CERTAIN IMPROVEMENTS IN THE CONSTRUC- TION OF SUSPENSION CHAINS FOR BRIDGES, VIADUCTS, AQUEDUCTS, AND OTHER PURPOSES, AND IN THE CONSTRUCTION OF SUCH BRIDGES, VIADUCTS, OR AQUEDUCTS
Year: 1836

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
DREDGE, of the Parish of Walcot, in the City of Bath, and County of
Somerset, Brewer, send greeting.
WHEREAS His present most Excellent Majesty King William the Fourth,
by His Royal Letters Patent under the Great Seal of Great Britain, bearing
date at Westminster, the Seventeenth day of June, in the sixth year of His
reign, and in the year of our Lord One thousand eight hundred and thirty-six,
did, for Himself, His heirs and successors, give and grant to me, the said
James Dredge, His especial license, full power, sole privilege and authority,
that I, the said James Dredge, my executors, administrators, and assigns, or
such others as I, the said James Dredge, my executors, administrators, or
assigns, should at any time agree with, and no others, from time to time and
at all times during the term of years therein mentioned, should and lawfully
might make, use, exercise, and vend, within England, Wales, and the Town of
Berwick-upon-Tweed my Invention of "CERTAIN IMPROVEMENTS IN THE CONSTRUC-
TION OF SUSPENSION CHAINS FOR BRIDGES, VIADUCTS, AQUEDUCTS, AND OTHER PURPOSES,
AND IN THE CONSTRUCTION OF SUCH BRIDGES, VIADUCTS, OR AQUEDUCTS;" in which said
Letters Patent is contained a proviso, obliging me, the said James Dredge, by
an instrument in writing under my hand and seal, particularly to describe and
ascertain the nature of my said Invention, and in what manner the same is to
be performed, and to cause the same to be inrolled in His Majesty's High

page_text: Court of Chancery within six calendar months next and immediately after the
date of the said in part recited Letters Patent, as in and by the same,
reference being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
James Dredge, do hereby declare that the nature of my said Invention, and
the manner in which the same is to be performed, are particularly described
and ascertained in and by the following description thereof, reference being
had to the Drawings hereunto annexed, and to the letters and figures marked
thereon (that is to say):-
My improvements in the construction of suspension chains for bridges, and
other erections to be supported on the principles of suspension and in the con-
struction of such bridges and other suspended erections, have for their objects,
first, a means of affording greater strength and stability than has been obtained
by any of the varied constructions of suspension bridges, piers, or other
erections of that kind, which have been heretofore constructed of corresponding
magnitude and extent; and, secondly, the economy of materials and labour
required to be expended in such erections. These objects I effect, in the first
instance, by so arranging and connecting a series of parallel links to constitute
the chains, that the chain may diminish in breadth, and consequently in weight,
as it recedes from the point or points of suspension; secondly, in applying such
chains to the purposes of constructing suspension bridges and other similar
erections in connection with inclined suspension bars or rods (instead of the
usual perpendicular suspension bars or rods), by means of which I am enabled
so to connect the longitudinal bearings of the horizontal platform or roadway
to the hanging chains, that the weight or principal leverage of the erection
may be removed from the centre and be sustained by the stronger parts of the
chains, increasing toward the abutments; thirdly, in the employment of
transverse tie-beams of a peculiar construction for confining the longitudinal
bearings of the horizontal platform or roadway; and, fourthly, the adaption
of a ball-and-socket bearing to the inclined suspension bars or rods, by means
of which the level or proper position of the platform may be readily adjusted.
In the accompanying Drawings Fig. 1 represents a portion of chain formed
by sets of links placed side by side in parallel series. a, a, a, a, a, a, b, b, b, b, b,
c, c, c, c, d, d, d, d, e, e, e, e, and f, g, h, i, k, l, connected together by transverse
bolts,,,,,, the liuks of each of which series diminish in number as
they recede from the pier or points of suspension. Fig. 2 represents a side
elevation of a suspension bridge constructed with chains of this description,
and inclined suspension rods or bars m, m, m; Fig. 3 is a plan or horizontal

page_text: view of the same; and Fig. 4 is a transverse section, taken through the bridge
in a vertical direction; Figure 5 represents a portion of one of the suspension
rods m, shewing its lower end with the ball-and-socket bearing o, having a
screw nut p for the purpose of adjustment. The ball bears against a recess or
socket formed in the under part of the saddle piece q, through which the
longitudinal bar r, r, passes that supports the platform; Fig. 6 is another
representation of the same, taken transversely. & is a part of one of the
transverse tie-beams, which it will be seen by Figure 4 is bowed upward, and
t is the string or tension rod which confines it. The means by which the
transverse tie-beams s and their tension rods t are connected to the saddle
pieces. q, that the lateral longitudinal bars r pass through, will be seen by
reference to the Figure 5 and 6, and require no further explanation. They
are intended to confine the longitudinal bars, and to prevent the structure
from vibrating in lateral directions, while the peculiar manner in which the
suspending rods m, m, are applied will prevent vibrations in vertical directions.
On the top of the tie-beams the planking u, u, is placed for the reception of
the roadway v, v. I would here remark, that if it is thought desirable, two
or more inclined suspension rods may diverge from each link of the chain to
different parts of the platform instead of only one, as shewn in the Drawings,
and be connected thereto in any convenient manner. And, lastly, I desire it to
be understood, that I do not intend to confine myself to any particular
dimensions of the parts of which the suspended erection shall be formed, nor
to any particular number of the links to be connected in each parallel series in
the chains, nor to any particular angles from the perpendicular at which the
suspending rods shall be placed; but that which I do claim as my Invention is,
the construction of a chain to be applied to the purposes of suspension which
shall diminish in breadth and weight as it recedes from the point or points of
suspension; also the construction of a bridge or other suspended erection by
means of such chains in connection with inclined suspension rods supporting
the platform or horizontal part of such erection; likewise the manner of
bracing the parts together by the transverse bow and string tie-beams, and
the mode of adjustment by the ball and socket connections.
In witness whereof, I, the said James Dredge, have hereunto set my
hand and seal, this Fourteenth day of December, in the year of our
Lord One thousand eight hundred and thirty-six.
JAMES (L.E.) DREDGE.

page_text: AND BE IT REMEMBERED, that on the Fourteenth day of December, in
the seventh year of the reign of His Majesty King William the Fourth,
the aforesaid James Dredge came before our said Lord the King, in His
Chancery, and acknowledged the instrument aforesaid, and. all and every
thing therein contained and specified, in form above written. And also the
instrument aforesaid was stamped according to the tenor of the Statute made
in the fifty-fifth year of the reign of His late Majesty King Georgo the