporates the 
upper and lower rail assemblies 102 and 122, the crossmembers 150 and 
(FIG. 10) a tunnel section 164. That frame structure also includes 
vertical posts 166 and horizontal beams 168 that are provided at their 
intersections with standard lock-receiving fittings 170 for attaching the 
ISO container 84 to a support surface or another container. 
Illustrated in FIGS. 14 and 15 is the bottom wall/side wall interface area 
of a container including an alternative lower rail construction. In 
particular, that interface area includes a lower rail assembly 172 
including a main rail section 174. The main rail section 174 includes the 
above-mentioned flanges 134 and an outwardly facing surface 176 to which 
the inwardly facing surface 92 of a side wall is adhesively bonded. The 
lower rail assembly 174 also includes an outer rail section 178 having a 
recessed surface portion 180 adhesively bonded to the outwardly facing 
surface 94 of the side wall. The outer rail section 178 is also adhesively 
bonded at its lower end to the main rail section 174. Thus the side wall 
skin 90 is sandwiched between and adhesively bonded to the main and outer 
rail sections 174 and 178 to form a double lap shear joint 182. The lower 
rail assembly 174 also includes an angled inner rail section 184 that is 
similar to inner rail section 138, except that inner rail section 184 is 
not bonded to the side skin members 90. 
Illustrated in FIGS. 16-19 are sectional views showing modifications to the 
container structure illustrated in FIGS. 11-13. In particular, those 
modifications include a modified side wall 186 including (FIG. 16) closely 
adjacent or abutting pultruded side skin members 190 arranged in coplanar 
relation. To join the side skin members 190, the side wall 186 is provided 
with splice members 192 (only one is shown) that extend the length of the 
side skin members 190. As shown in FIG. 16, each splice member 192 is 
adhesively bonded over adjoining side skin members 190 to form a splice 
joint 194. In a preferred embodiment, the side skin members 190 and the 
splice members 192 are all pultruded of fiber-reinforced plastic composite 
material, however, in other embodiments other materials could be used. 
The modified side wall 186 also includes side posts or stiffeners 196 
adhesively bonded to the side skin members 190 to reinforce those members. 
Each of the stiffeners 196 is provided with a hat portion 198 having a 
thickened crown 200 for added reinforcement and flanges 202, and each of 
the stiffeners 96 is also pultruded of fiber-reinforced plastic composite 
material. As shown in FIG. 16, intermittent ones of the stiffeners 196 are 
placed over each splice joint 194 to protect that joint. In the event of 
damage to one of the stiffeners 96, that stiffener can be easily repaired 
by adhesively bonding a patch member 204 thereover. As also shown in FIG. 
16, the patch member 204 has an inside configuration that matches the 
outside configuration of the stiffeners 196. 
The modified side wall 186 also includes an upper rail 230 which is 
preferably pultruded of composite material. As shown in FIG. 18, the upper 
rail 230 includes an inwardly extending flange 206 that supports the roof 
bows 148. The upper rail 230 also includes an inner surface 232 having a 
recessed surface portion 234. The inner surface 232 is overlapped by the 
side skin members 190 which are bonded thereto with adhesive material A, 
and the hat portion 198 at the top of each stiffener 196 is removed to 
permit the flanges 202 to extend up over the recessed surface portion 234. 
If desired, a pultruded angle member 208 is adhesively bonded to the 
inwardly extending flange 206 and the side skin members 190 to provide a 
double lap seal joint 209. 
The modified side wall 186 also includes a lower rail 210 which in the 
illustrated embodiment is pultruded of composite material and includes a 
Z-shaped cross-section. The lower end portions of the side skin members 
192 are adhesively bonded to the lower rail 210. 
The modified container structure of FIGS. 16-19 also includes a modified 
bottom wall 212. Bottom wall 212 includes generally T-shaped crossmembers 
214 (see FIG. 19) having flanges 216 that each extend downwardly at a 
slight angle indicated by reference numeral 218. The crossmembers 214 are 
attached to the lower rails 210 using clips 152 and adhesive material 
and/or fasteners 218 as described above. 
The bottom wall 212 also includes (FIG. 17) modified floor panels 220 which 
are preferably pultruded of fiber-reinforced plastic composite material. 
As shown in FIG. 18, the outermost floor panels 220 overlap a 
corresponding lower rail 210 and are adhesively bonded thereto. An 
optional pultruded angle member 223 can be bonded to the interface area of 
the floor panels 220 and the side skin members 190, if desired to provide 
a double lap seal 222 at that joint. The floor panels 220 are also 
preferably adhesively bonded to the tops of the crossmembers 214 (see FIG. 
19), and the angled flanges 216 provide additional space for adhesive 
material A. 
Advantageously, the upper and lower rail assemblies of the containers 
described herein provide double lap shear joints (i.e., double lap shear 
joints 46, 120, 140, 162, 182, 209 and 222) at the intersections of the 
container walls. The double lap shear joints are structurally very sound 
and also provide double adhesive seals against leakage. 
Various features and advantages of the invention are set forth in the 
following claims.