Improvements relating to Electric Railway Conduit Systems.
Year: 1899

page_text: Date of Application, 13th Oct., 1899
Complete Specification Left, 16th May, 1900-Accepted, 14th July,
1900
PROVISIONAL SPECIFICATION.
Improvements relating to Electric Railway Conduit Systems.
I, HIRAM STEVENS MAXIM, of 18, Queens Gate Place, in the County of Middlesex,
Chevalier of the Legion of Honour, Civil and Mechanical Engineer, do hereby
declare the nature of this invention to be as follows:-
This invention relates to electric railways working on the conduit system, that
is to say those in which the electric conductors are supported by insulators
within conduits located below the road-bed, these conduits and the road-bed
being longitudinally slotted at the upper part to enable the contact devices by
which the current is conveyed from the conductors to the electro-motors on the
electrically propelled vehicles to reach and remain in electrical contact with said
conductors as the vehicles travel along. The iron conduits hitherto proposed
to be used are of considerable dimensions and also of great strength to resist
the crushing pressure to which they are liable to be subjected by the passage
over them of heavily laden vehicles forming part of the ordinary road traffic.
In laying these conduits extensive excavations of the road have to be made and
in England where water, gas and other pipes are embedded only a short distance
below the surface of the road, it becomes practically impossible to lay the con-
duits without seriously interfering with these pipes; indeed in most cases it
would be necessary to take up and relay these pipes which would entail such
expense as to render a conduit system of the ordinary kind incapable of competing
with an overhead system.
Now according to my invention I overcome the objectionable features above
stated and enable a conduit system to be constructed without materially inter-
fering with the water, gas and other pipes and without the necessity of providing
man-holes at constant intervals, so that the expense of construction is compara-
tively small, in fact less than that for an overhead system. The conduits can
be made of great strength and need not occupy more than six to ten inches of
vertical space in the road-bed. I do away completely with the cross girders of
cast iron hitherto used and provide for a certain amount of elasticity to my
structure, providing the road-bed itself is yielding.
My improved conduit comprises a trough shaped or U-shaped steel body-
portion constituting the bottom and sides thereof and supporting at its upper
edges a pair of slot-rails arranged in such a manner as to sustain a very great
weight. Each of these rails is provided with a. horizontal or approximately
longitudinal
horizontal web from which project downward two flanges to form a
channel or cavity to fit over the upper edges of the said body portion of the
conduit. The flange that lies on the inside of the said body portion is longer
than the other, so as to effectually resist any tendency of the slot-rail to descend
under heavy weights passing over its exposed part on the surface of the road.
I also provide at the outer edge of the aforesaid web a small upward flange to
form with said web a trough for receiving and holding asphaltum. To connect
the slot-rails to the body of the conduit I employ steel pins or bolts passed
through the sides of the said body portion and engaging with the longer flanges

page_text: of the slot rails thus retaining the slot-rails detachably but firmly in place on
the body portion. In order to obtain access to the interior of the conduit without
recourse to manholes, these pins or bolts are removed to release a length of the
slot-rails and thus permit it to be detached.
Adjacent to the troughs formed by the aforesaid upward flanges on the hori-
zontal webs of the slot-rails, I prefer to insert in the surface of the road-bed
blocks of jarrah or other suitable wood, so that they can be easily removed when
desired; and each of the blocks in proximity to the aforesaid pins or bolts, I
prefer to identify by a difference in shape or by a sign thereon, so that in order
to disconnect the slot-rails from the conduit these blocks are removed and
expose the pins or bolts which can then be readily removed to disconnect the
slot-rails without disturbing the other parts of the road-bed.
Within the conduit I provide T-shaped or other supports for the conductors,
said supports being carried by insulated standards mounted on the inside sur-
face of the conduit. When the supports are T-shaped, they are arranged
horizontally, the stem of the T being perforated and adapted to fit around the
upper end of the insulated standard, the conductor lying against the face of
the said T. Each of the standards is preferably made in two superimposed
pieces or lengths, insulated from each other by mica or similar hard substances
and these two pieces or lengths are preferably formed with depression's in
proximity to their adjacent ends. I surround these ends with a steel sleeve by
the lateral compression of which at the parts contiguous to the said depressions,
is caused to conform to the shape of the two pieces or lengths of the standard
and to thereby effectually join them together, so that they cannot turn rela-
tively to each other. Suitable insulating material such as mica or paraffin paper,
is preferably arranged between said sleeve and the two lengths of the standard
it surrounds. Instead of mica or paraffin paper, melted enamel or porcelain may
be inserted between the said sleeve and the standard.
