Apparatus for Ascertaining Distances and Directions at Sea by means of Sound Signals, thereby Facilitating Navigation.
Year: 1891

page_text: Date of Application, 25th Aug., 1891
Complete Specification Left, 24th May, 1892-Accepted, 25th Aug., 1892
PROVISIONAL SPECIFICATION.
Apparatus for Ascertaining Distances and Directions at Sea by means
of Sound Signals, thereby Facilitating Navigation.
I, HENRY PATRICK DOWLING 66 De Burgh Street Riverside Cardiff Clerk
G.W.R. Cardiff do hereby declare the nature of this invention to he as follows:-
The combination of apparatus for sending sound signals simultaneously through
water and through air from any place on shore or on board ship, with apparatus,
which may also be on shore or on board ship, for receiving and registering
automatically such sound signals separately, so that the difference in time occupied
by the sound in traversing the distance between those places through the two media
can be used to measure that distance, and thus furnishing a means of determining
a ship's position, even in a fog, and of preventing loss of life and property thereby.
Each sounding apparatus to consist of two portions, situated at least approximately
in the same vertical line, one portion in the air and the other in the water, by
which similar sounds can be produced at the same time. They may be of any of
the following kinds; viz.,-
Any apparatus for exploding gunpowder, &c., or,
Any form of bell or vibrating plate, capable of emitting a sound when struck by
a hammer to be worked either mechanically or electrically, or,
Any form of whistle or syren to be sounded by steam, water, compressed air,
or any combination of these.
The receiving apparatus to consist of two portions, situated approximately in the
same vertical line, one in the air and the other in the water, each of which portions
shall contain an elastic plate or diaphragm, capable of vibrating under the influence
of sound, and a contact-breaker by which electric currents may be controlled,
automatically by the vibrations of the said plate or diaphragins and from which
wires shall be carried to the battery and registering instrument. The vibrations of
the plate or diaphragm may also be made to control the registering instrument by
pneumatic or mechanical means, if desired.
The registering instrument to have one or more pairs of electro-magnets,
according to the number of receiving instruments in use on any ship or at any
station on shore, with armatures placed close to them in such a manner that they
shall move to and fro in accordance with the variation of the magnetization of
the electro-magnets, controlled automatically by the vibrations of the plates or
diaphragms previously mentioned. These armatures to cause similar motions to
pencils or pens, connected therewith, which shall register these motions on a strip
of paper moved along at a regular rate by clockwork.
The pencils or pens to be placed in a line across the paper, at right angles to the
direction of its motion.
If the pneumatic or mechanical method of controlling the registering instrument
be adopted, the electro-magnets and armatures will not be required, as the pencils
or pens can then be caused to move without their interposition. The clockwork to
mark or puncture the paper at regular intervals of time, as, once in every second,
or preferably once every 3.6 seconds, (that is assuming that 3.6 seconds is the time
gained by sound in travelling a nautical mile through water as compared with its
travelling the same distance through air). If desired the marks may be at fractional
parts of the latter named intervals.
By noting the number or fractional parts of such intervals marked by the clock-
work between the registering of a signal by the instrument connected with the
water, and the registering of the same signal by the air connected instrument, the
distance of the sounding station can be read in nautical miles, or fractions thereof.

page_text: In this way a permanent record of the signals is taken and the difference in time,
and therefore, the distance is shown at a glance, without having recourse to the
uncertain reading of a watch, and calculating the distance therefrom.
The indications thus given by one pair of receiving instruments shows the
distance of the sounding station, but by combining the readings of two or more
pairs placed at different points, as near the bow and stern of a ship respectively,
the direction can also be determined with considerable accuracy. In this way the
officer in charge of a ship can, even during a dense fog when all other methods
hitherto known are useless, determine the relative position of his ship and other
ships or stations on shore, and thereby avoid collision or shipwreck.
Dated this 21st day of August 1891.
HENRY P. DOWLING,
66, De Burgh Street, Cardiff.
COMPLETE SPECIFICATION.
Apparatus for Ascertaining Distances and Directions at Sea by means
of Sound Signals, thereby Facilitating Navigation.
I, HENRY PATRICK DOWLING 66 De Burgh Street, Riverside, Cardiff Clerk
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 :-
The combination of apparatus for sending sound signals simultaneously through
water and through air from any place on shore or on board ship, with apparatus,
which may also be on shore or on board ship, for receiving and registering
automatically such sound signals separately, so that the difference in time occupied
by the sound in traversing the distance between these places can be used to measure
that distance, and thus determine a ship's relative position even in a fog, so that
collision and shipwreck may be avoided, and life and property saved. Each
sounding apparatus to consist of two portions situated, at least approximately, in
the same vertical line, one portion in the air and the other in the water, by which
similar sounds can be produced at the same time. This may be of any of the
following kinds; viz.,
Any apparatus for exploding gunpowder, guncotton &c.
Any form of bell or vibrating plate capable of emitting a sound when struck by
a hammer to be worked either mechanically or electrically.
Any form of whistle or syren to be sounded by steam compressed air, water, or
any combination of these.
In all forms the sounds to be started or stopped at once in both portions, by one
handle, contact breaker &c.
The receiving apparatus to consist of two portions, situated at least approximately
in the same vertical line, one in the air and the other in the water, each of which
shall contain an elastic plate or diaphragm capable of vibrating under the influence
of sound, and a contact breaker by which electric currents may be controlled
automatically by the vibrations of the said plate or diaphragm, and from which
wires shall extend to the registering instrument and battery. The vibrations of
the plate or diaphragm may also be made to control the registering apparatus by
pneumatic or mechanical means if desired.
The registering instrument to have one or more pairs of electro magnets
(according to the number of instruments in use on any ship or at any station on
shore), with armatures placed close to them in such a manner that they shall move
to and fro in accordance with the variations in the magnetization of the magnets,
controlled automatically by the vibrations of the plates or diaphragms previously
mentioned. These armatures to cause similar motions to pens or pencils or other
marking instruments connected therewith, which shall register these motions on a
strip of paper moved along at a regular rate by clockwork. The pens or pencils &c.

