Fall Protection
If the risk of a fall at the workplace cannot be eliminated by a collective protective device, personal fall protection is required.
This equipment must secure a person to an anchor point in such a way that a fall is either completely prevented or safely arrested.
Even though a user will hopefully never fall, this equipment must be worn all day and should be comfortable enough not to hinder work.
Anchor Point & Anchoring Equipment
Anchor point: Generally refers to a secure attachment point (e.g., beam, scaffolding, railing).
The anchor point must
- have a static strength of > 10 kN for 3 minutes (EN 795b).
- be mounted high enough so that the user does not fall to the level below in the event of a fall. It should be positioned as vertically as possible above the work area.
Anchor device: Used to attach the lanyard to the anchor point or the anchor device (webbing, steel sling, beam grab, etc.). - Must be suitable for the respective anchor point and have a static strength of at least 15 kN for 3 minutes (EN 362).
Full-Body Harness
Full-body harness: The part of the personal protective equipment worn by the user.
- Serves to arrest the user in the event of a fall, preventing injury or slippage from the harness.
- The only protective equipment permitted for fall arrest situations is the full-body harness.
- Positioning straps, on the other hand, can be used for work positioning and as part of restraint systems.
- When selecting a fall arrest harness, the task to be performed and the work environment should be taken into account.
- Each fall arrest attachment point on a harness must have a static strength of > 15 kN for 3 minutes (EN 361 and EN 358).
Lanyards
Lanyard devices: This important component connects the harness to the anchor point or anchoring device (e.g., a lanyard with or without a shock absorber).
- It serves to limit the user’s free-fall distance and must be selected by taking into account the work to be performed and the environment.
- To determine the type of lanyard required, the potential fall distance must be calculated.
On their own, these components do not provide protection against a fall. However, when used correctly together, they form the personal protective equipment that is vital for workplace safety and the entire fall protection system.(Wikipedia)
Assessment
The physical consequences of a fall can be estimated if the magnitude of the acceleration due to gravity (g = 9.81 m/s²) and the deceleration (negative acceleration a) are known. If the deceleration exceeds approximately 10 times the acceleration due to gravity (10 g), forces act on the body that make serious internal injuries highly likely.
From the laws of falling bodies (s: distance, t: time):
- Speed, braking time, braking distance, and deceleration can be determined.
The falling speed is influenced by air resistance and does not exceed a maximum value of approximately 200 km/h (≈ 55 m/s), which is reached at a fall height of around 145 meters.[1] To avoid exceeding the maximum deceleration of 10 g, a braking distance of at least s = h/10 and a corresponding braking time are required at lower speeds.
Values at maximum deceleration:
Height [m] – Speed [km/h] – Braking distance [m] – Braking time [s] – Example
- 1m 15,8km/h
- 2m 22,7km/h
- 3m 27,7km/h
- 4m 32,4km/h
- 5m 35,6km/h
- 6m 39,2km/h
- 10m 50,4km/h
- 20m 71,3km/h
- 200m 226km/h
- 1000m 250km/h
Fall (Accident)
DIN 4844-2 W015 – Warning of Fall Hazard
A fall is an accident that, unlike a trip, stumble, or slip, results from falling from an elevated position.
Occurrence
Fall accidents occur, for example:
- during work on buildings, scaffolding, ladders, or other elevated locations
- during the use of aircraft (e.g., accidents during parachuting)
- during sports such as mountaineering and hiking (mountaineering accidents, falls onto ropes), gymnastics, and horseback riding
- as a consequence of panic, especially in fires
Even a fall from a low height, e.g., from a ladder, can lead to very serious injuries. Falls from low heights usually do not allow the use of limbs to break the fall, so severe injuries often result.
The consequences depend on many factors, for example:
- the height of the fall
- the body parts involved in the impact
- the impact surface (a fall onto rocks will result in more severe injuries than a fall into powder snow)
- obstacles in the fall trajectory; a fall onto a protruding object, such as a reinforcing bar, can be fatal even on level ground
- the behavior of the person falling; injuries may be less severe if the person is unconscious or if muscle tension is reduced
- body type (very young children often survive falls even from great heights; cats can turn in mid-air and land on their limbs)
- age (e.g., bone structure becomes more brittle with age)
- rescue options (e.g., in mountaineering, long-term damage can occur due to cold or being suspended in a rope)
Braking can be achieved by:
Absorbing the fall
Using an elastic climbing rope. A fall would be fatal if the rope suddenly brought a person to a halt after only a few meters. To survive a standard fall from a height of approximately 4 meters, a deceleration distance of at least 40 cm is required if the deceleration is not to exceed 10 g. Modern climbing ropes therefore have an elasticity under high load of at least 9%.