The conductor is preferably connected to the T-shaped supports by bending
its edges around the edges of the face of the T, a length of mica or other
suitable insulating material being introduced between the face of said Tand
the conductor. I also insulate the stem of the T-shaped support from the
standard carrying it, by an insulating ring arranged around the standard where
it passes through the stem. Above and below the said stem 1 provide insu-
lating washers which are held in place by means of the screw nuts employed
for securing the T-shaped supports to the standard. I may also provide at
the upper end of the aforesaid sleeve an insulating washer. The manner of
connecting the conductors to the T-shaped supports enables said conductors
to be readily detached when required.
In some cases where extreme shallowness of the conduit is necessary, instead
of using the aforesaid standards screwed into the bottom of the conduit, I may
employ strips or lengths of suitably insulated wood screwed to the inner sides
of the conduit. The ends of the said strip are preferably made of greater
thickness than the intermediate portion so that a space exists between them.
The screw or other fastening device by which the strip is connected to the
conduit passes preferably through said strip midway of its length and at such
part the strip is provided with a boss or enlargement on the side next the
conduit so that said strip touches the conduit only where the boss is formed.
The length of the strips may be about two or three feet and by constructing
them as above stated, it will be obvious that the conductor will be secured
thereto only at the ends while the strip itself will be secured to the conduit
only at the middle. Therefore in order for the current from the conductor to
reach the conduit it would be compelled to pass longitudinally through the
strip. The wood from which the said strips are formed should be seasoned in
a very thorough manner and then be placed in a strong. iron cylinder from
which the air is subsequently extracted and the temperature raised to the
boiling point of water. The wood should then be subjected to a bath of melted

page_text: paraffin wax which should be forced into the pores of the wood. This treat-
ment will not only preserve the wood but render it a good insulator.
With a shallow conduit of the kind I have described it is necessary to
provide for the ready escape of rain water, which I do by tapping the bottom
of the conduit at frequent intervals and connecting it with the sewer or with
drain pipes communicating with the sewer. Or said drain pipes may be led
to some convenient point suitable for discharge of the water without being
connected with the sewer at all.
When the water is conducted to the sewer it may be necessary to construct
a trap between the conduit and the sewer. For this purpose I may provide
immediately below the conduit a chamber, into which extends a vertical pipe
leading from the bottom of the conduit. The said chamber communicates at
its upper part by a lateral passage with the sewer and the lower end of the said
vertical pipe extends below this passage and dips into the water at the bottom
of said chamber so that a trap is formed between said vertical pipe and the
lateral passage leading to the sewer. For flushing the trap a tube of oval or
flat cross section may be inserted between the slot rails from the surface of
the road and be placed into the said vertical pipe and water be allowed te
flow from the water main through said tube whereby any sediment which may
have collected in the trap would be effectually removed.
I may form the upper end of the said vertical tube with a flange for entering
a recess around the hole through which said pipe extends to reach the aforesaid
chamber. The pipe could then be easily removed when the slot rails were
detached from the body portion of the conduit. A washer is preferably located
between the flange on the pipe and the said recess in the conduit.
To support the rails upon which the electrically propelled vehicles run, I
use plain or corrugated steel bars or plates which may be about five-eights of
an inch in thickness and about four to ten inches in width. These bars or
plates are so disposed that their inner ends lie beneath the conduit and their
outer ends carry the rails, the whole being supported upon a concrete bed.
The rails are held equidistant from the trough by long bolts extending from
the webs of the rails to the sides of the conduit. In this manner the rails
are supported wholly by their own foundation and a weight passing over them
heavy enough to depress or injure the foundation would displace the latter
without straining the conduit, because the conduit and the rails are practically
supported on independent foundations.
