PRIOR-REFERENCE
The present application is a Patent of Addition from a prior Patent Application
No.201831048771 for "MAN PORTABLE ASSAULT BRIDGE".
FIELD OF THE INVENTION
The present invention relates to a pre-engineered modular construction of "Half
Through Type" modular rigid truss bridge. More particularly, the present invention relates
to building a bridging and/or support structure and/or portable roadway, in particular for
constructing a corrosion free, pre-fabricated modular truss panels for a bridging and/or
module support structure usable as heavy weight vehicular bridge of any kind in order to
solve the problem of bridging the gap without intermediate support quickly for two-way
movement.
BACKGROUND OF THE INVENTION
In a typical "Bailey Bridge" there are provided a main girder at each side of the bridge
and lateral member between girders and timber decks supported on lateral member. The
main girders are formed from rectangular diamond shape panels of steel secured in vertical
direction so as to provide the required depth of girder and construction the width of road
way limited to 4250mm maximum using timber decks.
Bridges of the above type are often used as temporary structures where total fatigue
weakness have been determined, for example to replace bridges in disaster like destroyed
during flood, earthquake or any force majeure.
One inherent fault of such rectangular steel panel bridge trusses is that when adjacent

panels are pinned or bolted together at the top and bottom chord connections to form the
main supporting side girders of the bridge, sag of the side girders occurs due to heavy
weight.
Existing portable bridges or temporary bridges are not recommended for two-way
traffic and also not for permanent application due to total fatigue weakness which cannot be
used in certain areas such as urban and villages'areas etc.
Above type bridges particularly use for one way traffic only. If required two-way, two
set of "Baily Bridge" may be constructed. There is a need in the art for a modular quick
launch bridge that is also strong enough for two-way movement in addition to its strength
and fatigue life.
To overcome the above said situation, M/s GRSE invented (also patented, 201699) a
double lane portable steel bridge to replace the existing temporary bridges. But the carriageway
width was considered for 7.35m which is further revised as per latest standard of IRC 6 into
7.50m carriageway width with extra congestion factor became the prime necessity were
invented to withstand the maximum load carrying capacity i.e. IRC Class-70R and Class-A
loading both without using support of different element.
Also, earlier due to less traffic congestion upto Indian Road Congress (IRC)
Class-24R/Class-'B' loading, capacity of bridge was sufficient and thus stiffened steel decks
units had been invented by M/s GRSE to ready replacement of timber decks without changing
the load class & support of different element i.e. Stringer Plain and Stringer Button (earlier
used) kept unchanged and withstand the load capacity upto IRC Class-24R/Class-'B' Loading
only. This invention also relates to a two-way traffic modular steel bridge with time requirement
for bridges capable to carry heavy loaded two vehicles where goes on increased than the
earlier model with timber deck. Hence this invention is also capable of heavy duty decking

units became the secondary necessity. Based on above the new heavy duty steel deck units
were invented to withstand the maximum load carrying capacity i.e. IRC Class-70R and
Class-A loading both without using support of different element i.e. Stringer Plain & Stringer
Button and Kerb which is ready to assemble/ dismantle a steel bridge which is ideally suited
for spanning voids or chasms in difficult terrain which is much faster than the earlier model
with timber deck. Furthermore, this invention also relates to a two-way traffic modular steel
bridge which is using less decking components i.e. 'heavy duty crosswise lateral road bearer',
'heavy duty deck units', 'holding down bolts & saddle washer' than earlier gives easy to
handle and easy to launch/erect at site in gap and has the beneficial effects of having saving
manpower cost, reducing labour intensity, and having safety and reliability.
In order to avail further benefit and overcoming existing difficulties, the present
invention is developed to produce rigid permanent modular bridge structure ready solution
for different span of bridge.
OBJECTIVE OF THE INVENTION
There has long been a need for two-way portable modular truss bridges to cross a
gap with improved fatigue life and strength characteristic.
Thus, it is an object of the present invention to provide a two-way modular truss
bridge.
It is another object of the present invention to provide a two-way portable modular
truss bridge, strong enough for traffic of heavy vehicles and for transporting the heavy
equipments.
It is still another object of the present invention to provide a two-way portable modular

