IMPROVEMENTS IN THE CONSTRUCTION OF.. SLIDING OR ROLLING BRIDGES
Year: 1865

page_text: LETTERS PATENT to Michael Kenney, of 6, Herbert Place, Irishtown;..
Dublin, for the Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF..
SLIDING OR ROLLING BRIDGES."
Sealed the 19th January 1866, and dated the 26th July 1865.
PROVISIONAL SPECIFICATION left by the said Michael Kenney at the
Office of the Commissioners of. Patents, with his Petition, on the 26th.
July 1865.
I, MICHAEL KENNEY, of 6, Herbert Place, Irishtown, Dublin,.. do hereby
declare the nature of the said Invention.for "IMPROVEMENTS IN THE CONSTRUCTION
OF SLIDING OR ROLLING BRIDGES," to be as follows:-
This Invention relates to that class of bridges designated sliding or, rolling.
bridges in which the length of the roadway of. necessity exceeds the width of
the opening which they are employed to span, and. which bridges are
withdrawn longitudinally in the direction of the roadway to permit of a clear
passage being effected along the line of way spanned by the bridge when
closed.
My improvements consist in constructing a rolling bridge of either iron or
wood that when it is closed and in use it is perfectly secure, and the roadway

page_text: of the bridge and approaches continuous, level, and unbroken, and suitable
for locomotive, tramway, or horse traffic, and when opened and withdrawn
longitudinally it leaves a clear opening or passage way through the portion
spanned, and the roadway or tail end approaches unaltered or interfered with or
broken. These improvements are effected by constructing the bridge as follows:
-Of two or more main beams or girders of iron or wood, the span of the
opening to be crossed and the length necessary for a counterbalance supported
and travelling on bearing rollers, and withdrawn or moved forward by a rack
and pinion, chains, or other mechanical arrangements. The flooring or
roadway constructed in two separate parts, one half or portion attached to
the main beams, and the other half or portion constructed and attached
to the said main beams or girders, but separately framed, and capable of
being raised between the said girders the depth of the flooring or thereabouts
by screws, levers, chains, bydraulic or other mechanical appliances found most
lesirable, thus allowing the bridge to be withdrawn horizontally the width of
the opening spanned longitudinally without interfering with the approaches or
the disruption of the mechanical construction of the bridge, and when
moved forward and shut the raised portion lowered and in situ presenting a
level, perfectly firm roadway, suitable for either locomotive, tramway, or horse
traffic. The details of construction are made to suit the required spans.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Michael Kenney in the Great Seal Patent Office on the
26th January 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MICHAEL
KENNEY, of 6, Herbert Place, Irishtown, Dublin, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-sixth day of July, in the year of our Lord
One thousand eight hundred and sixty-five, in the twenty-ninth year of Her
reign, did, for Herself; Her heirs and successors, give and grant unto me, the
said Michael Kenney, Her special licence that I, the said Michael Kenney;
my executors, administrators, and assigns, or such others as I, the said Michael
Kenney, 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

page_text: CONSTRUCTION OF SLIDING OR ROLLING BRIDGES," upon the condition (amongst
others) that I, the said Michael Kenney, 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 Michael Kenney, 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 and accompanying Drawings (that is to say) :-
My Invention relates to that class of bridges designated sliding or rolling
bridges in which the length of the roadway of necessity exceeds the width of
the opening which they are employed to span, and which bridges are
withdrawn longitudinally in the direction of the roadway to permit of a clear
passage being effected along the line of way spanned by the bridge when
closed.
My improvements consist in constructing à rolling bridge of either iron or
wood that when closed and in use is perfectly secure, and the roadway of the
bridge and approaches continuous, level, and unbroken, and suitable for
locomotive, tramway, or horse traffic, and when opened and withdrawn
longitudinally it leaves a clear opening or passage way through the portion
spanned, and the roadway or tail end approaches unaltered or interfered with
or broken. These improvements are effected by constructing the bridge as
follows: Of two or more main beams or girders of iron or wood, the span of
the opening to be crossed and the length necessary for a counterbalance
supported and travelling on bearing rollers and withdrawn or moved forward
by a rack and pinion, chains, or other mechanical arrangements. The flooring
or roadway constructed in two separate parts, one Lalf or portion attached to
the mainbeams, and the other half or portion constructed and attached to the
said beams or girders, but separately framed, and capable of being raised
between the said girders the depth of the flooring or thereabouts by screws,
lovers, chains, hydraulic or other mechanical appliances found most desirable,
thus allowing the bridge to be withdrawn horizontally the width of the opening
spanned longitudinally without interfering with the approaches or
disruption of the mechanicul construction of the bridge, and when moved
forward and shut the raised portion lowered and in situ presenting a level,
perfectly firm roadway, suitable for either locomotive or tramway or horse
traffic
the