page_text: and the marker worked by said clockwork, as hereafter described, to be placed so
that their points of contact with the paper shall be in a straight line at right angles
to the direction of motion of the paper. The motion communicated by the
armatures to the pens &c. may be either towards the paper and receding from it, or
across the paper.
In the former case the lines drawn to represent the signals would be intermittent;
blank spaces intervening where no signal was registered. In the latter arrange-
ment the lines would be continuous; being straight where no signal was registered
and curved or sinuous to represent a signal.
If the pneumatic or mechanical method of controlling the registering instrument
be adopted, the battery, electro-magnets and armatures will not be required, as the
vibrations of the above-named diaphragms can be communicated to the pens &c.
without their interposition.
The clockwork before mentioned to mark or puncture the paper at regular
intervals of time as once every second, or, preferably once every 41 seconds, (that
is, assuming that 4.1 seconds the time gained by a sound in travelling a nautical
mile through water as compared with its travelling the same distance through air).
If required, the marks or punctures may be at fractional parts of the latter named
interval.
As the sounds produced in the air and in the water respectively to form any
sound-signals, as herein described, shall commence and cease respectively at the
same instants of time, so the registers of those sounds made by the registering
instrument, herein described, shall be of the same length, but the signal which has
travelled through the water will be registered in advance of the signal which has
travelled through the air, by a distance exactly proportional to the distance from
which the signal came. By noting the number or fractional parts of the intervals,
marked or punctured by the clockwork, between the registering of a signal by the
two pens &c. as above described, the distance travelled by the signal is seen at a
glance; that is to say, every such interval represents a nautical mile distance from
the sounding station, and cach fractional part of such interval represents a similar
fractional part of a mile. In this way a permanent record of the signals is taken,
and each automatically shows its own distance, so that the distance of a ship or point
on shore from which a signal is received is at once ascertained, even when, owing
to fog or other cause, the said ship or shore station may be invisible.
The indications thus given by one pair of receiving instruments shows the
distance of a ship or shore station from which a signal is received; but by com-
bining the readings of two or more pairs placed at different points, as, near the bow
and stern of a ship respectively the direction also may be determined with
considerable accuracy.
In this way the officer in charge of a ship can ascertain the position of his ship
relatively to other ships or points on shore from which he receives signals and the
officer in charge of a shore station can ascertain the position of ships in the
neighbourhood of his station even when fog or other cause prevents optical observa-
tions being made, so that collision and shipwreck may be prevented, and life and
property saved.
The registering instruments may be placed in the wheel-house, on the bridge, or.
in any other convenient position on board ship or at a shore station, and the
receiving instruments, controlling the same, may be placed, permanently or
temporarily, at one or more points to suit the requirements of any particular
case.
DESCRIPTION OF DRAWINGS OF APPARATUS, AND METHOD OF USING SAME.-
Fig. 1. Section of side of ship, showing position of double syren, one portion A
in the air, and the other B. in the water.
Fig. 2. Section of side of ship showing position of receiving apparatus, one
portion E in the air, and the other F. in the water.