truss bridge, which can be easily and readily transported in pieces to a larger distance.
It is yet another object of the present invention that the bridge can be assembled
manually as a self-supporting, projecting structure by relatively few people without using
any special equipment/tool.
It is further another object of the present invention to provide a prefabricated bridge
which can be rapidly assembled and deployed entirely from the home side of the gap to be
crossed.
It is another an object of the present invention to provide a bridge which can be easily
rolled over Rollers placed on home side of the gap for launching the bridge across gap.
It is still another object of the present invention to provide a bridge that can be
quickly assembled and dismantled by manually.
It is yet another object of the present invention is to provide a quick solution to traffic
re-routing.
It is further an object of the present invention is to provide portable bridge which is
simple in construction, easy to install and to reduce time required in installing.
Further objective of the invention is to develop a Two-way heavy duty modular truss
bridge system which is simple in manufacturing and easy in assembly with less number of
sub-parts.
Further objective of the invention is to develop a Two-way heavy duty modular truss
bridge system which is cost effective.

SUMMARY OF THE INVENTION
The bridge is of through type the two-road-way being carried between two main
girders. The main girder is formed from identical rhombus truss section of welded construction
of 3.0m long, 2.0m high and 0.2m width and weighing 430Kg, each one being pin jointed to
its neighbour end to end together in linear succession,by means of pins or bolts on top and
bottom, to span a gap.
The form of rhombus-shaped bracing incorporated in the modular truss panel section
is such that for all practical purposes, the panel will act as an analogous composite plate
beam, the upper and lower end chords acting as flanges, and verticals and diagonal chords
as a plate web. The pin hole connection are manufactured to close tolerances and when
panels are connected end to end, the effect of local stress covered using high tensile structural
steel block at the end.
The load carrying capacity of rhombus truss panel section can be increased by
adding another row alongside and on top of the original truss module.
At present, similar type double lane portable steel bridge is being manufactured by
us using lower strength normal panel for temporary and semi-permanent application, which
can span to bridge a gap of 120ft max for heavy vehicular movement. Presently need is felt
for designing such modular portable bridges of longer span i.e. more than 120ft; for heavy
duty traffic with congestion factor.
In another embodiment, these construction can also further reinforced by the additional
normal and or heavy chord to the upper and lower element of truss module.
Yet another embodiment, the truss module are connected crosswise by lateral road

bearers. These rest on the bottom chord of the panels and carry the roadway superstructure.
They are tied to the Panels chords by Bolts and fix the trusses in position at the required
distances apart and the same time carrying the two-way heavy load capable roadway decking
system.
In another embodiment, the truss module are connected by heavy bracings frames
side by side with connections made through dowels into the dowels holes in the truss panel
by which achieve a strength directly proportional to the number of panels module and
secures the additional deformation of trusses in longitudinally compare to raker used in
conventional Bailey Bridge.
Yet another embodiment, the bases of the post ends are made to seat on base plate
carrying a plurality of bearings. Individual base and bearing assemblies are provided
separately for each girder truss at two ends of the bridge whether the construction of bridge
is of single or double or triple truss/ storey to maintain bearing pressure. Bearing carrying a
round bar upon which the half round bearing of the end post rests.
In such an arrangement, It has been determined that the most practical way of
achieving the object is with a truss and integrated panel design. A truss design allows long
spans to form a bridge without the need for intermediate supports and related support
foundations and a modular truss panel allows very light structure in addition to stiffness.
The present invention allows the fabrication of such structure using the full strength
of high tensile structural steel material that have higher strength because of high strength
capacity of alloy steel. As an additional feature, the invention does not allow costly anodizing,
bake paint finishing, and is configured for easy transportation of all components to the
erection site. The fabrication of all components could also be made by numerically controlled
technologies that could increase accuracy as well as minimizing the fabrication time.

