Improvements in Ships' Logs or Apparatus for Indicating and Recording the Speed of Vessels.
Year: 1892

page_text: Date of Application, 8th June, 1892-Accepted, 5th Nov., 1892
COMILELE DE MULTICATION
Improvements in Ships' Logs or Apparatus for Indicating and
Recording the Speed of Vessels.
I, JAMES YATE JOHNSON of 47 Lincoln's Inn Fields in the County of Middlesex
Gentleman do hereby declare the nature of this invention (which has been com-
municated to me from abroad by La Société du Loch Graphique Berthomić
& Gombault of 90 Avenue de Villiers, Paris, in the Republic of France) and in
what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :-
This invention relates to a log which indicates and registers the speed of ships
& vessels to which it is applied. This log which my foreign correspondents term
the "Graphic Log" is not exposed to the action of the sea or water which may
be running in the same or a different direction to the course of the vessel and thus
in this respect differs from ordinary logs and forms virtually a part of the vessel.
Moreover it is capable of being adjusted in the same way as any mathematical
instrument so as to obtain perfect accuracy in the indications given independently
of the depth, shape or length of the vessel.
This Graphic log is based on the employment of a column of air of adjustable
volume in communication with a manometer or pressure gauge connected with a
needle or pointer indicating the actual speed of the vessel at the moment of
observation and also registering this speed in the form of a diagram upon a band
of paper or other like material which is moved forward with a regular motion
by clockwork.
This band of paper or the like is divided into spaces indicating hours and miles
by means of abcissa and ordinates upon which the curve of speeds is traced so as
to give the total distance traversed by the vessel and record its speed at all parts
of a voyage. It also indicates the time during which the vessel has been advancing
and the periods of stoppage. This Graphic log is thus enabled to give accurate
information to the captain in the course of the voyage and these indications being
registered and preserved may be afterwards consulted at any time.
And in order that the said invention may be fully understood I shall now
proceed more fully to describe the same and for that purpose shall refer to the
annexed drawings the same letters of reference indicating corresponding parts in
all the figures.
Figure 1 of the accompanying drawings illustrates the general arrangement of
the Graphic log in external elevation, the parts being arranged near together in
order to occupy little space in the drawing.
Figure 2 (drawn to a larger scale) illustrates in section the part communicating
with the water.
Figure 3 illustrates in horizontal section and transverse section a detail of the
inlet pipe.
Figures 4 and 5 illustrate (in elevation and plan respectively) the registering
apparatus.
In principle the Graphic log as illustrated is composed of the parts communicating
with the water an air chamber and compensator and a Graphic registering device.
Each of these parts is hereinafter separately described the combination and action
of the apparatus as a whole being afterwards explained.

