IMPROVE- MENTS IN METAL BEAMS, GIRDERS, AND TENSION BARS USED IN THE CON- STRUCTION OF ROOPS, FLOORS, AND OTHER PARTS OF BUILDINGS, AND IN THE CONSTRUCTION OF VIADUCTS AND SUSPENSION AND OTHER BRIDGES
Year: 1855

page_text: LETTERS PATENT to Henry Bessemer, of Queen Street Place, New
Cannon Street, in the City of London, for the Invention of "IMPROVE-
MENTS IN METAL BEAMS, GIRDERS, AND TENSION BARS USED IN THE CON-
STRUCTION OF ROOPS, FLOORS, AND OTHER PARTS OF BUILDINGS, AND IN THE
CONSTRUCTION OF VIADUCTS AND SUSPENSION AND OTHER BRIDGES."
Sealed the 11th April 1856, and dated the 17th October 1855.
PROVISIONAL SPECIFICATION left by the said Henry Bessemer at the
Office of the Commissioners of Patents, with his Petition, on the 17th
October 1855.
I, HENRY BESSEMER, of Queen Street Place, New Cannon Street, in the
City of London, do hereby declare the nature of the Invention for "IMPROVE-
MENTS IN METAL BEAMS, GIRDERS, AND TENSION BARS USED IN THE CONSTRUCTION
OF ROOFS, FLOORS, AND OTHER PARTS OF BUILDINGS, AND IN THE CONSTRUCTION OF
VIADUCTS AND SUSPENSION AND OTHER BRIDGES," to be as follows:-
In the construction of metal beams or girders it is of great importance to
render them as light as possible, consistent with their required amount of
stiffness and power of resisting fracture; this is especially the case where the
weight of the beams or tension rods form of themselves a considerable amount
of the load, as in the case of suspension bridges. The object, therefore, of this

page_text: Invention is to give the required degree of cohesive strength and rigidity to
beams, girders, and tension rods, with a less weight of metal than heretofore
used in beams of equal strength. For the purposes of this Invention, I put
refined or pig iron into a puddling furnace, and there work it in the usual way,
but leave off the operation of puddling before the whole of the carbonaceous
matters are driven off; about one per cent. of carbon should be retained, or
as much as by its combination with iron constitutes steel, or the metal may be
puddled until the whole of the carbon is driven off, and the powdery iron
resulting from this process may be afterwards converted into steel by cemen-
tation; or the refined or pig iron may be otherwise decarbonized, and reduced
to the state of steel, in either of which cases the metal is brought to a complete
state of fusion in pots, similar to those used in the melting of steel. When,
however, great toughness is desired, I prefer to use scrap iron, decarbonized
iron, or malleable iron, which I put into the pots alone, or mixed with charcoal
or other carbonaceous matters. When used alone, the product will be cast
malleable iron; but when mixed with carbonaceous matters, a partial cementing
of the iron will take place, and a mild or soft steel will result, peculiarly well
adapted to resist heavy shocks or sudden strains. The metal having, been
melted, I proceed to cast it into beams or girders of the desired form in sand
or loam moulds, or otherwise, and which are afterwards annealed; but when
beams, girders, or tension bars are required of great length, or are required to
be very light in proportion to their dimensions, I cast the fluid metal in iron
ingot moulds, and afterwards roll out the ingot of cast metal between rolls
until the ingot is reduced to the desired thickness. The ingots so cast are to
be made of such a form as will correspond with the intended plate or bar of
rolled metal. When a fish-bellied beam is required, the ingot should be made
straight at one edge and curved at the other, but of much less length, and
consequently much thicker than the finished plate is to be; so in like manner
other forms may be rolled. At the edges of the rolled plates where rivetting
is required, I form a raised rib on the ingot at each edge, and in rolling out
the ingot I use grooved rolls, so that an extra thickness of metal is formed at
each edge to compensate for the weakening of the plate by making the rivet
holes therein, and so in like manner I cast and afterwards roll long bars
having a raised angle running along their edges, for the purpose of strengthen-
ing them, and for facilitating the making of hollow beams without the use of
angle irons, as usually employed'; and in every case where the length of the
beam, girder, or tension bar admits, I prefer to roll it of the entire length, so
as to have no transverse joints, and thus a thinner plate will suffice. The
great cohesive force of rolled steel, and the facility the casting process affords
.

