A Means of Indicating Electrically the Presence of a Coast, Rocks, or Shoals, or Determining a Ship's Position in a River, Estuary, or Sea.
Year: 1892

page_text: Date of Application, 21st Mar., 1892
Complete Specification Left. 20th Dec., 1892-Accepted, 4th Mar., 1893
PROVISIONAL SPECIFICATION.
A Means of Indicating Electrically the Presence of a Coast, Rocks,
or Shoals, or Determining a Ship's Position in a River, Estuary,
or Sea.
CHARLES ALEXANDER STEVENSON 84 George Street Edinburgh Civil
Engineer do hereby declare the nature of this invention to be as follows:-
A conductor or conductors of electricity laid on the bed of the sea, estuary or
river with an electric current or currents flowing along it or them so as to act on &
recording apparatus on board vessels and so warn them of their proximity to a
The
coast rock or shoal or determine their position in a river estuary or sea.
conductors may be any form of submarine cable the current being produced by
batteries, magneto electric machines, dynamos, or other instrument for producing
currents; and the recording apparatus may be any voltmeter or ammeter or
galvanometer or needle or other instrument suitable for detecting the presence of
a current or field of magnetisation.
CHARLES A. STEVENSON.
COMPLETE SPECIFICATION.
A Means of Indicating Electrically the Presence of a Coast, Rooks,
or Shoals, or Determining a Ship's Position in a River, Estuary,
or Sea.
CHARLES ALEXANDER STEVENSON, Civil Engineer, 84 George Street,
Edinburgh do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement :-
My invention consists of an entirely new method of warning vessels electrically
of their position or of their approach to a coast, shoal, mines or other danger.
The apparatus consists of a submarine wire or wires laid down in the bed of the
sea, river or estuary or out to any danger or anchorage or safe channel, through
which intermittent currents are made to pass or the electrical state of which is
made to alter by means of some form of electrical machine, generator or battery.
These currents or changes of electrical state are detected by means of a detector,
of such currents or of the change of magnetic influence, or whatever it may be
called, in the neighbourhood of the wire or wires through which such currents are
made to flow, which detector may be on the ship or let down by rope or cable or
coiled round the hull of a vessel. Whenever therefore a vessel comes into the
neighbourhood or over the top of the wire those on board can detect its presence,
and in consequence can locate their position. The currents have, if desired,
different characteristic just as lighthouse apparatus have.
The
One preferred method of carrying the invention into effect is shewn on the
plan where A is one or more magneto electric or other machines, and AC
or A D is an electric wire or cable laid down in the bed of the sea.
cable AC being connected to only one pole of the magneto machine becomes
charged and discharged by the magneto machine or gets its electric or magnetic
properties changed by the magneto machine; this is done every time the bobbins
pass the magnets and consequently rapid alterations are passed through the cable.
A ship therefore with any of the numerous detectors of electricity or magnetism
on board could detect the alterations. One of the preferred detectors is a
telephone (T) on board the ship (B). 'ETE is the telephone circuit, and on

page_text: the approach of the vessel to the cable F the alterations in the cable F can be
distinctly heard at T, the passage of the bobbins producing a musical note in
the telephone corresponding to the number of vibrations. These sounds are
broken and made with any periodicity that may be desired by means of a switch.
When the danger is another vessel, they can make known their presence and
position to each other, by means of their detectors, in which case the wire is simply
wound round a core and placed in the bow of the vessel, and currents sent through
the wire, or the detectors themselves can be so used.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed I declare that what I
claim is :-
(1st) An apparatus for determining a ships position by means of a submarine
wire or wires through which electric currents are made to pass, the influence of
such currents on a detector on board the ship showing her proximity to the
submarine wire and hence her position.
(2nd) And also the warning of vessels approaching each other electrically in
the manner above described.
Dated this 10th d... of
1000