UKH

Base jumping - minimum height needed?

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This issue came up in this thread https://www.ukhillwalking.com/forums/crag_access/access_restriction_and_possible_tom_cruise_sighting_at_darlton_quarry-734075 after Cragtyke reported watching people base jump the wall on the left as you walk into Goddard's Quarry at Stoney Middleton. Cragtyke said they jumped close to the route Sheffield Tape Archive (6a+) which the Rockfax App has down as 28 mtrs. So I'm sure there are a few more metres to the very top of the crag, but it can't be much higher than 35 mtrs. This is obviously enough for a modern BASE canopy to deploy, I really didn't realise that you could base jump such (relatively low) heights. Does anyone know what the minimum height is? How can the canopies deploy so quickly?

 profitofdoom 27 Apr 2021
In reply to TobyA:

It depends how much you want to avoid dying. Some base jumpers will jump from 100 feet with special gear. Skydivers will always open at a minimum of 2000 feet and that's the latest, because they want time to deploy the reserve if anything goes wrong

2
 mondite 27 Apr 2021
In reply to TobyA:

I guess if you are low enough then the chute has less work to do? That does seem low though given that the "official" minimum one is 29m and didnt count a slope underneath.

 wintertree 27 Apr 2021
In reply to TobyA:

When I saw the thread you linked, I did wonder how much difference ridge lift from the wind at a quarry could make.

In vaguely related news, we're months away from the 30th anniversary of the release of Point Break. 

 Carless 27 Apr 2021
In reply to TobyA:

Ever hear about the one in St Paul's in London?

New low altitude record of 31m in 1990

https://basejumpingcouk.wordpress.com/base-jumping-inside-saint-pauls-cathedral/

 Lankyman 27 Apr 2021
In reply to profitofdoom:

I think it could be worked out by trial and error? Maybe the odd broken leg or neck though.

In reply to TobyA:

Dunno but I saw a couple of guys base jumping Cheddar. Chutes opened about half way down.

 LastBoyScout 27 Apr 2021
In reply to TobyA:

Number of differences between BASE and skydive rigs for low altitude jumps.

In the case of the Westminster Cathedral jump, he had a buddy hold the pilot 'chute, so a virtual static line jump, so you'd do that and probably also ditch the slider, which would usually slow down the opening at terminal velocity, but you wouldn't be going that fast on such a low jump.

I've never packed a BASE canopy, but there are ways of folding the leading edge to slow the opening of a freefall deployment - someone I used to jump with used to pack one rig a certain way, or he'd be talking in a high voice on landing - so you wouldn't do those. Material and age can be a factor, too - a new rig in zero porosity fabric would open a lot faster than an older rig that's getting porous. You might also jump a smaller canopy than usual, which takes less time to inflate.

If it all goes wrong, though, you've got no time at all to consider options.

In reply to :

I'm currently designing a new chute using the technology from pop up tents, and using the gyroscopes in your phone to trigger deployment on descent (yes, of course it is has an app, iPhone only for now).

We are aiming to bridge the gap between normal base jumping and highball bouldering - it should be just the ticket for evening solo sessions on the grit.

My main testers are unavailable after some teething problems - I'm looking for some volunteers to give me some feedback. 

In reply to TobyA:

local paper is pissing itself with this movie shoot, didn’t get this worked up when Dead mans shoes was shot 😁

Seriously though, shouldn’t the franchise be renamed to Mission Possible? so far, every mission has been possible so why continue with this non sense? Anyhoo, if BASE continues to develop fast opening canopies, TPS could well be downgraded to HS (with BASE) There, i said it.

In reply to TobyA:

there's a video of someone base jumping of ilam rock. think hes called dan harker on instagram

In reply to Carless:

That photo even made it into High magazine, didn't have as much background as your link so thank you

 Tom V 27 Apr 2021
In reply to Dan Arkle:

I think I'd be asking for advice from the people at Martin-Baker.

 Mr Lopez 27 Apr 2021
In reply to TobyA:

Not sure what the lowest stands at the moment, but it's ridculously low. Probably around the 25m mark or a smidge under if landing gracefully is a requirement. Less if there's a talus underneath giving the canopy room to get flying.

Other than the canopy's design (made by magical elves with unicorn threads and perfected over centuries) the canopies deploy that quick because in low jumps it is 'attached' to an anchor up top with a break cord, so that the deployment is done via that static line which breaks once everything is out, stretched and loaded. At that point the canopy 'just' needs to pressurize and there's where the magical elves come in.

 wintertree 27 Apr 2021
In reply to Dan Arkle:

Your post may be a tad whimsical but it got me wondering...  

