Benvenuti al più ampio studio sulle cadute in arrampicata

Negli ultimi due anni abbiamo

misurato e analizzato centinaia di cadute

Grandi, piccole, con arrampicatori pesanti e leggeri

e un sacco di attrito

"Non riesco a fare sicura dinamica così!"

All'inizio avevo due domante principali

a cui volevo rispondere

in questo studio; la prima è

la quantità di lasco incide sulla caduta?

Se l'assicuratore dà più corda, ovviamente

l'arrampicatore farà una caduta più lunga, e se

cadrà verticalmente la caduta sarà

più dura perché cadrà di più.

Tuttavia, nell'arrampicata si verifica spesso

un piccolo pendolo, una piccola oscillazione

verso la parete, quindi la domanda è:

cadere di più riduce questo pendolo?

Riduce la forza dell'impatto con il quale l'arrampicatore

colpirà la parete? E la seconda parte dello

studio cerca di rispondere alla domanda

"qual è il miglior metodo per assicurare?"

Compareremo il saltare in alto con

il fare un passo avanti, e come bonus se cambia

if the blayer is heavier and as an extra

bonus we also compared against the tube

style soft catches where you let the

Rope slide through the device and while

my curiosity started with these two

questions I actually discovered way more

including some peculiar cases how

lightweight blayer can cause harder

catch when a heavier

blay so let's begin now the problem of

making such studies is a sheer number of

variables every fall is different we

have different weights of the climber

and the Blair the position of the

climber before the fall fall height and

the friction and also the Rope might get

stiffer over multiple fs and of course

the big one is how the Blair will handle

the catch so so I thought okay challenge

accepted I'm going to put a force

measuring device on the climber and do

as many different faults as needed to

see the patterns and off we went

measuring and measuring and measuring

hundred hundreds of Falls and I was

building a huge database of

results and after a lot of work I

understood something and oh [ __ ] moment

happened what we were actually measuring

was the peak Force to the climber's

harness which happens around this moment

of the Fall however this moment is not a

problem for the climber what is the

problem however is how hard the climber

will hit the wall I always felt sorry

for these lightweight climbers who are

slammed into the walls and end up with

broken or sprained

ankles so let's fix that now while the

peak forces should have a correlation

with how hard the climber will hit the

wall I needed to find a way to prove it

and here I was mounting a camera to the

wall with the hope to calculate the

speed at which the climber would hit the

wall based on slow motion footage and

here was a tricky part due to

perspective Distortion objects that are

further away look smaller and in

addition to that every camera lens

introduced extra Distortion so I really

needed to mount the camera as

perpendicular to the climber's falling

plane as possible and it's not like I

can just float the camera anywhere in

space I want but after a bit of root

searching and then a lot of object

tracking combined with a lot of custom

code I wrote I got these beautiful

velocity and acceleration

graphs and now we can do hundreds of

more fults and make sense of them all

right let's begin with the question how

does different amount of slack affect

the fall what we did was a series of

incremental Falls where the Blair does

nothing basically causing a hard catch

the first fall was with zero slack and

even though it's a small fall I was

swung towards the wall really

hard for the second fall we used about

half of arm of slack and despite the

fall being a little bit bigger this time

the peak horizontal velocity was

lower now of course on such overhanging

routes the more the Climber Falls the

further the wall gets and that's why I

was measuring horizontal speed and the

peak of that speed usually happens at

the bottom of the pendulum and it's a

very good indicator of what would happen

if the wall would not be overhanging all

right let's try with even bigger Falls

Charlie was clearly enjoying this yeah

subscribe and the result was interesting

the horizontal speed was nearly

identical to the previous fall however

the peak acceleration was bigger which

means that the climber would reach the

peak speed faster so based on this it

seems that having a little bit of slack

was better than no slack but having even

more was

questionable however despite us trying

to Mim Mig hard catches these faults

weren't that hard The Faults were

relatively small and the blayer was

still pulled up a lot and the reason I'm

saying this is that in the past I have

done similar tests under this bridge

where I have discovered that once the

fall is hard enough it exceeds the

rope's ability to absorb the impact and

the climber experiences a bounce back

effect and this causes harder false for

