AN IMPROVED METHOD FOR EXPEDITIOUSLY ECONOMICALLY AND EFFECTUALLY BLOCKING THE CHANNEL TUNNEL OR ANY OTHER SIMILAR TUNNEL.
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by Frederic Barnett at the Office of
the Commissioners of Patents on the 30th May 1882.
FREDERIC BARNETT of 106 Queen Victoria [Street] in the City of London
[Civil Engineer] AN IMPROVED METHOD FOR EXPEDITIOUSLY ECONOMICALLY AND
EFFECTUALLY BLOCKING THE CHANNEL TUNNEL OR ANY OTHER SIMILAR TUNNEL.
That the object of this Invention is to effect a prompt inexpensive and effectual
method by which the English Channel Tunnel can for as long or as short a period
as may be desired, be rendered useless (on the English Coast) for the passage of
Men, Material of any nature, Trains Boats Rafts or any other means of locomotion
or transport and that such barrier can be effected in a very few hours at a trifling
expense without the employment of Explosives Chemicals or the use of any
destructive agent or the use of any solid bodies or of any means that would be
prejudicial to the Structure of the Tunnel.
But that the blocking should be effected by such a simple System that when
desired the Tunnel should be again available in a few hours for the passage of
Trains with Passengers and Merchandise the Tunnel and its approaches being at
once wholesome and safe to pass through
My improved System is to be carried out as follows.
That the main body of the Tunnel such part as shall extend from the English
Shore under the Sea shall not be interfered with but that, within the length of the
Land Tunnel Approach or Approaches there shall be one or more Dips, fashioned
as follows, that is to say there shall be two inclines of the road meeting from
opposite sides to a common centre each Incline to be about one thousand feet long
the two lines on which the rails will be laid will together extend over a distance
of about two thousand feet.
The gradient of each Incline to be about one foot in fifty feet.
The rails and ground on which they are laid to run as usual equidistant to the
Roof of the Tunnel, so that the fall of one foot in fifty in a thousand feet length
will give a Dip of twenty feet just where the two Inclines meet, it would then
follow that either from an inlet from the Sea or from Reservoirs otherwise provided

page_text: that when the water is allowed to flow in from adjacent inlets to the inclines or
Dips the spaces between the Inclines would be filled to a depth of twenty feet and
assuming that from the base of the Tunnel to its summit measured twenty feet the
whole space from base to Roof would be filled with water.
But should the altitude of the Tunnel not exceed fifteen feet then the Inclines
need only be seven hundred and fifty feet long or one thousand five hundred feet
together in length.
But more than probable a less depth than fifteen feet of water would suffice
effectually to block locomotion of men and material
The means of influx of water either from the Sea or Reservoirs will be a matter
of simple engineering and equally easy arrangement can be established for drawing
off the water when required in a few hours, such arrangements for flooding to
prevent the possibility of failure could be so established by employing various
conduits of sufficient Calibre controlled from several protected places so that the
flooding of the Dips could be effected surely and with safety almost instaneously
blocking and rendering impassible those selected parts of the land tunnel-By
such simple prompt and comparatively inexpensive means The Tunnel under the
Channel would be always preserved intact and uninjured and in good working
order so soon as the water should be drawn off the Dips between the Inclines in
the Tunnel Approach or Approaches.