At the parts of the system where the conduits extend round corners, I
prefer to make the conduit in segmental sections of the required curvature and
connect them together in any suitable manner. In this case the said sections
preferably consist of steel castings.
Dated this 13th day of October 1899
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant
Improvements relating to Electric Railway Conduit Systems.
I, HIRAM STEVENS MAXIM, of 18. Queens Gate Place, in the County of Middlesex,
Chevalier of the Legion of Honour, Civil and Mechanical Engineer, 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:-
:―
This invention relates to electric railway conduit systems, that is to say
those

page_text: in which the electric conductors are supported by insulators within metal con-
duits located below the road-bed, these conduits and the road-bed being longi-
tudinally slotted to enable the contact devices by which the current is conveyed
from the conductors to the electro-motors on the electrically propelled vehicles,
to reach and remain in electrical connection with said conductors as the vehicles
travel along the rails. The metal conduits hitherto used have necessarily been
of considerable dimensions and of great strength to enable them to resist the
crushing pressure to which they are liable to be subjected by the passage over
them of heavily laden vehicles forming part of the ordinary road traffic. In
laying these conduits extensive excavations of the road have been necessary and
in places where water, gas and other pipes are embedded only a short distance
below the surface of the road, it has been practically impossible to lay the con-
duits without great interference with these pipes; indeed in many cases these
pipes have had to be taken up and relaid thus entailing such expense as to
render the conduit system incapable of competing with the overhead system.
Now according to my invention I avoid the difficulties above stated and
enable a conduit system to be employed without materially interfering with
the water, gas and other pipes and without the necessity of providing man-
holes at constant intervals, so that the expense of construction is comparatively
small, in fact but little greater than that of an overhead system. The conduits
according to my invention can be made of great strength and need not occupy
more than six to ten inches of vertical space in the road-bed. I avoid the
necessity for the cross girders of cast iron hitherto used and obtain a certain
amount of elasticity of my structure, providing the road-bed itself is yielding.
My improved conduit. comprises any desired number of trough-shaped lengths
or sections each of which is made of a steel body-portion constituting the bottom
and sides thereof and supporting at its upper edges a pair of slot-rails which
are constructed and arranged in such manner as to sustain a very great weight.
The slot-rails are connected with the body portion of the conduit by detachable
fastening devices, so as to enable them to be readily removed without unduly
disturbing the road-bed.
Within the conduit I provide insulated supports for carrying the con-
ductors, such supports being constructed in the manner hereinafter explained.
With a shallow conduit of the kind I employ it is necessary to provide for
the ready escape of rain and other water, which I do by tapping the bottom
of the conduit at frequent intervals and connecting it by means of loose drain
pipes with the sewer through a trap. Or said loose drain pipes may be led to
some convenient point suitable for discharge of the water without being con-
nected with the sewer.
To support the rails upon which the electrically propelled vehicles
run, I
use, at suitable intervals, plain or corrugated steel bars or plates which are so
disposed that their inner ends lie beneath the conduit and their outer ends
carry the rails, the whole being supported upon a concrete bed. The rails are
held equidistant from the conduit by long bolts extending from the webs of
the rails to the sides of the conduit."
In order that my said invention may be clearly understood and readily car-
ried into practice I will proceed to describe the same more fully with reference
to the accompanying drawings in which:
Figure 1 is a sectional perspective view of my improved system.
Figure 2 is a detail sectional view drawn on a larger scale, of the right
hand portion of the conduit, slot rails, conductors and insulated supports
employed in the above system.
Figure 3 is a transverse section on the line 1, 1 of Figure 2 taken through
one of the insulated supports.
Figures 4 and 5 are transverse sectional views shewing a modified form of
the insulated supports.

page_text: form of the insulated supports.
Figures 8 and 9 are respectively an elevation and a plan of the insulated
supports illustrated by the last preceding figures.
Figure 10 is a transverse section on the line 2,2 of Figure 9.
Figures 11 and 12 are transverse sectional views shewing modified means
for connecting the slot-rails to the conduit.
Figure 13 shews one of the bolts by which the connection is effected.