Using the legs and rolling. With practice, a jump from a height of 2 meters can be mastered safely. Absorbing the fall with the feet and legs and rolling allows for a braking distance of more than 50 cm. A trained stunt performer can survive even greater heights through appropriate technique.
In a crumple zone. A head-on collision with a car at 50 km/h – corresponding to a jump from a height of 10 meters – can be survived if the crumple zone compresses by more than 1 meter.
Friction
- Ground friction. Falling from a bicycle often results in abrasions from sliding on the asphalt. If the distance to the nearest obstacle (e.g., a lamppost) is sufficiently long, more serious injuries can be avoided.
- Water resistance. A jump from a height of 10 meters into a swimming pool requires a water depth of at least 1 meter. Reports that 70 centimeters would suffice may be based on the assumption that the pool floor provides an additional “cushion” of at least 30 centimeters.
- Air resistance. A parachute increases air resistance significantly, while an umbrella provides virtually none.
An unbraked fall from a height of 2 meters onto the head can be fatal. The required braking distance of 20 centimeters corresponds to more than half the diameter of the head. To survive a fall from great height, smooth deceleration over at least 25 meters must be possible. → See also Curiosities.
Injuries
Depending on the height of the fall, injuries can affect almost any organ. Fatal accidents most frequently occur at heights of less than 10 meters or more than 25 meters, as these falls usually result in a head impact. Because the instinct is to land feet first, fractures of the ankle, knee, legs, spine, and pelvis are common. Approximately 75 percent of victims die within the first few seconds after impact.[1] Particularly critical are:
- Skull fractures (basal skull fracture) and cerebral hemorrhages
- Vertebral fractures
- Internal injuries (abdominal trauma), such as splenic rupture, rupture (tear) of the aorta, vena cava, or liver
- Puncture wounds from broken bones or impalements, causing severe blood loss
In addition, other injuries typically occur, such as:
- Bruises, abrasions
- Concussions
An analysis of 100 suicides at the Golden Gate Bridge in San Francisco (75 meters, impact speed 120 km/h) revealed numerous causes of death: pulmonary contusions, collapsed lungs, exploding hearts, and a rib-pierced aorta or vena cava.[1]
Oddities
The record for the greatest height survived from a fall is held by Vesna Vulović. She reportedly survived a fall from a height of 10,160 meters on January 26, 1972.
On December 7, 2007, two window cleaners, Alcides and Edgar Moreno, fell from the 47th floor of a building in New York City, a height of approximately 144 meters, while working on scaffolding. Edgar Moreno died instantly, while his brother survived with serious injuries. (Wikipedia)
Fall Protection
Risk of Falling
The best protection against falls is to avoid accessing elevated areas where a fall is possible. If this cannot be avoided, the fall edge must be secured with a suitable railing. If working in areas with fall risk is unavoidable, climbing harnesses or fall arrest harnesses are generally used in combination with dynamic ropes and, if necessary, energy absorbers.
If a fall into a rope is possible, rapid rescue must also be ensured, as prolonged suspension can lead to significant health risks.
Rescue harnesses are used when individuals cannot rescue themselves (e.g., when working in confined spaces).
The consequences of falls from low heights can be reduced by wearing protective equipment such as spine, knee, and elbow protectors, as well as helmets.
Personal Protective Equipment Against Falls from Height
- Working harness system – consists of a working harness, lanyard, and anchor point.
- Fall arrest system – consists of a full-body harness, lanyard, energy absorber, and anchor point.
When technical fall protection measures are not possible, the use of safety harnesses is mandatory. These include:
- Full-body harnesses (several straps from thighs to shoulders with rear or front attachment points)
- Working harnesses (taut lanyards that keep workers away from fall edges; not suitable as a fall arrest system)
- Firefighter harnesses
- Lanyard devices (safety ropes, lanyards)
- Additional components such as energy absorbers, fall arresters, or descenders