IMPROVEMENTS IN LOGS FOR INDICATING THE SPEED OF SHIPS AND OTHER VESSELS
Year: 1853

page_text: PROVISIONAL SPECIFICATION left by Auguste Edouard Loradoux
Bellford at the Office of the Commissioners of Patents, with his
Petition, on the 7th July 1853.-A communication.
(Void by reason of notice to proceed not having been given within the
time prescribed by the Act.).
T, AUGUSTE EDOUARD LORADOUX BELLFORD, of 16, Castle Street,
Holborn, City, London, Patent Agent, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN LOGS FOR INDICATING THE
SPEED OF SHIPS AND OTHER VESSELS" to be as follows, viz. :-
This Invention of improvements relates to that description of log
consisting of a vane which is attached to some part of the vessel below
the water line, and has a spring applied to it so as to influence it in the
opposite direction to that in which it is influenced by the resistance of
the water while the vessel is passing through it, and which is so
connected with an indicating apparatus as to show the degree in which
the resistance of the water to the vane, caused by the passage of the
latter through the water, is made to counteract or overcome the resis-
tance of the spring, and thereby, by showing the resistance to the vane,
to show the speed at which the vessel is then proceeding.
The first improvement consists in a certain combination of mechanism
for transmitting the effect of the spring to the vane, and comecting

page_text: the vane with the indicator, which admits of the vane being released
readily from the influence of the spring, and disconnected from the
indicator, whereby, on the instant the observations to determine the
vessel's speed are completed, the spring may be relieved from unneccs-
sary tension, and the vane may be caused by the resistance it encounters
from the water to assume such a position that it will cease to obstruct
the motion of the vessel through the water.
The second improvement consists in a certain method of compensating
for favorable and adverse currents, and for variations in the vessel's
draught, and consequent variations in the density of the water, by
adjusting the action of the spring upon the vane in such a manner as
to make the indicator show the true speed of the vessel.
The construction and operation of the Invention is illustrated in the
accompanying Drawing, in which,-
Fig. 1, is a side view of one of the improved logs.
Fig. 2, is a vertical section of the same, taken through tlie centre at
right angles to Fig. 1, or transversely to the vessel.
Fig. 3, is a top view of the same complete.
Fig. 4, is a top view of the same with the top or dial-plate removed.
Fig. 5, is an horizontal section of the vane, and part of the keel of
the vessel, showing the recess in which the vanc is received when the
log is not in use.
Fig. 6, is a small sketch of part of the side of a vessel showing the
position of the log.
Fig. 7, is a corresponding sketch of the stern of a vessel.
Similar letters of reference indicate corresponding parts in the several
Figs.
The instrument is represented in the Drawing about half size, but
the shaft A, of the vane, and the tube B, which encloses the said shaft,
are shown broken in Figs. 1, and 2, as their -length, requiring to be
sufficient to reach from the bottom of the vessel to the cabin or deck
where the indicator is placed, prevents their being shown entire. The
tube B, is made of any suitable, metal, extending upwards vertically to
the deck, or any suitable point above the water line, and terminating
with the water-tight joint in the vessel's bottom; its upper end has a

page_text: circular plate C, forming the base of the indicator firmly secured to it.
This plate C, supports two two other plates D, E, of similar size and form
by means of pillars a, a, and these three plates form the frame for the
indicating mechanism. The shaft A, passes centrally through the tube
B, and protrudes through the bottom of it, the position of the tube
being such that a recess b, (see Fig. 2,) has to be made in the side of
the keel K, of the vessel to receive the protruding part of the shaft.
The bottom of the shaft rests in a step bearing c, within the keel, and
its upper end works through a guide bearing in the plate D; it is
further held steady by a guide at the bottom of the tube. The vane F,
is secured to the protruding part of the shaft, and when it is not in use
it is received in a recess d, (see Fig. 1, and 5,) made in the side of the
keel abaft the shaft, so that it encounters no resistance from the water.
A toothed pinion G, is fitted to that part of the shaft above the plate C,
so as to be capable of turning freely; this pinion is supported by the
said plate, which is slightly recessed (see Fig. 2.) to receive it, and it is
connected by a strong spiral spring H, which surrounds the shaft with
a collar I, which is fitted to the shaft at some distance below the
pinion in such a manner as to slide freely up and down thereon, but not
to turn. The spring is coiled in such a direction that if the pinion
were held stationary the influence which the vanes receives in passing
through the water would wind it up. The toothed pinion G, gears
with a rack J, which is moveable on the plate C, to which it is confined
by a screw e, screwing into the plate, and a metal loop f, secured to
the edge of the plate, a slot g, being made in the rack to
screw e, and allow of the longitudinal motion of the rack.
receive the
The loop f
is just wide enough to allow the rack to pass through it freely, but a
spring h, is secured to the plate C, and applied to the back of the rack
in such a manner as to force its face against one side of the loop, which,
being thus caused to enter a place between two teeth, will hold the
rack firm in any position.
When the log is in use the vane occupies a position nearly at right
angles to the keel, and it is represented in the Drawings in this position
in all the Figs. but Fig. 4, where it is supposed to be within the recess
in the keel, though the keel is not shown. The vane is brought into