In fabricating the modular truss panel as above described, the various truss members
are cut to length and located as per Fig.3 and joining the truss members by gusset.
Manufacturing of modular truss panel is simpler compare to convetional panel of Bailey
Bridge. All components are jig manufactured to precise tolerances and all components can
be handled by less person. Using horizontal, vertical, diagonal and other miscellaneous
gauges ensures all similar parts are completely interchangeable and the simplicity of
construction of parts ensures rapid construction.
Other and further advantages of the present invention will be obvious upon an
understanding of the illustrative embodiments about to be described or will be indicated in
the appended claims, and various advantages not referred to herein will occur to one skilled
in the art upon employment of the invention in practice.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
FIG. 1 is an elevation view of spanning two areas of different elevation so as to
provide access between the two areas in an embodiment of present invention.
FIG.2 shows a side view of a perspective view of the modular rigid truss bridge use
in system of the present invention.
FIG.3 is a perspective view of the modular rhombus high strength truss panel use in
a system of the present invention.
FIG.4 is a view of high strength modular truss panel as shown in FIG.2 with a
reinforcing chords joined together.
DETAIL DESCRIPTION
The high strength modular Truss Panel (1) is designed in such a way that are joined

end to end forming the girders and welded construction of 3.0m long, 2.0m high and 0.2m
width and weighing 430Kg. Each pair of girder are firmly held in plane by means of horizontal
bracing frame (9) and vertical bracing frame (10). The ends of panels are attached to post
end (4) hold by panel pins (8). The chords at top (14) and bottom (15) of the panel constructed
at one end in a male eye lug (16) and the other end in female eye lug (17) made of high
tensile structural steel with all welded joints enables the end to end connections of heavy
modular truss panels with high strength alloy steel Panel Pins (8) as stated in Fig.2 and
Fig.3.
The holes provided in top and bottom chords to take chord bolts (18) to connect
panel (1) together vertically forming multiple storey or connect reinforcement element (2) to
reinforce the girder.
In another embodiment, as stated earlier, Fig. 2 shows a sectional view of crosswise
by lateral road bearers, at the end of which there are firmly attached a plurality of panels (1)
by bolts. Two crosswise by lateral road bearers (3) seating are provided on the bottom chord
(15) of the modular truss panel to accommodate the crosswise by lateral road bearers (3)
and end verticals of modular truss panel have a holes on top for fixing of rakers or tie
channels (13). Also chords and verticals top and bottom holes are provided for fixing of
horizontal bracing frame (9) and Vertical bracing frames (10) along with crosswise by lateral
road bearers (3) to secure all trusses against wind forces.
Yet another embodiment, the post end of male and female attached to each of main
load bearing girder truss to transmit the end reaction of bridge to the bearing (6). The two
holes are provided at the top end of the post (4), the lower one for connecting to the bottom
storey panel and the upper one for the second storey panel. Connections are made with
panel pins (8). The bottom end of the post embodies a half round bearing block, which fits
over the bearing (6) as stated in Fig.2.

The bases of the post ends (4) are made to seat on base plate (5) carrying a plurality
of bearings (6). Base seating arrangement is designed to spread the load from the bearing
evenly over an area of the ground. It is welded steel assembly of which the centre forms a
deep-set platform to accommodate the bearing.Individual base (5) and bearing (6) assemblies
are provided at both ends of the girder truss of the bridge whether the construction of bridge
is of single or double or triple truss/storey to maintain bearing pressure.
Bearing (6) carrying a round bar upon which the half round bearing of the end post
rests. For bridges on fixed supports bearing can move slightly to assist in erection and also
allows for expansion of the bridge.
In another embodiment, heavy load carrying capacity steel decks (7) which passes the
two-way traffic are placed on and secured to crosswise by lateral road bearers (3) which are
firmly fixed to the girders by means of bearer bolts (19). Eye drop pattern are usually made
on the upper surface of such decks with effectively prevents skidding. Theses decks are held
in place without any lateral displacement with the help of holding down locking bolts. Steels
decks are of varying dimensions, namely long, short, side, end decks. Accordingly, heavy
curbs (14) are also made of varying lengths e.g. Long, Short and end curbs. The levels of
roads and top of the deck are substantially the same, which ensures a smooth two-way
traffic flow of vehicular traffic without any bump or jerk as stated in Fig. 2.
Panel pins (8) is used to connect modular truss panels together and join with
post end (4) and is made from special alloy steel of high yield strength, which is usually
electro-zinc plated to avoid corrosion. Panel pin inserted through holes in the male and
female lugs in the panels and secured with split pin.
Yet another embodiment,Tie channel (13) illustrated in Fig. 2 of the drawings secures
the all three truss in first storey of bridges at each end of all bridge configuration. It is fixed
to the modular truss panel and across post end with post bolt (20).

