ground Electrical Conductors and to Apparatus for Use in Connection therewith.
Year: 1885

page_text: ground Electrical Conductors and to Apparatus for Use in
Connection therewith.
I, WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake & Co Patent Agents
Southampton Buildings, in the County of Middlesex, do hereby declare the nature
of my invention for "IMPROVEMENTS RELATING TO ARRANGEMENTS OR SYSTEMS
OF UNDERGROUND ELECTRICAL CONDUCTORS AND TO APPARATUS FOR USE IN
CONNECTION THEREWITH and in what manner the same is to be performed, to
be particularly described and ascertained in and by the following statement:-
"
This invention is an improvement in systems of underground electrical conductors,
the improvement being directed to facilitating the laying and distribution of the
conductors throughout a city or any part of the same; to the better insulation of
said conductors, and the prevention of inductive or other injurious effects arising
from the close proximity of circuits for different purposes, such as telegraphing or
telephoning on the one hand, and electric lighting on the other.
The system is comprehensive and complete, in so far as it provides for the
economical laying and working of all circuits which the present needs of business
and communication require; in other words, it provides for the running in close
proximity of circuits for carrying the strongest and most intense currents, as well
as those for carrying the most feeble electrical impulses such as are produced in
the operations of telephony, and this, in such manner that there will be no danger
to any circuit, while all are brought within ready and easy access.
The system comprises main and branch pipes or conduits, in which the conductors
are carried in the manner hereinafter specified. The mains consist of three separate
and independent pipe lines; one, containing such wires as are required for commu-
nication with distant points, or other cities, and which will be hereinafter designated
as trunk lines, another pipe contains the wires of circuits used in local communi-
cation, such as telephone lines, fire and burglar alarm circuits and the like, while
the third contains the circuits used for electric lighting, transmission of power or
those industrial and domestic applications of electricity which require powerful
currents.

page_text: The lines are run through the streets of a city at such a distance below the
surface as will insure protection against bending or injuries from repair of the
streets, subsidence of the surface soil and the like. Generally and whenever
convenient the lines are run midway between the buildings on either side of the
way, and with the trunk line between the other two.
At the intersections of the streets the three lines are run into what are termed
man-holes, that is subterranean chambers large enough to permit a man to enter
them for obtaining access to the pipes or conductors therein. These man-holes are
constructed in a way to keep out water and other matters, and are provided with
suitable detachable covers. The pipes pass through their sides and the wires are
carried from one pipe to another as may be required.
Between the man-holes and along the blocks or squares, are numerous subter-
ranean chambers which are designated hand-holes. These are placed as nearly as
practicable opposite the dividing line between the buildings, so that in places
where the buildings are of about the same frontage two hand-holes are required
for each group of four houses, as will be shortly explained.
The hand-holes are for the purpose of running branches from the two pipe lines
on either side of the trunk line, which latter does not pass through them. They
are much smaller than the man-holes, though constructed on the same principle.
The pipes containing the signalling and those with the electric light wires, enter these
boxes and one or more of the wires or branches from the same are brought up to a
higher level and taken off into smaller branch pipes to the buildings. Four of the
small pipes run from each hand-hole, one to each of the four nearest buildings, and
in laying the hand-holes and branches it is desirable to locate the former as near as
possible to each other in order that all the branches may be placed, in laying, in
one small trench. Of the two branch pipes that run to each house, therefore, one
contains the wires of an electric light circuit, the other those of a telephone or
other signalling circuit. In the case of the former there may be one or more
leading and return wires for the same house circuit, or the leading wire or wires to
one house and the return wire or wires form another. This is obviously a matter
of choice and not essential to the main features, that of isolating the electric circuit
from the others.
The material preferred for the pipes, man-holes and hand-holes is a compound of
coal-tar, paraffine, silicious sand, pulverized ashes and cinders, oxide of manganese
and ammonium chloride, in about the proportions hereinafter specified.
Inasmuch as the mains are buried deep, and are of comparatively large size they
are advantageously made of this insulating compound alone, but it is extremely
undesirable to bury the branch pipes deep, in fact they should be but little below
the surface or flagging of the street, and as they carry, usually, only one or two
wires they should be made quite small. Instead of making them of the compound
alone, iron pipes are used which are filled with the compound through which
passages are formed for the wires. By this means the requisite strength and
insulation are obtained.
With this general description of the nature of the system, the specific con-
struction and composition of the parts of the same, will be now described by
reference to the drawings.
Figure 1, is a general plan or diagram of a portion of the system as applied to a
city or town.
Figure 2 is a vertical central section of one of the man-holes.
Figure 3. is a plan view of the same.
Figure 4 is a plan view of a part of the line exhibiting the arrangement of the
hand-holes.
Figure 5 is a broken section of figure 4, taken through the centres of the
hand-holea.
Figure 6 is a longitudinal section of a part of one of the branch pipes.
In figure 1, is illustrated a portion of a city at the intersection of two streets.
The underground lines are laid at, or near the middle of the street, and are inclosed