the climber however when we tried the

same with soft catches there was no

bounce back and the swing was

lower so back to real Rock let's leave

the hard catches for the reference and

see how the soft catches will compare

starting with zero slack we can see that

the trajectory of the Fall is more

gradual and that the horizontal speed

and acceleration was lower significantly

lower next fall was with half arm of

slack and despite the climber falling

more horizontal speed was actually

almost

identical so let's try bigger okay

one two oh okay let's

go o that was soft don't you think I I

was too scared to think so despite

nearly pulling my Blair into the first

bolt and colliding with him the

horizontal speed again was nearly

identical so at least in this test case

scenario falling more combined with soft

catch had no benefits but as they say

one test is no test and that's why I was

rigging another one in the spot where we

will be able to do even bigger Falls

falling hardish so we started with zero

amount of slack and Charlie giving the

softest catch he can however the fall

was described as hard

dish

ready yeah one two three

falling softer and this time adding a

little bit of slack felt softer for the

climber and also did reduce the

horizontal speed by a little bit so

let's see what happens with even bigger

Falls you good whenever you want one two

three

falling take a big pop very soft very

soft and if we look into the graphs the

horizontal speed was even lower this

time so we went even bigger to 1 and 1

half M of slack which is quite a lot one

two three

falling

woo that was soft but there was this

kind of D yeah yeah I I noticed it

myself so this time the climber felt

more jerk on the initial impact of the

Rope however the horizontal speed was

further reduced and looking into all of

these faults we can clearly see

correlation how increasing the amount of

slack decrease reles the horizontal

speed into the

wall and since that was contradicting

with our previous findings we had to do

more Falls and in this scenario falling

more was also better you can even see

the visual

difference and here is one more example

this time the climber was falling from

lower position and we had less friction

once again falling more had softer

impact with the wall so a summary of

this segment is that the swing or the

pendulum into the wall can be reduced by

extra slack however if you exceed R's

ability to absorb the impact the Rope

will bounce the climber back into the

wall and then things might be even worse

and obviously falling more gets you

closer to exceeding that limit but more

importantly hard catch can get you there

very quickly so for example here is one

of the most common mistakes where the

bler simply throws a ton of slack but no

effort in making a soft

catch

okay and here is another one first a

soft

catch and now a hard one

that okay we had the same amount of

slack but the difference was

massive you can clearly see the

bounceback effect how the climber is

being pulled back

up what was your

impressions one elbow versus two elbows

versus three elbows no elbows between

one elbow and two you'll have to measure

that mass masso menos more or less what

it's going to be but I think that's The

Sweet Spot how was no slack at all

difficult to give the soft catch it's

difficult to give the soft catch yeah

with no slag is really hard

to hit the timing perfectly yeah so what

we all noticed is that with zero slack

it's really hard to give a soft catch

because you don't have enough time to go

down and jump up maybe with the

exception If the fall is really big then

the climber is falling for quite a while

and then you have time but on very very

small Falls you would have to have some

cat reflexes and go like super fast but

in general the most comfortable was

between half to full arm of slack and

that caused the softest catches for the

climbers and more than that is very very

rarely beneficial and simp simply asking

for some collisions or dragging the

blayer into the first bolt or simply a

bunch of extra Pull-Ups for the climber

after the fall and uh the bigger ones

like three elbows like I say between one

and two elbows is The Sweet Spot like

one and two is more or less the same for

me personally three is also softer Anna

says but just a little bit harder to

judge again but it's harder to judge

when to jump mhm the EAS the climber is

falling faster already exactly exactly

now I can see how lightweight blers are

probably already typing no slack for me

I fly up anyway so we actually did

testing on that and we got some

interesting results but before that I

just wanted to quickly say thank you for

all my friends and supporters who helped

in creating all of this study it's been

the biggest project I've ever tried both

in terms of time and energy and money so

it would definitely not be possible

without all of you so huge thank you and

