IMPROVEMENTS IN TUBULAR STRUCTURES FOR COMMUNICATION UNDER WATER
Year: 1882

page_text: LETTERS PATENT to Henry Nathan Maynard and Henry John Cooke both of
No 7 Westminster Chambers Victoria Street in the County of Middlesex for an
Invention of IMPROVEMENTS IN TUBULAR STRUCTURES FOR COMMUNICATION
UNDER WATER.
PROVISIONAL SPECIFICATION left by the said Henry Nathan Maynard
and Henry John Cooke at the Office of the Commissioners of Patents on the
12th December 1882.
HENRY NATHAN MAYNARD and HENRY JOHN COOKE both of No 7 Westminster
Chambers Victoria Street Westminster in the County of Middlesex
MENTS IN TUBULAR STRUCTURES FOR COMMUNICATION UNDER WATER
"
"IMPROVE-
Our Invention relates to the method of constructing tubular structures for
communication under water, wherein separate lengths of such tubular structures
are consecutively sunk under water and when in position are connected together in
a water tight manner so as to form a continuous tubular structure or tunnel. Our
improvements relate more particularly to the method of constructing such structures
described in the Specification to H. N. Maynards Patent No 3557 of 1875, one part
thereof has for its object firstly to enable the said structures to be sunk more or
less into the bed of the river or other water, instead of being merely laid on the
surface of such bed, so as to obtain a firm level foundation for the entire
structure to rest upon, and also to prevent the structure from interfering with the
water way.
For this purpose, the tubular structure, which may be of any desired sectional
form has projecting downwards from its sides a web or rim, which when the tube
reaches the bed of the river form an enclosed space between the underside of the
tube and the earth, which enclosed space is kept free from water by air pressure as
in a diving bell, and is accessible through an aperture in the bottom of the tube
connected by a shaft with the surface of the water, so that workinen can enter the
said space and excavate the earth below the tube and thus cause this to descend
any desired depth underground. As the section of the tube descends, a coffer dam or
rectangular enclosure is built up all round its top side, which is thus kept free

page_text: 1
from the water and earth, and at the end surface of the section of tube to which
the next section is to be attached the said coffer dam is provided with projecting
side flanges which serve as guides along which the meeting end of the next
section together with its coffer dam descends, and which thus keep the meeting ends
clear of earth.
For forming the water tight joint between the sections we employ in combination
with the method of securing them together by means of screws described in the
before mentioned Specification an arrangement consisting of a metal ring contained
in a corresponding recess in the end surface of the one section, from which recess
it is forced outwards by means of internal screws, so as to bear with its external
edge on a corresponding ring of packing material fitted in the meeting face of the
next section, thus forming a watertight joint between the two.
In order to provide a watertight packing for the holes of the screw bolts that
serve to connect the meeting faces of the sections together, a recess is formed round
the screw bolt, into which is fitted a cup leather which is secured by an external
gland pressed inwards by the head of the screw bolt.
In some cases where it is desired to leave a permanent communication from
above water line with the interior of the tubular structure, we allow the before
described coffer dam to remain attached to the tube, in which case we construct it
of metal. Or in other cases we form such coffer dam of larger dimensions than the
tube, which is then placed within it, the coffer dam having in this case a closed
bottom with downwardly projecting flanges, to allow of excavation beneath, as
described with reference to the tubular structure.
17
In this case also, the tubular structure may be made entirely of masonry instead
of metal. The coffer dam would be constructed in sections with closed ends, to be
joined together in the same manner as described with reference to the tube.
Within the coffer dam are arranged vertical shafts communicating with the top of
the tubular structure, through which goods discharged from ships lying alongside
the coffer dam_ could be directly lowered into trucks in the tubular, structure
below. The structure' so formed, may be with advantage employed to form a
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By:

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Henry Nathan Maynard and Henry John Cooke in the Great Seal
Patent Office on the 23rd May 1883.
HENRY NATHAN MAYNARD and HENRY JOHN COOKE both of N° 7 Westminster
Chambers Victoria Street in the County of Middlesex IMPROVEMENTS IN
TUBULAR STRUCTURES FOR COMMUNICATION UNDER WATER">
Our invention relates to the method of constructing 'tubular structures for
communication under water, wherein separate lengths of such tubular structures
are consecutively sunk under water, and when in position; are connected together
in a watertight manner so as to form a continuous. tubular, structure or tunnel:
Our improvements relate more particularly to 'the, method of constructing, such
structures described in the Specification to H. N. Maynard's Patent No 3557*
of 1875; one part thereof has for its object firstly to enable the said structures; to
be sunk more or less into the bed of the river or other water, instead of being.
merely laid on the surface of such bed, so as to obtain a firm level foundation, for
the entire structure to rest upon, and also to prevent the structure interfering
with the water way. Secondly, this invention relates to means for forming a
watertight joint between the sections, and thirdly, to a modified construction of the
tunnel whereby it is made to serve also as a dock or quay wall.
r
:
The construction of and mode of sinking such structures according to our present
invention will be readily understood on reference to the accompanying drawings.
Fig. 1 shews a longitudinal section of several sections of the tubular structure; ono
of which is in process of being sunk; Fig 2 shews a cross section and Fig 3 shews
a plan.
The separate sections of the tubular structure are composed of an inner tube A
and an outer tube B secured together by the annular end frames C C and also at
intermediate points by struts and ties or ribs in any convenientimanner. The
outer tube B has on each side a wedge shaped part D projecting downward some
distance below the bottom of the tube so as to form beneath the latter an enclosed
space D¹ of sufficient height to enable; workmen to operate therein.. Access is
gained to this space through a tube E passing through openings F temporarily
formed through the section, the tube E being of such a height as to reach up above
the water level when the section has been sunk to the required depth. Above the
section a temporary rectangular coffre dam or caisson of wood or other suitable
material G is built which acts as a guide to the next section when this is being
sunk.
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The mode of sinking the sections is as follows:-The, lower part. of the annular
space between the shells A and B having been filled with concrete and the end'
openings being temporarily closed in a watertight manner by: shields H, the section
is floated out to a point immediately above that which it is required to occupy
when sunk. Additional filling is now introduced into the annular space so as to
cause the section to sink gradually down in the water. If it be the first section
that is sunk it is guided in its descent by suitable guides or stays, fixed in the bed.
of the water way or otherwise, but, assuming one section to have been already sunk,
then its caisson G serves as a guide for sinking the next section. For this purpose:
the caisson provided with projecting flanges G¹; on one side, shewn to an enlarged
scale at Fig. 4, between which the contiguous end of the next section with its:
caisson is caused to slide down as it descends. When the section has arrived on.
the bed of the river, compressed air is forced into the space D'.so as to keep it free

