IMPROVEMENTS IN METALLIC BRIDGES
Year: 1859

page_text: LETTERS PATENT to Mathieu Castay, of Paris, in the Empire of France,
Clergyman, for the Invention of "IMPROVEMENTS IN METALLIC BRIDGES."
Sealed the 7th October 1859, and dated the 12th April 1859.
PROVISIONAL SPECIFICATION left by the said Mathieu Castay at the
Office of the Commissioners of Patents, with his Petition, on the 12th
April 1859.
I, MATHIEU CASTAY, of Paris, in the Empire of France, Clergyman, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
METALLIC BRIDGES," to be as follows:-
Metallic bridges formed with articulations are superior in elegance and less
costly than the bridges hitherto constructed, & at the same time are equally
strong as rigid structures. These bridges may be of a span of upwards of one
hundred yards, thus permitting of their application to large rivers, over ravines
for the establishment of railroads and other communications. 1st, the frame
or girder of a metal bridge consists of (see Fig. 1) three longitudinal rods
a, b, c, d, e, f, which may be of any length, & say from nine inches to a foot
wide, and about 1 inches thick, which dimensions should be arbitary. On
these longitudinal bars a, b, c, d, e, f, suitably placed in position, are bolted
metal plates of cast iron or other metal g & h, which by intersecting one
another form a series of lozenge-shaped divisions. If only one series is used,

page_text: as in Fig. 1, it is suitable to double the number of longitudinal bars a, b, c, d, e, f,
viz., to superpose a second bar a, b, on the inside, & the same with c, d, e, f,
so that the series of cross bars are bolted between longitudinal bars at top,
bottom, and the middle, making six in all. If instead of a single series of
plates, a second series is applied on the first, this second series may be fixed
to the longitudinal bars or rods a, b, c, d, e, f, by means of the same bolts which
fix the first series. On the contrary the under series may be fixed by means
of separate bolts to the longitudinal bars between the joints of the outer series
of lozenge-shaped plates, which arrangement will also form a double system,
but with the plates in juxtaposition. In either of these arrangements bars i
may be applied if necessary.
2ndly, the lozenge-shaped plates may be replaced by metal circles as in
Fig. 2, which overlap to a point sufficiently near their centres as at k. This
arrangement may be either on the single or double system, and either super-
posed or in juxtaposition as above described. In this arrangement the
diameters and the chords may be variously combined; but it is preferable, for
greater strength, that the metal circles should be always of exactly the same
size, the thicknesses of the sides and circles, as also the chords and diameters,
and the width, may be varied according to the span of the bridge.
3rdly, instead of circles half circles may be used intersecting each other
reciprocally as at Fig. 3, and forming a half circular, single, or double arrange-
ment either superposed or in juxtaposition.
4thly, metallic ellipses may be substituted for the half circles alternately
superposed and forming an elliptical single or double arrangement either
superposed or in juxtaposition.
5thly, for girders with solid sides when forming the sides, instead of rivetting
sheet iron plates of one thickness only, two or three thicknesses may be
superposed to form a single plate, and give it the required thickness, forming a
system of closed sides, consisting of plates in superposition.
6thly, the flooring of bridges. I place on one or other or on two of the
longitudinal bars or rods, but generally on the centre and the lower one at the
same time, and this especially when the girder is curved (it may be as well
to observe that on this system girders may be of any form). When the
flooring is of great width, cross pieces or diamond-shaped ties may be used to
stretch from one girder to the other.
7thly, the application of these improvements is simple, easy, and inexpensive.
For example, about fifteen yards from an abutment I erect a scaffolding
raised on supports fixed in the bed of the river or otherwise, the longitudnal
rods forming the girder are then thrown out from the abutment to the scaffold,

page_text: there only remaining to bolt on the outside the series of diamond-shaped
plates, circles, &c., fixing the nut of each bolt by means of a suitable key or
cotter, in proportion as the plates are applied; the cross bars of the flooring
must be bolted to the longitudinal rods, so that the roadway progresses at the
same time. When the bridge is constructed up to the scaffolding it is con-
tinued to a second stage, care being taken to increase the distance, and when
the second stage is attained in the same manner, the first scaffolding is
removed further off, and so on until the structure is completed.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Mathieu Castay in the Great Seal Patent Office on the 11th
October 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MATHIEU
CASTAY, of Paris, in the Empire of France, Clergyman, send greeting.
. WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twelfth day of April, in the year of our Lord
One thousand eight hundred and fifty-nine, in the twenty-second year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Mathieu Castay, Her special licence that I, the said Mathieu
Castay, my executors, administrators, and assigns, or such others as I, the
said Mathieu Castay, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN METALLIC BRIDGES," upon the condition (amongst others).
that I, the said Mathieu Castay, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the same
to be filed in the Great Seal Patent Office within six calendar months next
and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Mathieu Castay, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the Sheet of Drawings hereunto annexed,
and to the letters and figures marked thereon (that is to say):―

