IMPROVEMENTS IN THE CON- STRUCTION OF BRIDGES
Year: 1864

page_text: LETTERS PATENT to Angelo James Sedley, of 38, Conduit Street, in the
County of Middlesex, for the Invention of "IMPROVEMENTS IN THE CON-
STRUCTION OF BRIDGES."
Sealed the 2nd June 1865, and dated the 10th December 1864.
PROVISIONAL SPECIFICATION left by the said Angelo James Sedley
at the Office of the Commissioners of Patents, with his Petition, on the
10th December 1864.
I, ANGELO JAMES SEDLEY, of 38, Conduit Street, in the County of Middlesex,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN THE
CONSTRUCTION OF BRIDGES,' to be as follows:-
This Invention has for its object a new mode of constructing bridges without
the use of centering, so as to combine the lightness of the principle of
suspension with the rigidity and strength obtainable by the arch or girder
principle.
In constructing a bridge according to this Invention, the piers are made
portions of the construction of the bridge, consequently in constructing a pier
for a bridge of this nature, arrangements are to be made for the building in
of a portion of the bridge which is required to be inshore into and along with
the masonry or materials of which the pier is composed, so that this portion
of the bridge is actually bonded into and forms a portion of the pier itself.
The portion of the bridge and the suspension bars, which descend from the

page_text: upper part of the tower are anchored further back behind the pier in any of
the best known modes of anchorage for suspension bridges; but I prefer that
system where a hollow iron cylinder of suitable size is sunk at an angle to the
requisite depth to secure a good holding, and to add to and secure the requisite
counterbalance. This cylinder is pierced in the sides, so that iron holding bolts
may be driven through in various parts to prevent the cylinder from being
drawn out of the earth when the strain of the cantilevers comes upon it.
I will now,describe the girders and the manner of projecting them over a
river or other place to be crossed without the use of centering.
It is desirable here to state, that in the construction of these bridges in
which lattice, tubular, or plate girders may be used, it is necessary that all
parts should be rigidly united when in position, one part to the other, so that
no part shall be loose or subject to any movement or strain which does not
affect the whole structure.
The form of the cantilever projecting from the pier towards the centre of
the span, and which constitutes a part of the bridge, takes the shape of any -
acute angle with a shoe at the bottom of the part touching and projecting
from the pier outwards, the point of the angle being towards the centre of the
span, the greater portion of the angle being above the level of the roadway,
and the smaller portion below. It is found that the bridge can be constructed
with the least amount of metal and greatest strength by making these
cantilevers rather more than one-third of the span each.
In constructing a bridge of this kind having first prepared the pier, and
that inshore portion of the bridge, as before described, the remaining portion
of the cantilevers will be built out in the following manner:-The pier and
land portion of the bridge having been properly constructed and secured as
before described, the first portion of the projecting structure is lifted from a
barge or vessel or other position into position, and is adjusted in its place and
there held, till by screw bolts and nuts or rivets it is fixed to the portion
forming part of the pier, and so on till all the parts have been lifted and fixed
in their places, the projecting part of the bridge increasing in length as each
portion is connected up to the preceding parts.
The suspension part of the structure above the roadway commencing at the
towers, is attached to these parts before described, and may be proceeded with
at the same time as the parts constituting the projecting cantilevers are raised
and fixed. In box or plate girders the method of erection is similar, except
that in box girders the longitudinal girders to the roadway will be piled
horizontally on the top of one another to the level of the roadway, and from
above the roadway the method of construction of the suspension parts will be.

page_text: that before described. The main cantilevers having been projected and
finished and cross braced from the piers on either side of the river or valley
towards the centre, as above described, extending over somewhat more than
two-thirds of the span; the remaining portion or centre is next to be bridged
over, and the whole united into one structure. For this purpose, according
to the span, I use lattice, box, or other girders, of any suitable form as a shoe
to unite the ends of the two sets of cantilevers. The bottom of the central
girders is fixed to the upper surfaces of the other girders or cantilevers, and
stops are placed on the cantilevers to abut against the ends of the centre
girders, so as to obtain thereby the rigidity of au arch. The central girders
may be raised into position entire or may be moved or projected out from
either of the projecting cantilevers till received by the cantilevers projecting
from the other side.
The construction of roadway for these bridges consists by preference of a
system of diagonal girders formed of plate and angle iron, and rivetted together
in the form of a diamond; by this means, the weight and strains will be more
equally distributed over the bridge; on the top of this buckled plates or
timber may be placed.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Angelo James Sedley in the Great Seal Patent Office on
the 10th June 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ANGELO
JAMES SEDLEY, of 38, Conduit Street, in tho County of Middlesex, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Tenth day of December, in the year of our Lord
One thousand eight hundred and sixty-four, in the twenty-eighth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Angelo James Sedley, Her special licence that I, the said
Angelo James Sedley, my executors, administrators, and assigns, or such
others as I, the said Angelo James Sedley, 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

page_text: condition (amongst others) that I, the said Angelo James Sedley, 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 Angelo James Sedley, 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 a new mode of constructing bridges
without the use of centering, so as to combine the lightness of the principle
of suspension with the rigidity and strength obtainable by the arch or girder
principle.
In constructing a bridge according to this Invention, the piers are made
portions of the construction of the bridge, consequently in constructing a
pier for a bridge of this nature arrangements are to be made for the building
in of the portion of the bridge which is required to be inshore into and along
with the masonry or materials of which the pier is composed, so that this
portion of the bridge is actually bonded into and forms a portion of the pier
itself. The portion of the bridge and the suspension bars which descend from
the upper part of the tower on the pier are anchored further back behind the
pier by screw piles, or in any of the best known modes of anchorage for
suspension bridges; but I prefer for spans above one hundred feet clear that
system where a hollow iron cylinder of suitable size is sunk at an angle to the
requisite depth to secure a good holding, and to add to and secure the requisite
counterbalance. This cylinder is pierced in the sides, so that iron holding
bolts may be driven through in various parts to prevent the cylinder from
being drawn out of the earth when the strain of the cantilevers comes
upon it.
I will now describe the girders, and the manner of projecting them over a
river or other place to be crossed without the use of centering.
It is desirable here to state that in the construction of these bridges in
which lattice, tubular, or plate girders may be used, it is necessary that all
parts should be rigidly united when in position, one part to the other, so that
no part shall be loose or subject to any movement or strain which does not
affect the whole structure.
The form of the cantilever projecting from the pier towards the centre of

