Submarine cable laying and repairing

SURVEYING THE ROUTE. 13
showing number of fathoms. The curved arm carrying this
wheel moves in a vertical plane similarly to the lever F in the
type last described. There are two horizontal springs tending
to pull this arm inwards, and apply the brake to the wire
reel. While the wire with sinker and tube is running out over
the small wheel the weight keeps the wheel and arm down, in
which position the brake band is slack, but immediately the
weight is taken off by the sinker touching bottom, the springs
pull up the wheel and arm, thus applying the brake in the
manner described, and stopping the reel. When used for
taking flying soundings—that is those taken while the ship
is under way (generally at about half-speed)—a correction
has to be applied for the lead of the wire, but this is some-
times avoided by the simultaneous use of pressure tubes
or gauges, which indicate the depth by the sea pressure.
Lock Screw. Hand Wheel for Setting Brake Spring.
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