page_text: of making a large and suitable shaped piece for rolling with angles or webs
formed thereon, enables me to form beams or girders of great strength and
.rigidity in proportion to their weight, as compared with iron beams of the
usual construction.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Bessemer in the Great Seal Patent Office on the
17th April 1856:
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
BESSEMER, of Queen Street Place, New Cannon Street, in the City of London,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria,, by Her Letters
Patent, bearing date the Seventeenth day of October, in the year of our Lord
One thousand eight hundred and fifty-five, in the nineteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Henry Bessemer, Her special licence that I, the said Henry Bessemer,
my executors, administrators, and assigns, or such others as I, the said Henry
Bessemer, 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 METAL BEAMS,
GIRDERS, AND TENSION BARS USED IN THE CONSTRUCTION OF ROOFS, FLOORS, AND
OTHER PARTS OF BUILDINGS, AND IN THE CONSTRUCTION OF VIADUCTS AND SUSPENSION
AND OTHER BRIDGES," upon. the condition (amongst others) that I, the said
Henry Bessemer, 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 Henry. Bessemer, 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:-
.
In the construction of metal beams or girders it is of great importance to
render them as light as possible, consistent with their required amount of

page_text: stiffness and power of resisting fracture; this is especially the case where the
weight of the beams or tension rods form of themselves a considerable amount
of the load, as in the case of suspension bridges. The object, therefore, of this
Invention is to give the required degree of cohesive strength and rigidity to
beams, girders, and tension rods. with a less weight of metal than heretofore
used in beams of equal strength. For the purposes of this Invention, I put
refined or pig iron into a puddling furnace, and there work it in the usual way,
but leave off the operation of puddling before the whole of the carbonaceous
matters are driven off. About one per cent. of carbon should be retained, or
as much as by its combination with iron constitutes steel; or the metal may be
puddled until the whole of the carbon is driven off, and the powdery iron. re-
sulting from this process may be afterwards converted into steel by cementation;
or the refined or pig iron may be otherwise decarbonized and reduced to the
state of steel; in either of which cases the metal is brought to a complete
state of fusion in pots, similar to those used in the melting of steel. . When,
however, great toughness is desired, I prefer to use scrap iron, decarbonized
iron, or malleable iron, which I put into the pots alone, or mixed with charcoal
or other carbonaceous matters. When used alone, the product will be cast
malleable iron; but when mixed with carbonaceous matters, a partial cementing
of the iron will take place, and a "mild" or soft steel will result, peculiarly
well adapted to resist heavy shocks or sudden strains. The metal having been
melted, I proceed to cast it into beams or girders of the desired form in sand
or loam moulds, or otherwise, and which are afterwards annealed; but when
beams, girders, or tension bars are required of great length, or are required to
be very light in proportion to their dimensions, I cast the fluid metal in iron
ingot moulds, and afterwards roll out the ingot of cast metal between rolls,
until the ingot is reduced to the desired thickness; the ingots so cast are to be
made of such a form as will correspond with the intended plate or bar of rolled
metal. When a fish-bellied beam is required, the ingot should be made
straight at one edge and curved at the other, but of much less length, and
consequently much thicker than the finished plate is to be.
An ingot of metal suitable for rolling into a fish-bellied beam is represented
in the annexed Sheet of Drawings; Figure 1 being an end elevation thereof,
and Figure 2 a side elevation. When an ingot of cast malleable metal of this
shape is rolled in the direction of its greatest length, it will when sufficiently
elongated produce a plate of metal such as is represented in elevation at
Figures 3 and 4, and so in like manner when a beam or girder is required,
having its under side of an arched form. An ingot should be cast of the form
represented at Figures 9 and 10, which may afterwards be rolled to form the

