Features and functions of fall arrest systems

When working at heights, there is a danger of inadvertent falls, which could result in loss of health or life. To prevent accidents, the safety regulations require the use of special safety equipment. Its types are different, and their choice depends on the goals and tasks performed by the user in certain conditions.

The fall arrest system is considered to be part of the protective equipment that must be used in working conditions at height. The main function of this system is to prevent falls or sudden downward movements. Protective equipment is used not only when working at height, it is sometimes necessary in extreme disasters, for working in wells, its use is justified and in demand in the field of production and construction. Safety systems for work at height are made of power buckles and synthetic slings. The design is worn over clothing, it does not restrict mobility and does not have much weight.

Such equipment is applicable not only for the purpose of protection against falls, but also for creating minimal injury to the worker in the process of this fall. When decelerating a falling body, the dynamic load on it should not exceed 6 kilonewtons - only in this case, the person will not receive internal injuries and remain alive. The safety structure provides for the presence of special cushioning systems capable of partially absorbing the energy caused by the body's sudden downward thrust. During operation, the shock absorbers will lengthen, so with a small margin of height, a person can get hit on the ground.

A fall arrest system used to provide protection against falls from a height regulated by GOST R EN 361-2008, according to which there are requirements for the design of equipment.

• Materials for making - use homogeneous or multifilament synthetic tapes and threads for sewing them, capable of withstanding a mass several times greater than the weight of an adult. The tensile strength of the material must be at least 0.6 N / tex. When sewing, threads are used that are contrasting, different from the color of the ribbons - this is necessary for visual control of the integrity of the line.
• The harness has straps for placement on the shoulders and legs in the hip area. These straps should not change their position and loosen on their own. In order to fix them, special fasteners are used. The width of the main straps of the safety structure is made at least 4 cm, and the auxiliary ones - from 2 cm.
• Fastening elementsintended for braking the free fall of a person should be placed above the center of gravity - in the chest, back, and also on both shoulders.
• Fastening Buckles are designed so that they are fastened in only one correct method, excluding other options. Increased requirements are imposed on their strength.
• All fittings are made of metal regulated by anti-corrosion requirements.
• Safety equipment markings and all texts must be in the language of the country for which these products are intended. The marking contains a pictogram that draws attention to the importance of this information, the letter "A" at the attachment points of the elements necessary to stop a fall, a sign of the type or model of the product, and the standard number.

Safety equipment items must be accompanied by detailed instructions for use, which indicate the method of donning, operating conditions, characteristics for the anchor point and attachment points for other elements. The safety equipment is marked with the manufacturer's stamp, in addition, it contains information about the release date, since the shelf life of such a protective equipment is no more than 5 years.

All protective equipment designed for work at height is divided into a number of basic types, depending on the composition of the elements included in their design.

• Restraining equipment - regulates the range of movement and does not allow the user to suddenly find himself in the place of an unforeseen fall from a height. This partial blocking is provided by the anchoring device and the horizontal anchor line. In addition, the protection is a harness that holds the sling or rope in the form of a shock-absorbing system and a system of carabiners. If it is not possible to install the anchor line above the user's head, counterweight weights in the form of stationary support structures are used. Counterweights have a mass of 2 tons. Such a design will not be able to exclude the fall process, since it serves only to limit the user's area of ​​work.

• Safety lanyard system - consists of a safety sling with a shock-absorbing subsystem, a carabiner system, an anchor device and a horizontal line, and a safety harness is also used here. With the help of a safety sling, the worker fixes himself to the anchor line. In the event of a sharp jerk on the line, the shock absorber will automatically block the movement, it will extinguish the force of the jerk in the event of a fall.

• Slider system - consists of a safety slider element, an anchor device and an inclined anchor line, a shock absorber system and a safety harness. This type of system is used for construction work on sloping and inclined surfaces. During the dynamic force in the fall, the fall arrest system will be locked and locked with a slider, which will stop the rapid downward movement.

• Retractable device system - consists of an anchor system, a retractable personal protective device and a safety harness. The retraction system is fixed permanently, a sling is extended from it, which is attached to the leash at the worker. During movement, the sling comes out of the block or automatically retracts. In the process of a sharp jerk, the structure automatically slows down such a supply of the line and prevents the downward movement.

