Improvement in the Construction of Trellis Girders or Beams.
Year: 1896

page_text: PROVISIONAL SPECIFICATION.
Improvement in the Construction of Trellis Girders or Beams.
JULES ARTHUR VIERENDEEL, of 45 rue St. Jacques, Bruges, Belgium Engineer,
do hereby declare the nature of this invention to be as follows:-
The object of this invention is to suppress the diagonal plate of the trellis-
girders or beams, whether of iron or steel, as used for bridges or any frame-work.
These girders or beams are, according to my system, composed exclusively of the
upper and lower soles and of the simple standards (vertical or inclined) connect-
ing them. There are no diagonal plates connecting the foot of one standard with
the head of the adjoining one. The standards are joined to the soles in a perfectly
rigid manner; they may, in some cases, have an intermediate connexion between
themselves, by means of several ribs arranged parallel to the soles.
The method of arrangement of the girders or beams, according to my system,
consists, substantially, in the suppression of the diagonal plate in trellis-girders and
obtaining a rigid assemblage or framing by a brace or otherwise, between the
soles and the standards, such assemblage or framing being firmer than can be
obtained by the use of the diagonal plate.
My invention comprises any and every application of trellis beams or girders,
solely composed of soles and standards without the intervention of diagonals; in
other words, every system of beams of the kind called trellis-girders, whereby the
use of diagonals is abolished.
The advantages offered by my system are of a two-fold nature:
1) Technical The girders or beams, according to my system, are firmer.
stronger, less yielding or flexible, less exposed to the attack of rust, less subject to
dynamical effects, and, lastly, more durable than those trellis-girders which are
constructed with diagonals or of solid parts.
2). Commercial.-The saving effected varies from 15 to 25 and 30 % as
compared with trellis-girders having diagonals or made of solid parts.
Datod this 11th day of September 1896
L. DUVINAGE,
Agent for Applicant.
Improvement in the Construction of Trellis Girders or Beams.
I, JULES ARTHUR VIERENDEEL, of 45 rue St. Jacques, Bruges, Belgium, Engineer,
do hereby declare the nature of this invention, and in what manner the same is
to be performed to be particularly described and ascertained in and by the
following statement:-
The object of the present invention consists of a new system of trellis girders or

page_text: beams in iron or steel for road, railway and foot-bridges (upper, lower or inter-
mediate floor) and for any timber and iron work whatever.
The process consists in the suppression of the diagonals, or in other words in
the suppression of all triangulation in the trellis-girders or beams, straight or
bent, in iron or steel, in the applications above-mentioned.
These trellis-girders or beams are, in my process composed exclusively of an
upper and a lower sole, and of uprights (vertical or inclined) joining them. There
are no diagonals connecting the foot of one upright with the head of another and it
is essentially upon the complete suppression of this diagonal connexion that my
invention dwells. The uprights are put together on the soles in a rigid way; they
are sometimes intermediately connected by one or several ribs, as will be seen in
course of the description.
The composition of the trellis-girders or beams of my system and the principal
types of these beams are represented in the annexed drawings.
Fig. 1 represents an elevation of a beam constructed after the principles
enunciated above, and whose upper sole takes a parabolical form.
Fig. 2 shows an elevation of a beam whose uprights are provided with an inter-
mediate rib; this beam also assuming a parabolical form at its upper part.
Fig. 3 is an elevation of a beam with parallel soles and whose uprights form
simple arches.
Fig. 4 represents an elevation of a beam of a bridge whose soles are rigid and
continue the whole length, as likewise do the three preceding ones, and composed
of a simple flat iron which is hollowed; and a section of the bridge-rail which the
beam forms.
Fig. 5 shows a beam whose uprights are made of cast steel.
Fig. 6 represents an elevation of a beam whose soles have articulations or joints
Fig. 7 shows an elevation of a similar beam which has joints at the lower sole
only.
Fig. 8 is a part elevation of an arched beam.
My process consists therefore, essentially in the suppression of the diagonal in
trellis girders or beams and its substitution by a rigid assemblage obtained by
a brace or otherwise, between the soles and the uprights an assemblage which
must be much more rigid and much more firm than in the case where diagonals
exist.
In Fig. 1 the soles are composed of flat irons A, A connected by means of angle
irons I on one side to a flat iron B strengthened by another flat iron r, and also
to another iron 13 to which is rivetted a flat iron arched, connected angularly
with the flat irons C, C forming the upright and strengthened by the flat
irons D, D.
The strengthening plates R, R are rivetted to the pieces A, A in the narrowest
of these flat parts, which are connected with the uprights C; these, cut according
to the bends of the parts r, are connected with the latter by means of corner pieces.
Fig. 2 represents a beam in which the uprights are intermediately connected by
a rib. This beam has also a parabolical form.
The soles are made in the same way as in the foregoing case, and the flat
irons R, R are here bent in such a way as to form ogives harmonizing with the
gothic style which we wish to give to the bridge.
In the example of beam shown by Fig. 3 the soles are made of one flat iron, M,
fixed to small soles N N by means of corner-pieces, and the flat iron N is bent at
its upper part in the form of a basket-handle.
The example represented in Fig. 4 is a beam composed of one flat of the height
of the beam itself; cut or rather hollowed so as to form uprights from its own sub-
stance and following a certain section, the bends of these uprights being
strengthened.
The curbs are always made of iron or flattened but the uprights may be of cast-
steel and then they are rivetted or bolted to the curbs as shown in Fig. 5.

page_text: The upper and lower soles of my beams may be rigid and continued from one
end of the beam to the other, or they may have a joint midway between two up-
rights as shown in Fig. 6.
This joint may even exist only on one of the two soles as shown in Fig. 7.
In any case, the best system is without any joint at all.
Fig. 8 represents an arched beam on the same principle.
The advantages which my system offers are:
1. Theoretical advantage-The calculation of my beams with jointed soles or
entirely rigid soles may be made without having recourse to any hypothesis what-
ever which is not at all the case with the ordinary trellis girders or of the rigid
type used in Europe. This calculation is quite as exact and quite as rigorous as
that of a latticed beam completely jointed of the type used in America.
My beam being entirely rigid possesses consequently the theoretical advantages
of the beams entirely articulated, and it avoids the practical inconveniences which
are: difficulty of execution and defective way of proceeding during current
service.
My beam being rigorously calculable offers more security than beams as they
are executed in Europe.
My system constitutes the collective type purely rational for beams in iron and
steel.
2. Technical Advantages: My system of trellis-girders or beams are firmer,
stronger and better connected in all their parts; they are less flexible, not so sub-
ject to vibrations, effects of rust and to the dynamic effects of trains or other
vehicles, in fact they are more durable than trellis-girders with diagonals (the
European or American type).
3. Commercial Advantage: Through the fact of my type of beams being more
exactly calculable and of its being a more rational construction than that of trellis-
girders and beams with diagonals, it results that it can realize the same solidity
with an economy of weight, from which results a financial economy of from, at
least, 10 to 25% according to their different use.
Having now particularly described and ascertained the nature of this said in-
vention and in what manner the same is to be performed I declare that what I
claim is :-
1. A new system of construction of bridges in iron and steel having for special
features the use of trellis-girders or beams exclusively composed of soles and up-
rights without the intervention of diagonals, in other words, without any
triangulation.
2. The suppression of diagonals in trellis girders.
3. The application of trellis girders without diagonals to all kinds of metallic
constructions.
11
T
1000
L. DUVINAGE,
Agent for Applicant.