page_text: PARTS COMMUNICATING WITH THE WATER.
In
The apparatus communicates with the water as near to the keel of the ship or
vessel as possible say at about rds of the length from the stem. The parts which
so communicate consist of an inlet pipe j of very small bore (say about 1.5 millimetres
in transverse section) contained in and protected by a tube i passed through the
shell T of the vessel. This tube is attached to the shell by means of a cock R
firmly attached to the interior of the shell from which it is insulated by means of
a suitable washer x in order to prevent the formation of an electric current and the
consequent rapid destruction of the parts under the action of salt water.
the socket or shell of this cock the plug being in an open position the tube i is
introduced, being also passed through a stuffing box p in order to prevent leakage.
The external portion of the tube i is of triangular form in transverse section in
order to present as little resistance as possible and contains a small chamber j¹
communicating with the tube i. In this chamber is secured a small nozzle or inlet
pipe perforated with a small hole in the side in the direction of the fore part of
the vessel.
The section of the chamber ¹ and that of the tube i are so proportioned that
there is a space between the two, ensuring free communication between the interior
of the tube i and the external water.
At the upper enlarged part of the tube i there is a cock the shell of which at
the part above the plug communicates with the pipe j. The plug of this cock is
worked by a lever n'n¹ by means of cords or chains o o' carried over guide pulleys
arranged so as to be operated from any part of the vessel, preferably from the part
where the registering apparatus is placed. A flexible pipe N N' connects this
cock with an air chamber H which may be at any suitable distance.
AIR CHAMBER.
This air chamber H containing approximately about 1 cubic decimeter is secured
by collars sliding upon a vertical rod L firmly fixed to a board J arranged if
possible above the tube j communicating with the external water and at such a
height in the vessel that it is possible to adjust the said air chamber on a level
with the water line. A lanyard or chain K enables the air chamber to be adjusted
vertically by sliding it upon the rod L being provided at its extremity K¹ with
knots holes or the like for fixing it in position. The guide pulleys and the lanyard
or chain K are preferably arranged in such a manner as to enable it to be operated
from the place where the registering apparatus is situated.
GRAPHIC REGISTER, FIGS. 4 & 5.
The register is formed by a band D say of paper which is unwound from a
drum T and wound upon another drum T¹ worked by clockwork suitably arranged
in its interior. On leaving the drum T the band of paper passes over the rollers & t
before it is wound upon the drum T¹. A brake q acting upon the drum T enables
the tension of the paper to be adjusted.
This band of paper is provided beforehand with equidistant horizontal lines and
arcs of circles whose radii are equal to the distance from the style to the centre
of oscillation of the lever B hereinafter referred to. The horizontal lines represent
distances say in nautical miles or knots and are numbered from the top to the
bottom whilst the arcs represent divisions of time say hours, half hours and quarters
of hours. The arcs are not equidistant. In regulating the distance between them
the gradual increase in the diameter of the winding on drum T" has to be taken
into account. Any suitable number of horizontal lines and arcs may be employed.
Facing the band of paper D works a tracing style b' carried on the outer end of
an arm or lever B which is caused to oscillate by a manometer A connected by a

page_text: flexible pipe I with the upper part of the air chamber H. The arm B may be
provided at the other extremity with a needle or indicating hand working over a
fixed dial divided into distances say nautical miles or knots.
Upon the arm B is provided an adjustable weight which enables the apparatus
to be adjusted by sliding the weight upon the arm so as to increase or diminish the
resistance. A rod t placed on a lever enables the tracing style 6' to be removed
from the paper if required.
The registering apparatus thus constituted and enclosed in a box F having a
lid G is placed in a suitable position such as the captain's cabin or in the
deckhouse.
Upon the flexible pipe I is a cock f communicating with the atmosphere for the
purpose of enabling the registering apparatus to be stopped or set at work as
required. From this cock proceeds a branch pipe leading to a manometer Q
which being placed near the steering gear indicates the speed of the vessel upon a
suitably graduated dial. This manometer gives the same indications as the hand
or indicator hereinbefore referred to as working over the fixed dial.
ACTION.
When at rest, the ship being in port, the cock is open and is retained in this
position by means of the cords or chains o o'. This cock and also the cock / on
the pipe I are kept open all the time that the ship is stationary. Under these
conditions the level of the water in the interior of the apparatus is the same as the
external level of the water.
At the moment of getting the vessel under way the following operations are
performed viz.
1stly. The cock on the air chamber H is opened and this chamber is raised or
lowered as required until the operator by observing the flow of water from the said
cock ascertains that the surface of the water in the chamber is on a level with
the cock.
The chamber is then fixed at this level which corresponds with the level of the .
external water and the cock on the chamber H is closed.
It is of the
2ndly. The cock f is now to be closed and afterwards the cock r.
greatest importance to perform these operations in proper order as stated because if .
the cock were closed before the cock f the column of water would rise so that
the proper effect would not be produced.
When the ship is under way the water is forced into the pipes through the nozzle
or inlet with a force directly proportionate to the speed of the vessel. The
water forces up
the air which is compressed in the chamber H. This compression
acts upon the manometer A and causes the arm B to move over the band
of paper.
The amplitude of its movement is directly proportionate to the pressure which
varies with the speed of the vessel. This arm B being provided with the tracer
and the band of paper being drawn forward by the action of the clockwork the
band of paper receives a curve or diagram indicating with great accuracy the
speed of the vessel at all times of the voyage. The band of paper thus not only
enables the variations in the speed of the vessel to be ascertained but also the
times at which they have taken place. It indicates moreover the times of the
It is in short a record
stoppages and the distance traversed in a given time.
of all the phases of the voyage comparing the hours with the distance passed over.
Moreover the hand or indicator combined with the arm B indicate upon a fixed
dial the speed of the vessel at the moment of observation. The manometer Q
branching from the main pipe I affords the same indications to the steersman.
Although this log is specially arranged for registering it may be made to work
without registering, the indicating hands or pointers and the manometer Q being
alone employed.
In case of any doubt arising as to the proper working of the apparatus it is

