IMPROVEMENTS IN SHIPS' LOGS
Year: 1870

page_text: LETTERS PATENT to Henrik Ramsten, of Carlskrona, in the Kingdom
of Sweden, Lieutenant in the Royal Swedish Navy, for the Invention
of "IMPROVEMENTS IN SHIPS' LOGS."
Sealed the 17th January 1871, and dated the 18th July 1870.
PROVISIONAL SPECIFICATION left by the said Henrik Ramsten at the
Office of the Commissioners of Patents, with his Petition, on the.
- 18th July 1870.
I, HENRIK RAMSTEN, of Carlskrona, in the Kingdom of Sweden,
Lieutenant in the Royal Swedish Navy, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN SHIPS' LOGS," to be as
follows:
The objects of my Invention are to construct a ships' log or apparatus
for indicating the speed of a ship through the water in such a manner
that the working parts shall be completely protected from damage;

page_text: secondly, that there shall be less slip, or friction of the screw than at
present; thirdly, that facility should be given for ascertaining the state
of the dial at any moment without loss of time; fourthly, that by an
arrangement of blades on the exterior casing the log should be kept just
below the surface of the water, to avoid seaweed and other floating
bodies; fifthly, to cause the log frame or casing to be kept in one
position in the water; and, sixthly, to provide means for guiding
the log to keep it away from the ship, whether on the port or starboard
side,
The Invention consists in the construction of a cylindrical casing, the
front of which is protected by a grating, preferably conical, to prevent
the entrance of seaweed. Inside the casing a screw is free to revolve;
the screw is connected to a train of wheelwork for moving the index
hand or pointer on a dial which is fixed in the bottom of the apparatus.
The screw is much smaller than the inner diameter of the casing, to
obviate the influence of the friction of the water against the inside of the
cylinder. The cylinder or casing is provided with a weighted keel to
keep it in one position. Inclined vanes or plates are arranged on the
outside to cause it to sheer some distance below the surface of the
water,
The fore part of the apparatus or the tow line is provided with a
rudder or plate fixed at an angle to ensure its taking a course at a
distance from the ship's side from which it is preferred to work it, and
the rudder is fixable on either side of the apparatus to suit the side of
the ship from which it is used. A trip line is provided by which the
apparatus can be hauled in at any time.
-The Invention is also applicable to existing logs, such as those known
as Massey's, Walker's, and others, for, if a body of suitable shape is
constructed with flanges and a rudder as above described, such body may
be carried in front of any revolving log, and thereby cause it to keep at
a proper distance from the ship's side, and also below the surface of the
water. Any log could then be carried alongside instead of over the
stern of the vessel.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henrik Ramsten, in the Great Seal Patent Office
on the 18th January 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRIK
RAMSTEN, of Carlskrona, in the Kingdom of Sweden, Lieutenant in the
Royal Swedish Navy, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighteenth day of July, in the year
of our Lord One thousand eight hundred and seventy, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Henrik Ramsten, Her special licence that
I, the said Henrik Ramsten, my executors, administrators, and assigns,
or such others as I, the said Henrik Ramsten, my executors, adminis-
trators, and assigns, should at any time agree with, and no others, from
time to time and at all times thereafter during the term therein expressed,
should and. lawfully might make, use, exercise, and vend, within the
United Kingdom of Great Britain and Ireland, the Channel Islands,
and Isle of Man, an Invention for "IMPROVEMENTS IN SHIPS' LOGS," upon
the condition (amongst others) that I, the said Henrik Ramsten, my
executors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, should particularly describe and
ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Henrik Ramsten, do hereby declare
the nature of my said Invention and in what manner the same is to
be performed, to be particularly described and ascertained in and by
the following statement thereof, reference being had to the Drawings
hereunto annexed, that is to say:-
The objects of my Invention are to construct a ships' log or apparatus
for indicating the speed of a ship through the water in such a manner
that the working parts shall be completely protected from damage;
secondly, that there shall be less slip or friction of the screw than at
present; thirdly, that facility shall be given for ascertaining the state

page_text: of the dial at any moment without loss of time; fourthly, that by an
arrangement of blades on the exterior casing the log should be kept just
below the surface of the water to avoid seaweed and other floating
bodies; fifthly, to cause the log frame or casing to be kept in one
position in the water; and, sixthly, to provide means for guiding the log
to keep it away from the ship, whether on the port or starboard side.
The Invention consists in the construction of a cylindrical or other
shaped casing, the front of which is protected by a grating or shell,
preferably conical, to prevent the entrance of seaweed. Inside or at the
tail of the casing a screw is free to revolve; the screw is connected to a
train of wheelwork for moving the index hand or pointer on a dial which
is fixed in the apparatus. The screw is much smaller than the inner
diameter of the casing to obviate the influence of the friction of the water
against the inside of the same. The cylinder or casing is provided with
a weighted keel to keep it in one position, and inclined vanes or plates
are arranged on the outside to cause it to sheer some distance below the
surface of the water.
The fore part of the apparatus or the tow line is provided with a rudder
or steering plate fixed at an angle to ensure its taking a course at a
distance from the ship's side from which it is preferred to work it, and the
rudder is fixable on either side of the apparatus to suit the side of the ship
from which it is used. A trip line is provided by which the apparatus
can be hauled in at any time.
The Invention is also applicable to existing logs, such as those known
as Massey's, Walker's, and others, for, if a body of suitable shape is con-
structed with flanges and a rudder as above described, such body may be
carried in front of any revolving log, and thereby cause it to keep at a
proper distance from the ship's side and also below the surface of the
water. Any log could then be carried alongside instead of over the stern
of a vessel.
The Invention will be well understood by referring to the accom-
panying Sheet of Drawings, in which Figure 1 is an exterior view of a
complete log of the construction before spoken of, and Figure 2 is a
sectional view of the same a front end view being shown at Figure 3.
a is a casing of cylindrical form which carries at one end of it a
conical grating or ribbed front b, to allow the passage of water to the

