Bungee Jumping Equipment
Specifications here are for
informational purposes only. If you attempt to bungee jump without proper instruction
& guidance you will only be putting you life in danger. Proper training is even more
important than equipment. Bungee accidents are almost invariably the result of human
error.. If you attempt to bungee jump without proper instruction
& guidance you will only be putting you life in danger. Proper training is even more
important than equipment. Bungee accidents are almost invariably the result of human
error.
Bungee Cords:
There are two main types of bungee
jumping cords, sheathed and all-rubber.
Sheathed cords were the
first cords used for bungee jumping, initially by England's Oxford Dangerous Sports Club.
These cords are also called shock cord or mil-spec (from military specification, they were
designed to connect parachutes and heavy equipment such as jeeps, when dropping the load
from an aircraft, the cords absorb the shock of the canopy opening, to prevent damage to
the parachute). They have a rubber core, encased in a cotton, and/or nylon sheath. These
cords look like bigger versions of the bungee cords you use to strap a load to your car
roof, hence the name bungee.
Depending on their weight, an
individual jumps on three to six 5/8" diameter cords bundled together. Each cord has
a minimum breaking strength of 1500 pounds, and high altitude jumps have been done from
aircrafts with over 1000 feet of a single cord. By the correct number of cords for a
specific body weight the cords stretch to approximately 2.1 times their resting length
while jumping and have a breaking strength that is ten times greater that the force
exerted on them during jumping. Variations of this cord with a longer elongation have been
developed for bungee jumping.
All-rubber cords were developed in
New Zealand specifically for bungee jumping. They comprise over 1000 individual strands of
rubber tied together into one solid cord. The all-rubber cord stretches to approximately 4
times it's resting length while jumping. This results in less impact or G-forces acting on
the jumpers body, than when sheathed cords are used. The lack of the sheath results in
less friction and heat generation, and hence less loss of energy than in the case of
sheathed cord. These factors result in bigger rebounds on all-rubber cords. Approximately
85% on the first rebound versus about 75% on sheathed cords. Variations of this cord with
less elongation have been developed, stretching to approximately 3 times their resting
length. This results in cords with a longer life, about 1000 jumps versus 400, however I
feel this results in a jerky ride and less rebound. Another variation of the cord is to
include 1" static webbing built onto the cord, such as the cord at left. This serves
as a back up and to keep the cord from over-elongating.
Chest and waist harnesses should be
used for beginners and while doing shorter jumps. With these harnesses the cord is
connected to your body very close to your center of gravity/rotation. This setup produces
the least stress on your body.
Ankle harnesses allow for head
dips, graceful jumping and advanced stunts. They should be used by jumpers with a
experience. If you jump and just stand straight up, the cord will whip you upside down
when you reach the end of your free-fall. Also, at the end of your jump when you are
waiting to be raised to the jump platform or lowered to the ground, you are either hanging
upside down or have brought yourself into the pogo position.
|