page_text: the span, and which constitutes a part of the bridge, takes the shape of an
acute angle with a shoe at the bottom of the part touching and projecting
from the pier outwards, the point of the angle being towards the centre of
the span, the greater portion of the angle being above the level of the road-
way, and the smaller portion below. It is found that the bridge can be con-
structed with the least amount of metal and greatest strength by making
these cantilevers rather more than one-third of the span each.
In constructing a bridge of this kind, having first prepared the pier and
that inshore portion of the bridge, as before described, the remaining portion
of the cantilevers will be built out in the following manner:-The pier and
land portion of the bridge having been properly constructed and secured, as
before described, the first portion of the projecting structure is lifted from a
barge or vessel, or other position into position, and is adjusted in its place,
and there held till by screw bolts and nuts or rivets it is fixed to the portion
forming part of the pier, and so on till all the parts have been lifted and fixed
in their places, the projecting part of the bridge increasing in length as each
portion is connected up to the preceding parts.
The suspension part of the structure above the roadway commencing at the
towers is attached to these parts before described, and may be proceeded with
at the same time as the parts constituting the projecting cantilevers are raised
and fixed. In box or plate girders the method of erection is similar, except
that in box girders the longitudinal girders to the roadway will be piled
horizontally on the top of one another to the level of the roadway, and from
above the roadway, the method of construction of the suspension parts will be
that before described. The main cantilevers having been projected and
finished, and cross braced from the piers on either side of the river or valley
towards the centre, as above described, extending over somewhat more than
two-thirds of the span, the remaining portion or centre is next to be bridged
over, and the whole united into one structure. For this purpose, according
to the
span, I use lattice, box, or other girders of any suitable form as a shoe
to unite the ends of the two sets of cantilevers. The bottom of the central
girders is fixed to the upper surfaces of the other girders or cantilevers, and
stops are placed when desired on the cantilevers to abut against the ends of
the centre girders, so as to obtain thereby the rigidity of an arch. The
central girders may be raised into position entire, or may be moved or pro-
jected out from either of the projecting cantilevers till received by the
cantilevers projecting from the other side.
The construction of roadway for these bridges consists, by preference, of a
system of diagonal girders formed of plate and angle iron, and rivetted

page_text: together in the form of a diamond, by this means the weight and strains will
be more equally distributed over the bridge; on the top of this buckled plates
or timber may be placed.
I will now proceed to describe the manner of construction adopted by me
in building bridges of this kind without centering or supports during the
erection.
Figure 1, P, P, P, P, represents the piers; C, C, C, the cantilevers built
into the pier; L, L, the lugs or fastenings by which the tail end C is further
secured into the masonry of the pier; B, B, represent screw bolts built into
the masonry, and fastened through the lower part or flanges of C, C, C;
J, J, joints in cantilever, which enable it to be constructed piecemeal, as will
be hereafter described; S', screw pile, to which is attached the tension
bars T, T; T, the tower, over which the bars T, T, are led to screw piles,
or other mode of anchoring; C' is the point of connection of the tension
bar T with the outer end of the cantilever C, C, C; M, M, is the middle
girder, which may be of any suitable form, which when placed in position is
rivetted down to the cantilever C, C, C, or otherwise secured at the part
indicated by M and C¹.
Figure 2 shews the method of erection. The piers P, P, having been
built up to the lines a, a, the lugs L, L, and the screws B, B, being built in
at the same time, the pier is now ready to receive the portion of the
cantilever A¹. The manner of raising and adding the second portion, A³,
being shewn in Figure 1 as fixed, and Figure 2 as being raised to its position
A' and A' are adjusted in a similar manner, and the tension bars T, T, are
then attached to the top flange of the complete cantilever, as shown in
Figure 1, at C. The tension bar may be adjusted by means of screws or
cotter pins, or keys to any degree of tightness that may be found desirable.
The centre girder, Figure 2, shewn suspended is then raised into position by
suitable means, as shewn by Drawing, Figure 2. The road girder and railing,
and wind ties are then placed in position to complete the bridge.
⚫ It is desirable to describe that in constructing bridges of over 100 feet in
clear span, that the tension or suspension bars T, T, may be supported by
vertical or inclined bars, which will have a tendency to support and stiffen the
tension bars, and in conjunction with the cantilevers produce that stiffness
which is necessary in erections of this kind which are to be subjected to the
action of heavy rolling weights.
I claim as my Invention, the combination and arrangement of the parts as
before described, by which the unsteadiness of a suspension bridge is done
away with at a trifling excess in weight over and above that ordinarily

page_text: employed in the construction of a suspension bridge, whilst at the same time
the accumulation of weight in girder bridges (whether lattice, plate, or box,)
towards the centre of such girder is for the most part dispensed with, and
the dead weight necessary to secure the girder is obtained, as herein
explained.
In witness whereof, I, the said Angelo James Sedley, have hereunto set
my hand and seal, this Tenth day of June, in the year of our Lord
One thousand eight hundred and sixty-five.
ANGELO JAMES SEDLEY. (L.S.)