IMPROVEMENTS IN THE MANUFACTURE OF RAILWAY BARS
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 "IMPROVEMENTS IN THE
MANUFACTURE OF RAILWAY BARS."
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 THE MANUFACTURE OF RAILWAY BARS," to be as follows:
In the process of manufacturing malleable iron rails as at present practised,.
the small fragments of puddled iron which are collected together to form a
puddle ball are more or less oxidized on their exterior surfaces, and are other-
wise coated or mixed with scoria and other extraneous matters. In the squeez-
ing or rolling process which follows a large proportion of these extraneous
matters are driven out, but so much of them is often retained as to prevent an
equal and perfect union of the surfaces of all the numerous pieces of which the
mass of iron is composed. In the operation of rolling a considerable elonga-
tion of the metal takes place, and consequently those parts of the iron which
are prevented from uniting by the scoria, oxide, or other matters, are also

page_text: much elongated, forming what are called flaws or sand cracks, and giving a
more or less detached or feebly coherent lamelar texture to those parts of the
iron. The rolling of heavy wheels over such a material tends to elongate
the upper stratum, which ultimately becomes loosened and detached from
the general body of the rail, and which defect is augmented by the soft and
malleable condition common to iron that is entirely deprived of its carbon.
Now, the object of my said Invention is to lessen or remove these defects,
and to produce as nearly as may be an homogeneous mass of metal, free from
the admixture of oxyde, scoria, or other extraneous matters before referred to,
and at the same time to have combined with it as much carbon as will give it
a greater degree of hardness and power of resisting the laminating action of
the wheels which pass over it, and in which state of combination the metal is
commonly termed steel.
In carrying my said Invention into practical operation, I take, by preference,
refined iron, and put it into the ordinary puddling furnace, where it is at first
treated in the usual way, being raked about until it has thrown off the greater
part of its carbon; but care should be taken not to carry this process of decar-
bonization too far; about one per cent. of carbon should be retained. A
knowledge of the most advantageous point to leave off the puddling operation
will be readily acquired in practise, a good test to the workmen being the
facility with which the metal will fuse in the succeeding operation. The metal
having been.brought to the desired point of decarbonization is raked out of
the puddling furnace and allowed to cool; these products may be mixed in
large quantities to equalize the quality, or it may be drawn into fire clay
crucibles, arranged in furnaces such as are now commonly employed for melt-
ing steel; a little charcoal or other carbonaceous matters are to be thrown
into the crucibles among the pieces of metal, which will assist in reducing the
oxide formed by the previous operation. The fires in the melting furnaces are
to be kept up vigorously until the complete fusion of the metal takes places;
it is then to be poured in a fluid state into iron ingot moulds, placed vertically
or nearly so, with open tops, the shape of the moulds being such as to give
the ingot of cast steel more or less the intended form of the rail; the ingot.
being, however, much more massive, in order that it may afterwards be reduced
in thickness and increased in length, by rolling, in a similar manner to that
already practised in rolling railway bars formed of malleable iron. The raw
ends of the steel bars may be cut off and remelted by mixing them with fresh
portions of metal from the puddling furnace. The combination of such a
quantity of carbon with the iron as to constitute steel will greatly increase its
power of resisting the laminating action of the engine and carriage wheels, and

page_text: at the same time add to its stiffness and cohesive strength, as compared with
malleable iron rails of the same sectional area. As some of the details of my
said Invention admit of considerable variation, and as by such means a differ-
ence in the quality and cost of the rails will be made, I deem it necessary to
give a description thereof. I have herein-before described how the puddled
iron is made to retain about one per cent. of carbon; now, instead of this, in
carrying out my second modified process; I allow the puddling operation to be
continued until the carbon is dissipated as far as practicable, the iron being
reduced to a dry and powdry state; when it is to be raked out of the puddling
furnace, and be afterwards converted into steel by cementation with powdered
charcoal in close vessels, after the manner employed in the making of blister
steel, or, by preference, by a continuous operation in vertical retorts, for which I
obtained Letters Patent, dated the 18th day of June 1855; or, in lieu of the
puddled iron, small pieces of scrap iron may be used alone or mixed with a
portion of puddled iron, and be then converted into steel by cementation with
charcoal; these matters may then be melted and otherwise treated, as herein
firstly described. In some cases, however, the process of cementation may be
carried on advantageously in the melting crucibles, the pieces of scrap or
puddled metal being mixed with charcoal or other suitable carbonaceous
matters. When this method is employed, a very "mild" steel is obtained, con-
taining very little carbon, and partaking of the quality of wrought iron in
toughness, and is in consequence well calculated to stand the powerful shocks
to which rails are sometimes exposed; in any case, the rails after they are
rolled should be annealed, or allowed to cool slowly, in order that they may
retain as much toughness as possible. I have herein-before described how the
melting of the steel may be effected by means of the kind of furnaces and
crucibles already in use for melting steel, but I would have it understood that
I believe the same may be accomplished in a cheaper and more convenient
manner by the use of crucibles of a larger kind than those generally in use, and
provided with holes in the lower part of them for the purpose of tapping out
or discharging the metal from them without the removal of the said crucibles
from the furnace; the particulars of which mode of melting steel may be
ascertained by reference to the Specification of a Patent granted to me for
"Improvements in the Manufacture of Cast Steel, and Mixtures of Steel and
Cast Iron," and bearing date the 18th day of June 1855.