It takes time for a ram air canopy to become inflated and function as a lifting airfoil.  Could this be sped up by having chemical gas generators distributed throughout the enclosed volume?  Some system triggered by the pseudo-static line (created by the accomplish holding the pilot chute) that mixes a sufficient quantity of liquid acid and powdered base, to near instantly inflate the wing?  

Edit: The few skydivers I know would be rightly aghast at the idea of putting chemicals in their canopies.  But it might have some traction for a one-shot attempt at lowering the BASE record...

Last week the kitchen sink blocked and I couldn’t find the plunger.  I bailed it out, suctioned a small anmount of fluid from the trap, poured in a load of bicarbonate of soda, then poured in some boiling vinegar and rapidly slammed the plug in, holding it down forcibly.  After a few violent noises, the blockage was gone.  It’s amazing how much gas you can produce in no time this way....

Funny that this post came up now, this last week my mind’s been drifting back to a noddy parawing flight I did 30 years ago towed behind a speedboat, and I’ve been thinking about parasailing as a new pursuit.

Post edited at 22:28
1
In reply to Mr Lopez:

Cheers - interesting.

Would you agree that over the last decade the climbing world and the base world seem to separated quite a lot? I've read Tim Emmett writing about how he just seemed to be going to funerals regularly of base jumping friends and that's why he stopped. Houlding doesn't seem to be doing it at all (?) or much these days. Then quite a few high profile deaths among American climber/BASE jumpers seems to have taken the shine off it there as well. I know that Jottnar got loads of coverage sponsoring the canopies of those guys who were jumping off mountains round Scotland two winters ago - that footage went global in a big way. But otherwise it seems either less climbers are base jumping or if they are, they keep more quiet about it than in the past. 

1
 waitout 27 Apr 2021
In reply to TobyA:

I recall Dean Potter saying when he was going to 'free base' the Eiger that so long as he didn't fall in the first 100ft he should be OK.

 Mental.

 Mr Lopez 28 Apr 2021
In reply to TobyA:

Not particularly no. I think it's more the case that base jumping went back underground, not in the way of keeping it secret, but more into the not being used for publicity or marketing/self-promotion purposes. Very few people are trying to get publicity/fame/free shoes by putting videos out there now. It's just not sustainable and the sport has matured to realise that.

There was a honeymoon phase when it was all over youtube and people thought it was all fun and games but reality hit back hard with a few punishing seasons and most people came to the conclusion that if you are going to be doing something so stupid you might as well do it for yourself, for the experience or for the company rather than doing it for a few stickers and a t-shirt with a logo on it or £300 from the Daily Mail. People go through a similar honeymoon phase and when that wears off or you get a wake up call you have a thought about your life choices and make a call. Plenty people decide to quit. Plenty keep doing it in a more subdued manner.

That said, that mainly applies to mountain stuff. The type of low jumps as per the thread where never big on publicity or major accidents and it's almost a different 'sport' altogether.to be fair.

Post edited at 00:36
 Baron Weasel 28 Apr 2021
In reply to TobyA:

A friend who helps base jumpers with access told me a modern canopy opens opens in 85 feet with the sliders down and that 105 feet is the minimum jump height allowing 20 feet canopy flight. This was a  few years ago and may have changed though. 

Sounds like putting a needle in your veins to me!

 Big Bruva 28 Apr 2021
In reply to TobyA:

> Does anyone know what the minimum height is? How can the canopies deploy so quickly?

Military parachute training towers are sometimes little more than 30m high, and they're used by beginners. With a fixed line, a parachute can pratically open within the length of its lines. 

Post edited at 06:33
In reply to wintertree:

Or how about the gas producing modules in car air-bags. You could use these to inflate an inflatable tent frame type construction and then fill it with gas ready to glide. 

In reply to wintertree:

Either gas inflation or fans are used in avalanche airbag inflations currently - I think they go up not quite instantly but very fast. No idea, but I guess that's sort the same idea.

 LastBoyScout 28 Apr 2021
In reply to Big Bruva:

> Military parachute training towers are sometimes little more than 30m high, and they're used by beginners. With a fixed line, a parachute can practically open within the length of its lines. 

But most military parachuting uses round canopies, which I think is what you're referring to - you're only going to get to squares for special forces and HALO jumps.

 wintertree 28 Apr 2021
In reply to LastBoyScout:

Quite.  They’re totally different devices operating on totally different principles.  One is a drag device and the other is a ram air inflated wing.  Skydivers don’t tend to learn canopy flying and landing from training towers because on the whole they don’t want to die.  I’m not aware in fact of anywhere where people learn canopy flying from a static tower.  

 Mr Lopez 28 Apr 2021
In reply to Baron Weasel:

> A friend who helps base jumpers with access told me a modern canopy opens opens in 85 feet with the sliders down and that 105 feet is the minimum jump height allowing 20 feet canopy flight. This was a  few years ago and may have changed though. 