page_text: plate represented at Figures 11 and 12. Either the fish-bellied plate or the
arched plate may be used between wooden beams, or they may be rivetted to
other pieces, so as to form a hollow beam or girder of their respective forms.
When beams or girders having a top and bottom flange are required, I. cast
the ingot of the shape shewn in Figures 13 and 14, and. afterwards: roll it into
the form shewn in Figures 15 and 16; and so in like manner when bars of
aT shape are required, I make an ingot of the form shewn in Figures 17
and 18, and which may afterwards be formed by rolling into the T'shaped metal
bars shewn in Figures 19 and 20, and so in like manner other forms may be
rolled. At the edges of the rolled plates where rivetting is required, I form a
raised rib on the ingot at each edge, and in rolling out the ingot I use grooved
rolls, so that an extra thickness of metal is formed at each edge to compensate
for the weakening of the plate by making the rivet holes therein; and so in
like manner I cast and afterwards roll long bars, having a. raised angle-running
along their edges for the purpose of strengthening them.
In the making of hollow beams and girders by rivetting together plates of
rolled metal, those parts of the plates where the line of rivet holes occur are
much reduced in strength, whereby a much smaller amount of force will tear
or. break the metal plate along the line of rivets than would be required to
tear asunder the metal at other parts of the plate where no holes occur. In
the making of plates of rolled metal for the construction of beams or girders, I
.therefore make the plate of greater thickness at the edges where the line of
rivet holes is to be made; the ingot for this purpose should have two raised
parts at its opposite edges, as shewn in end elevation at Figure 23.
At Figures 21 and 22, I have also shewn end elevations of ingots for angle
bars, which may be rolled out and used to form a hollow beam, such as repre-
sented in Figures 24 and 25, and in which beam the rolled ingots 21, 22, and
23 are combined. For facilitating the making of hollow beams without the use
of angle irons, as usually employed, and in every case where the length of the
beam, girder, or tension bar admits, prefer to roll it of the entire length, so as
to have no transverse joints, and thus a thinner plate will suffice. The great
cohesive force of the rolled steel and the facility the casting process affords
of making a large and suitable shaped piece for rolling with angles or webs
formed thereon, enables me to form beams or girders of great strength and
rigidity in proportion to their weight, as compared with iron beams of the usual
construction. But when beams or girders of very large size are required, so
that several plates must be combined, I prefer to place the thick edges of the
plate so as to form the vertical joints, as represented at Figure 26, which is a
side elevation of a portion of a beam so constructed; a horizontal section of

page_text: which (on a larger scale) is also shewn at Figure 27, where the plates are
shewn as secured with butt joints, having a plate on both sides. Tension
bars with enlarged ends may also be formed by rolling, provided the ends
of the ingots are enlarged in the required proportions; an example of this is
shewn at Figures 5 and 6, which represent the ingot, which may afterwards
be rolled into the form shewn at Figures 7 and 8.
Having thus described my Invention, and the manner in which the same
may be carried into practical operation, I desire it to be understood that I do
not confine myself to the precise details herein-before described, so long as
the peculiar features of my said Invention be retained; but what I do
claim is,-
Firstly, the casting or founding in malleable iron and steel, beams, girders,
and tension rods used in the construction of roofs, floors, and other parts of
buildings, and in the construction of viaducts and suspension and other
bridges.
Secondly, I claim the rolling of ingots or masses of cast malleable iron, also
ingots or masses of cast iron containing more carbon than ordinary bar or
plate iron, but a less quantity than is found in steel; also ingots
cast steel or of iron. containing as much carbon as ordinary cast steel, and
forming thereby, or by the junction of one or more pieces so produced, beams,
girders, and tension bars suitable for the construction' of roofs, floors, and
other parts of buildings, and for the. construction of viaducts and suspension
and other bridges.
Lastly, I claim forming an extra thickness at the edges of cast ingots of
'malleable iron and steel, in the manner and for the purposes herein described.
In witness whereof, I, the said Henry Bessemer, have hereunto set my
hand and seal, this Seventeenth day of April, in the year of our Lord
One thousand eight hundred and fifty-six.
Witness,
B. GOBEY,
4, Old Square, Lincoln's Inn.
HENRY BESSEMER. (L.S.)