Some improvements have recently been made by Mr. Alexander Glegg and the
inventor in the well-known Jamieson grapnel used for raising submerged
submarine cables. The chief feature of the grapnel is that the flukes,
being jointed at the socket, bend back against a spring when they catch
a rock, until the grapnel clears the obstruction, but allow the cable
to run home to the crutch between the fluke and base, as shown in the
figures. In the older form the cable was liable to get jammed, and cut
between the fixed toe or fluke and the longer fluke jointed into it.
This is now avoided by embracing the short fluke within the longer one.
The shank, formerly screwed into the boss, is now pushed through and
kept up against the collar of the boss, by the volute spring, which at
the same time presses back the hinged flukes after being displaced by
a rock. The shank can now freely swivel round, whereas before it was
rigidly fixed. The toes or flukes are now made of soft cast steel, which
can be straightened if bent, and the boss is made of cast steel or
gun-metal.
[Illustration: JAMIESON'S GRAPNEL.]
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