IMPROVEMENTS IN THE PERMANENT WAY OF RAILWAYS
Year: 1876

page_text: LETTERS PATENT to John Paterson Smith, of Glasgow, in the County of Lanark,
Civil Engineer, for the Invention of "IMPROVEMENTS IN THE PERMANENT WAY
OF RAILWAYS."
aled the 28th March 1877, and dated the 1st November 1876.
PROVISIONAL SPECIFICATION left by the said John Paterson Smith at the
Office of the Commissioners of Patents on the 1st November 1876.
_JOHN PATERSON SMITH, of Glasgow, in the County of Lanark, Civil Engineer.
"IMPROVEMENTS. IN THE PERMANENT WAY OF RAILWAYS:"
The first part of my Invention relates to the construction of railway chairs, but
more particularly to that class which act also as sleepers and known as sleeper▾
chairs, and to their use in combination with the rails in such manner as to adapt
them to advantageously resist the combined vertical and lateral forces to which
they are subjected by the action of the wheels of passing vehicles.
It is well known to those acquainted with the working of railways that there is
great difficulty in maintaining the rails at the proper angle of "tilt" and in pre-
venting the distance between them, that is, the gauge, being altered in consequence
of the lateral pressure to which the rails are subjected outwards by the action of the
wheels against their inner edges. This lateral or side action takes place to some
extent on straight lines of railway from the side swing which the vehicles partake
of when in motion, but is greatest on curves in consequence of the centrifugal force
pressing the wheels against the inside of the outside rail; more especially has the
injurious effect of this lateral pressure or force been observed when the rails are
resting upon and secured by sleeper chairs made of cast or malleable metal and
connected together by cross tie bars of malleable iron having small bearing surface.
When sleeper chairs of this description made in the ordinary way are used, it is
found that the lateral action of the wheels, by causing the rails to be forced out-
wards, cause the outside of the sleeper chairs to "dig" into the ground and bend
the cross tie bars, the result being loss of the proper gauge and angle of "tilt" of
rail.
Now the object of my Invention is to remedy these defects in the permanent way
of railways, and I carry my Invention into effect in manner following, that is to
say I first determine the centrifugal force due to the heaviest vehicle at its

page_text: maximum speed passing round the curve of smallest radius on any particular line
of railway; the centrifugal force thus ascertained is the side thrust on the rail
outwards. This thrust or pressure outwards being compounded with the pressure
due to the load on the wheel, I obtain the line of the resultant of their forces and
proceed to so devise my chairs, and more particularly sleeper chairs and combine
them with the rails so that the line of the said resultant shall divide equally a line
representing the base of the cross section of the sleeper chair and give equal bearing
areas on either side of a line drawn at right angles to the line of cross section
through the point of intersection.
Sleeper chairs proportioned, constructed, and used in this manner will not have
any tendency to "dig" or dip into the ground at their outer edges, but will maintain
a true and horizontal bearing.
The form of the chairs and sleeper chairs may be varied. They may be cast or
fashioned from plates, but in practice I prefer to use a modified chair having
embossations as covered by Patent No. 3990 of the year 1875.
The second part of my Invention relates to improvements in the construction of
railway sleeper chairs made from wrought iron or steel plates whereby the elasticity
is greatly increased and the necessity for any elastic packing between the sleeper
and rail obviated. I have found in experimenting upon sleepers made from steel
and iron plates that the form heretofore usually adopted has a very small limit of
elasticity and gave way by "setting" down immediately below the bottom of the
rail with a comparatively light load, and did not regain its shape again when
released. I therefore under this part of my Invention make the sides and ends of
such sleeper chairs of the form known as an "elastic curve." In this way a very
large range of elasticity is obtained, and the sleepers recover their original form
after being subjected to considerable pressure.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Paterson Smith in the Great Seal Patent Office on the 30th
April 1877.
JOHN PATERSON SMITH, of Glasgow, in the County of Lanark, Civil Engineer.
"IMPROVEMENTS IN THE PERMANENT WAY OF RAILWAYS."
The first part of my Invention relates to the construction of railway chairs, but
more particularly to that class which act also as sleepers and known as sleeper
chairs, and to their use in combination with the rails in such manner as to adapt
them to advantageously resist the combined vertical and lateral forces to which
they are subjected by the action of the wheels of passing vehicles.
It is well known to those acquainted with the working of railways that there is
great difficulty in maintaining the rails at the proper angle of "tilt" and in pre-
venting the distance between them, that is the gauge, being altered in consequence
of the lateral pressure to which the rails are subjected outwards by the action of the
wheels against their inner edges. This lateral or side action takes place to some
extent on straight lines of railway from the side swing which the vehicles partake
of when in motion, but is greatest on curves in consequence of the centrifugal force
pressing the wheels against the inside of the outside rail; more especially has the
injurious effect of this lateral pressure or force been observed when the rails are
resting upon and secured by sleeper chairs made of cast or malleable metal and
connected together by cross tie bars of malleable iron having small bearing surface.
When sleeper chairs of this description made in the ordinary way are used it is
found that the lateral action of the wheels by causing the rails to be forced out-
wards cause the outside of the sleeper chairs to dig into the ground and bend
the cross tie bars, the result being loss of the proper gauge and angle of tilt of
rail.

page_text: Now the object of my Invention is to remedy these defects in the permanent
way of railways, and I carry my Invention into effect in manner following, that is
to say I first determine the centrifugal force due to the heaviest vehicle at its
maximum speed passing round the curve of smallest radius on any particular line
of railway; the centrifugal force thus ascertained is the side thrust on the rail
outwards. This thrust or pressure outwards being compounded with the pressure
due to the load on the wheel, I obtain the line of the resultant of their forces and
proceed to so devise my chairs, and more particularly sleeper chairs, and combine
them with the rails, so that the line of the said resultant shall divide equally a line
representing the base of the cross section of the sleeper chair and give equal bearing
areas on either side of a line drawn at right angles to the line of cross section
through the point of intersection..
Sleeper chairs proportioned, constructed, and used in this manner will not have
any tendency to "dig" or dip into the ground at their outer edges, but will maintain
a true and horizontal bearing.
The form of the chairs and sleeper chairs may be varied. They may be cast or
fashioned from plates, but in practice I prefer to use a modified chair having
embossations as covered by Patent No. 3990 of the year 1875.
The second part of my Invention relates to improvements in the construction of
railway sleeper chairs made from wrought iron or steel plates whereby the elasticity
is greatly increased and the necessity for any elastic packing between the sleeper
and rail obviated. I have found in experimenting upon sleepers made from steel
and iron plates that the formn heretofore usually adopted had a very small limit of
elasticity and gave way by "setting" down in the crown immediately below the
bottom of the rail with a comparatively light load and did not regain its shape
again when released. I therefore under this part of my Invention make the sides
and ends of such sleeper chairs of the form known as an "elastic curve." In this
way a very large range of elasticity is obtained and the sleepers recover their
original form after being subjected to considerable pressure.
Having now described the nature of my said Invention and particularized the
same in such manner that others will be enabled to carry the improvements into
practice, I would have it understood that what I claim is, the construction, arrange-
ment, and combination of parts, all substantially as herein described for the purposes
set forth.
In witness whereof, I, the said John Paterson Smith, have hereunto set my
hand and seal, the Twenty-fifth day of April, in the year of our Lord One
thousand eight hundred and seventy-seven.
J. P. SMITH. (LS.)