• Position selectable system - consists of slings for different positioning and harness, anchor system, a number of carabiners and shock absorbers. The slings of the structure hold the user at a predetermined height and provide him with a fulcrum, minimizing the risk of downward movement when the worker takes certain postures. The system is used to perform actions when there is firm support for both legs, but the hands must be free.

• Rope access system - allows access to works by moving along a flexible inclined anchor line. The method is applicable in cases where the cradle of the lifting tower is not accessible. The system consists of an anchor device, an anchor line, a shock absorber, a sling, carabiners, a safety catcher and a safety harness. 2 different ropes are used for the fall arrest system and the rope access system.

• Evacuation system - in the absence of the possibility of a quick descent during a dangerous situation, systems of rescue devices are provided that allow the user to descend independently within 10 minutes, thereby preventing the development of injuries arising from a person in a suspended state.

The types of safety systems are divided into stationary and individual. Personal fall arrest systems are self-supporting and designed to distribute dynamic forcearising from a jerk when falling from a height.

Stationary systems are anchor devices and anchor lines of various modifications. With their help, the user can move horizontally, vertically or work with an inclined surface. A complete stationary system covers the entire working area, while the lengths of anchor lines are up to 12 m. Unlike mobile systems, stationary structures are fixed in their permanent place.

Made of a wide waist belt to which 2 shoulder straps are attached. The use of a chest harness alone without the use of leg straps creates the possibility of injury, since with a long suspension that occurs during a fall, it presses heavily on the chest area, thereby provoking fatal suffocation. For this reason Separate chest harness without leg harness is not used.

There are different types of chest straps.

• Eight-shaped - the chest harness is made in the form of the figure "8". There is a possibility of adjustment to the required size using buckles, but there are also non-adjustable models in a ready-made size design.
• T-shirt - made of a girth along the chest line, to which 2 shoulder straps are attached. This is a common harness option, as it can be adjusted to any size, and in addition, it has additional loops for equipment.

Convenient and practical model, which has many forms of execution.

• Belt - waist circumference with a sling attached to the lining fabric. Provides grip and reliability during a fall, which depends on the number of retaining buckles. The location of the buckles can be symmetrical (right and left) or asymmetric (1 buckle). The symmetrical version is most convenient for adjusting the size.
• Leg loops - can be without the possibility of regulation by the size of the leg or adjustable with the help of power buckles.
• Power loop - this element of a sewn lanyard connects the leg loops with the belt, and also serves as a means for connecting belay devices.
• Power buckles - serve to adjust and fix the belts. Fixation comes with a counter-flow used for long-term performance of work, and there is also a Doubleback option, which allows you to quickly tighten all fastening elements to your size.
• Discharge loops - are made of plastic or sewn slings. They are needed for hanging additional equipment, they are not used for insurance.

The design is a combination of top and bottom straps. It is considered the most reliable and is used for difficult mountaineering and rock climbing. Often this type is positioned as a five-point attachment system that reliably holds even children, providing maximum safety conditions.

The choice of safety equipment depends on the type of work performed and the activity of the user. According to the scope of application, protective equipment is divided into several types.

• Systems for climbers - are convenient and comfortable, you can stay in them for a long time in a suspended state. It is made of a waist belt with a wide base and adjustable leg straps. It is not uncommon for users to add gear loops to such a system.

• Climbing systems - This is the most lightweight version of the equipment, which includes non-adjustable leg straps, a narrow waist belt and 2 unloading loops. Such a system is not intended for long-term work in suspension, since its role is only insurance.

• Systems for industrial climbers - bulky, limiting the range of motion, but creating convenience during long work at height. Consists of a waist belt and adjustable leg loops. In addition, there are additional attachment points, which are located on the sides of the structure, and wide-sized discharge loops.

• Systems for cavers - perform the tasks of multiple ascent and descent along a fixed rope. Suitable for work in narrow areas, as there are no unnecessary parts in the design. The fastening buckles are located on the inner surface of the legs, the unloading loops are thin, the harness is made of friction-resistant materials.

In order not to shorten the life of the fall arrest system, it requires regular maintenance after use. It is allowed to wash equipment using laundry soap, it is better to clean it from dirt by hand. After washing, the structure must be dried, but not on the battery. Materials made from polymers must not be cleaned with organic solvents or other chemicals.

Before each use, the protective system must be carefully checked for its integrity.and also inspect metal parts for deformation or breakage. If defects are found, the equipment is not subject to use.

See the next video on how to choose the right belay system.