Improvements in Tunnels.
Year: 1894

page_text: Date of Application, 14th Aug.. 1894-Accepted, 15th Sept., 1894
עם JLI
Improvements in Tunnels.
I, Alexander SPOTSWOOD DANDRIDGE, Civil Engineer, of Shepherdstown,
in the County of Jefferson, and State of West Virginia, United States of America,
do hereby declare the nature of this invention and in what manner the same
s to be performed, to be particularly described and ascertained in and by the
following statement:-
My improvements are applicable to tunnels of various kinds, but are especially
useful in the case of subaqueous tunnels &c., where surrounding moisture has to
be contended with. The main object of my invention is to avoid the danger of
chemical action upon and within the structure, and incidentally to utilize the shell
of the tunnel as a means of conveying liquid hydro-carbons or other fluid from one
extremity thereof to the other.
My invention therefore consists primarily in a tunnel shell the main core of
which is protected by one or more longitudinal chambers containing a suitable
liquid or semi-liquid, which protects the said main core against oxidization or other
harmful chemical action; and secondarily, in combining with said longitudinal
chamber or chambers means for supplying the same with a fluid at one end and for
withdrawing the fluid at the other end of the tunnel.
My invention also includes the use of corrugated metal for the walls of the
longitudinal fluid chambers, and for both of them and the main core of the tunnel
also when desired, for the purpose of affording a certain degree of elasticity to the
shell without endangering the structure as a whole. By this means the tunnel can
safely be allowed to adapt itself to any slight inequalities in support along its
length, and to compensate for expansion and contraction under variations in
temperature, a result of no small importance when the tunnel is of considerable
length.
My invention also includes a special form of joint between the sections of the
main core which can be packed from the interior; and the combination with the
main core and its protectory shell, of an exterior non-metallic covering, substantially
as herein set forth.
In the accompanying drawings I illustrate diagrammatically the practical
embodiment of my improvements in a tunnel of cylindrical form, although I do
not confine myself to the exact construction and arrangement of parts shown,
since it is obvious that various modifications may be made in meeting the require-
ments of special use and situation without departing from the spirit and intent of
niy invention.
Figure 1, is a transverse section through the main structure of my improved
tunnel;
Figure 2, a central longitudinal section therecf, at both ends, the central portion
being omitted;
Figure 3, is a view illustrating a special form of joint for use between the sections
of which the main core is composed;
Figure 4, a central longitudinal section of both ends of the tunnel showing the
main core corrugated as well as the protecting shell;
Figure 5, is a sectional detail indicating the arrangement of parts when only the
outside of the core is protected by a chamber containing liquid.
The form of the tunnel T, in transverse section is of secondary importance, and
may be varied as desired; it being shown circular in cross section in the accom-
panying drawings for convenience of illustration. The main metallic core C, is
built up in any convenient manner. Wrought or cast iron may be used although

page_text: I do not limit myself to the use of iron. The core C, may be either plain in
surface as shown in Figure 2, or formed with transverse corrugations c, as indicated:
in Figure 4.
Preferably the core C, is protected both on the exterior and interior by a longi-
tudinal chamber, or chambers a, a, containing liquid or semi-liquid of a character
that will protect the core from oxidization or other chemical action. Only one side
of the core C, may be thus protected if desired, Figure 5, showing the liquid
chamber on the outside only of the core. In either case the longitudinal chamber a,
is filled with oil or any other non-oxidizing fluid; or if preferred with a semi-fluid
substance of like protecting properties.
These chambers a, are designed to be continuous from one end of the tunnel to
the other, so as to virtually form longitudinal passages for the flow of an oil or
other fluid from one end of the tunnel to the other. The chambers a, may thus be
used not only as a means of protecting the core C, but also as a means of trans-
porting hydro-carbon oils or other liquids, under pressure from one extremity of
the tunnel to the other. Thus, in Figure 2, an elevated tank E, is shown as
supplying, say kerosene to the annular passage a, surrounding the core C, at one
end of the tunnel, while at the other provision is made for drawing off the oil
through a pipe and valve P, p. In this arrangement the elevation of the tank E,
insures the flow of the liquid through the passage a, but the liquid may be forced
through by other means, as by pumping.
The outer walls, a', a', of the chambers a, are preferably formed of copper,
and are corrugated transversely although in so far as the mere provision of the
liquid passages a, is concerned the corrugating of the walls a', a' is not essential.
When however it is desired to afford a structure which will yield more or less
both to lateral strain and to expansion or contraction, I propose to corrugate not
only the walls a', a', of the chamber a, but also to corrugate the main core itself,
as indicated in Figure 4.
The interior of the tunnel is lined with brickwork B, or other suitable material;
and the exterior is preferably protected by a suitable thickness of concrete or other
suitable non-metallic covering M.
Where the core C, is made in sections, I propose to join these sections together
by the form of joint shown in Figure 3, although I do not limit myself exclusively
to the use of that particular form of joint. The joint J, shown however has the
advantage of accessibility from the interior from which it may be packed between
the flanges c¹, c², on the exterior of the core C, and the flange j,j, on the inner
edges of the joint J. This joint J, and packing allows a slight degree of flexibility
between the opposed ends of the adjoining sections of the core, which is of
advantage in the work of construction.
The walls a', a', of the longitudinal passages are held supported at suitable
intervals by rests r, r, of any suitable size and shape, and preferably made of
a material which is a poor conductor of electricity thus avoiding the possibility of
galvanic action between the metals. These rests are comparatively small, and are
arranged with relation to each other as to break joints, and not to impede the flow
of liquid.
As a means of transportation for oils and other liquids my improved construction
of tunnel is of practical utility; while the protection which may be afforded to
the core or shell against chemical action and deterioration is of still more
importance.
The slight degree of flexibility of the structure is also a feature of importance in
practical construction and use, especially in the case of long tunnels.
Having now particularly described the nature of my said invention and in what
manner the same is to be performed, I declare that what I claim is,
First. A tunnel formed with a metallic core or shell, and with a longitudinal
chamber surrounding said core filled with a liquid or semi-liquid substance, for the
purpose and substantially in the manner described.

page_text: Second. A tunnel formed with a metallic core or shell, and with a longitudinal
chamber on both the outside and inside of said core filled with a liquid or semi-
liquid substance, for the purpose and substantially in the manner described.
Third. In combination with a tunnel formed with a metallic core or shell, and
with a longitudinal chamber surrounding said core, means for introducing a fluid
under pressure into said longitudinal chamber at one end of the tunnel and for
drawing off the fluid at the other end of the tunnel, substantially in the manner
described.
Fourthly. A tunnel formed with a metallic core or shell and with a longitudinal
chamber surrounding said core having metallic outer walls which are corrugated
substantially in the manner and for the purpose described.
Fifthly. A tunnel formed with a transversely corrugated metallic core and with
a longitudinal chamber surrounding said core having metallic outer walls which
are corrugated transversely substantially in the manner and for the purpose
described.
Sixthly. A tunnel formed with a metallic core or shell, with a longitudinal
chamber surrounding said core filled with a liquid or semi-liquid substance, an
outer metallic wall to said longitudinal chamber, and an exterior coating of a
non-metallic substance, for the purpose and substantially in the manner described.
Seventhly. In combination with the metallic core C, of the tunnel, formed with
the exterior flanges c¹, c², the joint J, formed with the interior flange j, substantially
in the manner and for the purpose described.
Dated this 13th day of August 1894.
F. BOSSHARDT & Co.,
4, Corporation Street, Manchester, Agents to Applicant.