page_text: in the pipes. That indicated in continuous lines is the trunk line and is lettered A.
The conduit B, is in dotted lines and contains the local signalling circuits, while C,
in broken lines contains the electric light and power circuits. The three lines or
systems are laid in the same trench, on the same or on different levels, and prefer-
ably, with the trunk line in the centre. At the intersections of the streets the
three pipes enter the man-hole D.
The details of the construction of this are shown in figures 2 and 3. It is a large
box or chamber made of moulded slabs, or in one piece, of the insulating compound
described, and consisting of the residuum of partially distilled coal-tar, paraffine,
silicious sand, pulverized ashes and cinders, oxide of manganese and ammonium
chloride in about the proportions of 50 gallons of coal-tar, two of paraffine,
150 pounds of silicious sand, 50 of ashes and cinders, two pounds of oxide of
manganese and one of ammonium chloride. These ingredients, when thoroughly
mixed and heated, form a plastic compound which is moulded in the desired shape
and which, when cool becomes extremely hard. The man-holes have a contracted
opening at the top, which is closed by the following means. A metal rim E is
placed in the mould or on the material while soft. On hardening, the compound
adheres to the rim, but it may be secured by other means if deemed expedient. A
cross-bar F is properly secured in the rim and the cover is held down by.a screw-
belt C that passes through the cross-bar.
The man-holes are preferably made oval or oblong in cross section, as shown in
figure 3, and the mains are introduced through its broader sides. The mains are
made of the same material as the man-holes and they are joined to it by passing
their ends through holes in its sides and ramming in some of the same material,
while soft, around their ends. In each man-hole is a partition H, or several, if
desirable, that extends up above the level of the mains dividing the space within
the man-hole into compartments. In one of these compartments the electric light
wires enter so that they are entirely shut off from the other circuits by a wall of
insulating material. The mains enter and leave the man-holes on opposite sides,
but where it is necessary to run either trunk lines or local circuits off on side
streets, other circuits K, L are joined to the man-holes, as shewn in Figure 1.
The man-holes permit easy access to all the circuits. The entering wires are
here distributed to the proper conduits, repairs or tests made, or new circuits
introduced.
The mains are for this purpose made with a certain number of ducts or
passages a (Figure 2) through which the wires are drawn.
For running the circuits to the different houses, the junction boxes or hand-
holes P shewn in Figures 4 and 5 are used. These are connected with the electric
light and local wire conduits only, and are placed as near together as practicable;
in order that the pipes running from them may be laid in the same trench.
These hand-holes are made of the same material as the conduits and man-holes,
are similar to them in many respects, and are provided with the same or similar
covers. They are much smaller and shallower, however, extending down only
slightly below the level of the mains. The latter are joined to them in the same
manner as to the man-holes.
In the diagram Figure 1, are represented the houses and buildings along the.
street. The division lines between the buildings are designated by M and as near
as practicable in line with these, two hand-holes are placed. Tubes run direct from.
the hand-holes to the buildings. From the hand-holes N, on the electric light
conduits run the branch pipes m n and m n¹ and from the haud-holes O, on the
local signalling circuit conduit run branches op o¹ pl. There will be four branch
pipes from each hand-hole and they enter them considerably above the level of the
mains and just below the surface of the street. Such wires as are necessary are
taken up from the mains and carried through these branches.
It is desirable that these branches should be small, and that they should be near
the surface, but it is desirable under these circumstances, to make them of stronger.
materials than are used in the mains. For this reason iron pipes or tubes provided"

