IMPROVEMENTS IN THE MEANS AND APPARATUS FOR INDICATING LEEWAY AND SPEED OF VESSELS."
Year: 1876

page_text: "
LETTERS PATENT to Charles Denton Abel, of Southampton Buildings, in the
County of Middlesex, for the Invention of IMPROVEMENTS IN THE MEANS
AND APPARATUS FOR INDICATING LEEWAY AND SPEED OF VESSELS."
A com-
munication from abroad by Daniel Iffland and Ernst Hadenfeld, both of
Hamburg, in the German Empire.
Sealed the 23rd March 1877, and dated the 27th October 1876.
PROVISIONAL SPECIFICATION left by the said Charles Denton Abel at the
Office of the Commissioners of Patents on the 27th October 1876.
CHARLES DENTON ABEL, of Southampton Buildings, in the County of Middlesex.
IMPROVEMENTS IN THE MEANS AND APPARATUS FOR INDICATING LEEWAY AND
SPEED OF VESSELS."
This Invention relates to apparatus whereby the leeway and speed of vessels are
simultaneously indicated, and thereby the speed of lateral currents is ascertained.
For this purpose a vertical tubular axis is mounted in bearings so that it can
revolve freely, such axis passing through the deck and bottom of the vessel at the
sides of the keel; its lower extremity is bent presenting on the one side a funnel
mouth and on the opposite side is fixed a projecting blade or vane. On the top of
the axis is fixed an index over a graduated dial plate, and within the axis there is
a float from which a wire extends upwards and terminates in an index in front of a
vertical graduated plate. In shallow water the axis can be raised by turning a nut
working in a screwed part of it, so that its bent end and vane can be brought close
up to the vessel's bottom at the side of the keel. When the vessel is in sufficiently
deep water the axis is lowered so as to bring its bent end and vane some distance down
below the vessel's bottom. In this condition the vane being acted on by the water
through which it is moved takes a position in the line of actual motion through the
water, the direction of which relatively to that of the longitudinal axis of the
vessel is indicated by the index on the dial above.
The funnel mouth of
the tubular axis being thus presented in the direction of movement, the column of
water within the axis and the float upon it are raised by the pressure due to the
velocity of the vessel which is indicated by the index on the float wire. Thus at
any time the direction of the vessel's movement relatively to its longitudinal axis
being ascertained, and also its velocity through the water by means of the apparatus

page_text: above described, and the speed of the vessel in the direction of its length, being
otherwise known, the speed of a lateral current may be readily computed being
represented by one side of a parallelogram of forces, the other side of which
represents the speed of the vessel in the direction of its length, and the diagonal of
which represents its speed through the water as determined in amount and
direction by the apparatus.
The above described apparatus may also be employed without the arrangement
for indicating the speed when it is only desired to obtain an indication of any
lateral current without determining its force.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Denton Abel in the Great Seal Patent Office on the 10th
April 1877.
CHARLES DENTON ABEL, of Southampton Buildings, in the County of Middlesex.
"IMPROVEMENTS IN THE MEANS AND APPARATUS FOR INDICATING LEEWAY AND
SPEED OF VESSELS." A communication from abroad by Daniel Iffland and Ernst
Hadenfeld, both of Hamburg, in the German Empire.
This Invention relates to apparatus whereby the leeway and speed of vessels are
simultaneously indicated, and thereby the speed of lateral currents is ascertained.
For this purpose a vertical tubular axis is mounted in bearings so that it can
revolve freely, such axis passing through the deck and bottom of the vessel at the
side of the keel; its lower extremity is bent, presenting on the one side a funnel
mouth and on the opposite side is fixed a projecting blade or vane. On the top of
the axis is fixed an index over a graduated dial plate, and within the axis there is
a float from which a wire extends upwards and terminates in an index in front of a
vertical graduated plate. In shallow water the axis can be raised by turning a nut
working in a screwed part of it, so that its bent end and vane can be brought close
up to the vessel's bottom at the side of the keel. When the vessel is in sufficiently
deep water the axis is lowered so as to bring its bent end and vane some distance
down below the vessel's bottom. In this condition the vane being acted on by the
water through which it is moved takes a position in the line of actual motion
through the water, the direction of which relatively to that of the longitudinal axis
of the vessel is indicated by the index on the dial above. The funnel mouth of
the tubular axis being thus presented in the direction of movement, the column of
water within the axis and the float upon. it are raised by the pressure due to the
velocity of the vessel which is indicated by the index on the float wire. Thus at
any time the direction of the vessel's movement relatively to its longitudinal axis
being ascertained, and also its velocity through the water by means of the apparatus
above described, and the speed of the vessel in the direction of its length being
otherwise known, the speed of a lateral current may be readily computed, being
represented by one side of a parallelogram of forces, the other side of which
represents the speed of the vessel in the direction of its length, and the diagonal of
which represents its speed through the water as determined in amount and direction
by the apparatus.
The above described apparatus may also be employed without the arrangement
for indicating the speed where it is only desired to obtain an indication of any lateral
current without determining its force.
.

page_text: R is a hollow spindle passing down through the bottom of the ship on one side of
the keel K below which it terminates in a bend o having a trumpet mouth o¹, and
opposite the mouth a blade or vane The tubular axis R is constructed in
lengths screwed together in sockets and secured by keys, as shewn at r²; it is
supported in bearings at S¹ by means of a collar m secured by set screws, and at S by
the boss of the bevil wheel t screwed thereon, the lower end passing through a
stuffing box p fixed water-tight to the bottom of the vessel. At its upper end the
tube is supported in a bracket on which is formed a graduated dial K₁, and above
this the tube carries a pointer K, which as the tube turns in one direction or the
other in obedience to the action of the current on the vane will indicate such
motion upon the dial. A certain length of the tube at the point where the wheel t
is fitted thereon is formed with a screw thread, so that when for the purpose of
docking the ship it is required to raise the lower end of the tube, .so that it does
not project below the keel; this is effected by turning the bevil wheel t upon the
tube by means of the wheel t¹ and winch T. Inside the tube R is a float n to
which is connected. a rod n¹ passing up through the upper end of the tube, above
which it is provided with a pointer n² at the side of which is fixed a scale n³.
On the ship moving through the water, the vane being acted upon by the relative
current will take a position in the actual line of motion through the water, the
direction of which relatively to the longitudinal axis of the vessel is indicated by
the pointer . At the same time the funnel mouth o' being thus presented in the
direction of movement, the column of water within the tube and the float upon it
are raised by the pressure due to the velocity of the vessel which is indicated by
the pointer n² on the scale n³. By these means the speed of any lateral current
acting on the ship can readily be computed in the manner herein-before described.
The wheel t is drawn back out of gear with t by means of the handle at A when it
is not required to raise the spindle R.
Having thus described the nature of this Invention as communicated to me by
my foreign correspondents, and in what manner the same is to be performed,
I claim,
First. The use for indicating lateral currents on board ship of a rotatable axis.
passing vertically through the bottom of the ship, below which it is provided with a
blade or vane, and having at its upper end a pointer, whereby any deviation of the
vane from the longitudinal axis of the ship is indicated on a dial, substantially as
herein described.
Second. In apparatus constructed as described in the preceding claim, making
the axis hollow with a trumpet-mouthed opening opposite the vane at bottoni, and
providing therein a float having an index, whereby the level of the water in the
axis may be ascertained, substantially as and for the purposes herein set forth.
In witness whereof, I, the said Charles Denton Abel, have hereunto set my
hand and seal, this Fifth day of April, in the year of our Lord One thousand
eight hundred and seventy-seven.
CHA³. D. ABEL. (L.S.)