this is a dynamic climbing rope one can

take hundreds of these massive Falls and

it will still provide a soft Landing for

the climber Now Let's ignore the blue

protective shift and pull out the core

so this white strands is the core of the

Rope which is responsible for majority

of rope's strength if I would untwist

the core strand eventually I would get

to this thing which is called a

multi-filament and if I would dig deeper

and try to separate the smallest part of

the Rope I would get to a single

filament which I can barely see so this

is a single filament

so this filament is about 10 times

thinner than the human hair and there is

about 50 to 80

000 of them in a single rope and all of

them run across entire length of the

Rope now during the fall this filaments

stretch but also they slide past each

other which creates friction and this

friction helps to dampen the impact

however if we would make a rope wet

water on the surface of the filaments

would act as a lubricant this would

allow the filaments to slide easier past

each other which would reduce the

dampening effect also you can probably

imagine that as I want to stretch the

Rope out it needs to shrink in diameter

however if the Rope is full of water in

order to shrink in diameter first it

needs to spit the water out however if

the impact is hard enough the water

cannot Escape faster it's like when you

belly flop on the water and the water

doesn't have enough time to flow around

your body and things get even more

interesting from here if we would look

deeper deep deep inside the filament we

would find this but don't worry the only

thing you need to know that this is a

monomer which joins together to form a

polymer chain and this chain can be very

long very very long which is really

great for making filament fiber and this

is where things get interesting notice

that some parts of this fiber are

arranged neatly in order these parts are

called crystalline and they have polymer

chains packed so close together that

they form an attraction for each other

and this happens because hydrogen from

one chain really likes the oxygen from

the other chain so all of this makes

these parts really strong with which is

great for the strength of the Rope

however it also makes these parts really

stiff which is not so great when you

want your dynamic rope to stretch and

that's what these other parts that look

like spaghettis are four they are called

amorphous and they have much bigger gaps

between the chains which allows them to

stretch

so when the force is applied on the

fiber these spaghetti Parts stretch and

the crystalline Parts provide the

strength you can probably imagine that a

very stiff rope

wouldn't be great for climbing but

neither the Rope which would stretch too

much because when I fall I want to land

not on the ground so by controlling the

ratio between spaghettis and crystalline

Parts rope manufacturers can create this

great strength but at the same time

perfect Force absorption which is quite

impressive now remember I said that

hydrogen really likes the oxygen guess

what else has a lot of hydrogen and

oxygen that's right water good news is

that water cannot really penetrate into

the crystalline parts of the fiber

because the chains there are very packed

close together already however spaghetti

Parts have gaps and that allows water to

come in and bond to the chains and this

bonding increases the distance between

the chains and it also weakens the

intermolecular attraction so now if the

the force is applied when the fiber is

wet spaghettis might stretch more than

what they are capable to recover from

and that might damage the entire

structure of the fiber but all of that

is in theory so let's see if that theory

applies to real world climbing

situations

[Music]

and if you're wondering who goes

climbing in the rain well this was my

birthday and we came up with a brilliant

idea to climb 34 routes in a day and

half of the day was raining

so yeah let's say I have some wet

experiences but my anecdotal experiences

are not science and to do proper science

I needed to go to the place where the

ropes are properly tested

[Music]

[ __ ] there's a lot coming out

[Music]

that's a lot

and before we begin a strange fact I

checked a lot of user manuals of dynamic

climbing ropes from various Brands and

about half of them have various warnings

about wet drops however the other half

doesn't mention anything

hmm okay so here is the question

will dry rope cause harder catch on

realistic fault scenario

well we would say over time yes in the

beginning probably not

so you mean on a first fall maybe not

yes and on the repeated Falls probably

yes exactly that's not my first

statement made

now since we wanted to mimic real world

scenarios

and heartfalls rarely exceed 4

kilonewtons we needed to modify the drop

tower to produce the forces between

three and four kilonewtons

so we overshoot yes we did buy a lot

[Music]

okay

which took a bit of adjustment on this

old drop tower Mammoth actually has a

way more advanced drop tower which I

already had a pleasure to use when we

were testing the cut resistance of the

ropes which was super interesting yeah

that's easier with the other one because

it works electronically you can put in

the number where you want to go and then

it's aligns it by itself but we are not

allowed to use it not for the water

it doesn't like water yeah so this one

doesn't like the water this one also

doesn't like weather no as soon as these

get wet rust will appear off the wall

and then friction has a big influence on

the yeah but this one we don't use this

for any development or production

control yeah that's why we are allowed

to make it wet exactly

4.11

[Music]

