|
> Design
and Construction > Harness Design
According to Poynter’s Parachute Manual,
“the harness is an arrangement of cotton, linen, nylon,
or Dacron® webbing, which is designed to conform to the
shape of the load (usually the body) to be carried in order
to secure it properly so that the opening forces and the weight
of the load are evenly distributed during opening and descent.”
The earliest harness was nothing more than
a swing seat that the parachutist sat on and then held onto
the risers or suspension straps. It soon became apparent that
if the openings were anywhere uneven, it could be very precarious
for the parachutist. While the sling seat worked for the ride
down, it was necessary to add additional straps to secure the
parachutist. These straps included the leg, back, and chest
straps. The standard harness configuration is equipped to secure
a torso, head, arms and legs with straps.
Figure 2-12. Military harness.
Figure 2-13. Super Swooper harness
Others have been added over time for additional
purposes such as survival kits or cushions. Figure 2-12 shows
a basic military style harness. This harness configuration has
seven points of adjustment to allow fitting of most military
personnel. Most of the early parachute systems had the harness
detachable from the containers. This allowed interchangeability
for various models. In the 1970s, skydiving systems began to
integrate the harness into a true harness/ container assembly.
This was accomplished by sandwiching the harness between the
container and backpad and sewing them together. Figure 2-13
shows one of the earliest custom systems called the “Super
Swooper.” This harness was the precursor of today’s
sport harnesses. As skydiving and the sport parachute industry
has grown, most of the equipment is now custom-built for each
individual. The standard piggyback harness configuration of
today is a fixed main lift web with adjustments only at the
chest and leg straps. [Figure 2-14] Elimination of theextra
hardware and webbing has resulted in a dramatic reduction in
weight of modern systems. Along with this has been an increase
in comfort and flexibility. One of the most innovative designs
adopted in recent years is the articulated” harness. This
design incorporates metal rings at the hip junction and the
chest-strap attachment.
Figure 2-12. Military harness. [Figure
2-15] These rings allow a full range of motion
Figure 2-14. Standard piggyback harness.
Figure 2-15. Articulated harness configuration.
both in the air and on the ground and increase
the fit and comfort of the harness. An added benefit is that
this style of harness is stronger under high shock loads. This
is due to the natural alignment of the webbing during the opening
process. With a nonarticulated harness, the webbing junctions
warp and load unevenly. [Figure 2-16] Because of this, point
loading occurs, stitching breaks, and the junction can fail
with disastrous results. In recent years and with the increasing
popularity of vertical skydiving or “freeflying,”
greater speeds are experienced.
Figure 2-16. Standard harness junction
warping.
Experienced with corresponding higher loads
on the harnesses. For many years, harnesses were overbuilt as
they were basically copies of military designs. As the sport
has progressed, equipment has been made lighter and smaller.
|