page_text: The mode of construction and the various details connected therewith will
"be more readily understood reference being made to the accompanying
Drawings, representing a rolling bridge as constructed for a single line of rails
for fifty feet waterway, the scale being five feet to an inch.
Fig. 1 shows a longitudinal sectional elevation of the bridge, and repre-
sents two longitudinal wrought-iron beams having a series of wrought-iron
transverse beams or joists to support the flooring, attached for one half the
"bridge permanently to the main beams, as shown at A, A, and the other half
or thereabouts of the transverse flooring joists framed in themselves and
attached to the main beams, but free to be raised up and down about its own
thickness, as shown at B, B, to allow the flooring to recede back over the
ground line C to admit of the bridge being opened. I propose raising the
platform by cam wheels, a continuous rod or chain D, D, and spur gearing,
as shown E, E, or by balanced wheels and pulleys and suspension chains
connected by bars or chains with the spur bearings or by any other mechanical
The construction of wrought
means that may be thought more desirable.
iron girder adopted is the ordinary I section, consisting of plates and angle
irons, as shown in Fig. 2, to the bottom portion of which the malleable iron
bearing rails and cast-iron racks are attached, the rails bearing on cast-iron
bearing rollers F, F, resting on pedestals bolted to the masonry, on which
rollers the bridge travels, and is moved by spur gearing E, E, and a pinion
gearing into aforesaid racks. The end of the bridge is received and locked by
a deflection cam or roller G. Fig. 2 shows the lifting platform of the bridge
bedded and in situ, having the rails level with those on the permanent way
C, C. Fig. 3 shows the platform raised in position to pass back over the
permanent way C, C. It will be seen by these sections that the main
beams never 'leave the bearing rollers when either opening or shutting the
bridge.
Plan Fig. 4 shows the general arrangement of the fixed and lifting platforms
for a bridge for a single line of rails.
As various modifications would be necessary, depending on the span load to
be sustained and material to be employed, only general sections and details
are given in the above Drawings.
In case of a double bridge being required, I would adopt one made in two
parts, so that in case of repair one line of rails or side can be used while the
other is open.
The following enumeration of the various details indicated in the Drawings
will serve to complete the description of my Invention. Fig. 1 represents a
longitudinal sectional elevation of the bridge, of which 1 is a deflection roller

page_text: or cam to receive and lock the bridge; 2, the waterway; 3, connecting shaft
for lifting gear; 4, bearing roller and carriage set in pit prepared for their
reception; 5, semicircular bearing rails attached to under side of main
girders; 6, rack rail attached to under side of main beams besides bearing
rail; 7, spur gearing and pinion gearing with rack; 8, bearing rollers and
carriage; 9, line of ballasting; 10, line of rails on permanent way; 11,
connecting bar or chains attached from spur gearing to lever wheels on each
side; 12, roller or barrel; 13, balanced lever wheel; 14, guide bar; 15,
roller or barrel; 16, balanced lever wheel; 17, roller or barrel to receive
lifting chains which are attached to flooring joists; 18, balanced lever wheel
connected by tension rods or chains; 19, spur gearing connected with lifting
rollers driven by hand; 20, level of rails on fixed floor. Fig. 2 represents a
transverse section of bridge in situ; a, rails; b, connecting rod and chains to
gearing; c, counterbalanced lever wheel; d, bearing shaft; e, carriage for
rollers; f, lifting chain; 9, pulley for lifting chain; h, rack. Fig. 3 is a
section showing moveable floor raised. Fig. 4 is a general plan, one half
showing fixed portion of floor, the other showing floor constructed for lifting;
a, rails; b, main girders; c, diagonal bracing; d, guide bars; e, capstan to
work cam. Fig. 5 is a sectional view shewing the details of beam bearing
rails and rollers.
Having thus described my Invention, I will only add that I do not restricţ
myself to the precise details herein-before set forth and indicated in the
accompanying Drawings, as they must of necessity vary, being dependent on
the span load to be sustained and material used in construction. I also retain
for myself the option of raising the tray or lifting half the floor by any
mechanical means found most suitable.
In witness whereof, I, the said Michael Kenney, have hereunto set my
hand and seal, this Twenty-fourth day of January, in the year of
our Lord One thousand eight hundred and sixty-six.
MICHAEL KENNEY. (L.S.)