IMPROVEMENTS IN THE CONSTRUCTION OF BRIDGES
Year: 1868

page_text: LETTERS PATENT to Edward William Young, of 8, New Street,
'Spring Gardens, in the County of Middlesex, Civil Engineer, for
the Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF BRIDGES."
Sealed the 14th August 1868, and dated the 19th February 1868.
PROVISIONAL SPECIFICATION left by the said Edward William Young
at the Office of the Commissioners of Patents, with his Petition, on
the 19th February 1868.
I, EDWARD WILLIAM YOUNG, of 8, New Street, Spring Gardens,
in the County of Middlesex, Civil Engineer, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN THE CONSTRUCTION OF
BRIDGES," to be as follows:-
This Invention consists in the construction of bridges of a compound
character, of which the essential characteristic is the supporting of a
suspension bridge by two cantilevers. In such bridges a portion of

page_text: the superstructure at and for a certain distance on each side of the
centre of the span acts as a suspension bridge, the parts between this
and the pier acting as cantilevers.
This Invention is an improvement on the form of bridge described
by me in a former Patent, numbered 633, and dated 7th March A.D.
1865, and consists in substituting a suspended structure or suspension
bridge of any approved form for the part between (a) and (b), Fig. 1 on
the Drawing attached to the Specification of the said Patent, shewn as
a truss and described as such in the Specification.
The central or suspension part of the structure does not contribute
in any way to the support of the side or cantilever portions.
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 17th August 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
WILLIAM YOUNG, of 8, New Street, Spring Gardens, in the County
of Middlesex, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Nineteenth day of February, in the year
of our Lord One thousand eight hundred and sixty-eight, in the thirty-
first 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 administrators, by an instrument in writing under

page_text: 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 my said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement :-
This Invention consists in the construction of bridges of a compound
character, of which the essential characteristic is the supporting of a
suspension bridge by two cantilevers. In such bridges a portion of the
superstructure at and for a certain distance on each side of the centre
of the span acts as a suspension bridge, the parts between this and the
pier acting as cantilevers.
This Invention is an improvement on the form of bridge described by
me in a former Patent, numbered 633, and dated 7th March A.D. 1865,
and consists in substituting a suspended structure or suspension bridge
of any approved form for the part between (a) and (b), Fig. 1 on the
Drawing attached to the Specification of the said Patent, shewn as a
truss and described as such in the Specification.
The central or suspension part of the structure does not contribute in
any way to the support of the side or cantilever portions.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 is an elevation, and Fig. 2 a plan of a bridge of a single span
of 1,200 feet clear on my improved system.
The central part a, a', is a suspension bridge 360 feet in length, a, b,
and a, b, being the cantilever portions of the structure. In this
example the suspension chains c, c, are braced by means of diagonals
d, d, capable of acting either as struts or ties. The cantilever portions
a, b, and a, b, are formed of vertical struts c, e, inclined tie bars f, f, a
top member 9, 9, in tension composed of metal in the form of links or
Fig. 1 is an elevation, and Fig. 2 a plan of a bridge of a single span
of 1,200 feet clear on my improved system.
The central part a, a', is a suspension bridge 360 feet in length, a, b,
and a, b, being the cantilever portions of the structure. In this
example the suspension chains c, c, are braced by means of diagonals
d, d, capable of acting either as struts or ties. The cantilever portions
a, b, and a, b, are formed of vertical struts c, e, inclined tie bars f, f, a
top member 9, 9, in tension composed of metal in the form of links or
plates, and a bottom member π, π, in compression.
The cantilevers a, o,

page_text: and a, b, are supported by towers i, i, and are secured by back tics k, l,
anchored in the ground. The suspension chains are allowed to bend
freely at the points a,.a, where they join the cantilevers, and also at
the point at the centre of the span. The platform of the bridge is
made capable of bending freely at points m, m, and 7. Allowance for
end motion due to contraction and expansion should be made at
points m, m. The wind tics n, n, for the platform are shewn in Fig. 2
on the left-hand half of the Figure, and the wind ties o, o, for the top
member of the cantilever on the right hand.
Fig. 3 represents a bridge on my improved system with one centro
and two side spans. In this example the top member of the cantilever
portions is curved and the struts inclined at an angle with the vertical;
towers are also dispensed with. p, p, the suspended portion of the
structure is made rigid by means of diagonal bracing p, q, and p², q',
are the cantilever portions.
Fig. 4 is an example of a bridge wherein rigidity in the suspension.
bridge portion is effected by means of a horizontal truss "", "¹.
"
Fig. 5 shews a mode whereby this system may be applied to bridges.
of several spans. The alternate spans v, t,--u, wo, are formed on. iny.
improved system, the portions 8, s¹, being suspension bridges, which in
this case are shewn as formed of straight suspension bars held in
position by light struts; the other spans, as t, u, are smaller, and the
superstructure is formed of a bowstring truss a, a, the dead weight of
which is either wholly or partially counterbalanced by the weight of
the structure in the adjoining spans, the strain being communicated
by means of the chain y, y. When the spans v, t,-u, w, are loaded,
span t, u, being unloaded, the resistance of the truss x, x, to upward
transverse strain enables it to perform the duty of an anchorage to these
spans. Again when span t, u, is loaded, spans v, t,-u, w, being unloaded,
the resistance of the truss a, a, to downward transverse strain prevents
the superstructure of the spans v, t,-u, w, from being lifted out of
position.
The method herein described of constructing the span t, u, is not
claimed by me.

page_text: What I claim is, the method herein described of constructing a bridge
compounded of cantilever portions and a suspended portion.
In witness whereof, I, the said Edward William Young, have
hereunto set my hand and seal, this Seventeenth day of August,
in the year of our Lord One thousand eight hundred and sixty-
eight.
EDWARD WILLIAM YOUNG. (L.S.)
EDWARD WILLIAM YOUNG. (L.S.)
EDWARD WILLIAM YOUNG. (L.S.)
Witness,
JOHN FARROW (Clerk to Sir Charles Fox & Sons),
9, Annis Road, South Hackney,
London.