page_text: with suitable couplings and filled with the material composing the mains are used,
and through these, ducts or passages are formed for the wires. The method of
making them is to place an iron pipe of the desired length over one or more smaller
rods or tubes fixed rigidly at one or both ends, the intervening spaces being then
filled in with the hot and soft insulating material which is tamped down to form a
solid mass.
The rods or tubes are then withdrawn and the compound allowed to
barden.
These pipes are joined to the hand-holes in the same manner that the insulating
mains are united to the man or hand-holes. As the hand-holes are only designed
to afford access to the wires in one pipe they are much smaller than the man-
holes,
Of course in practice, the system may or may not be carried out in all its
described details. For instance, it is not requisite that branches be carried to
every house on a block, as all the buildings may not need or use them; nor is the
invention limited to a single pipe for the trunk line or either of the others, as the
necessities of particular cases may require two or even more of one or all kinds of
pipe named. Further, so far as the general plan of distribution is concerned, it is
largely immaterial how, or of what materials the conduits and their appurtenances
are made.
The particular advantages derived from this method of running underground
lines are these. The conductors of different classes of circuits are entirely isolated
from each other, so that injurious electrical inductive disturbances are reduced to a
minimum and the greatest safety assured. At the same time all the lines are
brought into positions of easy access at the man-holes, one of the latter only, being
required for the three lines.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, as communicated
to me by my foreign correspondent I declare that what I claim
First. In an electrical underground system for cities and towns, the combination
with three parallel and independently protected lines or groups of circuits; to wit,
a trunk line or lines, a local signalling line or lines, and an electric light line or
lines of man-holes or subterranean chambers placed at the intersections of the
streets, and through which all the lines pass, and hand-holes or junction boxes
located along the conduits of the local signalling and electric light lines only, and
insulated branches from said hand-holes to the buildings along the streets, as herein
set forth.
Second. In an underground system for cities and towns, the combination with
three independent and parallel conduits, one containing the trunk lines, another the
local signalling lines, and the third, electric light lines, of man-holes or subterranean
chambers placed at the intersection of the streets, and to which all the conduits are
led, hand-holes placed at intervals along the conduits containing the local signalling
and electric light lines and branch pipes or conduits leading from said hand-holes
to the buildings on opposite sides of the street, the said branch pipes being placed
above the main conduits and near the surface of the street and enclosing branches
from the conductors therein, as set forth.
Third. In an underground system for cities and towns, the combination with
three independent and parallel conduits, one containing the trunk lines, another
the local signalling lines and the third the electric lines, of man-holes placed at the
intersections of the streets and into which all the conduits are led, the man-holes
being divided into compartments by one or more insulating partitions whereby the
electric lines will be separated or isolated from the others, hand-holes placed at
intervals along the conduits containing the local signalling and electric light lines,
and branch pipes or conduits from said hand-holes to the buildings on opposite
sides of the street enclosing branches from the conductors in the main conduits, as
Bet forth.

page_text: Fourth. In an underground system, the combination with deeply buried main
conduits composed entirely of a plastic insulating material, of branch conduits from
the same to the buildings along the way, buried nearer the surface of the street or
roadway and made of iron pipes filled with an insulating material as set forth.
Fifth. A pipe or conduit for underground conductors composed of an outer
casing or tube of iron and a filling of a hard insulating compound adhering to the
iron and provided with one or more passages or ducts for containing electric
conductors, as set forth.
Sixth. An underground conduit composed of sections, each formed of an iron
casing or tube with couplings, and a filling of a hard insulating compound adhering
to the tube, and provided with one or more passages or ducts for containing electrio
conductors, as described.
Seventh. A man-hole or subterranean chamber for systems of underground
electric conductors, composed of a plastic insulating material and formed with
one or more moulded interior partitions, as set forth.
Eighth. A man-hole or subterranean chamber for systems of underground
electric conductors, having one or more interior insulating partitions, the whole
being formed or moulded in one piece of a plastic insulating material and oblong
or oval in shape, in combination with two or more lines of pipes or conduits
entering the compartments through the broader sides of the chamber, as herein
set forth.