page_text: simply necessary to pull the chain o o' so as to open the cock r. The delivery from
this cock being greater than the quantity of water admitted in the same time by
the nozzle to the inlet pipe j, the water forced out returns to the sea through the
pipe and the arm B of the registering apparatus as well as that of the manometer Q
fall back to zero. When the pointer has returned to zero it is simply necessary
to close the cock and if the apparatus be working properly the arm B and
that of the manometer Q will rise to the same point and indicate the same speed as
before.
ADJUSTMENT OF THE APPARATUS.
The shape and dimensions of the vessel having an influence (independently of
the speed) over the rush of liquid into the nozzle 2 it is necessary to provide for
regulating the Graphic log. Various means may be employed for this purpose. In
the first place we may adjust the band of paper marked with more or less wide
spaces or divisions or the adjustable counter-weights threaded upon the arm B
may be adjusted in such a manner as to set the indications of speed forwards or
backwards. The air chamber H may also be adjusted by raising it or lowering it
by means of the cord or chain K.
In order to repair or examine the inner pipe the tube i is first drawn up until
its lower extremity is above the plug of the cock R, which is then closed, after
which the said tube can be removed. The tube may be replaced in position by
reversing the order of operations. By this means no water is admitted and repairs
and examinations are enabled to be made with the greatest facility.
The dimensions of the log are optional and its constituent parts may be
constructed of any suitable materials. The air chamber H may be combined with
the part communicating with the sea and the latter in this case may be arranged in
the sides of the vessel, being placed either on the port or starboard side without in
any way affecting the indications given.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
:-
1. A Graphic log or apparatus for indicating and recording the speed of ships or
vessels comprising a manometric registering apparatus provided with a moveable
band D and a tracer, a moveable air chamber H and a communication with the
sea or external water formed by an inner pipe j and a nozzle projecting in
the direction of the movement of the vessel the said Graphic log recording by the
intervention of a column of air and a column of water the different phases of the
progress of the vessel as regards speed and distance traversed substantially as herein-
before described with reference to the accompanying drawings.
2. The arrangement of the band D.having equidistant horizontal lines repre-
senting the distances and arcs representing periods of time the said band D being
propelled by a clockwork movement and combined with a tracer subjected to
the influence of the varying speeds of the vessel by the intervention of a column
of water and a column of air which tracer traces upon the said band a curve or
diagram for comparison of the hours with the distances traversed substantially as
herein before described and illustrated in the accompanying drawings.
3. The special arrangement of the air chamber H sliding upon a fixed board or
support and suspended so as to be capable of being adjusted on a level with the
water line the said air chamber being interposed between a pipe j and a manometer A.
to which it is connected by the flexible pipes 1 and N N₁ substantially as herein-
before described and illustrated in the accompanying drawings.
↑
4. The arrangement of the inner tube in a tube or pipe i provided with a
cock the said inner tube j having a nozzle projecting in the direction of the
movement of the vessel and being placed at about two thirds of the length of the
said vessel reckoning from the stem substantially as hereinbefore described with
-reference to the accompanying drawings.

page_text: 5. The combination of the pipe i enclosing the inlet tube j with a cock R fixed
to the shell of the vessel in the required position and insulated therefrom in any
suitable manner substantially as and for the purpose hereinbefore set forth.
6. The combination and arrangement of parts constituting a log or apparatus for
indicating and recording the speed of ships or vessels substantially as hereinbefore
described and illustrated in the accompanying drawings.
Dated this 8th day of June 1892.
J. H. JOHNSON & Co.,
Agents.