IMPROVEMENTS IN GIRDERS MANUFACTURED IN IRON. STEEL, OR OTHERWISE COMBINED WITH TIMBER
Year: 1866

page_text: LETTERS PATENT to Constantine Henderson, of 48, Parliament Street,
Westminster, Architect, for the Invention of "IMPROVEMENTS IN GIRDERS
MANUFACTURED IN IRON. STEEL, OR OTHERWISE COMBINED WITH TIMBER,"
PROVISIONAL SPECIFICATION left by the said Constantine Henderson
at the Office of the Commissioners of Patents, with his Petition, on
the 4th June 1866.
I, CONSTANTINE HENDERSON, of 43, Parliament Street, Westminster, Archi-
tect, do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN GIRDERS MANUFACTURED IN IRON, STEEL, OR OTHERWISE COMBINED WITH
TIMBER," to be as follows, that is to say :-
Referring to the Patent No. 335, and dated the 7th day of February 1865,
granted to me for Improvements in the Construction of Roadways, Pave-
ments, and Iron Girders,specially Applicable for the purpose of Constructing
Roads, Pavements, Bridges, and all Description of Bridges," I would have it
understood that the present Invention I now seek to secure by Letters Patent
is an improvement in the several modes and forms of constructing the said
girder therein mentioned.
The girder herein consists of a webb and abutment or skewbacks, to which

page_text: will sometimes be added flanges, and used in conjunction with brick, stone,
tiles, or timber or iron arch or arches secured by the abutments or skew
backs forming part of the girder, which girder is generally constructed of
metal cast or otherwise manufactured, but in some cases the webb of the said
girder inay be in part formed of iron bands and timber or other suitable
materials combined. The girders are applicable to all the purposes to which
girders are at present applied and likewise to the construction of roadways,
bridges, viaducts,and tunnels, also in the construction of railways and parts of
railways, and to the construction of ships of every description of building.
The abutments or skewbacks herein mentioned are either cast or otherwise
manufactured in metal,and maybe solid or hollow. The inner side thereof is
formed to the particular angle to suit the radius of the intended arch or
arches that are constructed within the span or space between the two abut-
ments. I form a teuon or slot to receive the ends of the webb as herein-before
mentioned.
The webb of the girder may be rolled or cast metal, and may sometimes be
madein timber in conjunction with hoop iron bands,orotherwise strengthened
by braces running parallel therewith, but in common the webb will be of
metal, the form thereof usually being that of a longitudinal flitch or plank and
the ends thereof are either dovetailed or turned up to fit the tenons or slots or
other mode of fastening in the before-mentioned abutments or skewbacks; I
ther place the skewbacks or abutments in position and securely fix the webb
to the skewbacks by dropping or placing the dovetailed or turned-up ends of
the webb into the tenons or slots of the skewbacks, or I secure them together
by such other means as may appear best suited to the particular occasion;
the arch or arches is then constructed within the span or space of or between
the abutments and built up clear of the top of the webb; which is never
subject to vertical pressure, but is firmly supported by the arches on either
side. By this peculiar form of tension girder I obtain very considerable
additional strength over all other kinds of girders, and the amount of labor
now required in the manufacture of girders is greatly reduced. The lightness
of the girders and ease and economy of space with which they are capable of
being packed or stowed away are additional improvements and advantages
over the girders now in use, and these advantages will also greatly reduce the
carriageof the girders forexportation orotherwise which is nowveryexpensive
These girders are also particularly applicable to the formation and construc
tion of tire-proof floors and roofs, and the only additional arrangement
necessary in constructing the floors is simply the elongation or widening out
of the skewbanks or abutments before mentioned.

