IMPROVE_ MENTS IN THE CONSTRUCTION OF SUBMERGED TUNNELS
Year: 1858

page_text: PROVISIONAL SPECIFICATION left by Peter Schuyler Bruff at the Office
of the Commissioners of Patents, with his Petition, on the 19th January
1858.
I, PETER SCHUYLER BRUFF, of Ipswich, in the County of Suffolk, Civil
Engineer, do hereby declare the nature of the said Invention for. "IMPROVE_
MENTS IN THE CONSTRUCTION OF SUBMERGED TUNNELS," to be as follows:-
This Invention relates to a peculiar construction and arrangement of sub-
marine or submerged tunnels, and to the mode of laying or depositing the
same, and consists in the application and use to and in the construction of
tunnels of this description of metal cylinders or tubes made in sections or
lengths of suitable dimensions and shape, such tubes resting upon or being
sunk into the bottom of rivers or arms of the sea required to be crossed, and
are adapted for roads, railways, and other communications which may require
to be established through or under the same. The cylinders or tubes may be
of cast or wrought metal, but I prefer wrought iron, ribbed-and plated similar
to an iron ship. They are made in sections or lengths, and are protected
from corrosion by any of the known appliances used for that purpose. They
may be constructed of one, two, or more thicknesses of plating with ribs,
stringers, and kelsons, of angle iron or other form, the whole being securely
bolted, screwed, and rivetted together. The transverse dimensions of these
cylinders or tubes will necessarily be governed by the objects to be obtained,
but the length of the sections will be regulated by the situation and character
of the ground upon which they are to rest, which as a general rule, where the
[Price Sd.1

page_text: bottom is compact, I prefer to be in a prepared trench nearly equal in depth
to the outside vertical diameter rather than upon the natural unprepared
surface or bed, although where this is soft alluvium previous dredging will be
unnecessary, as the cylinders or tubes will be themselves sufficiently therein,
being secured by an adequate quantity of rubble stonework. It is thus that
increased stability of position will be secured whilst little or no obstruction
whatever will be afforded to navigation and the flow of the current. These
sections are to be made water-tight, and temporarily closed near to their ends.
so as to form caissoons, which may be towed from any convenient place on
shore to the site of the tunnel, and there submerged with proper guides and
stays to insure their correct position. In some cases the trench is to be
roughly prepared beforehand by the usual dredging process, assisted by divers,
and to be completed as each section is deposited by operators from within
such deposited section, who will use them as diving bells, it being understood
that each section is to be adapted for that purpose. Or, if found desirable,
the sections may be sunk by their own gravity, and deposited in their places
by the aid of divers. On arrival at the site where it is to be deposited, the
section is to be ballasted and properly prepared for use by the removal of a
portion of the bottom plates, and making the requisite air connections.
When a double plating is used with intervals between, such intervals or
spaces may he employed as air or water chambers at convenience for the
purpose of facilitating movement, as in the hydraulic diving machine known
as the nautilus. To form the sections into a continuous cylinder or tube it
will be necessary to connect them together either by flange conical-shaped
socket or half-lap bed and covering joints, plain or articulated, formed on the
ends of each section, with an elastic paving to exclude the water, the whole
secured with fixtures of eyes, pins, and other fastenings, and completed after-
wards in a more perfect manner with bolts, screws, rivets, and additional
plating, with supplemental stringers and kelsons. As the sections are
brought together the water is to be withdrawn from the space between the
recessed ends, which may then be used as a temporary air chamber, from
which their connection may be perfected, and such chambers may be after-
wards used as pneumatic locks" for facilitating the passage of men and
materials between the inside and outside of the perfected extremity of the
tunnel. So soon as a number of sections of the submerged tunnel are com-
pletely connected and permanently secured in position, a lining of hydraulic
masonry or concrete may be built within them, so as to form a complete
tunnel of imperishable materials. In all cases these submerged tunnels are
to be permanently weighted sufficient to overcome their buoyancy and secure

page_text: their stability of position, either by their being placed sufficiently below the
natural bed of the river or sea to be passed under, or in cases where that is
not found advisable on account of expense or difficulty of any kind, they may
be secured by Mitchell's screw moorings, or with a slope or prism formed of
concrete blocks or rubble stone on either side with holding down attachments,
and under, some circumstances the crown of such tunnels should be covered
with rubble or concrete, which would afford some protection against external
injury, as in the case of vessels dragging their anchors or otherwise. It
is obvious that in all submerged tunnels provision must be made for supplying
fresh air to and withdrawing foul gases, which will accumulate at the lowest
part thereof when completed, and at the lower extremities of the workings
during construction; this is frequently required in the formation of tunnels upon
land. and effected by well-known appliances, and will be similarly accomplished
in the practice of this Invention. It is intended to facilitate the formation of
submergeil tunnels by applying the electric telegraph with properly insulated
wires for communicating between the workmen employed in the sections as
they are being submerged and connected and those employed upon the surface
of the craft-motion. tackle, &c., and also by the adoption of the atmospheric
railway for the ready transmission of men and materials, which system of
propulsion will be adapted for permanent use where such tunnels are to be
applied to railway purposes. In some cases it will be found advantageous to
ballast each section before it is submerged by partially lining it with masonry
or concrete, but not quite suflicient to destroy buoyancy, otherwise it will be
found difficult, if not impossible, to place them in correct position for attach-
ment. with those previously deposited. And it is also to be understood that
although I have spoken of adopting the principle employed in the nautilus
machine" for moving these sections in the formation of the submerged tunnel,
I do not intend dispensing with floating craft slings and the ordinary surface
appliances used in connection with the diving bell.