page_text: 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
THE MANUFACTURE OF RAILWAY BARS,"-upon the condition (amongst others) that.
I, the said Henry Bessemer, my executors or administrators, by an instru-
ment 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 imme-.
diately 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 per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:-.
In the process of manufacturing malleable iron rails as at present practised,
the small fragments of puddled iron which are collected together to form a
puddle ball are more or less oxydized on their exterior surfaces, and are other-
wise coated or mixed with scoria and other éxtraneous matters. In the
squeezing or rolling process which follows, a large proportion of these extra-
neous matters are driven out, but so much. of them is often retained as to
prevent an equal and perfect union of the surfaces of all the numerous picces
of which the mass of iron is composed. In the operation of rolling a consider-
able elongation of the metal takes place, and consequently those parts of the
iron which are prevented from uniting (by the scoria, oxide, or other matters,)

page_text: are also much elongated, forming what are called flaws or sand cracks, and
giving a more or less detached or feebly coherent lamelar texture to those
parts of the iron. The rolling of heavy wheels over such a material tends to.
elongate the upper stratum, which ultimately becomes loosened and detached
from the general body of the rail, and which defect is augmented. by the soft.
and malleable condition common to iron that is entirely deprived of its carbon..
Now, the object of my said Invention is to lessen or remove these defects, and
to produce as nearly as may be a homogenous mass of metal, free from the
admixture of oxyde, scoria, or other extraneous matters, before referred to,.and
at the same time to have combined with it as much carbon as will give it a
greater degree of hardness and power of resisting the laminating action of tho
wheels which pass over it, and in which state of combination the metal is
commonly termed steel. Although in some cases the quantity of combined
carbon may be so reduced that a metal much softer than ordinary steel will be
produced, one of the greatest objects of my Invention being the attainment of
the greatest amount of solidity and cohesion of all the particles of metal of
which the rail is composed by bringing the metal to a sate of fusion, and
allowing such fused or fluid metal to run into any suitable mould or cavity
capable of holding the fluid metal, and also capable by its size and form of
giving to the metal (when consolidated therein) such a configuration as will be
suitable for the formation of a rail or railway bar of any desired sectional form.
In carrying my said Invention into practical operation, I take by preference
refined iron, and put it into the ordinary puddling furnace, where it is at first.
heated in the usual way, being raked about until it has thrown off the greater
part of its carbon; but care should be taken. not to carry the process of decar-
bonization too far; about one per cent. of carbon should be retained. A.
knowledge of the most advantageous point to leave off the puddling operation
will be readily acquired in practise, a good test to the workman being the
facility with which the metal will fuse in the succeeding operation. _
The quantity of carbon left in combination with the iron may, however, be
considerable varied, and thus the rails may be rendered peculiarly adapted to.
the various strains and wear to which they will be subjected when in use; thus,
for rails over which very heavily loaded goods trains have to pass I prefer to
make the rails of well carbonized steel of a hard quality, and thus prevent as
far as possible their wear and tear; but where a rail is to be used for light
passenger traffic, I prefer to deprive the iron of nearly all its carbon, and thus
form a metal of a softer quality, nearly resembling soft iron in toughness, and
well adapted by reason of this quality to withstand concussions consequent on
the rapid rate at which passenger trains are moved.

