IMPROVEMENTS IN SUBAQUEOUS COMMUNICATIONS AND APPARATUS FOR EFFECTING THE SAME
Year: 1870

page_text: PROVISIONAL SPECIFICATION left by John Imray at the Office of the
Commissioners of Patents, with his Petition, on the 11th February
1870.
I, JOHN IMRAY, of 28, Great George Street, Westminster, in the
County of Middlesex, Engineer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN SUBAQUEOUS COMMUNICATIONS AND
APPARATUS FOR EFFECTING THE SAME," to be as follows:-
My Invention relates to the construction and laying of tubes on the
beds of channels or watercourses to serve for communication from shore
to shore.
A tube for the transit of goods and passengers in carriages or railway
trains is necessarily of considerable diameter, and must therefore be
built up of numerous parts of moderate.. weight and bulk. It is
necessary that the jointing of the parts should be water-tight, and yet
that the whole structure should::be: somewhat flexible to admit of the
operation of laying, which is hereafter described, and also to allow the
tube to accommodate itself to the irregularities of the bed.on, which it is
laid. Such irregularities in many cases-consist-of-moderate-slopes-

page_text: without sudden variations of level, and it is to cascs of this kind that
my Invention applies. The tube consists of a metallic external casing
lined internally with wood. The casing may be of wrought iron in
parts rivetted or bolted together, but cast iron is preferred as cheaper
and more durable under water. As this material has little flexibility in
itself the parts are jointed together in such a way as to admit of a littlo
yield or play at every joint, the wood lining being sufficiently elastic to
permit the required amount of flexure. The cast-iron casing is made
in short cylindrical lengths, which may be joined together in various
ways. One way is to make each length with a flange at either end
projecting externally all round it. Two lengths being brought together
end to end an internally recessed cylindrical ring made in halves is
placed over the junction, the recess in the ring receiving the two flanges
of the tubes. The two halves or semicircular portions of the ring are
then secured together by bolts and nuts or by keys, and certain play
being allowed for the flanges in the recess of the ring the joint between
the flanges is caulked from the inside of the tube with caulking material
somewhat soft and elastic, such as oakum served with tar or pitch;
or the flanges of the tube are made to project. inwards, and the joining
ring is made in picces placed inside instead of outside, one of the pieces
being driven as a wedge or key to keep the ring in place. The flange
joint in this case is caulked from the outside. Otherwise one end of
cach length of tube is made with numerous oblique flanges projecting
from it like short pieces of screw threads, and the other end is made
as a socket with corresponding oblique flanges projecting inwards. Onc.
length being then applied to another so as to enter its socket it is turned
partly round so that the two sets of oblique flanges ongage with one
another as a screw in a nut, the joint between the end of the one tube.
and the bottom of the socket of the other being caulked and screwed
up tight by still farther turning the added length. One or more keys:
are then driven into ways prepared for them in the socket to prevent
the added length from turning. Or again, each length of tube is made
with the one end tapering a little outwards and the other end as a
socket tapering inwards towards the mouth, the mouth of the socket
being nevertheless sufficiently large to admit freely the enlarged a
end of the next length. This end being inserted into the socket
so as to leave a conical annular space all round it, a key ring in
segments is driven into this space and the joint at the bottom of the
socket is caulked from the inside of the tube; or the tube may be

page_text: -
made of lengths with spigot and faucet joints secured together in
the following manner:-A groove is formed all round the spigot end
externally, and a groove is formed all round the faucet internally,
the latter groove having one or more tangential passages to the outside
of the faucet. When the spigot end of one length is inserted into
the faucet of another the two grooves face cach- other, forming a
channel all round, sunk partly in the spigot and partly in the faucet.
A bar of wrought iron or steel is inserted into the tangential passage
and pushed or driven in so that it bends round into the grooved channel
and thereby acts as a circular key, preventing the spigot from drawing
out of the faucet. Instead of driving a single bar round the joint
pieces of bar may be inserted one after another by the tangential
passage or passages through the faucet and driven home. Or instead
of driving a ring in whole or parts through a tangential passage
numerous pieces of bent iron may be inserted from the front of the
socket and canted by wedges so as to make. their front edges enter
the groove in the socket while their back edges bear against the side
of the spigot. groove. The spigot and faucet being made tapering
and with considerable clearance between them, the clearance space
is caulked from inside and from outside towards the key ring. By
whichever of those methods the short pieces of tube are jointed thero
is in no case required any accuracy of fitting, sufficient allowance
being made for irregularities of casting, and this allowance admits of
the degree of flexibility required, the object of the jointing described
being to secure the parts together so that they cannot be drawn
asunder, the tightness of the joint depending on the caulking. When
several lengths of tube are jointed together by any of the modes
above described on a suitable stage or platform on the shore of the
channel they are lined with wood, put in preferably in two. thicknesses.
The wood may be served with antiseptic material and with pitch or
tar, and may be bedded on soft material, such as pitched felt, which
may also be laid between the two thicknesses of wood.. As the wood
employed has to be fitted within a cylinder, each piece being of the
form of the voussoir of an arch, it is preferred to make them fit loosely,
so as to leave sufficient freedom for the insertion from the: inside of
the last voussoir. One or more of the joints are then caulked so as
to bring all the joints into close contact. The inner lining is laid. so
that the pieces-of-which-it-consists-cover-the-joints-between-the-pieces-
of the cuter lining. The tube thus constructed is generally cylindrical