now back to lightweight blers so we

started with zero

slack wa that looked

harder yeah visually and we can already

see something interesting once the robe

gets tight the speed of the climber

starts to drop however as soon as the

blay is pulled off the ground the speed

of the climber starts to increase again

the climber experiences a double fall

effect okay let's increase the amount of

slack we still get this double fall

effect but the horizontal speed is

reduced so let's go

bigger and here we have the same pattern

a double fall but the horizontal speed

is even further

reduced so let's try even bigger with

crazy one and a half arms of

slack you ready yeah three two one soft

catch and here the double fall effect is

very visible but same as in previous

experiments we see a strong correlation

that the bigger the fall the slower the

horizontal speed for the climber so the

softer impact with the wall and while

that wasn't a surprise what was however

a surprise is when we swapped her and me

naturally I was expecting that the

heavier Blair should cause a harder

catch for the climber but if we compare

Anna's no slack versus mine you can see

that my catch was significantly

softer

and here is Anna's half arm of slack

compared to

mine and same results my catch was

softer again and to be fair we were

asking her to give a soft catch

one two and give a soft catch you ready

yeah soft catch on three 2

1 and finally Anna's full arm of

slack versus

mine and to my surprise I was giving

softer catches for the climber than the

lighter

belayer however I think this has more to

do with the fact that lighter blers

usually fly up anyway so they don't have

enough practice to give soft catches but

let me give you another example so this

experiment was slightly different 118

here Me and Charlie did a bunch of soft

catches but this time we measured the

forces to the climber this was the

average line of Charlie's catches this

was mine and this was the average of

averages and we also did some hard

catches for the

reference that was much harder all right

and now let's compare this to a light

Blair no no and the first catch was

really bad in fact as hard as our heart

catches you jumped way too soon you've

got to wait till she sucks you you're

down here and when you can feel her

sucking you you push up with

her look at her once she starts falling

you go down up I am getting scared

come

on no now the second catch was much

better but still not what we were

expecting so we did some

practicing oh that was super soft

falling and then this

happened

that look quite nice 12

121 so as you can see experience plays a

bigger role than being lighter and

although lighter blares very rarely

cause hard catches for

climbers however with enough friction

light Blair becomes heavy and actually

recently I saw one really nasty fall

where a bler was a light girl a climber

was relatively light girl a lot of

friction and a huge slam into the wall

and then a poor girl had to get

assistance to get back to the

car and I'm curious did you ever got

unexpectedly hard catch from a light

blayer write down in the comments I want

to see how often that happens all right

so we have seen how both slack and soft

catch has a big effect on the fall but

there is something even more important

here is a hard catch with no

slack and here is a soft catch with a

little bit of slack so we can see the

best and the worst case

scenarios but now check what happens

when the Climber Falls from slightly

different position I simply changed my

legs but I was not pushing away from the

wall

[Music]

[Laughter]

[Music]

I anticipa a bit too much there that's

why you wear a

helmet that would have been a what was

it a trip straight to the yard a trip

straight to the yard that would be

go but if we look into the graphs we can

see that this new fall

had harder fall than the hard catch

before despite Charlie trying to give it

a soft catch with his

head so as you can see how the Climber

Falls can be more important than the

amount of slack or a soft catch and here

sometimes you can see beginners pushing

away from the wall during the fall and

combine that with another inexperienced

delayer and a hard catch and that's a

good recipe for sprained ankles so so do

not push it's very rarely beneficial to

push away unless you're clearing some

kind of slab but otherwise do not push

now in the second part of this study I

wanted to figure out which blay method

is the best so we compared jumping up

versus stepping forward and also does

that change if the player is heavier or

there is a lot of friction in the system

but since all of this is already SL slly

different topic I'm going to split all

of this in a part two of this video but

before you go I wanted to share

something with you that you might find

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researches see you in the next one