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Irish
Coast Guard Historic |
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Setting the Scene |
THE LUFF TACKLE. The “Luff tackle” is
the name given to the set of pulley blocks and rope used for tensioning
the jackstay. The Luff tackle is a nautical term and it consists of
two double pulley blocks (blocks with two sheaves), one with a hook
attached to one end, the other with an eye one end and two tails about
one fathom (1.80 meters) long attached the other end. About 25 fathoms
(45 meters) of rope completed the set. The tackle is assembled as
follows; The block with the hook is laid out on the floor on its side
with the hook facing left; the other block is laid out about eight
feet (2.44 meters) away with the eye facing the other block. The rope
is attached to the eye by means of a Bowline or an Eye splice and
reeved (threaded) through the other block from the bottom. It is reeved
through the first block from the bottom (making sure the rope is not
crossed) and back to the second and again back to the first block.
The end of the rope should be at the first block and facing away from
the two tails. The Luff tackle is now ready for use. The block with
the hook is attached to the anchorage ring, the two tails on the other
block are attached to the Jackstay, using the special fastening, the
Jackstay can now be tensioned, or the tension released using the Luff
tackle. ANCHORING THE SYSTEM. To enable the Jackstay to be tensioned after it has been secured to the ships mast, the Luff tackle has to be attached to a secure anchorage point on the land. If a natural anchorage point is available such as a strong tree, rock etc, this may be used. In the absence of such a natural anchor point an artificial anchorage must be used. Two items are supplied with the rocket cart, a “Single fluke” anchor, and an “Anchor backer & chain”. The anchor is a stockless anchor with a large ring in the end and only one fluke (hook). The anchor backer is a plank of timber 5 ft x 12 inches x 4 inches (1.50 x 300 x 100 mm ) with 6 ft (1.80mts) of heavy chain with a large ring one end, the other end is attached to the middle of the plank. In solid ground the anchor is “Dug in” with the ring exposed, in sandy ground a hole 6 ft x 2 ft x 6 ft deep (1.80 x 600mm x 1.80) is dug, the anchor backer is dropped in and the hole filled in leaving the ring exposed on the surface. The Luff tackle is hooked onto the ring and tied to the Jackstay, the breeches buoy is attached to the traveller block and the jackstay tensioned, the system is now ready to commence the rescue operation. Other methods of anchoring can be used, such as a 3-2-1 set of steel pickets 5 ft (1.50mts) long hammered into the ground, as well as a heavy vehicle such as a Coastguard Land Rover with the Luff tackle attached to the rear spring, side on. If the Land Rover has a Capstan winch it can be secured with the pickets end on and the capstan used to tension the Jackstay or work the whip line. |