冲坠系数详解

I_have_to_work

Fall Factors Explained

冲坠系数详解

by Rockfax

作者 Rockfax

The following article is based on text from the book Trad CLIMBING + published by Rockfax. This article version was written by Adrian Berry and Alan James, and the illustrations are by Ray Eckermann.

下面的文章基于由Rocktex发行的书Trad CLIMBING+。本文由Adrian Berry和Alan James改写，Ray Eckermann配图。

When you fall off a route the piece of equipment that contributes the most to absorbing the energy of the fall is the rope. In general, the more rope freely available to stretch during the fall, the safer the fall will be and this can be measured by using a ratio known as the fall factor.

当你从线路上脱落时，对吸收能量贡献最大的装备是绳子。通常来说，绳子可以自由伸缩的长度越长，这次冲坠就越安全，这可以用一个比率来衡量，就是众所周知的冲坠系数。

The fall factor is simply the distance fallen, divided by the amount of rope available to absorb that fall. The principle is that, the lower the fall factor, the safer the fall. The distance fallen isn't important on its own and in some situations longer falls are safer than shorter ones, which is contrary to what most people might expect. The important thing is how much force is transmitted to the top piece of protection and this is where the fall factor comes into play - a large fall factor (which can be a very short fall if low on a pitch) transmits a large force, and a small fall factor (which can be a huge 'winger' if high on a pitch) transmits a smaller force.

冲坠系数就是简单地以掉落的距离除以绳子在这次冲坠中的有效长度。原则是，冲坠系数越小，就越安全。单独讨论掉落距离是没有意义的，在某些情况下长冲坠比短冲坠更安全，这点出乎大多数人的意料。重要的是有多少力量会传到最顶上的保护点，这时就看冲坠系数 - 大的冲坠系数(可能是一个很短的冲坠，如果你处于分段的起步)传输了一个很大的力，小的冲坠系数(在分段的高处也可能会冲很远)传输一个很小的力。

The illustrations below show several different situations and the fall factors you might experience.

下面的插图展示你可能遇到过的几种不同情景下的冲坠系数。

Here, a climber has taken a 2m fall with 10m of rope out giving a fall factor of 0.2 (2/10) - a very soft fall.

这里，攀爬者掉落2米，绳长10米，冲坠系数为0.2(2除以10) - 很柔和的冲坠。

If the climber had been twice as high on the route (20m), and taken a longer fall of 3m, the fall factor would be only 0.15 - significantly less - and safer - even though it might have been a bit more scary!

当攀爬者爬到两倍的高度时(20米)，来了一个稍长的冲坠，3米，冲坠系数仅仅为0.15 – 明显更小了 – 也及更安全 - 虽然它可能会更吓人一些！

In this example, the climber has once again fallen 3m, but is had only just moved above the belay, and so only had 3m of rope out - giving a high fall factor of 1.0.

在这个示例，攀爬者再次掉落3米，但他刚刚离开保护点，所以只有3米的有效绳长 – 冲坠系数是1.0。

Here, our friend has fallen 6m, with only 3m of rope to absorb the fall, producing a very large fall factor of 2.0. If the belayer had quickly reacted and taken in some slack (an intuitive reaction) while his friend was whistling past (an armful is about 0.5m), the fall factor would have increased to a very worrying 2.4.

这个情况，这哥们掉落6米，而仅仅有3米的绳可以吸收冲坠，带来了非常大的冲坠系数2.0。当他哥们呼啸而过的时候 ，如果保护者反应迅速并收紧绳(直觉反应)(收一手绳大概0.5米)，冲坠系数会增加到非常令人担忧的2.4。

Real world fall factors

现实世界中的冲坠系数

The fall factor is a very useful way of understanding just how the forces of a fall are dissipated and the role of the rope in not just stopping a fallen climber but stopping them gradually.

冲坠系数是一种很好的方法去理解冲坠的力量是如何消散，以及绳子的作用不仅仅是拉住掉落的攀爬者，还要缓缓地停止他们。

The examples above are highly simplified and in each example the rope is running perfectly free. In practice, each time the rope runs against either a karabiner or the rock, it reduces its ability to absorb force through its full length.

上面的示例都被高度简化了而且在每个例子中绳子是完全自由伸展的。在实践中，任何时候绳子都是被锁具或者岩石限制着的，这降低了绳子通过全部长度吸收力量的能力。

In the example on the right, the presence of only four twenty degree bends in the rope caused by runners is enough to more than double the fall factor from 0.3 to 0.6 due to the added friction in the system.

看上边的例子，绳子只是被快挂(原文字面意思是绳圈，译成快挂，下同)折了4个20度，这对系统增加的摩擦力就已足够导致冲坠系数翻倍，从0.3变成了0.6。

A more severe point of friction, such as a ledge where protection has been placed at the back, or the lip of an overhang, where protection has not been sufficiently extended, can as much as double the force on the top piece of protection - taking it into the realm of failure.

一个更严峻的摩擦点，例如一个平台(保护点设置在它的背面)，或者仰角岩壁上壶口，这些保护不能充分伸展的地方，都可以将顶保护点的受力翻倍 - 将它带到一个失效的领域。

So are long falls safe?

那么说长距离的冲坠就安全了？

Far from it, since there are many other crucial factors you need to consider. The further you fall, the more likely you are to hit something - this could be the ground, of course, but it could also be a ledge, or a protruding section of rock. In addition, the effects of a swing are increased if you fall further.

远离它，因为还有很多重要的因素你需要考虑呢。你掉得越远，你撞到什么东西的可能性就越大 - 可能是地面，当然，平台也是可能的，或岩石的突出部位。另外，摆荡的效应也会增加。

The main point to learn from fall factors is that a fall from low on a pitch often transmits more force to a runner than one from high on a pitch, even if you only fall a short distance. When you fall past a belay, the fall factor can become critical. The way to counter this is make sure your early runners are good ones, and place a few when leaving stances on multi-pitch routes.

从冲坠系数中学到的要点是，从低处掉落通常会比高处掉落给快挂带来更大的受力，甚至你仅仅掉落很短距离。当你掉落时越过了保护点，冲坠系数会变得非常致命。对应这种情况，确保你前几个快挂的质量，在结组线路，刚离开落脚点的时候要多放置几个。

阿华

图片打不开

司令

没法看图片

铜川郎

学习了