Climbing vertically is the very essence of walking a via ferrata. Rising we expose ourselves to an intrinsic risk and with potentially fatal consequences: the fall. Monteaineering extends a series of techniques and uses specific equipment with the aim of reducing and mitigating the consequences of a possible fall. In following a via ferrata, compared to taking a mountain route, we can count on a series of installed equipment that serve as a basis for safety during progression with the aim of reducing the consequences of a possible fall. Let's look into some aspects.
The wire rope or chain (from now on only "rope"), in addition to showing us the way of progression along the climb, acts as a locking system in the event of a fall. The rope is anchored to the rock by nails or taproots that have the function, not only to keep the rope stretched for progression but, above all, to stop a possible fall.
When I took the first via ferrata, the first advice I received was "You don't fall in via ferrata"Which must be interpreted more precisely as"You should not fall on a ferrata"Considering that a possible fall is traumatic and potentially dangerous. This aspect differentiates via ferratas from sport climbing routes in a significant way. In fact, flight and fall are intrinsic aspects in sport climbing routes and must learn to fly.
Considering that the force of gravity will inevitably push us down, it is useful to clarify a couple of concepts.
The speed with which we fall will grow linearly with the time of fall and, specifically, follows this formula:
v = gt
that is, speed (v) increases as a product of gravity (g) for the time (t), where the force of gravity it is always 9.81 meters per second. The mass with which we fall generates akinetic energy that we will have to contain (dissipate) to arrest us.
During the fall our body is connected to the rope by two carabiners which, in turn, are connected to the harness by two lanyards of about one meter. Following a fall the deformation of the lanyard is proportional to the length of the lanyard itself (given how long the strings are from bungee jumping?). As the length of the lanyard is contained, the kinetic energy would be discharged onto the hiker's body. The discharge of this kinetic energy on the human body can have serious consequences on the joints, in particular on the spine.
To contain the effects of this problem a device has been invented that dissipates the kinetic energy due to the fall: the heatsink. This device is placed at the base of the two pieces of lanyard before connecting to the harness. The heat sink takes care of significantly reducing the kinetic energy before it can reach the hiker's body. The principle is quite simple: the heat sink slides a string through narrow holes on a metal slab. Since the holes are narrow, the rope runs with difficulty and the clutch dissipates the kinetic energy before it reaches the human body.
Before delving into the topic of Falling Bills, and in particular the Fall Factor in the case of a via ferrata, let's focus on the Stop Force.
To stop a fall, you will need a force that eliminates the speed at which we are falling. There Stopping Force it is the force to which our body is subjected during the fall to stop us. The force that is generated in the fall is transmitted to the insurance chain. In the case of climbing, three players are considered: the climber, the insurer and the point of reference. Whoever has made sure in climbing knows that, in the event of a fall, he will also receive "a blow”From the fall, or rather he will feel a force transmitted to him during the fall. In the case of via ferrata, the insurer is missing and the Stop Force is split between those who board and the cable-taproof system that serves as a self-insurance. The impact generated by this force can have serious consequences for the body and it is for this aspect that the heat sink comes into play.
The Fall Factor is a number that indicates how dangerous a fall is and is calculated by a simple formula:
Fc = Ac / Lc
Where Fall Factor (fc) is the review between theheight of fall (B.C) and the rope length (Lc) to which we are connected.
In the example above, during a climb free the review between the height of fall and the length of the rope derives a factor of fall 0.25, or the climber falls for 2 meters with a length of rope of 8 meters.
Low fall factors are considered to be those below 0.25, average ones between 0.25 and 1, high ones above 1. In mountaineering practice the value of Falling Force is always between 0 and 2.
In via ferrata this value can be exceeded and it is for this reason that without a sink a fall could be fatal for the spine.
Let's try to clarify with a practical example: we are climbing a vertical via ferrata, just before moving the carabiners to the next tap we lose the balance and we fall. The distance between our harness and the taproot to which we will fall is 3 meters plus the length of the 1 meter lanyard for a total drop height (Ac) of 4 meters. The length of the rope (Lc), precisely the lanyard, is 1 meter.
The complete Ferrata Set
Explained why the heatsink is a mandatory device and that could save our lives, let's clarify why we recommend buying a complete Ferrata Set compared to the classic homemade heatsinks (although they are still sometimes seen around). All the major brands of mountaineering material sell via ferrata sets complete with lanyards, snap-hooks laced to the lanyards and heat sinks to be connected to the loop of the harness with a knot choke. By putting safety as a priority, we recommend the purchase of complete Ferrata Sets, especially given the low price they are available on the market. For more information on the necessary equipment and optional equipment to cover the via ferrata, read this in-depth article.
A final clarification: in the event of a fall, the heat sink is activated and the Ferrata set must be replaced.