IMPROVEMENTS IN THE CONSTRUCTION OF IRON BRIDGES
Year: 1854

page_text: LETTERS PATENT to John McGaffin, of Liverpool, in the County of
Lancaster, Engineer, for the Invention of "IMPROVEMENTS IN THE
CONSTRUCTION OF IRON BRIDGES."
Sealed the 12th September 1854, and dated the 14th July 1854.
PROVISIONAL SPECIFICATION left by the said John McGaffin at the
Office of the Commissioners of Patents, with his Petition, on the 14tli
July 1854.
I, JOHN MCGAFFIN, of Liverpool, in the County of Lancaster, Engineer,
do hereby declare the nature of the Invention for "IMPROVEMENTS IN THE
CONSTRUCTION OF IRON BRIDGES" to be as follows:-
This Invention consists in constructing corrugated iron bridges or roofs
(galvanized or ungalvanized), by rivetting or screw-bolting corrugated plate
or sheet iron together, either straight or in an elliptic form, an are or segment
of a circle, and placing the sheets so jointed together of the required width
across the place to be bridged, and several of these curved or straight sets of
sheets are to be placed over each other at distances according to the span and
the thickness of the plates or sheets used. The space or spaces between each

page_text: set of sheets are to be filled up at certain intervals with pieces of wood, cut out
into corrugations, so as to fit the sheets; or wrought or cast iron corrugated
bearers in one or more picces may be used in place of the wood, and bolted or
screwed to the sheets. Either one or more sets of corrugated sheets may be used;
or the sheets, instead of being separated by the wood, cast or wrought corru-
gated iron, may be placed close to each other, and rivetted or screwed together,
and as many layers of sheets may be used as are deemed requisite, according to
the span and the thickness of the sheets or plates. These bridges may be
strengthened by tension rods from the piers, having a knuckle to help to stiffen
them. Corrugated angle or T iron, rivetted or screwed, may be placed across the
bridge to give it transverse rigidity. The tension rods are to be secured to the
above angle or T iron, and as many of these corrugated angle or T iron pieces
put across the bridge as are deemed requisite, according to the span and width.
These transverse corrugated wrought or cast iron bearers may be in one or
more pieces, so as to obviate any risk of their being bent or broken. The space
with
or spaces between the piers and the rise of the bridge may be filled up
corrugated iron pipes or cylinders laid in concrete or other material. These
pipes may also be bolted or rivetted together; they extend across the bridge in
layers, so as to form a foundation for the carriage way. The corrugated pipes
consist of corrugated iron plates or sheets of iron bent into a circle, in one or
more picces, and rivetted or bolted together to any length required.
The construction of roofs upon this principle is in substance the same as for
bridges, viz, by placing one or more layers of galvanized or ungalvanized sheets
or plates of iron at distances from each other, so that there are, as it were, one
or more roofs one over the other. The interval between each set of sheets or
roofs is regulated by the span and the thickness of sheets used, and will be
filled with pieces of wood cut to fit the corrugations, bolted or screwed to the
sheets, and at intervals running longitudinally with the roof, that is, across the
corrugations; the angle corrugated iron, if used, will be placed as already
described, bolted or screwed between the sheets at such intervals as may be
deemed requisite.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John McGaffin in the Great Seal Patent Office on the
11th January 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
MCGAFFIN, of Liverpool, in the County of Lancaster, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourteenth day of July, in the year of our Lord
One thousand eight hundred and fifty-four, in the eighteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said John McGaffin, Her special licence that I, the said John McGaffin, my
executors, administrators, and assigns, or such others as I, the said John,
McGaffin, 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 CONSTRUC-
TION OF IRON BRIDGES," upon the condition (amongst others) that I, the said
John McGaffin, by an instrument in writing under my hand and seal, 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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John McGaffin, 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 consists in constructing corrugated iron bridges or roofs
(galvanized or,ungalvanized,) by rivetting or screw-bolting corrugated plate or
sheet iron together, either straight or in an elliptic form, an arc or segment of
a circle, and placing the sheets so jointed together of the required width across
the place to be bridged, and several of these curved or straight sets of sheets
are to be placed over each other at distances according to the span and the
thickness of the plates or sheets used. The space or spaces between each set
of sheets are to be filled up at certain intervals with pieces of wood, cut out
into corrugations, so as to fit the sheets; or wrought or cast iron corrugated
bearers in one or more pieces may be used in place of the wood, and bolted or
screwed to the sheets. Either one or more sets of corrugated sheets may be used;

page_text: or the sheets, instead of being separated by the wood, cast or wrought corru-
gated iron, may be placed close to each other, and rivetted or screwed together,
and as many layers of sheets may be used as are deemed requisite, according
to the span and the thickness of the sheets or plates. The bridges may be
strengthened by tension rods from the piers, having a knuckle to help to stiffen
then. Corrugated angle or T iron, riveted or screwed, may be placed across
the bridge to give it transverse rigidity. The tension rods are to be secured to
the above angle or Tiron pieces put across the bridge as are deemed requisite,
according to the span and width. These transverse corrugated wrought or cast
iron bearers may be in one or more pieces, so as to obviate any risk of their
being bent or broken. The space or spaces between the piers and the rise of
the bridge may be filled up with corrugated iron pipes or cylinders laid in con-
crete or other material. These pipes may also be bolted or riveted together;
they extend across the bridge in layers so as to form a foundation for the
carriage way. The corrugated pipes consist of corrugated iron plates or
sheets of iron bent into a circle, in one or more pieces, and riveted or bolted.
together to any length required.
The construction of roofs upon this principle is in substance the same as for
bridges, viz, by placing one or more layers of galvanized or ungalvanized sheets
or plates of iron at distances from each other, so that there are, as it were, one
or more roofs one over the other. The interval between each set of sheets or
roofs is regulated by the span and the thickness of sheets used, and will be
filled with pieces of wood cut to fit the corrugations, bolted or screwed to
the sheets, and at intervals running longitudinally with the roof, that is, across
the corrugations; the angle corrugated iron, if used, will be placed as already
described, bolted or screwed between the sheets at such intervals as may be
deemed requisite.
Having thus described the nature of my said Invention, I will proceed to
describe the means of performing the same.
DESCRIPTION OF THE DRAWING.
Figure 1 shows a section of an arch suitable for a bridge or roof. It
consists of four sets of plates a, a, of angle iron, kept apart at intervals by
supports b, b, of wood or other suitable material. It is not essential that
the several sets of corrugated sheets of which an arch is composed should
in all cases be kept at a distance one from the other; but it is preferred
that such should be the case. Figure 2 shows part of a plan of one of
the sets of sheets. a, a, are four sets of sheets, but more or less sets may
be combined in making an arch, whether for a bridge or roof. b, b, are

page_text: the interposed supports for keeping the sets of plates apart and parallel;
c, c, are bolts passing through the supports and through the plates; d, d, are
tubes or cylinders of corrugated iron to fill up and make level the roadway,
the corrugations of such tubes or cylinders being round the same. No ties
or strengthening ribs of angle or other iron are shown in the Drawing, but
they may be used when desired.
In witness whereof, I, the said John McGaffin, have hereunto set my
hand and seal, this Sixth day of January, in the year of our Lord One
thousand eight hundred and fifty-five.
Witness,
GEORGE ANDERSON,
Bookkeeper,
Liverpool.
JOHN MCGAFFIN. (L.S.).