page_text: My Invention relates to a new system of cast and wrought-iron bridges
formed of parts jointed together, which bridges are superior to ordinary ones
in elegance, with saving in first cost, at the same time they are equally strong
and durable.
My improved bridges may be used for spanning broad rivers, chasms,
ravines, as also in forming railroads, as a substitute for the iron wire suspension
and stone bridges, which are often difficult to construct under such circum-
stances. These bridges may be formed of the length of one to two hundred
yards, or even longer.
BRIDGES FORMED OF LOZENGE-SHAPED PARTS JOINTED TOGETHER.
The frame or girder of a bridge constructed according to this part of my
Invention consists of (see Figs. 1, 4, 5, & 6,) three longitudinal bars a, b, c, d,
e, f, which may be of any required length and of various widths and thick-
nesses, according to the span of the structure intended, which dimensions
should be arbitrary. These three bars, as représented at Fig. 1, are united
together by a series of metal plates g, h, (Fig. 2,) of cast iron or other metal,
which intersect each other, and form diamonds or lozenge-shaped figures,
presenting, at the points of intersectionj, i, k, k, l, m, on the intermediate bar c, d,
angles of about 70 degrees. The three longitudinal bars render all movement
of the jointed plates in the direction of their length impossible. If only one
series is used, as in Fig. 1, it is advantageous to double the number of longi-
tudinal bars a, b, c, d, e, f, viz., to superpose a second bar on a, b, on the outside
of the series of cross bars or metal plates; and the same with c, d, & e, f, in such
manner that they will be bolted between two longitudinal bars at top and
bottom and in the middle, making six in all. Instead of placing the one.
series of cross bars immediately behind the others so as to be hidden, it is
preferable to bolt them to the longitudinal bars a, b, c, d, e, f, midway between
the joints of the upper series of cross bars. Thus the hinder series of cross
bars k, h, i, g, j', l, are bolted at k, i, j, o, h, g, l, instead of at k³, i, j, v²,
h, g', . I term the first arrangement (the superposed system).
In either of these arrangements diagonal pieces may be adapted to the cross
bars in a vertical position.
The girder instead of being perfectly straight or horizontal may be made,
first, of the curved form, see Fig. 4, in which case the three bars a, b, c, d, e, f,
are concentric with each other; secondly, of a double curved form or kind of
elongated ellipsis having two longitudinal bars a, b, & e, f, see (Fig. 5,) curved
in opposite directions, and with a straight bar placed intermediate; thirdly, of
the form represented at Fig. 6, in which the girder or frame is composed of a