Figure 14 is a plan of one of the slot rails shewing an arrangement of the
paving blocks for permitting ready access to the nuts at the upper ends of the
aforesaid connecting bolts.
Figure 15 is a detail sectional view showing one of the drains and drain
pipes for the conduits.
Figure 16 is a diagrammatic plan of a portion of the railway shewing how
the conduits and slot-rails meet at a point where two lines join.
Figures 17 and 18 are transverse sectional views taken approximately on the
lines 3, 3 and 4, 4 of Figure 16 and drawn on a larger scale.
Like letters of reference indicate similar parts in all the figures.
AA are the trough shaped body portions of the conduit. B, B are the slot-
rails C, C the insulated supports for the conductors D, EE the drain pipes for
the conduits, FF the bars or plates for supporting the rails G, and HH, the
bolts connecting these rails with the conduit.
The various lengths or body portions composing the conduit are connected
together by bent fish-plates aa and screws aa¹ (see Figures 4 and 6) each
length being formed by rolling a single piece of steel to the desired trough
shape. The slot-rails B are formed in suitable lengths and connected together
at their adjacent ends by fish-plates band screws 61. Each of these slot rails
has a horizontal or approximately horizontal web B₁ from which project down-
wardly two flanges B2 B3 to form a longitudinal channel or cavity to fit over
the upper edges A¹ of the upright members of the conduit. The flange B²
that lies on the inside of said conduit is longer than the other flange 133 so that
it will obtain a satisfactory bearing surface against the inside of the vertical
member of the conduit and thereby effectually resist any tendency of the slot-
rail to become displaced under heavily laden vehicles passing over its exposed
parts on the surface of the road. The outer edge of the said web B' is pro-
vided with an upwardly projecting flange B to form with said web a trough
for receiving paving of asphaltum, wood, metal or the like as hereinafter more
fully explained. To connect the slot-rails to the conduit I employ any suitable
fastening devices capable of being conveniently reached by the workmen and
detached when it is desired to remove one or more of the slot-rails from the
conduit. In Figures 1, 2, 4 and G I have shewn plain pins or bolts II passed
transversely through the flange B3 of the slot-rail and the upright portion of
the conduit and engaging with the inner flange 12 of the slot-rail. Adjacent
to the slot-rails, I place on the surface of the road-bed, blocks of jarrah or
other hard wood JJ as shown in Figures 1, 2, 4, 5, 6 and 7 so that they can
be easily removed when desired. Each of these blocks that lies in proximity
to the aforesaid pins I, may be identified by a peculiarity of shape or by a
sign thereon or otherwise, so that in order to disconnect the slot-rails from 'the'
conduit only these identified blocks need be removed to expose the pins which
can then be readily detached.
Instead of using the aforesaid plain pins, I sometimes employ screw pins K
which are adapted to extend through the web B₁ of the slot-rail and enter a
screw threaded hole formed in the upper part of the upright members of the
conduit as represented in Figure 7. I find, however that the most satisfactory
means for connecting the slot rails to the conduit consist of angle bolts L such
as are represented in Figures 11, 12 and 13. The vertical portion of these bolts
extends through the web B of the slot-rail while the horizontal portion of said

page_text: bolts extends through a hole formed transversely through the upright member
of the conduit and receives a nut or nuts !. Lis insulating material sur-
rounding the stem of the bolt. The upper end of the bolt lies within an
opening m formed through the paving block M, such opening being filled with
sand, or similar loose material which can be readily removed to expose the nut /
at the upper end of said bolt and permit of its being unscrewed when the slot-
rail is to be detached from the conduit. I prefer, when using these means for
connecting the slot-rail and conduit, to employ a metal shoe N for the paving
blocks (see gures 12 and 14) and to line the opening in said block with
a metal sleeve m² so as to avoid the liability of the block to be split by the
passage of heavy vehicles over it. These metal shoes may, if desired be employed
with all the paving blocks used immediately above the slot rails. I prefer
however to arrange them alternately with wooden blocks as represented in
Figure 14 and in this case each of the shoes is provided with lateral lugs n to
engage with the wooden blocks on each side thereof.
