A NEW OR IMPROVED LOG OR SPEED INDICATOR FOR SHIPS
Year: 1880

page_text: LETTERS PATENT to James Russell Neill, of Glasgow, in the County of Lanark,
North Britain, Engineer, for an Invention of "A NEW OR IMPROVED LOG
OR SPEED INDICATOR FOR SHIPS."
PROVISIONAL SPECIFICATION left by the said James Russell Neill at the
Office of the Commissioners of Patents on the 17th July 1880.
'
JAMES RUSSELL NEILL, of Glasgow, in the County of Lanark, North Britain.
Engineer.
"A NEW OR IMPROVED LOG OR SPEED INDICATOR FOR SHIPS."
This Invention relates to a new or improved construction of ship's log or speed
indicator, which is intended to be in constant use when the the ship is under steam
or sail, and is designed to give a continuous indication and enable a complete record
of the vessel's speed at all times during the voyage to be kept, and be taken without
the necessity as heretofore of each time paying out the line or heaving the log and
engaging the time and attention of a number of seamen; whilst the action of the
improved indicator will be more efficient and the "dead reckoning" more reliable
than when calculated from the ordinary log.
Under one modification the improved log or speed indicator consists of a circular
metal disc forming the log chip, and having a straight rod or stiff wire rivetted,
screwed, or otherwise attached at its centre, and to this wire the log line, which is
preferably a strong galvanized iron or copper wire, is attached.
This wire is made of sufficient length extending out from the ship's stern to.
allow the circular disc to remain quite out of the dead water in the wake of the
ship when the log is in use, and its end is either connected by means of a cord or
rope passing round guide pulleys, or directly attached to a bolt, bar, or rod, forming
part of the speed indicating apparatus, fitted in the wheel house or other part of the
vessel's deck. This bar or rod passes through the edge or side of a circular casing,
somewhat like that of a large steam. gauge, and is connected to a crosshead inside
working between guides, and which crosshead is held or retained in its normal
position of rest against the tension or drawing action of the log line and bar by
means of one, two, or more spiral springs attached to the crosshead and to
fixed lugs in the casing. The crosshead has fitted at or near its centre and opposite
the tension bolt a small toothed rack in gear with a pinion on a spindle fitted in
Duins & J

page_text: the centre of the circular casing, having a pointer or indicating hand also fixed on
it, which, when the tension bar, crosshead, and rack are drawn by the action of the
log line and disc against the power of the springs, is turned round with the pinion
and spindle, and points to figures on a scale marked round the face of the casing or
indicator, corresponding to the number of knots or miles per hour at which the
vessel is sailing for the time being. The marks on the indicator face are graduated
to correspond to the increasing resistance of the water to the passage through it of
the log disc as the speed of the ship becomes greater, and may be made to indicate
knots, miles, or any other degrees of measurement as required. The log disc or chip
is paid out and allowed to remain in the water during the whole voyage, and the
indications of speed may be read off from the indicator face or dial every hour or
as often as desired.
The construction of the speed indicator and fittings is susceptible of considerable
modification, as for example, the tension or pull of the log line may be made to
actuate the crosshead, with the rack and pinion and indicating pointer, against the
action of a spiral-spring-or-springs-in compression, or against the power of steel
bows or blades or rubber springs. Or the tension bar or rod to which the log line
is attached may be fitted inside a spiral spring under tension or compression, and
have an indicating pointer directly attached to move in a straight line and mark
the indications of speed outside a tubular casing surrounding the spring, and
through which the pointer would pass in the same manner as in a common form of
spring balance. The form of log chip or disc may also be varied, and, if desired,
the ordinary triangular chip may be used in combination with the improved
indicating apparatus; but I have experimentally found the circular disc described to
be most suitable, particularly when three or four small holes are pierced through it
radially round the centre, which has the effect of causing the disc to follow in a
straight course in the longitudinal line of the vessel. In every case the log chip
or disc is made of an area more than suffices with the resistance of the water to
counter balance the action of the springs of the indicator, and for the purpose of
preventing the jerking motion of the log disc in heavy seas from affecting the
indicator, the guide pulleys round which the log line passes may be held by suitable
friction, as by rubber sheets bearing against the sides of the pulleys, the tension of
which may be regulated as desired.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Russell Neill in the Great Seal Patent Office on the 18th
November 1880.---
-
JAMES RUSSELL NEILL, of Glasgow, in the County of Lanark, North Britain,
Engineer. "A NEW OR IMPROVED LOG OR SPEED INDICATOR FOR SHIPS."