I've heard you're going like oh

the frustration

and not only we needed to make sure that

our samples are between three and four

kilonewtons but also that each of them

is as similar as possible how is it

going we have a method of how we can

always make the nuts equal later we will

have fun

it's a group activity it's a team

building yes how many samples do we need

depends on you how many samples do we

need

depends on how many people we have

making them

[Music]

so what's going on equal length is equal

everything is equal having samples as

similar as possible was actually really

important because as Adriana said

textiles is a very tricky and Moody raw

material to work with Moody it's very

moody yes so although we cannot control

the mood of the Rope but in order to

make the nice statistics that you're

gonna see later in this video we needed

to try our best

too long so basically we are massaging

back and forth to get uh yeah it's what

we in German call it Sisyphus are bite

no we got it you think so if not it's

time for lunch

either we succeed or we eat

everybody click

three points

yeah when I was editing this I thought

wow if you ever wondered how Geeks are

celebrating life this is a prime example

anyway the next question was is our test

setup repeatable meaning will we get

second fall to be close to the first one

if we don't get that then we five hours

more

don't make a night session work till

five and then you go bouldering we have

time limit

because we need to go bouldering because

we need to completely

very nice that's very good very Swiss

accurate

our setup was working really well and

now we needed to collect a lot of data

this might take if we wait three minutes

and we do five Falls that's 15 minutes

just waiting times three times six

fifteen

I the eyes are getting bigger and bigger

and here are the results if we average

all the samples we get the Baseline of

how the force is increasing with every

fall which shows that rope doesn't have

enough time to fully recover so let's

see what happens when the ropes are wet

look how much air is coming out

all the air is escaping from the Rope

during the fall the water will be trying

to escape trying to blast out of Europe

we wanted to do three different tests

where the ropes were soaked for 1 5 and

15 minutes and what was interesting that

fully submerging the Rope for just one

minute was enough to almost completely

saturate the Rope meaning that soaking

for longer did not add any extra weight

and after we dropped all the wet samples

and enjoyed the splashing of the water

everywhere

[Laughter]

oh my God

here are the results since the

difference in water absorption was

minimal the forces were actually very

similar and if we take the average of

all the wet samples we can see that the

first fall was only slightly harder

however the difference increases with

the subsequent false

you know it's combining everything to

family so statistically significant

very good today we made a page

science a little future me Interruption

since I got more information the peak

forces that we measured obviously do

contribute to how hard the catch will be

for the climber however it's not the

only Factor

the big Force to the climber usually

happens around this moment but even on

the hardest Falls this moment is not

hard enough for the human body to be a

problem what is the problem however is

how hard the climber will hit the wall

as I mentioned earlier as the Rope is

stretching the filaments are rubbing

against each other which dampens the

energy and and if the Rope would be able

to absorb all the energy during the fall

it would stretch and then stop however

that's not what happens on hard Falls

normally the Rope will act like a spring

it will stretch and then bounce back

that bounce back usually creates more

energy going towards the wall and if the

Rope is wet the filaments are sliding

easier past each other which reduces the

dampening effect so the bounce back into

the wall should be harder so I was

really curious to test this however this

requires more advanced testing

facilities but luckily after I left

Mahmoud did this test in another

facility and sent me the results here is

the force graph where the initial Peak

was said to be around 3.6 kilonewtons

and after that we can see how the Rope

bounces couple of times now in the case

of the wet rope the peak is only

slightly higher however the spring

effect is much higher and this is the

same graph after five consecutive Falls

the initial Peak was 23 percent harder

however the bounce was much harder so

the spring effect was much bigger

alright so far we confirmed that wet

robes might cause harder Falls but also

according to the theory wet drops might

lead to some permanent damage to the

Rope

let's see so we left the last rope

hanging overnight

so technically now it's dry and

um and rested

so we dropped this rope once again and

the fall was harder compared to the

Baseline which definitely hints that

there was some permanent damage done to

the Rope alright so far so good and

there was two more experiments I wanted

to make first of all we did all our

tests on classic ropes so I was curious

how dried treated ropes would perform on

the same tests and in case you don't

know dry treated ropes are soaked in

certain chemicals that make them more

water resistant our dry ropes we add the

chemical first to the core so to the

strands they get a drop application then

we braid the rope together and then we

submerge it in a chemical bath and we

take it out and we dry it and then you

have a dry roll so basically core is

separately submerged into chemical and

then entire rope now the cooler get a

drop application you need

just a little drop every every couple

seconds is enough to make it uh water

resistant interesting and then the

entire rope goes into the thing yeah

when it's finished so let's see how good

that treatment is in practice

[Music]

so at first we did a lot of drops

without water and that allowed us to

compare treated tropes with classic ones

and it was good to see that treatment

has no negative effect when the ropes

are dry so let's see if it has a

positive effect when the ropes are wet

number two number two you want to get

the shot of how

treated robes Stone bubble or duvet

bubble wait maybe I don't want to

look it doesn't bubble as much as the

other one

what if you squeeze it a bit but no

squeezing

and yes dry treated ropes absorbed

significantly less water

ah I know what can be the problem that

ends I see bubbles coming from the ends

a little bit although we sealed the ends

but most of the bubbles are coming from

the tip of the Rope maybe I'm gonna keep

that tip just a little bit out

yeah I mean you can always have like

little holes where it could get in with

these kind of things if it's not seared

well in the end you have like a

capillary effect of that the water

traveled along the fiber okay let's see

I'm super curious

[Music]