In another embodiment, horizontal (11) and vertical sway braces (12)both are fabricated
from angle section and fitted diagonally along each braces between the two lateral support
bearer per bay lending the strength and stability of the bridge structure in horizontal and
vertical both.
Although the foregoing description of the present invention has been shown and
described with reference to particular embodiments and applications thereof, it has been
presented for purposes of illustration and description and is not intended to be exhaustive
or to limit the invention to the particular embodiments and applications disclosed. It will be
apparent to those having ordinary skill in the art that a number of changes, modifications,
variations, or alterations to the invention as described herein may be made, none of which
depart from the spirit or scope of the present invention. The particular embodiments and
applications were chosen and described to provide the best illustration of the principles of
the invention and its practical application to thereby enable one of ordinary skill in the art to
utilize the invention in various embodiments and with various modifications as are suited to
the particular use contemplated. All such changes, modifications, variations, and alteration
should therefore be seen as being within the scope of the present invention as determined by
the appended claims when interpreted in accordance with the breadth to which they are
fairly, legally, and equitably entitled.

We claim :
1. A prefabricated two-way modular truss bridge, comprising of:
a modular truss from a plurality of interconnected rhombus shape modular truss
panel (1) made of material having higher strength and stiffness;
each said panel (1) having a parallel longitudinal top chord and bottom chord of
equal length with ends thereof rigidly connected to ends of said panel into the shape of a
rhombus;
each said panel having non-standard vertical and diagonal chords of equal length
with the ends connected with high strength gusset plate;
the ends of each longitudinal top chord and bottom chord is having tight fitting pin
holes therein;
each said truss having a second set of high strength panels, including at least one of
said panels, connected to said first set of panels and erected on top;
the panels in said second set of panels have the longitudinal top chord and bottom
chord;
wherein said top chords and bottom chords of both set of panels being connected at both
end of truss end-to-end with connecting elements placed in the holes in the ends thereof to
form a substantially straight line of chords.
2. The prefabricated modular truss bridge as claimed in Claim 1, wherein the

said mating blocks sockets have opening for insertion of metal pin or bolt to attach adjacent
panel together.
3. The prefabricated modular truss bridge as claimed in Claim 1, wherein the
reinforcing chords elements are attached to the top chord and bottom chord of each said
truss and to each other end-to-end.
4. The prefabricated modular truss bridge as claimed in Claim 1, wherein the
each said truss having a plurality of heavy duty crosswise lateral road bearer assembled two
per module on the truss of the bridge on which each bearer transfer the load on the ground
through modular truss panel.
5. The prefabricated modular truss bridge as claimed in Claim 4, wherein the
each said crosswise lateral road bearer having a plurality of heavy duty decks assembled per
module on the truss of the bridge on which each deck transfer the load on the ground
through crosswise lateral road bearer and modular truss panel.
6. The prefabricated modular truss bridge as claimed in Claim 1, wherein the
each said truss having a plurality of base plate and bearing assembled at both ends of the
bridge on which each girder transfer the load on ground.
7. The prefabricated modular truss bridge as claimed in Claim 1, wherein the
each said truss having a chords and verticals top and bottom holes are provided for fixing of
horizontal bracing frame and Vertical bracing frames along with crosswise by lateral road
bearers to secure all trusses against wind forces.
8. The prefabricated modular truss bridge as claimed in Claim 1, wherein the
each said truss having tie channel to secures the all trusses in first storey of bridges at one

end of bridge construction and another end connecting the vertical bracing frame to secures
the deformation of trusses.
9. The prefabricated modular truss bridge as claimed in Claim 1, wherein the
each said truss having horizontal and vertical sway braces to brace between the two lateral
road bearer per bay lending the strength directly proportional to the number of panels
module and stability of the bridge structure in horizontal and vertical both.
10. The prefabricated modular tru ss bridge as claimed in Claim 1, wherein the
bridge designed to be completely erected on rollers on one side of the gap to be bridged and
then launched across, without any temporary supports in the gap.