My said Invention relates to a new or improved construction of ship's log or
speed indicator, which is intended to be in constant use when the ship is under
steam or sail, and is designed to give continuous indication and enable a complete
record of the vessel's speed at all times during the voyage to be kept, and be taken
without the necessity as heretofore of each time paying out the line or heaving the
log, and engaging the time and attention of a number of seamen, whilst the action
of the improved indicator will be more efficient and the "dead reckoning"
more reliable than when calculated from the ordinary log.
And in order that my said Invention and the manner in which the same is to
be performed may be properly understood, I have hereunto appended for that
purpose a Sheet of explanatory Drawings, illustrating the construction and appli-
cation of my improved ship's log or speed indicator. In these Drawings the same
reference letters are used to mark the same or like parts where they are repeated.
Figure 1 is a front elevation of a modification of the indicating apparatus
forming part of my improved ship's log; Figure 2 is a corresponding elevation of
the same with the dial plate or face F¹ removed; and Figure 3 is a transverse
vertical section taken as at the line 1-1 in Figure 2, and showing the connecting
cord B¹ attached to the indicating apparatus, and passing from the vessel's deck
to the log line and "chip" A; Figure 4 is a sectional elevation, and Figure 5 is a
plan of the improved log "chip" or pressure receiving disc A, while Figure 6 is a
general view of a ship at sea, showing my improved log or speed indicator
in use.
5
Referring to these Drawings, the improved log or speed indicator comprises a
circular metal disc A forming the log "chip," and having a straight rod or stiff
wire A¹ rivetted, screwed, or otherwise attached at its centre, as shown in Figures
4 and 5, the disc A having a set of holes a pierced through it. To this rod A¹ the
log line B, which is preferably a strong galvanized iron or copper wire, is attached
through an eye a¹ at its extremity. This wire is made of sufficient length
extending out from the ship's stern, as shown in Figure 6 to allow the circular disc A
to remain quite out of the disturbed dead water and into the steady water in the
wake of the ship when the log is in use. The other end of the log line B is
connected by means of a cord or rope B', passing over a guide pulley C, carried
by a small bracket C¹ screwed or fixed to the taff rail or other convenient part of
the vessel's stern, and the cord B' is continued along to the wheel house or to any
other convenient part of the vessel's deck, where the speed indicating apparatus is
fitted, there passing under a second guide and friction pulley D, carried on a
bracket block D¹ secured to the deck, and thence the cord B¹ reaches up and is
attached by a shackle E¹ jointed to a movable bar or rod E, forming part of the
speed indicating apparatus shown in Figures 1, 2, and 3. This bar or rod E passes
through the bottom edge or side of a circular casing F, somewhat like that of a
steam guage, and is connected to a crosshead G inside, having grooved rollers G¹
on its ends working between guides formed by short rods G¹¹, fixed at their ends by
screws g to bosses g' projecting from the back of the case F. The crosshead G is
held or retained in its normal position of rest against the tension or drawing action
of the log line B and bar E by means of two or more spiral springs H, attached to
the crosshead G at one end and to fixed lugs h formed in the back of the casing F.
The crosshead G has fitted at or near its centre and opposite the tension bolt E a

page_text: small toothed rack I, formed by an upright bar fixed at its lower kneed end I' to
the crosshead G, and this rack I is kept upright by a guide I" in gear with a
pinion J on a spindle J¹ fitted in bearings ; in the centre of the circular casing F,
and passing through the dial face F, which is fitted on the casing F and held by
the screws at fand the bezel ring f¹. A pointer or indicating hand K is also fixed
to the spindle J, which, when the tension bar E, crosshead G, and rack I are drawn
by the action of the log line B, B₁, and disc A against the power of the springs H,
is turned round with the pinion J and spindle J¹, as indicated by the arrow in
Figure 1, and points to figures (as 1, 2, 3, 4, and so on) on a scale F2 marked
round the face F1 of the casing or indicator, corresponding to the number of knots
or miles per hour at which the vessel is sailing for the time being. The pointer K
fits loosely on the spindle J, and is held by means of a small disc or plate K¹
secured on the square end of the spindle J', this disc having a slot k in it through
which a screw-pin-on-the-pointer-K-projects,-and-is-fixed-in-position-by-the-head
outside, so that the pointer can be set at zero, as shown dotted in Figure 1, and
thus adjusted for any slight error of the springs or other parts in relation to the
index dial numbers. The marks on the indicator face F¹ are graduated to
correspond or agree to the increasing resistance of the water to the passage through
it of the log disc A against the power of the springs H, H, as the speed of the ship
becomes greater, and may be made to indicate knots, miles, and parts of these or
any other scale of measurement or speed, as required. The dial F1, F2, may be
covered with a glass face, as shown dotted at F¹¸ Instead of the index pointer K
moving over the face of the dial it may be made stationary, and the dial fitted on
the pinion spindle J₁ to be actuated by means of the rack I from the log disc A
and indicate the speed of the vessel. The log disc or "chip" A is paid out and
allowed to remain in the water during the whole voyage, and the indications of
speed may be read off from the indicator face or dial every hour, or as often as
desired.