page_text: in form, but at intervals there are introduced lengths which bulge.
to a larger diameter so as to afford at convenient distancés pockets.
or recesses into which workmen employed in the tube can retreat:
when it is in use for transit.. These bulging: parts may be mado
with tapering and pointed projections or legs on the under side and 5
cavities. for receiving water ballast. The pointed legs are for the
purpose of entering the bed of the channel in which the tube is laid.
and serving for its support and anchorage. They may be made with
tubular mouths, through which screw piles are passed from inside
the tube, the stems of the piles passing through stuffing boxes. The 1
cavities are provided with suitable cocks or valves by which water.
can be admitted into them or by which the water contained in them
can be discharged by pumping. The whole tube is made of such
thickness in proportion to its diameter that the weight of the material
is very nearly equal to that of the water displaced by the tube, so 1
that unless it be ballasted it floats when almost entirely immersed
in the water. It is also preferred to make it with one or more pro-
jecting ribs on the under side to act as a keel. The whole submerging
weight therefore consists of the water ballast ádmitted into the cavities.
Thus, when the tube is laid on the bottom of the channel it has not 2
to support any part of its own weight between the legs or bearings,
but these ballasted legs have rather to resist the floating tendency of
the tube between them. Thus the strain on the tube caused by the
Ioad of a passing train may be greatly diminished and the distance
between the bearings may be proportionally increased with safety. 2
The tube is formed on shore in sections of convenient length which
may be several hundred feet. The end lengths of each section arc
made with properly fitted bored and turned joints and with strong
tapering lugs projecting from them with cotterways. These lugs are
so made that those on the end of one section enter freely between 3
the lugs on the end of the other, and keys or cotters driven through
these lugs cause the spigot and faucet joint of the two sections to
be tightened up. Besides this fixing of the sections together by
cotters, which is for the purpose of uniting them casily and rapidly,
their spigot and faucet ends may be made with grooves for the insertion
of key rings as already described, or of key rings in segments set up
by screws, so that if the projecting lngs exposed externally to the
tube or their cotters should be injured the jointing of the sections
would still be complete. Each section when it is completed is closed.
-
'

page_text: ·
at both ends by diaphragms, which may be of wood, so that they can
be readily caulked up tight and can be rapidly removed when necessary.
It is then launched into the water and moored by the shore until all
the sections are completed. When the channel to be crossed is liable
to storms the sections may be sunk so as to protect them from the
action of the waves, their places being marked by buoys. In order
that this operation may be readily effected and that the sections may
be again floated up when required, a man-hole is provided at one end
of cach section, and this end is attached to a barge or buoy of sufficient
size to support half the ballasting weight of the section. When the
section has been floated out from the shore. workmen enter the tubo
by the man-hole, and passing to the far end of the section admit the
water ballast to each cavity successively. Thus the end of the tube
farthest from the buoy is caused to sink to the bottom, and when
all the ballast is in, the buoy has thus to support half its weight,
retaining the man-hole end above water. The workmen issue by the
manhole and close it tight, and this end of the tube is then lowered
by slacking out the buoying chain. For the purpose of again floating
up the section the man-hole end is buoyed up, workmen enter the tube
and pump out the water ballast.
When the sections have all been completed and floated, by preference
an equal number of them near either shore of the channel, and when
the weather is favourable the laying of the tube in its bed is effected
as follows:-Several sets of barges or suitable vessels are provided
with propellers to act both longitudinally and laterally. Two of
these vessels take a section of tube between them and two others take
another section. The two sets of vessels approach each other in mid-
channel and bring the two sections together end to end. The keys
or cotters are then driven through the lugs, and thus the two sections
are provisionally jointed together afloat. Workmen entering by the
man-hole make good the jointing of the two sections by keying and
caulking, and remove the temporary ends or diaphragms. Meanwhile
two other sections are brought one to cach end of the sections already
united, and these are united in their turn. To facilitate the operation
it is preferable to have a train of sections towed out from either
shore so that cach in its turn may be added to the tube without loss
of time. When a number of lengths have been so joined the workmen
inside the tube make good the man-holes by which they had entered,

page_text: and working each way from the middle remove successively the
diaphragms and admit the water ballast. Thus the middle portion
of the tube is sunk while the ends remain at the surface of the water,
the structure of the tube being of sufficient flexibility to admit of
the easy curvature required for this purpose. As section after section
is added at both ends a greater length of the middle is submerged, and
the operation is continued till the ends of the tube extend nearly
to either shore, the last or shore sections being run along suitable
ways to meet the sections already united. As these last sections
do not require to be floated they may be made stronger than the 1
rest of the tube so as to resist the action of waves along the shore.
They may also be sunk in channels excavated or dredged for their
reception and covered with concrete or other protecting material.