PETZL solutions for workers over 100 kg
Home - Resistance of the human body
to a dynamic load
Resistance of the human body to a dynamic load
This is the body's capacity to withstand a fall.
The European standards are based on studies which set the maximum acceptable deceleration at 6 G for a worker at height. On the basis of a deceleration not exceeding 6 G, the impact force experienced by the user depends on his weight: Sf = md
Petzl absorbers are designed to meet 6 G deceleration for the fall of a 100 kg user. The impact force transmitted to the body will not exceed the 6 kN standardized value: Sf = 100*6*9.8 = 5.9 (6 kN).
The same deceleration for a 140 kg user generates a greater impact force: Sf = 140*6*9.8 = 8.2 (8 kN). It is recognized that the body does not suffer injury as the deceleration is less than or equal to 6 G. Petzl therefore allows that an impact force of up to 8 kN is acceptable for a user of 140 kg (including equipment).
Similarly, we can accept an impact force Sf = 120*6*9.8 = 7.1 (7 kN)
for a user of 120 kg (including equipment).
In some situations, Petzl accepts that a user over 100 kg can undergo an impact force greater than 6 kN, provided that the maximum deceleration is limited to 6 G.
Sf = md
Sf = impact force expressed in kN
m = mass of the user with his equipment,
in kg
d = deceleration expressed in G, corresponding to "n times" the acceleration due to gravity at the Earth's surface: 9.81 m/s²
ime). For a given fall velocity, the time between the onset of braking and complete
stop determines the value of the deceleration, expressed in G. Sf = impact force expressed in kN
m = mass of the user with his equipment,
in kg
d = deceleration expressed in G, corresponding to "n times" the acceleration due to gravity at the Earth's surface: 9.81 m/s²
The European standards are based on studies which set the maximum acceptable deceleration at 6 G for a worker at height. On the basis of a deceleration not exceeding 6 G, the impact force experienced by the user depends on his weight: Sf = md
Petzl absorbers are designed to meet 6 G deceleration for the fall of a 100 kg user. The impact force transmitted to the body will not exceed the 6 kN standardized value: Sf = 100*6*9.8 = 5.9 (6 kN).
The same deceleration for a 140 kg user generates a greater impact force: Sf = 140*6*9.8 = 8.2 (8 kN). It is recognized that the body does not suffer injury as the deceleration is less than or equal to 6 G. Petzl therefore allows that an impact force of up to 8 kN is acceptable for a user of 140 kg (including equipment).
Similarly, we can accept an impact force Sf = 120*6*9.8 = 7.1 (7 kN)
for a user of 120 kg (including equipment).
Sf for 100 kg and 6 G = 100 x 9.81 x 6 = 5,9
Sf for 120 kg and 6 G = 120 x 9.81 x 6 = 7.1
Sf for 140 kg and 6 G = 140 x 9.81 x 6 = 8.2
Sf for 120 kg and 6 G = 120 x 9.81 x 6 = 7.1
Sf for 140 kg and 6 G = 140 x 9.81 x 6 = 8.2
In some situations, Petzl accepts that a user over 100 kg can undergo an impact force greater than 6 kN, provided that the maximum deceleration is limited to 6 G.