page_text: bottom longitudinal bar e, f, straight throughout its length, of an upper
longitudinal bar a, b, of a curved form, and an intermediate longitudinal
bar c, d, of a different curve to that of a, b; this shape is somewhat similar to
a figure of one half of an ellipsis with its directrix, the side of the ellipsis
being the upper bar e, f, and the lower bar a, b, its directrix.
Further, this last arrangement is preferable as being the one most adapted
for general adoption. The floor is supported by the lower bar a, b. ·The
girder may be made also of the form represented at Fig. 7, in which the lower
bar a, b, is of a curved form, and the upper bar e, f, also curved but of a less
raduis than that determined by the arc of the lower longitudinal bar e, f.
The distance between the two bars a, b, & e, f, increases from each extremity
towards the centre of the girder.
"SYSTEM OF JOINTED CIRCULAR PLATES."
Instead of the diamond or lozenge-shaped plates, I also make use of circles:
or rings of plate metal, which I superpose and overlap to a point sufficiently.
near their centres, as seen at k. This arrangement may be either employed
with single or double series of plates, and either superposed or juxtaposed, as
in the diamond shape before described.
Figs. 8, 9, 10, 11, 12, 13, 30, & 31, represent arrangements of circular,
plates, having their diameters and chords differently combined. For greater
strength the circular plates should be made of a single piece of metal. This
system of circles is applied to the three longitudinal bars a, b, c, d, e, f, and bolted
thereto, in the same manner as for the lozenge shapes before described.
Instead of complete circles semicircular plates may be used, intersecting
each other reciprocally, having single or double series superposed or in
juxtaposition, as seen in Figs. 14, 15, 16, 17, 18, 19, 20, 21, & 34.
"BRIDGES FORMED OF ELLIPTICAL JOINTED PLATES."
In this arrangement I substitute ellipses, as at Fig. 22, for the lozenge
shaped circular or semicircular plates, and apply them to all forms of girders.
Instead of rivetting plates of sheet iron together for girders with solid sides,
the sides may be formed of two or three plates of metal superposed to form
each plate, and to give it the required thickness, constituting a solid girder,
formed of superposed plates of metal. The flooring or roadway may be placed
on either of the longitudinal bars, but it is preferable to fix it on the middle
and lower ones together (see Figs. 24 & 25 cross sections of roadway),
especially when the girder is curved. I may here remark that in my improved.
bridgos; the girders may be made. of any form. When the flooring is of

page_text: great width cross pieces or diamond-shaped ties may be used for connecting
the girders together, as seen in Figs. 23 & 27. Fig. 26 represents the cap
of one of the cross pieces. The erection of bridges or girders constructed
according to my Invention is very easy and comparatively inexpensive; for
example, about fifteen yards from the abutinent I build a scaffolding, see
(Fig. 28,) composed of piles fixed in the bed of the river; the longitudinal bars
forming the girder are then thrown out from the abutment to the scaffold;
there only remains then to bolt on the series of diamond-shaped circular or
other shaped plates, fixing each nut by means of a suitable key or cottar,
Fig. 41; in proportion as the plates are bolted on, and the girders extended,
the cross pieces forming the support of the flooring must be also bolted to the
longitudinal bars, so that the roadway progresses at the same time. When
the bridge is constructed up to the scaffolding, it is continued to a second
stage at a further distance, and so on until the structure is completed. Instead
of fixing the piles one against the other, they may be placed end to end, in
which case there is a screw fitted into the one pile, see Fig. 29, which screws
into the end of the other, and thereby permits of the scaffold being raised or
lowered. In the system of circular, semicircular, and other shaped plates,
their diameters and chords may be varied and combined in numbers of ways
as illustrated by the modifications Figs. 30, 31, 32, & 33. For economizing
the metal, and at the same time increasing the strength of each part, a
thickness & may be added to the bars at the edges, forming protections in the
manner of T-iron; the lines of the edges of Fig. 35 represent these projec-
tions. Fig. 36 shows a cross section of a longitudinal bar for applying the
circles, angles, chords, radii, &c.; Fig. 37 represents a cross section of the
same in a line passing through the bolt holes; Fig. 38, a cross section of an
upper and lower longitudinal bar; and Fig. 39, a section of the same bars at
the bolt; Fig. 40 represents the method of bolting the bars together; Fig. 42
represents the end of one of the flooring ties which is bolted to the interme-
diate longitudinal bar of the girder, and Fig. 43 a similar view. Sometimes
the circular, diamond, and other shaped plates cover the intermediate bar, and
only have small parts uncovered; in this case the extremity of the flooring
tie (which must be bolted) is bent so as not to touch these bars, as shown
at Fig. 44.

page_text: section of a double T-form. To enable the bars and other similar parts to
fit properly when they are bolted or rivetted together, I apply on the one side
next the projecting edges, metallic parallelopiped shaped plates, Figs. 47 & 48,
which fit one another; thus the pin p of the plate Fig. 47 enters the hole o of
the other plate, Fig. 48. Fig. 45 represents these two plates connected
together. It will be understood that the cross pieces may be fixed in any
other manner than the one described, the manner of erection being determined
by the form of girder used.
In witness whereof, I, the said Mathieu Castay, have hereunto set my
hand and seal, this Sixth day of October, in the year of our Lord
One thousand eight hundred and fifty-nine.
M. CAST
(1.5.)

page_text: LONDON: Printed by GEORGE EDWARD EYRE and WILLIAM SPOTTISWOODE,
Printers to the Queen's most Excellent Majesty. 1859.