page_text: from water, and workmen, descending into the space through the tube E, excavate
the ground in the space beneath the section, so as to cause this gradually to
descend in the bed until the required depth has been attained. In order to insure
that the section in descending shall keep as close as possible to the end surface of
the previous section, it will be necessary to prevent the dirt as much as possible
from getting between the meeting surfaces. For this purpose we provide a hinged
guard or scraper I Fig. 5 at the lower part of the projection D, which gets pressed
against the surfaces of G and C, as it descends, and thus prevents any dirt from
passing up between these surfaces and the section:
When the section has been sunk into position, it requires to be attached in a
watertight manner to the section previously sunk. The mode of forming this joint
will be seen on reference to the enlarged details at Figs. 6 and 7.
For this purpose,
there is firstly provided in the end surface C a circular recess K within which is a
metal ring L at the back of which is a packing L' of elastic material and behind
this again is a metal ring L*. These parts are forced outwards by screws M
situated within the annular space of the section, until the ring L bears against an
elastic packing N, secured in the face of the other section. A watertight joint
having thus been made between the two sections, they are secured firmly together
by screw bolts O passing through the end plate of one section and screwing into
screwed holes in the other section, the hole being made trumpet mouthed at the
outer end so as to facilitate the entrance of the bolt. In order to prevent any
leakage of water through the holes, that of the bolt is provided with a cup leather O¹
secured by a gland O2, while the bolt hole is enclosed on its inner side by a closed
socket P. The outer joint having been made perfectly watertight by the bolts O,
the sections are further secured by ordinary bolts at 0³..
It will be seen that by means of the ring L a watertight joint can be made
although the sections may be situated close together at one point, as at Fig. 6, and
some distance apart at another point as at Fig 7. The parts X of the annular
space between the shells A and B where the bolts and screws are situated are of
course not filled in with brickwork.
The sections having been secured together, the caisson G and the tube E of the
section previously sunk are removed, and the holes F F are closed, the space D¹
having however been previously filled in with concrete, as shewn at the sunk
sections Figs. 1 and 2, so as to form a solid foundation for the section to rest on.
The tube E is provided at its upper end with an air lock E¹, or chamber having a
door closing the tube E and another leading into the outer air, so that while ingress
and egress are thus afforded to the tube, the air therein and in the space D' is
maintained under pressure as described.
In some cases, we combine with the tubular structure a permanent structure
reaching above the water line by constructing the caisson G of metal, thus
combining with the tunnel a dam, dock, or quay wall reaching above the water.
Fig. 8 shews a modified construction for this purpose, in which the tunnel Q is
constructed within the caisson R, which is built in sections sunk and secured
together as above described. The tunnel is in this case formed either entirely of
brick work or partly of brickwork and partly of concrete as shewn. The tube E,
through which access is gained to the space D' for excavating as before, inay be
allowed to remain in part, so as to serve as a communication from the top of the
dock or quay wall to the interior of the tunnel. Thus ships lying alonside the
dock or quay wall might have their cargo discharged directly down these tubes
into trucks situated within the tunnel.
Having thus described the nature of our invention and in what manner the same
is to be performed, we claim :-
First. The use for forming watertight joints between the sections of subaqueous
tubular structures, of a metal ring L in the one section which is forced by means
of screws against an elastic seating N on the other section, substantially as herein
described with reference to Figs, 6 and 7 of the Drawings.

page_text: Second. The use in combination with the metal ring referred to in the preceding
claim, of screw bolts O rendered water tight by cup leather packings O' for
screwing the sections together.
Third. The combination with the tubular sections of the enclosed spaces D' for
excavating beneath the section of caissons G with guiding flange G¹ for guiding
the section in its descent and ring L for forming a watertight connection between
the sections substantially as herein described with reference to Figs 1 to 7 of the
Drawings.
Fourth. The combined construction of tubular structure or tunnel Q and caisson R
herein described with reference to Fig 8 of the drawings.
In Witness whereof I the said Henry Nathan Maynard have hereunto set my
hand and seal this Twenty-second day of May in the year of our Lord One
thousand eight hundred and eighty-three.