PROVEMENTS IN AND RELATING TO SHIPS' LOGS OR APPARATUS FOR ASCERTAINING, AND IF NECESSARY, RECORDING THE SPEED OF VESSELS THROUGH THE WATER."
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by William Edward Carlile at the Office
of the Commissioners of Patents on the 27th May 1879.
IM-
WILLIAM EDWARD CARLILE, of Liverpool, in the County of Lancaster.
PROVEMENTS IN AND RELATING TO SHIPS' LOGS OR APPARATUS FOR ASCERTAINING,
AND IF NECESSARY, RECORDING THE SPEED OF VESSELS THROUGH THE WATER."
This Invention has for its object the accurato ascertaining of the speed of a vessel
at any given moment without having to heave and draw in the log specially for
each observation. It consists in a log towed at a suitable distance behind the ship
provided with a rotator or revolving vanes, which by suitable connections as it
revolves makes and breaks an electric circuit from the ship. The electric connection
can be in the cable by which the log is towed or in a separate cable, and there can
be two insulated wires, or only one, the return current in the latter case being
carried by the walls of the log ship, the water, and the screw or sheathing of the
ship as in an earth current.
The vanes are fixed to a spindle preferably carried in bearings at each end, the
hind bearing being of steel, phosphor bronze, or other hard material, so as to allow
only a small wearing surface. This bearing is carried by an arm from the casing;
the forward end of said spindle is preferably armed with a worm gearing into a
spur wheel, which by an eccentric and bell crank motion or otherwise at each
revolution of the spur wheel causes an impervious flexible diaphragm to be pressed.
The wheels and bell crank apparatus are enclosed in a chamber into which the water
has free access. The push of the bell crank apparatus on the diaphragm causes a
metallic or other conducting material on the other side of said diaphragm in an air
tight chamber to come in contact with the two poles of the circuit, thus connecting
them and ringing a bell, or making other electric signal on board, in the chart room,
pilot house, or elsewhere. By noticing the interval between these signals, the speed
of the ship can be calculated. The electric current, if made to traverse the coil of a
small electro magnet, can also draw back the armature of a counting or time
recording apparatus, and thus the ship's run and the speed at any hour can be
recorded.
The flexible diaphragm is required to keep the water out of the electric chamber
and yet carry the signals with little expenditure of power. As the log may sink to
considerable depths when the ship stops, I place a concave guard or plate on the
electric chamber side of the diaphragm to support it against the pressure of the
water when such sinking occurs. The metallic circuit maker already mentioned, but
TD
0.7

page_text: not described, is preferably a rod arranged to work in loose bearings on a con-
tinuation of the diaphragm guard plate. A spring working between one of these
bearings and a collar on the rod keeps the rod against the diaphragm when retreating
with the bell crank or piston on the other side. On the other side of the bearing
an insulated ring slides on an insulating collar on the rod and comes in contact with
the poles when the rod is pushed up. A spring round the rod keeps this in its
place and allows for wear of the eccentric and other parts of the bell crank
apparatus. The exact form of contact maker is however immaterial; and if only one
insulated wire be used, no insulator for the contact maker is necessary, and the whole
can be simplified.