page_text: interior. Inside the point of the head 6 is a swivel or socket plate c, to
hold one end of a double or twisted screw d, which can be acted
upon by the water in its passage through the log; the opposite end of
the screw blade d is supported by a socket or centre piece e to keep
the axis of the screw in the centre of the casing for its proper working.
Connected to the pin ƒ is a rod g leading to a train of wheelwork or dial
mechanism within a box, or what might be termed the keel at the
bottom of the log body to keep the same in one position in the water
and to prevent it turning with the screw, this keel is formed of
heavy material, or is weighted for the purpose. The exterior of the
casing has blades or vanes i, j, on it set at an angle or curved in
such a manner that the head or fore part of the log shall have a
tendency to incline itself downwards, and so keep the log below the
surface of the water while it is being drawn or towed along by the side
of the ship or vessel by the head or tow line k, which is fastened to the
front point, or to a link / attached thereto. In the Figures I have
shown a link or shakle 1, as by its use more freedom is given to the log
to adjust itself to its position when in action. Attached to this link / is
a blade or steering plate m set at an angle to force the log away from the
ship's side, it is capable of being fixed on either side of the shakle
according to the side of the vessel the log is intended to be used, and its
size is such that it exerts little or no unnecessary strain upon the tow
line. In Figure 1 I show the steering blade on one side of the shakle,
and in Figure 4 it is on the other side. The log thus referred to is
complete in itself and can be used both by sailing vessels and steam
vessels, it can be easily drawn inboard to ascertain the speed of the
vessel by hauling in the trip line n which is attached to the fore part of
the keel h, an operation which would require but a short space of time.
I have mentioned the casing as being of cylindrical form but it is not
compulsory to make it of that shape as other forms of casing are equally
applicable for the purposes of this Invention.
Figure 5 represents a plan of a vessel with the log being towed
alongside, the line being rove through an eye or a block of the
"cat-head" or "davit," so as to keep it clear of the vessel when first
thrown overboard, the trip line n is attached to the vessel abaft the
bridge, so that it can be hauled in by the officer in charge without the
necessity of his going forward. In the other make of logs it is essential.

page_text: from their construction that they be drawn "astern" of the vessel,
and this has always been the cause of errors in indicating the exact
speeds from the fact of their working in troubled or broken waters
which follow in the wake of the vessel, now by the use of my Patent
logs the exact speeds can be ascertained at any moment, as the logs
move through water which is not influenced by the motion of the vessel
as will be easily understood after a moments reflection on the subject.
As before stated the steering blade is capable of being adjusted to any
kind of log so as to make it available for being drawn alongside
instead of behind vessels. In Figures 6 and 7 I have shown another
form of log, the body of it is composed of two plates p, p, connected
together at their fore parts, and at the centre or near thereto by a
transverse pin q, which also supports the casing containing the mechan-
ism worked by the screw at its tail. The back top part of the body has
a plate, which with the assistance of the side flanges or wings & cause
the log to incline downwards and overcome the lifting action of the
tow rope or line which throws the shakle into the position shown in
Figure 6. In this view is seen the relative positions of each part of
the log when she is being drawn through the water. The screw is here
shown at the tail and has four blades for the water to act against to
revolve it, it is secured to the mechanism shell or casing in any
suitable manner to prevent the entrance of water which would interfere
with its proper working, but it may only have two blades if they are.
found sufficient. The lower part of this log is weighted at t and its
fore end has a shakle and stecring blade m, fitted in the same manner
as the first-mentioned log.
I do not confine myself to any special form of log, but those I have
shown and described in detail are what I prefer, as I have found them
to be the most efficient for the purpose, after an extended series of
trials and experiments.
And having now described the nature of my said Invention, and in
what manner the same is to be performed, I declare that I claim,―
.
Firstly. The construction and employment of logs or speed indicators,
which can be drawn alongside ships or vessels, substantially as described
and shewn.
Secondly. I claim arranging fixed or movable steering blades or
rudders to ships' logs in the manner and for the purpose herein-before

page_text: described, whether such logs are made in the manner before referred to
or otherwise.
In witness whereof, I, the said Henrik Ramsten, have hereunto
set my hand and seal, this Thirteenth day of January One
thousand eight hundred and seventy-one.