C
The insulating supports for the conductors shewn in Figures 1 and 2 consist
of T-shaped pieces c carried by insulated standards c', screwed into the bottom
of the conduit. The conductor ]) is connected to these T-pieces by bending
its edges around the edges of the face of the said T-pieces, with mica or other
insulating material * interposed between the face of the said T-pieces and the
conductor. The stem of the T-piece is fitted to the upper end of the standard.
Each of the standards is made in two lengths, insulated one from the other,
and these two lengths are formed with square or flattened ends c². These ends
I surround with a steel sleeve, which by lateral compression at the parts
contiguous to the flat or square portions is caused to conform to the shape of
the ends, thereby effectually joining the two lengths of the standards together
so that they cannot turn relatively to one another. Suitable insulating
material such as mica or paraffine paper is preferably arranged between the
said sleeve and the parts of the standard it surrounds." Instead of mica or
paraffine paper, melted enamel or porcelain may be inserted between the said
sleeve and standard. I also insulate the stem of the T-piece from the standard
carrying it by an insulating ring arranged around the standard, where it
passes through the said stem. Above and below the said stem I provide screw
nuts, for securing the T-piece to the standard. I may also provide the upper
end of the aforesaid sleeve, with an insulating washer cf.
In some cases, especially where extreme shallowness of the conduit is neces-
sary, I connect the aforesaid standards to the upright members of the conduit,
instead of to the bottom thereof. Such an arrangement is illustrated in
Figure 4. In this case, the upper length of the standard is formed in one piece
with the sleeve and is also adapted to receive a porcelain shield which may
be an insulator, while the lower length is bent at right angles and passes through
a hole provided for it in the said upright member of the conduit to which it
is secured by a nut or nuts. Insulating material is interposed between
the sleeve and the standard. In other respects the standard is similar in
construction to that already described with reference to Figures 1 and 2.
According to another construction of the insulated supports, I employ strips
or lengths of wood O, as represented in Figures 6 to 10. The ends of each
strip are provided with the T-pieces for the conductor to be connected to,
the said T-pieces being furnished with sockets c¹0 to fit around the wood strip.
The central portion of the said strip is adapted to be connected with the conduit
by a metal stirrup or strap o, having screw threaded ends o¹ which extend
through openings in the upright member of the conduit, and receive nuts for
securing said stirrup in place. A wooden fillet or block O¹ is interposed between
the wood strip and the conduit at the part where the aforesaid band is placed,
so that the said strip touches the conduit only at this part. By constructing
the wood strips in this manner it will be seen that the conductor is only con-
nected to the strips at the ends thereof, while the strips are secured to the

page_text: conduit only at the middle. Therefore, in order for the current from the
conductor to reach the conduit, it would be compelled to pass longitudinally
through the strip. The wood from which the said strips are formed should
be seasoned in a very thorough manner, and then be placed in a strong iron
cylinder, from which the air is subsequently extracted and the temperature
should be raised to the boiling point of water. The wood should then be sub-
jected to a bath of melted parathne wax which should be forced into the pores of
the wood. This treatment will not only preserve the wood, but render it a
good insulator. It will be found advantageous to form the upper portions of
the wooden strips of triangular shape as best seen in Figure 10 so that mud
and dirt entering the conduit through the slot rails will not tend so readily
to accumulate on the strips as would be the case if their upper portions were
of flat formation.
²² are the openings in the bottom of the conduit for the escape of rain
water, these openings being connected with the sewer, as represented in Figure 1
through the loose pipe E. In this case a trap E is interposed between the
drain-pipe and the sewer, the said trap being advantageously constructed and
arranged as illustrated in Figure 15, wherein it is represented as consisting of
a chamber e, having at its upper part a lateral passage e which communicates
with the sewer. The lower part of the chamber contains water into which the
loose vertical pipe E dips. This pipe may be formed with a flanged upper
end E fitted into a recess in the bottom of the conduit so as to support the
said pipe in proper position. This method of connection of the pipe with the
conduit permits the pipe's ready removal when desired.