page_text: position for operation by drawing the rack in the direction of the red
arrow shown near it in Fig. 3, by a handle, provided for the purpose,
and the rack J, being held by the loop f, holds the pinion in such a
manner that it cannot turn; hence the vane cannot move without
winding or unwinding the spring H.
The indicator dial is described upon the plate E, (sec Figs. 3,) and
the pointer p, is attached to the upper journal of a toothed pinion I,
which works between the plates D, and E. The movements of the
vane are transmitted to the indicator by an expending lever M, having
a toothed sector O, at one end, gearing with the pinion L, that part of
the lever which carries the sector being loose upon the shaft of the
vane, so that it may be released when desired, but being furnished with
a tonguej, by which it is connected with the other portion M, of the
lever. The part M, of the lever is firmly secured to the vane shaft,
and a piece N, is fitted to slide longitudinally on M, being confined
thereto by studs k, k, working in a slot. The inmost end of the piece
N, has a notch, to receive the tongue j, of the part of the lever
carrying the sector O, and when the tongue is in this notch the indicator
is in communication with the vane, but when the piece N, is withdrawn
far enough to leave the tongue, free, the indicator is released. Stops
s, s, are secured in the plate D, to prevent the sector working out of
gear with the pinion, and the indicator thereby losing its proper relation
to the vane; and a stop t, is secured in the same plate to prevent the
lever M, being forced by the spring E, or the action of the water upon
the vane to such a position as to carry the pointer backwards past the
zero point on the dial.
To take an observation to determine the speed of the vessel through
the water by this instrument the rack j, requires to be drawn out, as
shown in Fig. 3, to such a position that the vane will be thrown out
from the recess d, abaft its axis, to a position nearly at right angles
with the keel, and that when the indicator is connected, the spring II,
would be free from tension with the pointer at O, or the zero point on
the dial. The rack J, is secured in this position either by the side of
the loop, engaging between two of its teeth, or by a pin inserted
through it close to the edge of the plate C, to prevent its moving

page_text: inwards. The sector is then connected with the lever M, by sliding
the picce N, to make it receive the tongue j, in its notch. The resist-
ance encountered by the vane in passing through the water will be in
proportion to the vessel's speed, and will cause the vane to turn its
shaft and wind the spring II, to such a tension as will exactly balance
the pressure of the vane when all the parts of the instruments become
stationary. The pointer, provided the dial is properly graduated, will
then indicate the speed of the vessel in knots per hour, or in any other
relation of space to time. When the observation has been made the
sliding piece N, on the lever may be drawn out to leave the sectar free,
and the rack J, may be set free by taking out the pin r, or throwing
the teeth clear of the side of the loop f; tlic resistance of the water to
the vane will then throw it into the position shown in Fig. 4, where
the vane is supposed to be in the recess, in the keel.
The vane may be properly adjusted to indicate the truc velocity of
the vessel in currents, whether favorable or adverse, when the force of
the said currents is known. This is eflected for adverse currents by
adjusting the pinion G, by means of the rack J, so as to produce a
sufficient increase of tension on the spring H, to compensate for or
balance the pressure of the current upon the front of the vane, and for
favorable currents by adjusting the pinion so as to relieve the spring
of a sufficient portion of its tension to balance the pressure of the
current on the back of the vane. These adjustments may be regulated
by a properly graduated scale on the rack J. If it should be necessary
to adjust the action of the spring to compensate for the variation in the
density of the water consequent upon variations in the vessel's draught,
it may be effected by the rack and pinion in a similar manner to the
adjustment for currents, the increased draught and increased draught
and increased density requiring the spring to be strengthened, and
vice versa.