The
AND float is made from 75 mm diameter x 450 mm long x 1.6 mm thick mild
steel fencing pole, that is initially welded closed at the top end and
has three barbed net catching metal strips welded to the outside at the
closed end of the float. This is sealed with an epoxy resin on the inside
to ensure no air is able to escape through any bad welding. Sealed plastic
bottles are then placed inside the tube and a 5 mm round bar cross with
a loop in the middle of it to attach the anchorage cable, is welded over
the bottom end, care taken not to puncture the bottles when this is put
in place. Waterproof foam is then injected into the base of the tube around
the bottles leaving 10 mm of freeboard at the base into which is poured
some more epoxy sealant. This design will lift six meters of 5 mm galvanized
cable without effort. |