page_text: According to another method, in lien of the ordinary gir ter in use for
building and other purposes, I prepare anarch formed with perforas al bricks,
stone, iron, timber, or other suitable material, and in each brick ap rtion of
other material which forms the arch I make the perforations to allow of a
straight line of iron chain, rod, or twisted metal wire to pass through the
entire arch when formed, and this chain, rod, or twisted metal wire I securely
fix to the iron skewback or abutments as herein mentioned. And by this
method or construction,as in all other cases, I never allow the iron chain, rod,
or twisted metal wire to take the burden of vertical pressure, but its entire
duty is that of tension. In some instances I intend to form the skewbanks
of stone or other material.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Constantine Henderson in the Great Seal Patent Office on
the 30th November 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CONSTAN-
TINE HENDERSON, of 43, Parliament Street, Westminster, Architect, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourth day of June, in the year of our Lord
One thousand eight hundred and sixty-six, in the twenty-ninth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Constantine Henderson, Her special licence that I, the said
Constantine Henderson, my executors, administrators, and assigns, or such
others as I, the said Constantine Henderson, 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 GIRDERS MANUFACTURED
IN IRON, STEEL, OR OTHERWISE COMBINED WITH TIMBER," upon the condition
(amongst others) that I, the said Constantine Henderson, 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

page_text: within six calendar months next and immediately after the date of the said
Letters Patent..
NOW KNOW YE, that I, the said Constantine Henderson, 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 :-
My said Invention relates to certain peculiar methods of constructing
girders which are applicable to the formation of roadways, bridges, and rail-
way works, tunnels, viaducts. piers, fireproof floors, subways, roofs, archways,
lintels over all description of openings in ordinary buildings, supporting walls
over shop fronts, and in every other kind of construction where weight has to
be carried, and the said girders are also adaptable to the construction of
ships and the various parts thereof:
The peculiar and improved modes of constructing girders on the principle
referred to in my Patent, No. 335 (and dated the 7th day of February 1865),
and as herein described, consist of a webb or webbs (with or without flangers)
and abutments or skewbacks used in conjunction with an arch or arches of
brick, stone, tile, timber, or other material, the arch or arches being formed
between the abutments or skewbacks formingpart of thegirder. The webbs of
the girders are generally constructed of metal, cast or otherwise manufactured,
but in some cases the webs may be in part formed of iron bands or rods and
timber or other suitable materials combined. The abutments or skewbacks
herein mentioned are either cast or otherwise manufactured in metal; in
some instances, however, the abutments may be formed of timber or of timber
and metal together, and may be solid or hollow. The inner side of the abut-
ments or skewbacks are formed to the particular angle to suit the radius of
the intended arch or arches that are constructed within the span or space
between the two abutments, and in the centre or sometimes in other parts of
the said skewbacks or abutments I form a teuon or slot to receive the ends of
the webbs as herein-before mentioned. In some instances I form the abut-
ment incast or otherwise manufactured metal in the shape of a shoe or plate,
the lower side being horizontal to the wall or foundation, and the inner side
is made to incline to an angle suitable to the arch or arches which abut on to
the face of this shoe. The webb of the girder may be of rolled or cast metal,
and my sometimes be made in timber in conjunction with hoop iron bands
or otherwise strengthened by braces running parallel therewith, but in
commou the webb will be of metal, the form thereof usually being that of a
longitudinal flitch or plank, and the ends thereof are either dovetailed or
twined up to fit the tenons or slots, or in the before-mentioned abutments or