Yes that's about right. Some people so inclined take it a bit lower with more specialised set ups and techniques, but that's pretty rare.

Here's a good video showing roughly how it works youtube.com/watch?v=vQ3mlMduFDw&

 r0b 28 Apr 2021
In reply to TobyA:

I saw a video of a low base jump recently (can't find it now unfortunately) where the canopy was already open dangling off the cliff below them, then they jumped over the canopy and it inflated as their weight came on it. 

 Big Bruva 28 Apr 2021
In reply to LastBoyScout:

You're quite right in thinking that round and RAM parachutes work on very different principles. My point was more to do with the deployment mechanism, which was part of the OP's original question. If the jump in question was only around 30m high then it could only have been made with a static line

 Big Bruva 28 Apr 2021
In reply to r0b:

> I saw a video of a low base jump recently (can't find it now unfortunately) where the canopy was already open dangling off the cliff below them, then they jumped over the canopy and it inflated as their weight came on it. 

Can't have been super low. If you have the canopy hanging beneath you, you've already eaten up a few metres, then it has to flip the right way up before finally inflating. That whole process requires a considerable amount of height

 Big Bruva 28 Apr 2021
In reply to Baron Weasel:

> A friend who helps base jumpers with access told me a modern canopy opens opens in 85 feet with the sliders down and that 105 feet is the minimum jump height allowing 20 feet canopy flight. This was a  few years ago and may have changed though.

That's bit like saying if you fall from 15 feet above a bolt you will stop 45 ft lower because there will be a 30 foot initial fall + 10 ft of slack + 5 ft of stretch. In reality there are a lot of variables which can't be calculated with precision. 

Post edited at 11:31
 Big Bruva 28 Apr 2021
In reply to wintertree:

> It takes time for a ram air canopy to become inflated and function as a lifting airfoil.  Could this be sped up by having chemical gas generators distributed throughout the enclosed volume?  

Parachute manufacturers have found a simpler solution. Many Base canopies have flaps in the lower skin which allow air to enter from below. When the canopy starts flying forwards, the air coming in from the front closes off the flaps.

As well as allowing the canopy to inflate faster initially, it also allows it to stay inflated if the jumper flies into the wall and interrupts the flow of air. 

Post edited at 12:43
 Baron Weasel 28 Apr 2021
In reply to r0b:

> I saw a video of a low base jump recently (can't find it now unfortunately) where the canopy was already open dangling off the cliff below them, then they jumped over the canopy and it inflated as their weight came on it. 

That's called a McConky flip after Shane McConky.

 Billhook 28 Apr 2021
In reply to Dan Arkle:

> I'm currently designing a new chute using the technology from pop up tents,

> My main testers are unavailable after some teething problems - I'm looking for some volunteers to give me some feedback. 

Are any of your testers still alive?  I think I'd leave the bit about teething problems out from your next ad for volunteers.

7
 r0b 29 Apr 2021
In reply to r0b:

Found it, not as low as I remembered actually 

https://www.instagram.com/p/CNSlFHaHR6t/?igshid=126k3fmek8523

 Hooo 29 Apr 2021
In reply to Billhook:

I think they just whooshed over your head

 Carless 29 Apr 2021
In reply to r0b:

Have to admit to knowing nothing about base but the possibilities of that going wrong look quite high

1
 DerwentDiluted 29 Apr 2021
In reply to TobyA:

Pffffft. Lightweights. I've taken BASE jumping to the ultimate extreme. I jumped off the kerb outside my house.... without a parachute! How mad am I?  

 Mr Lopez 29 Apr 2021
In reply to TobyA:

This was shared today on FB.

85ft jump. In 1925... https://reuters.screenocean.com/record/451478

Post edited at 17:30
 Martin Wood 29 Apr 2021
In reply to TobyA:

> Does anyone know what the minimum height is? 

In a word, sufficient?

In reply to TobyA:

Is Raven crag Langdale high enough u recon? might have a go tomorrow 

In reply to C coldwell-storry:

> Is Raven crag Langdale high enough u recon? might have a go tomorrow 

https://www.bbc.co.uk/news/uk-england-derbyshire-56963442

It wasn't you was it, C Coldwell-storry?

 Martin W 03 May 2021
In reply to CantClimbTom:

"train bridge" FFS.  What is the BBC coming to?

Post edited at 08:55
In reply to TobyA:

The railway film set at Goddard's got base jumped at the weekend - I'm impressed. 

In reply to Dan Arkle:

Yeah saw that (it's Darlton not Goddard's though ). Climbed a route in Goddard's yesterday, and we were looking at the wall that got jumped - it's big but it's not that big! Just crazy! I guess the Mission Impossible jump is really mission quite possible in comparison. Higher and cleaner - more security about though!


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