page_text: The metal having been brought to the desired point of decarbonization is
raked out of the puddling furnace and allowed to cool; these products may be
mixed in large quantities to equalize the quality, or it may be drawn into fire-
clay crucibles, arranged in furnaces such as are now commonly employed for
melting steel; a little charcoal or other carbonaceous matters are to be thrown
into the crucibles among the pieces of metal, which will assist in reducing the
oxide formed by the previous operation; the fires in the melting furnaces are to
be kept up vigorously until the complete fusion of the metal takes place; it is
then to be poured in a fluid state into iron ingot moulds, placed vertically or
nearly so, with open tops, the shape of the moulds being such as to give the
ingot of cast steel more or less the intended form of the rail; the ingot being,
however, much more massive, in order that it may afterwards be reduced in
thickness and increased in length, by rolling, in a similar manner to that
already practised in rolling railway bars formed of malleable iron. The raw
ends of the steel bars may be cut off and remelted by mixing them with fresh
portions of metal from the puddling furnace.
The ingot moulds used for casting or forming blocks or ingots of metal to
be afterwards rolled into railway bars may (and I prefer them to) be made of
iron, the mould opening in two halves, which are detached, and which may be
held together at the time of casting by screw clamps, or by a ring passed over
them, into which a wedge is driven, so as to force the separate parts of the
mould in close contact. Before running the metal in them the mould should
be smoked, as already practised in preparing moulds for casting ingots of steel;
or, if preferred, the ingot or mould may be formed of sand, loam, or any
suitable material in which moulds for casting iron or steel have been found
convenient.
The combination of such a quantity of carbon with the iron as to constitute
steel will greatly increase its power of resisting the laminating action of the
engine and carriage wheels, and at the same time add to its stiffness and
cohesive strength, as compared with malleable iron rails of the same sectional
area.
As some of the details of my said Invention admit of a considerable varia-
tion, and as by such means a difference in the quality and cost of the rails will
be made, I deem it necessary to give a description thereof. I have herein-
before described how the puddled iron is made to retain about one per cent. of
carbon. Now, instead of this, in carrying out my second modified process, I
allow the puddling operation to be continued until the carbon is dissipated as
far as practicable, the iron being reduced to a dry and powdery. state, when it
is to be raked out of the puddling furnace, and be afterwards converted into

page_text: steel by cementation with powdered charcoal in close vessels, after the manner
employed in the making of blister steel, or, by preference, by a continuous
operation in vertical retorts, for which I obtained Letters Patent, dated the
Eighteenth day of June, One thousand eight hundred and fifty-five; or, in lieu
of the puddled iron small pieces of scrap iron may be used alone or mixed with
a portion of puddled iron, and be then converted into steel by cementation
with charcoal. These matters may then be melted and otherwise treated as
herein firstly described. In some cases, however, the process of cementation
may be carried on advantageously in the melting crucibles, the pieces of scrap
or puddled metal being mixed with charcoal or other suitable carbonaceous
matters. When this method is employed a very "mild" steel is obtained,
containing very little carbon, and partaking of the quality of wrought iron
in toughness, and is in consequence well calculated to withstand the powerful
shocks to which rails are sometimes exposed; in any case, the rails after
they are rolled should be annealed, or allowed to cool slowly, in order that they
may retain as much toughness as possible.
I have herein-before described how the melting of the steel may be effected
by means of the kind of furnaces and crucibles already in use for melting steel,
but I would have it understood that I believe the same may be accomplished
in a cheaper and more convenient manner by the use of crucibles of a larger
kind than those generally in use, and provided with holes in the lower part of
them, for the purpose of tapping out or discharging the metal from them
without the removal of the said crucibles from the furnace, the particulars of
which mode of melting steel may be ascertained by reference to the Specifica-
tion of a Patent granted to me for "Improvements in the Manufacture of Cast
Steel, and Mixtures of Steel and Cast Iron," and bearing date the Eighteenth day
of June, One thousand eight hundred and fifty-five; and here I would observe,
that partially decarbonized malleable metal suitable for the purposes of my
Invention may also be obtained in the manner set forth in the Specification of a
Patent granted to me for "Improvements in the Manufacture of Cast Steel,"
and which said Patent bears even date herewith, the Specification of which
has been duly filed simultaneously with this present one.
Having thus described my said Invention, and the manner in which the
same may be carried into effect, I desire it to be understood that I do not
confine myself to the precise details herein-before decribed, so long as the
peculiar features which characterize my said Invention are retained. What
I claim is,-
Firstly. The running (while in a fused or fluid state) decarbonized or
partially decarbonized iron into a mould, and thereby obtaining an ingot or

page_text: mass of iron suitable for and capable of being formed into a rail or railway
bar by the process of rolling, and the making from such ingots or masses of
malleable metal a rail or railway bar..
Secondly. I claim melting puddled or partially decarbonized puddled iron in
crucibles, and then casting the same into ingots, for the purpose of forming
rails or railway bars by the process of rolling.
Thirdly. I claim the melting and casting cemented puddled iron into ingots,
for the purposes of forming rails or railway bars by the process of rolling.
In witness whereof, I, the said Henry Bessemer, have hereunto set my
hand and seal, the 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.)