What is tested?
Exactly what is tested, how are the tests conducted, and what do the results mean for the practical performance of harnesses?
Pull from above
This test, in the standard loading situation, is by far the most important test of the standard. A standardised test dummy wearing the harness to be tested is fixed in an upright "head up" position, the rope is tied according to the standard, then the harness is statically loaded with a force of 15 kN (10 kN for children's harnesses). During this test, no load-bearing parts are allowed to break, buckles are only allowed to slip a maximum of 20 mm (because of this 20 mm slippage, a minimum remaining length of the harness webbing is necessary). The test force of 15 kN contains a large safety margin, because according to the standard the maximum impact force of a rope is not allowed to exceed 12 kN, and with falls that are braked dynamically, about 2.5 to 3.5 kN affects the body. This means: you would probably incur serious injuries before an intact harness breaks.
Pull from below
For this test, the dummy is fixed in a "head up" position and loaded with 10 kN from below (children's harnesses 7 kN). Once again, all force-carrying parts must remain intact, and the dummy is not allowed to slip out of the harness. This means: even in a head-first fall, the harness will hold without any problems. Of course, head-first falls should be avoided where possible due to the high risk of injury.
Practical tip: In ledgy terrain, where the danger of impact and twisting is particularly high, include more intermediate belays.
Harness webbing width
All components in contact with the body have to, due to the sudden force transmission, have a minimum width. This varies for the waist and leg harnesses. The minimum widths are necessary so that, for example, the thighs are not injured by the leg loops during a fall.
The tear resistance of the belay loop is separately tested. The necessary values, to which the «pull from above» load corresponds (15 kN, children’s harnesses 10 kN), are more than sufficient. However we recommend not tying the rope on to the belay loop, but directly into the waist loop and leg loop base. This gives more safety when falling due to redundancy and avoids wear damage on the belay loop, which you need for clipping on rappel or belay devices.