wow there was no splash of water

and here is the treated rope that we

soaked for 15 minutes as you can see

there is still barely any water coming

out of it and if we would compare this

to the classic ropes the difference is

huge

we're still here collecting the data

Never Ending Story how are we feeling to

you

yeah

here stopped for climbing and when it

comes to the treated tropes soaking them

up to 5 minutes showed no increase in

forces however soaking for 15 minutes

already was worse but not as bad

compared to the classic ropes so dried

treated ropes unsurprisingly were

performing better in wet conditions

however I know that many of you myself

included had a question how long does

dry treatment stay effective does it

wear off so this is a used truck that I

used for about a year actively almost

climbing every second or every third day

so we could get a sample of this

yeah that's it this orange rope that I

brought is actually perfect for our

comparisons because it's exactly the

same rope as the one we already tested

the only difference is the color

at first we did the test without water

so that we could compare how much

stiffer old rope gets compared to the

new one and to my surprise the

difference was very minimal one note

here is that we selected the test sample

from the middle of the rope that part of

the Rope usually is the least damaged

but that's good to know that if your

ends of the Rope are damaged and you

chop them off the rest of the Rope

should perform really well

[Music]

yeah

oh it's bubbling much more than new

ropes yeah and yes old rope absorbed

more water however it still performed

better compared to the classic rope

being new treated rope soaked for five

minutes let's see how it how well it

served

[Laughter]

[Music]

we actually washed the Rope but you can

still see that the water which comes out

of it

is still grayish a little bit

coming out does it hurt so you want to

blend my washing machine

and this is what happened with the wet

old rope the first fall was actually

identical which is very nice and then

the subsequent folds again had an

increase in forces

and if we would compare all wet drops

this is what we get

and the only thing missing here that we

had no time to do would be to test old

classic robes

so yes treated robes do lose their water

repellent magic Over time however they

still perform better compared to the

classic ropes however there is still one

very interesting thing to know let's

look into water absorption graph again

notice that classic crops are almost

fully saturated after five minutes

however treated tropes even after 15

minutes still have a trend up so then

the question is what's the full

saturation point of treated ropes so I

asked Adriana to do these tests and here

are the results turns out that all the

ropes were trending to the same around

40 percent level so that means even if

your rope is dry treated and you put it

under water and you leave it there for

long enough

I don't know why would you do that but

if you would do that eventually all of

these tens of thousands of tiny

filaments in the Rope would act as

capillaries and the water would find its

way in and it would probably perform

similar to the Rope being not treated

now before some of you will become

hydrophobic let me add a couple of

things yes wet ropes are significantly

heavier which sucks when you're climbing

and they might wear down quicker both

from false and from abrasion which sucks

to your wallet also there is a theory

that They are thicker with swell from

water

let's see

I soaked this rope for a few hours this

is supposed to be 9.8 rope and I'm

measuring

11.3 let's see the wet spot

okay

so I don't see any difference at least

on this rope which is worn out and it's

already thicker when it's nominal value

yeah so I didn't want to leave my fellow

climbers hanging like that so the next

day I took a bunch of different used

ropes soaked them and measured the

thickness and what I found out is that

indeed some of the robes did got thicker

like the green decathlon rope for

example however other ropes did not

change in diameter next I tested how

smooth the ropes run through belaying

devices and here my findings were mixed

again some of the ropes got sticky they

became harder to pull through belaying

device and more likely to lock the blank

device however other ropes got the

opposite result they became more

slippery as if water would lubricate the

billeting device so yes the laying does

change with water however it's unclear

how how the change will affect Europe

and about those other things well

honestly it's unlikely that you will

climb in such a wet conditions long

enough to even have those problems so if

your rope got a bit wet well try it but

if I would be going to cold wet ice

climbing places where people die

um yeah maybe having a treated rope

reduces the chance of dying this is so

hard she put I mean I don't know just

like being in a snowy or icy environment

it's recommended to have the dry

treatment because it's just an extra

safety buffer yeah there is one route in

Spain which crosses a waterfall in

multi-pitch

yeah I mean also if you're climb in very

humid conditions it's Thailand

we go there it's really humid and dry

rope makes sense

interesting so the little details shall

we go to Thailand to do some science

research trip

all right if you found this video

interesting I made the playlist for you

where I was nerding with Mammoth

Engineers on different topics very

interesting topics so thank you Mahmoud

for letting me to periodically come over

and play with your toys and thank you

Adriana for all their rope chemistry

explanations and thank you for watching

you in the next one