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
beneficial in order to create these nice
charts that you have seen in this video
I needed to understand how to take my
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researches see you in the next one