Improvements in Pavements.
Year: 1892

page_text: Date of Application, 17th May, 1892-Accepted 25th June, 1892
Improvements in Pavements.
A communication from JOHN ARMSTRONG CHANLER, of New York, United
States of America, Lawyer.
I, ALFRED JULIUS BOULT, of 323 High Holborn, in the County of Middlesex,
Member of the Institution of Mechanical Engineers, do hereby declare the nature
of this invention, and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
The following is a specification of this invention, reference being had to the
accompanying drawings.
Prior to this invention, pavements for streets of a durable character have been
constructed in a variety of ways, the principal of which are as follows:
First Of blocks of stone, set closely together from curb to curb, upon a suitable
foundation.
Second Blocks of wood similarly set.
Third
Continuous surface of asphalt.
Fourth Surface of broken stone commonly known as macadam.
:
Fifth Surface composed of asphalt for wheel tracks combined with a cheaper
and softer cemented surface for horse tracks.
Sixth Uneven or obstructed surfaces composed of sunken tracks of stone or iron
combined with raised surfaces of stones for horses.
All these forins of pavements present certain features of inferiority.
The pavements made of blocks of stone are rough, disagreeable. to ride over, and
easily become uneven by depression of individual blocks or sections.
The wooden pavements are found to be pleasant to ride over, but lacking in
durability, owing to the permeation of moisture.
The asphalt surfaces are convenient to travel over for the occupants of vehicles,
but are exceedingly slippery and dangerous for horses.
The macadam or broken stone pavement, while excellent as a holding
surface for horses' feet, are difficult to keep clean, especially if of an extended
character.
The combination of asphalt and other cemented compositions and of sunken
stone or iron and raised stoues, present such obvious defects that they never
have come into general use.
This invention is that of an improved pavement which will combine the good
features of former pavements, and obviate the difficulties, or many of the difficulties,
incident to each of them.
In the drawings annexed hereto, in which similar letters of reference refer to
similar parts throughout the various views,
Fig. 1 is a plan or top view of the proposed pavement or roadway,
Fig. 2, a cross section thereof on line 2-2,
Fig. 3 an enlarged detail top plan view and
Fig. 4 a cross section thereof on line 4-4.
The pavement and roadway are constructed as follows: I first lay upon suitable
ties or stringers, or both, a series of parallel flat rails, A, A, A,. sufficient to
accommodate the travel of the street or road.
I have illustrated in the drawings, three parallel lines of travel, and three pairs
of such rails, and in most cities the streets are wide enough for three or four lines
of travel, and three or four parallel lines of such rails.
These rails are made preferably of Bessemer steel, of suitable thickness, say
one half inch in thickness, and very much broader than ordinary rails, for

page_text: A breadth of from eight to twelve inches for each rail is recommended. These
rails may be set, if desired, upon steel or iron ties, or the ties or stringers may be
laid in a cement bed, to promote the durability of the structure.
At the sides of
the streets or roadways, between the exterior line of rails and the curb D, and
between each pair of rails at the points marked C, the surface is filled in with a
stone pavement, preferably of cobble stones or granite blocks. I also, sometimes,
lay a single line of cut blocks of stone along both sides of each line of rails,
as shown at E, E.
Between the rails of each pair, at the points marked B in the drawing, I fill
in, with a composition, such as macadam, and lay the same upon a suitable
foundation (hydraulic concrete preferred) which will insure, as far as possible,
the maintenance of the macadam at the plane of the upper surface of the rail A,
and the stone filling, C, of the street.
Thus this improved pavement consists essentially of a combination of flat
rails having their top surface flush with the general surface of the roadway, and
having between them a composition surface, such as macadam of the same level
as the rails, but differing from them in that it forms a proper holding surface
for the feet of horses.
The stone pavements, C, at the side of the street, and between the pairs of
rails, are an optional modification whose design is to keep travel in the centre of
the roadway as far as possible, and upon the line of rails, and the stone
bordering for the rails acts to protect the pavement from transverse traffic.
The rails will also tend to break up what would otherwise tend to be a
continuous surface of the macadam, will form levelling lines, by which the surface
can be always brought up to the true level, and will always afford a smooth and
easy surface for the wheels of vehicles.
Thus this pavement combines a smooth even surface for the wheels of vehicles,
and at the same time a good holding surface for the feet of horses, and means due
to the above combination of features which render the maintenance of the
roadway, at a true level, always easy and the composition or characteristic of each
part of the pavement tends to assist and render unobjectionable any otherwise
objectionable features of the other parts.
The use of the improved pavement will result in great economy both in the
wear and tear of vehicles, in the expenditure of force in drawing vehicles, and in
the saving of horses' feet in travelling over the pavements.
My correspondent has found, also, that in cities already paved with some one of
the usual pavements, such as granite or wooden blocks or asphalt, a very large
proportion of the expense of laying down the pavement embodying this invention
may be saved by simply applying to such pavements already laid, the broad flat
iron rails, A, laid with their top surfaces flush with the general surface of the
roadway, for wheel tracks, without substituting macadam or similar composition for
the old pavement in the horse track.
The breadth of the rail is one of the features of this invention. Heretofore
when rails have been used for vehicles, said rails have been provided with ridges
or grooves operating in conjunction with flanges on the wheels of the vehicles to
keep said wheels on said tracks; or said rails have been sunk below the general
surface of the roadway to accomplish this result. The annoyance caused by the
roughness and ruts of such pavements is well known. My correspondent has
discovered that by making the rails sufficiently broad to allow ordinary deviation of
the vehicle and yet not so broad as to interfere with the footing of the horses, no
ridges, grooves, or sunken rails are necessary to keep the wheels upon these rails,
and the general even surface of the roadway may be maintained. Horses naturally
will avoid the smooth surface of the rails.
The remainder of the roadway, whether of granite or wooden blocks, or of
asphalt, or any other ordinary road-bed, is left unchanged. If the original
road-bed is of stone, its comparative roughness serves to keep travel upon
the rails.

page_text: Thus the pavement comprises a roadway having a surface composed of flat iron
rails for the wheels of vehicles and filled in with a pavement or roadway of one
of the ordinary styles, the whole having a surface substantially plane.
Having now particularly described and ascertained the nature of the said inven-
tion, as communicated to me by my foreign correspondent and in what manner the
same is to be performed, I declare that what I claim is :-
1. The roadway constructed substantially as described, of flat iron rails laid
with their top surfaces flush with the general surface of the roadway, said flat iron
rails being of sufficient width and so located as to be adapted to wheels of common
vehicles, and filled in between with macadam or similar composition, substantially
as and for the purposes described.
2. The improved roadway, consisting of the flat iron rails, A, laid with their
top surface flush with the general surface of the roadway, the macadam or
composition B, and stone filling C, all combined together, substantially as and for
the purposes described.
3. In a roadway, the tracks or ways for the wheels of vehicles, which consist of
flat iron rails laid with their top surfaces flush with the general surface of the
pavement and broad enough to accommodate the wheels of vehicles throughout
the ordinary deviations of the horses between said rails, substantially as and for
the purposes described.
Dated this 17th day of May 1892.
W. P. THOMPSON & BOULT,
Agents for the Applicant.