The construction of the speed indicator and fittings is susceptible of considerable
modification, as, for example, the tension or pull of the log line B, B¹, may be made
to actuate the crosshead G, with the rack I and pinion J. and indicating pointer K,
against the action of a spiral spring or springs in compression, or against the power
of steel bows or blades or rubber springs; or the tension bar or rod E, to which the
log B is attached; may be fitted inside a spiral spring under tension or compression,
and have an indicating pointer directly attached to move in a straight line, and
mark the indications of speed outside a tubular casing surrounding the spring, and
through which the pointer would pass in the same manner as in a common form of
spring balance. The form of log "chip" or pressure receiving disc may also be
varied, and, if desired, the ordinary triangular "chip" may be used in combination
with the improved indicating apparatus; and instead of connecting the log disc to
the indicator by a wire or cord, other means may be employed, as by a lever on an
outrigger from the side of the ship; but I have found the circular disc A described,
connected by a wire and cord, to be most suitable, particularly when three or four
small holes a are pierced through it radially round the centre, which has the effect
(by the water passing through them) of causing the disc to follow in a straight
course in the longitudinal line of the vessel. In every case the log "chip" or disc
is made of an area more than suffices with the resistance of the water to counter-
balance the action of the springs of the indicator. For the purpose of preventing
the jerking motion of the log disc in heavy seas from affecting the indicator, the
guide pulley D round which the log line B₁ passes may be held by suitable friction,
as by rubber washers d, d, bearing against the sides of the pulley D, the tension of
which may be regulated, as desired, by means of a pinching screw d¹ and metal
washer d, as shown in Figures 1 and 3, which presses the side of the pulley D
between the rubber sheet or discs d, d.
Instead of carrying the log line out from the stern of the vessel, it may be
carried by an outrigger from the vessel's side, so that the log "chip" or disc A may be

page_text: out into the still water and free from contact with any waste or other materials
thrown overboard, while a shorter line may be safely used.
The divisions F2 representing knots or miles on the dial face will require to be
varied according to the size of log disc A and strength of springs H employed.
For example, the speed indicator shown in the Drawings is spaced and arranged to
suit the log "chip" or disc shown, the surface area of which is taken as nine square
inches. The dividing of the indicator scale F2 can be effected for different strength
of springs by trial with weights against the power of the springs, the weight
corresponding to any number of knots on the scale being calculated as follows:-
The ascertained pressure of water at a velocity of one knot per hour on a nine inch
disc counterbalances or corresponds to a weight of four ounces; at two knots speed
the corresponding weight will be sixteen ounces, the pressure being as the square of
the velocity or speed, and at four knots per hour the weight will be four pounds;
if therefore weights corresponding to these be suspended to the indicator bar E,
and allowance made for the weight of the wire B, B', and disc A and for friction,
the indicator disc may be correctly divided. If a larger disc A is used, correction
must be made for the increased resistance or pressure on the disc at the various
speeds.
Having thus described the nature of my said Invention and the manner of
performing the same, I have to state that. I do not confine myself to the precise
details herein described or delineated, but what I consider novel and original,
and therefore claim as the Invention secured to me by the herein before, in part
recited Letters Patent is,-
First. The general construction or combination of the parts of a log or indicator
for recording the speed of ships with a pressure receiving disc A in the water,
connected to re-acting springs H, divided index dial F, F, and pointer k, and
fittings connected therewith on board the ship, all substantially as or in the manner
and for the purposes herein described in reference to and shown in the accompanying
Drawings, or any mere modification thereof.
Second. The use of a pressure receiving disc in the water, connected by a wire or.
line to a re-acting spring speed indicator with divided index and moving pointer
for indicating the speed on board the ship, substantially as herein described in
reference to the accompanying Drawings.
Third. The construction and use of a ship's log with index dial and pointer on
board the ship, actuated by and connected to a pressure receiving disc in the water
against the power of a re-acting spring or springs for indicating the speed of ships,
all substantially as herein described in reference to the accompanying Drawings.
In witness whereof, I, the said James Russel Neill, have hereunto set my
hand and seal, this Fifteenth day of November, in the year of our Lord One
thousand eight hundred and eighty.
Witness,
W. R. M. THOMSON,
Patent Agent,
Glasgow.
JAMES R. NEILL. (L.S.)