page_text: Fig. 3. Enlarged section of double syren, showing two portions mounted on same
shaft, the upper portion A. being supplied with steam or compressed air through
tube a.; and the lower portion B supplied with compressed air or water under
pressure through tube b.; both tubes being opened or closed simultaneously by the
valves C. operated by handle D. through suitable gear, thus sounding both parts of
the instrument simultaneously. The shaft &c. to be protected by tubular casing as
shown.
Fig. 4. Sections of receiving apparatus E or F. in which G is a watertight deal
box fixed in suitable metal frame, to facilitate its being fixed in position, the frame
being so shaped as to expose the front and sides of the box. Inside G a wood or
ebonite frame H is suspended by indiarubber bands attached to the corners, or by
other similar means. To the upper and lower sides of the frame H are fixed
respectively two sets of metallic reeds J of various lengths whose free ends
terminate close to the metallic cross-piece I. with which they come in contact when
they vibrate.
The fixed ends of these reeds are all put in metallic contact through two strips
of metal fixed to their ends on the frame H, with one of the binding screws at the
back of the box G. The cross-piece I is connected with the other binding screw,
but is insulated from the reeds while they are at rest. These binding screws
are respectively connected, by means of double-wire cables with the batteries and
electro-magnets, as shown in Fig. 5. The frame H is also connected with the front
and sides of the box G by one or more wood or metal rods g, which transmit to it
the sound vibrations received by G. from the air or water respectively.
These
Fig. 5. EM is an electro-magnet and e a battery in electric communication with
receiving apparatus E. FM is an electro-magnet and a battery in electric
communication with F. When the contact is made at I by the vibrations of any
of the reeds J. in receiver F the armature k. is attracted towards FM. causing the
pen or pencil K to move in a similar direction across the paper R. When the reed
vibrates in the opposite direction and thus breaks contact, the armature k and
pen K are moved back to their initial position by the spring S, and these move-
ments are repeated so long as the reed continues to vibrate under the influence of
the sound waves communicated to it from the water through the box G
vibratory movements of the pen to and fro across the paper, while the latter is
being moved forward in a direction at right angles to these vibrations, cause the
trace made by the pen to become sinuous; and if the movement of the paper be
not sufficiently rapid to keep the successive sinuosities distinct, they combine and
form a thickened line as shown in Fig. 6. The length of this sinuous or thickened
portion corresponds exactly to the duration of the signal it indicates. Similar
motions are caused to the pen or pencil L by means of the electro-magnet EM and
springs when the signal through the air canses any of the reeds in the receiver E
to vibrate. The registers of any signal by the two. pens respectively will be of
the same length; but that traced by the pen I will be in advance of that traced
by L by a distance exactly proportionate to the distance the signal has travelled.
N. is a marker which marks the paper R once every 41 seconds, by the movement
of the rod T, to one end of which it is attached, the other end being pivoted.
The spring t presses the rod T against the circumference of the wheel O which
has ten cam teeth. On the same axle with O is mounted the wheel P having
41 teeth, which is geared to the wheel Q which has 60 teeth and makes one
revolution per minute. The wheels P and O thereby make one revolution in
41 seconds, and the ten cams on the latter cause the rod T and marker N to make
one vertical movement towards the paper R in each interval of 4.1 seconds,
corresponding to distances of nautical miles. Each of these intervals may be
subdivided into four parts by having 40 cam teeth on the wheel O. The distances
then indicated by the marks will be quarter-miles.
Fig. 6. The marks in the centre line correspond to quarter-miles while on the
left a signal received through the water is registered at an interval of four of these
marks in advance of the signal from the same point when received through the

page_text: air as shown on the right. The distance travelled by the signal is thus shown to be
a mile.
If directions are to be ascertained, at least two pairs of receiving apparatus and
a-corresponding number of electro-magnets, pens &c. are required, in which case
the additional pens are so placed as to touch the paper in the same straight line in
a direction at right angles to that in which the paper moves. In this case, one pair
of receiving instruments should be placed near the bow, and the other pair near
the stern of the ship; and the greater the distance separating them the more
accurately will their registers of signals indicate the direction.
If the signal comes from a point right ahead, it will be registered first by the
apparatus connected with the forward receivers, and vice versa; while if it comes
from a point on the ship's beam, both receivers will indicate it at the same time on
the paper, that is to say, the signal will be indicated at the same time by the
receivers in the water at the bow and stern respectively, but it will also be registered
by the two pens controlled by the receivers in the air at the bow and stern
respectively; the two former indications being in advance of the two latter
respectively by an interval corresponding to the distance travelled by the signal.
Intermediate directions can be determined, relatively to these, by the position of
the signal registers on the paper.
At shore stations the receivers may be placed at any convenient distance apart,
according to the nature of the adjacent coast-line &c. and two or more sets can
then be put into communication with one suitable registering instrument at the
central station, which will indicate the signals received by all the receivers, so that
the exact position of every ship whose signals are received can be accurately
determined even in foggy weather.
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. The utilization of the different velocities of sound in air and in water to
ascertain the relative position of a ship and other ships or points on shore respec-
tively, by means of apparatus for producing and receiving sound signals in the two
media respectively and registering them automatically, in combination with
mechanism for registering regular known intervals of time, substantially as
described.
2nd. The combination of apparatus substantially as described; for producing
similar sounds simultaneously in air and in water respectively, at points in or near
the same vertical line, at any place on shore or on board ship, with apparatus,
substantially as described, on shore or on board ship, for receiving and registering
the sounds so produced respectively, in such manner that the difference in time
taken by the sounds to traverse the distance between the place at which the sound
is produced and that at which it is received, can be utilized to ascertain that
distance, and thus determine the relative position of a ship and other ships or points
on shore.
3rd. The means of finding a ship's position, relatively to other ships or points on
shore, independently of optical observations, by producing and receiving sound
signals in air and water respectively, and registering these automatically together
with regular intervals of time, by apparatus substantially as described.
Dated this 02nd do of Mar 1899
HENRY PATRICK DOWLING.
HENRY PATRICK DOWLING.