page_text: In order to
skewbacks, or theyare formed to suit such other mode of fixing as the occasion
may require; I then place the skewbacks or otlier abutments in position, and
securely fix the webb to the skewbacks by dropping or placing the dovetailed.
or turned-up ends of the webb into the tenons or slots of the skewbacks, or:
secure them together by such other means as may appear best suited to the
particular occasion; the arch (or arches) is then constructed within the span
or space (or between) the abutments and built up clear of the top of the
webb, which is never subject to vertical pressure, but the weight or pressure
is firmly supported or carried by the arches on either side.
obtain the necessary length of the webb where the spans are of considerable
length, as will frequently be the case in bridge building, the webb will bo
formed by one or more plates or pieces of iron, steel, or other materials
placed together, bolted, and screwed together in the usual way or connected
in some other manner. These girders are also particularly applicable to the
formation and construction of fire-proof floors, and the only additional
arrangement necessary in constructing the floors is simply the elongation or
widening out of the skewbacks or abutments before mentioned.
According to another method, in lieu of the ordinary girder used for
building and other purposes, I prepare an arch with perforated bricks, stone;
iron, timber, or other suitable materials, and in each brick or portion of
other material which forms the arch. I make the perforation to allow of. a
straight line of iron chain, rod, or twisted metal wire to pass through the
entire arch when formed, and this chain, rod, or twisted metal wire I securely
fix to the iron skewbacks or abutments as herein-before mentioned, and by
this method or construction, as in all other cases, I never allow the iron chain,
rod, or twisted metal wire to take the burden of vertical pressure, but its
entire duty is that of tensiou.
And in order that my said Invention may be fully understood 1 shall now
proceed more particularly to describe the same, and for that purpose I shall
refer to the several Figures on the annexed Sheet of Drawings, the same
letters of reference indicating corresponding parts in all the corresponding
Figures.
Fig. 1 of iny Drawing represents an ordinary building girder in elevation,
shewing the brick arch A in its place; Fig. 2 is a plan of the same girder;
Fig. 3 is a plan of the same girder with the brick arch A removed; Fig. 4 is a
webb of the same girder on plan; Fig. 5 is an elevation of the webb of the
same girder; Fig. 6 is an end elevation of the skewback; Fig. 7is a section of
"girder on line A, B, shewing the arch A in section; Fig. 8 is an elevation of
skewback with arch removed; Fig. 9, elevation of dovetailed end of webb,

page_text: the dotted line shewing the section of webb on line C, D; Fig. 10 is a section
of webb shewing the dovetail end in elevation; Fig. 11 is a plan of an
ordinary girder of extra strength with two webbs and shewing the arches ",,a,
in position; Fig. 12 is a section of the double webb girder, shewing also the
arches a, a, a, and webbs B, B, in section; Fig. 13 is a perspective view of
an ordinary bridge shewing the positions of the webbs, B, B, B, B, &c., &c..
of the girders, and the arches A, A, A, A, &c., &c., the skewbacks being laid
on the piers C, C, C, C
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried
into effect, I would obs rve in conclusion that what I consider to be novel and
original, and therefore claim as the Invention secured to me by the herein-
before in part recited Letters Patent is,
-
First, I claim the peculiar form of my tension girder as unlike any girders
now made and in use, the construction being on a entirely different principle
to that of box rivetted or any other kind of girder now manufactured. The
webbs of these girders are simply made to retain the thrust of the arch or
arches, which are constructed within the space or span between the abutments
for the purpose of carrying the weight or burden above the opening. It will
thus be seen the webbs are simply in tension and are never subjected to
vertical pressure, which all other girders now made are. Again, generally
there being no rivets, bolts, or nutts of any kind in these girders renders them
less costly in every respect, and the webbs being always in tension in lieu of
offering vertical resistance gives my girders an immense advantage in strength.
The arch or arches prevent the possibility of my girders deflecting, which
frequently occurs with the girders now made, which is of very serious conse-
quence in any kind of building and often proves fatal to the entire structure.
Again, by the application of these girders a very great deal of time is saved in
building, and in consequence of their lightuess the advantages of using
these girders are very considerable; their form and lightness admit of close
packing for carriage and exportation, which also is of much importance as
causing a great saving in what is generally a costly item in such matters.
Second, the peculiar construction of skewback and the mode of applying
the same to the webb of the girder, substantially as and for the purposes
herein-before specified.
Third, the application of my peculiar girder and skewbacks or longitudinal
bars in the construction of fireproof building and other erections where it is
important to retain the thrust of the arch or arches within their immediate
spans as herein-before mentioned.

page_text: Fourth, the peculiar and particular application of these girders to bridge
building, in which construction the saving and economy of time is very
considerable.
In witness whereof, I, the said Constantine Henderson, have hereunto
set iny hand and seal, this Thirtieth day of November, in the year
of our Lord One thousaud eight hundred and sixty-six.
CONSTANTINE HENDERSON. (L.B.)