IMPROVEMENTS IN THE CONSTRUCTION OF BRIDGES
Year: 1856

page_text: LETTERS PATENT to Edward William Young, of No. 22, Maidstone Road,
Rochester, in the County of Kent, Civil Engineer, for the Invention of
"IMPROVEMENTS IN THE CONSTRUCTION OF BRIDGES."
Sealed the 6th January 1857, and dated the 19th July 1856.
PROVISIONAL SPECIFICATION left by the said Edward William Young at
the Office of the Commissioners of Patents, with his Petition, on the
19th July 1856.
I, EDWARD WILLIAM YOUNG, of No. 22, Maidstone Road, Rochester, in
the County of Kent, Civil Engineer, do hereby declare the nature of the
Invention for "IMPROVEMENTS IN THE CONSTRUCTION OF BRIDGES," to be as
follows:-
This Invention has for its object improvements in the construction of
bridges. For this purpose the platform or roadway of a bridge is suspended
from chains which do not hang in curves as in ordinary suspension bridges,
but descend in straight inclined lines from the points of suspension to the
platform of the bridge. From these chains, and at intervals between the
points of their suspension and their connections with the platform or roadway,
suspending rods descend in inclined or diagonal directions to the platform or
roadway of the bridge, and the chains are supported at intervals by props or
uprights, which at their lower ends are supported by the platform or roadway
at points near where the lower ends of the suspending rods from the chains
are connected with the platform or roadway. At the upper ends of such props
or supports they support the chains at points near where the next suspending
rods are connected to the chains.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Edward William Young in the Great Seal Patent Office
on the 19th January 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
WILLIAM YOUNG, formerly of No. 22, Maidstone Road, Rochester, in the
County of Kent, Civil Engineer, now of Conduit St., Bedford, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Nineteenth day of July, in the year of our Lord
One thousand eight hundred and fifty-six, in the twentieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Edward William Young, Her special licence that I, the said Edward
William Young, my executors, administrators, and assigns, or such others as
I, the said Edward William Young, 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 THE CONSTRUCTION OF BRIDGES," upon the condition (amongst
others) that I, the said Edward William Young, my executors or adminis-
trators, 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 Edward William Young, do hereby
declare the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say:―
This Invention has for its object improvements in the construction of
bridges. For this purpose the platform or roadway of a bridge is suspended
from chains, which do not hang in curves as in ordinary suspension bridges,
but descend in straight inclined lines from the points of suspension to the
platform of the bridge. From these chains, and at intervals between the
points of their suspension and their connections with the platform or roadway,
suspending rods descend in inclined or diagonal directions to the platform or
roadway of the bridge, and the chains are supported at intervals by props or
uprights, which at their lower ends are supported by the platform or roadway

page_text: at points near where the lower ends of the suspending rods from the chains
are connected with the platform or roadway, at the upper ends of such props
or supports they support the chains at points near where the next suspending
rods are connected to the chains.
Having thus stated the nature of my said Invention, I will proceed more
fully to describe the manner of performing the same.
This bridge possesses the following advantages over suspension bridges:-Its
platform is not liable to undulation, and its shape not altered when supporting
a heavy load at one point; it can also be constructed without scaffolding, and
takes less iron than any other description of bridge.
The peculiarity in this construction of bridge consists in the introduction of.
struts between the chain and the platform, and at the same time in making
the platform capable of resisting compression, the struts acting not merely as
stiffeners as when anything is braced, but to support the structure. Each strut
supports, to a certain extent, the weight of all that portion of the structure
between it and the centre of the span. This causes the strain on the main chains
to be greatest on those portions nearest the piers, whilst at the centre of the span
the sectional area of the main chains need only be a comparatively small fraction
of that near the piers. Each half span is independent of the other for support.
The ties or suspension rods, and the girders which support the platform and
have to resist the compressive force caused (in this case) by the inclined
suspension rods, likewise diminish in sectional area towards the centre of the
span. The result of this is that the greatest weight of metal is nearest the
piers instead of being at the centre of the span or evenly distributed, causing
thereby a saving of metal. I prefer to make the bridge with main chains
straight, with the struts perpendicular, and the suspension rods diagonal, as
being the most economical method of constructing a bridge of this kind; but the
chains may be made curved, or the struts inclined at an angle. The struts may
also be placed in a diagonal position, the reverse of that in which the suspen-
sion rods are shown in Figure 1, and the suspension rods vertically, if desired.
When a bridge of this kind is constructed across several spans, I prefer to use
a curved chain underneath the platform as a means of holding it down, and
preventing its being raised by a load coming upon any part of the bridge on
the other side of the piers, that is to say, on a different span; the strain is thus
5 conveyed from pier to pier to a mass of concrete or masonry on either bank;
of course any other suitable means may be adopted of resisting the upward pull
caused by the passing load, as, for instance, by making the platform to form
part of an inverted truss.

page_text: DESCRIPTION OF THE DRAWINGS.
That part of Figure 1 between A and B, shows an elevation of the bridge
complete, with the railing and moulding. The part from A to B, on Figure 2,
shews the plan of the same, and the main chains diminishing in strength
towards the centre of the span. Between B and C, in Figures 1 and 2, is an
elevation and plan of the girders, shewing the diagonal bracing which is
required to stiffen the platform laterally. a, a, are the struts; b, b, the suspen-
sion rods; c, c, the girders; d, d, are the main chains; e, e, is the curved chain
which resists the upward pull of the passing load. The extremities of each of
the main chains I prefer to connect to one pin, which passes through a slotted
opening in the ends of the two girders, which meet at the centre of the span;
the expansion and contraction of the bridge is thus provided for. Figure 3 is
a detailed side elevation of one bay with the moulding and timber bearers re-
moved, shewing the manner of bolting the girders together, &c.; Figure 4
is a sectional view of the same, shewing timber, cross bearers, moulding, &c.
Figure 5 shows an enlarged detail of the connection of the struts a and ties b,
with the main chains; d, a wrought iron pin passing through and connecting
them together. Figure 6 is an enlarged detail of the connection of the struts
a, suspension rods or ties b, with girders c; f, f, are rods by which the curved
chain is supported. A WI pin connects these latter, the suspension rods and
the girders together. The struts are bolted to the top flange of the girder. g
is a projecting flange on the girder to receive the timber bearer, which comes
opposite to the strut, and cannot rest on the top flange of the girder as the
others do, an end view of the diagonal bracing his shown on Figure 4.
The Drawings show only one method of carrying out my Invention. The
details may be varied and the materials also; thus wrought iron may be used
instead of cast iron in the struts and girders. What I claim is, the mode herein
described of combining the parts of a bridge.
In witness whereof, I, the said Edward William Young, have hereunto
set my hand and seal, this Fifteenth day of January, in the year of our
Lord One thousand eight hundred and fifty-saven
Witness,
HENRY YOUNG, Captain,
Conduit St., Bedford.
EDWARD WILLIAM YOUNG. (L.S.)