For Hushing the tiap, a tube of oval or similar cross section, may be inserted
between the slot rails from the surface of the road, and be placed into the mouth
of the said vertical pipe E. Water from the main may, then be allowed to flow
through the said tube, whereby any sediment which may have collected in the
trap, would be effectually removed.
To support the rails & upon which the electrically propelled vehicles travel,
I use at suitable intervals along the road-bed the corrugated steel bars or
plates F, which are so disposed that their inner ends lie beneath the conduit,
and their outer ends lie beneath and support the said rails, which may be con-
nected thereto by bolts f if desired, the whole being supported upon a concrete
bed. The said rails are held equi-distant from the conduit by the bolts H,
extending from the webs of the rails to the sides of the conduit. In this manner
the rails are supported wholly by their own foundation, and a heavily laden
vehicle passing over them, and of sufficient weight to depress or injure the
foundation, would displace the latter without straining the conduit, because
the conduit and rails are by this construction practically supported on inde-
pendent foundations.
At the parts of the system where the conduits extend round corners, I prefer
to make the conduits in segmental sections of the required curvature and
connect them together in any suitable manner.
In order that the insulated conductor supports may be more readily reached
from the exterior of the conduit, without having to remove the slot-rails, I
sometimes construct the said supports as represented in Figure 5. In this case
each support consists of an arm having a vertical stem C, to which a por-
celain insulator C is attached by means of a nut C engaging with the screwed
end of the said stem. This insulator is formed with a shoulder to rest upon
a corresponding shoulder formed in the wall of the chamber or extension Co
laterally disposed with respect to the conduit. Above the said insulator is a
dome or cover C, the upper part of which lies at the surface of the road bed.
so that the said cover can be easily reached and removed. By removing this
cover and inserting the screwed end of a rod into the screw threaded hole C8
of the aforesaid stem C2, the workman can support the said insulated arm C
while the porcelain insulator (³ is removed from its position around the stem

page_text: and, if desired, replaced by another. To facilitate the removal of the insulator,
it is provided with an annular channel C near its upper end, and the wall of
the chamber or extension C into which the said insulator fits is formed with
recesses (10 communicating with the said annular channel. By inserting into
these recesses a suitable tool, the insulator can be raised high enough to enable
the workman to grasp it with his hand and remove it. Suitable insulating
material is provided at C*.
a
In Figures 16, 17 and 18 I have shown how the conduits are arranged at
points where one line meets another. In this case the conduits A are in
straight line while the conduits A* form part of a curved line. The conduit A
is cut away to form an opening at A2 and the adjacent conduit A* is cut at
an angle to correspond with the opening A2, the adjacent portions being bolted
together through a shoe A located at the part A between the two lines.
A5 A5 are movable switches for guiding the vehicles from one line to the other.
These switches are of the ordinary well known construction and need no further
description herein.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is;-
-
1. The shallow trough-shaped body portion of the conduit made from a single
piece of steel bent to the required shape by rolling or otherwise for the purpose
specified.
2. The slot-rails constructed to be detachably connected to the conduit by
devices that permit of the said slot-rails being readily removed without unduly
disturbing the road bed, substantially as described.
3. The construction of the slot-rails with a deep depending flange to lie
within the conduit and against the side wall thereof substantially as and for
the purpose specified.
4. The construction of the slot-rails with a channel or recess to receive paving
blocks or paving material above the horizontal web thereor substantially as
described.
5: The support for the electric conductor, formed in two lengths electrically
insulated from each other and connected together by a metal sleeve squeezed
around the meeting ends of the two lengths substantially as and for the purpose
described.
6. The modified form of the aforesaid support, comprising a wooden bar con-
nected to the conductor at or near its ends and with the conduit at or near its
middle portion substantially as and for the purpose specified.
7. The combination with the aforesaid conduit of loose drain pipes for con-
ducting away the rain water substantially as and for the purpose specified.
8. The transverse bars or plates so disposed that their inner ends lie beneath
the conduit and their outer ends lie beneath the rails substantially as and for
the purpose specified.
9. An electric railway conduit system in which the various parts are com
bined and arranged substantially as described with reference to the accompanying
drawings for the purposes specified.
1011 1
1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant