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The post on the kill-line PC got me thinking. Can anyone give any thoughts on why BASE canopies aren't designed with retractable bridles similar to CRW-specific canopies? Was this setup ever tested in the BASE environment, and, if so, why was it rejected?

What would be the interest of such a system?
I can see it in CRW but in BASE it would just increase the complexity of the system and increase the risks linked to it.

People have had to cutaway in CRW after problems linked to the briddle and PC, often in tow..

Julien.

Like this? (originally posted in this thread in the crw forum)

It looks like a lot of added complexity for not a lot of gain.

Gus

I can't think of a lot of reasons to have this setup. What advantages do you see for BASE?

Friend jumps something similar as alternative to multi. Two rings, both on rib. Bridle is attached to front one and slide through rear one (more exactly rigger added 50cm or so of dacron line to bridle and this line slides in rings).

Tom

the more I read this forum and the longer I base, the more I realize how some people think about certain questions such as the kill line pc or the retractable bridles when asked online.

I think you once said that many of these ideas that are posted have already been thought of and there usually are reasons why they are not used.

I do think it is good though that people are continuing to think and explore, they might find or create something that is very useful to the base community.

FWIW
Le Roy

I can see less drag for better canopy performance but I hardly think it's worth the extra complexity.

If you're looking for less drag why not go with a standard reserve free bag set-up? This is not the best idea either because it adds the complexity of a bag and the chance for a baglock Plus you loose your pc and free bag on all of your jumps!

Jason

Althouigh rare, retraction systems on CRW canopies can get jammed up which will ruin your day on a BASE jump. Not good.

If you want a way to get more drive without using a bag, I use a pilot chute killer on my CRW rig that has a #8 grommet (I believe) on the bridle attached to a round piece of fabric (similar to how a dbag slides up the bridle and covers up the pc). This is packed with the canopy and slides up after deployment. I am sure a serach on the CRW forum can provide a photo.

Having what amounts to a sea anchor trailing behind the canopy will have a definite impact on the canopy's performance. Whether that has any advantages for BASE, I have to leave to those with the experience to comment. I was just wondering if the complexities of this system had ever been considered and tested (and then rejected) in the BASE environment.

The danger with this type of system is an unretracted bridle. I've flown 2 types of retractable designs, the 4 ring design used by Aerodyne and the 3 ring design used by PD. I've had unacceptable incidences of unretracted bridles on the 4 ring design which can be difficult to clear and even more difficult to fly and land if not cleared, and I would definitely consider this design NOT worth the risk. I've never had an unretracted bridle on the 3 ring design (either by luck or just one less component to ruin one's day). That's not to say that someone couldn't have one by misrouting the bridle, in fact, I've seen that result from a misinstalled bridle on the 3 ring design.

The 3 ring design seems to be very rugged and reliable, but I don't think I have sufficient experience to be able to make a statistically significant determination of it's reliability. I was wondering if there had ever been any studies by the gear manufactureres which showed this system to present an unacceptable risk.

Bob Lyon helped me with my design, but I think part of the effectiveness of the kill cone is the retracting bridle pushing it over the PC.

>>and, if so, why was it rejected?<<

When low altitude jumping began in earnest (early 1980s) BASE jumpers realized existing skydiving equipment is too complicated for the task. This was the nexus that produced the single canopy harness and container system that later became the Velcro shrivel flap closed BASE rig. The sport then faced the question did we really want to bet the farm on one parachute? Outsiders said we're crazy and we hear experienced skydivers saying things like, "I've made a thousand skydives with three reserve rides, heck, if I BASE jumped I'd be dead three times . . ." It's actually something you still hear at the drop zone today and it's an issue every skydiver turned BASE jumper has to reconcile.

However, it wasn't long before we realized why the malfunction rate at the drop zone is higher than the malfunction rate down at the Flat Iron Building. Skydiving rigs are designed to operate in a wider range of conditions. Skydiving rigs need to operate at terminal freefall speeds and be secure during tightly packed exits and freefall funnels. Modern skydiving rigs are also a product of decades of "improvement" as manufacturers raced to produce the "hot" rig. This added layer upon layer of further complication. None of this applied to BASE rigs. All is well at the drop zone as the saving grace, the thing that allowed for items like collapsible pilot chutes and the idea that line twists are now an acceptable malfunction that requires a cutaway, is skydivers carry a reserve canopy.

The reserve allows for the rig to be complicated, but the biggest bugaboo is it allows skydivers to jump with a mentality that allows slam pack jobs, deferred maintenance, and not so up to par skills. They have two shots at it and this allows even the most un-astute among us to survive. So you can turn the skydiving argument around by saying, "I've made a thousand BASE jumps, and if I jumped skydiving gear, I'd be dead three times over."

The two canopy concept is so ingrained in skydiving you often hear new jumpers say, "Well if two canopies are good, wouldn't three be better?" Whenever I hear this, and think of how it would apply to BASE, I remember John at Bridge Day 1986. He jumped with three canopies, a skydiving main, reserve, and tersh. And he could not get any of them to work. The only reason he survived impact into the river is he's trailing so much garbage.

So over tens of thousands of BASE jumps we have proved the single canopy system is viable. We even managed to keep the idea intact after we started asking more from our BASE gear when big wall jumping became an everyday practice. We added pins and stowed pilot chutes, but we did it in a way that's simple and works with the same reliability of Velcro and hand held pilot chutes. And without knocking those who are drop zone bound, BASE jumpers are generally more skilled in keeping themselves alive. There are very few "lucky" BASE jumpers who continue to stay lucky, while there are thousands of "lucky" skydivers who get away with it over and over again.

The point to all this is the single canopy system works as long as we continue to understand why it works. If we add Capewells (sorry Jaap, I couldn't resist) or more so collapsible pilot chutes we are adding a layer of complication the single parachute system can't support. Sure, in very capable hands these things could work over the long haul, but not across the board for every BASE jumper. It is quite remarkable how well our system of longer bridles and larger pilot chutes do work. Of the few pilot chute related BASE deaths that have occurred most can be attributed to using skydiving gear. The only exceptions are the last potato fatality (bridle length and being in over his head "may" have been factors) and the fellow at the cliff that neglected to secure the BASE pilot chute to his canopy.

A more direct answer to the collapsible pilot chute thing, besides the obvious fact un-cocked ones kill in single parachute systems, is this. Collapsible pilot chutes are invented to address issues that don’t, in a very large way, affect the type of canopies we jump. To me using a collapsible on a large BASE canopy is as questionable as jumping a large BASE pilot chute on your Stiletto . . . However, I will give into the idea a non- collapsible pilot chute does degrade a large BASE canopy's performance somewhat, but there is no current collapsible system that's fool proof enough to make their use rational in BASE.

We are approaching, we all realize, a time when BASE starts are up to an all time high. It is more important than ever that we reinforce what works, and why it works, on a new generation who may not have the patience earlier generations exhibited. I had a recent discussion with a BASE jumper who said the earlier generations were the "daredevils." But, I know that mentality is more in evidence today than ever before. Jumpers are doing difficult things much earlier in their carriers, and they are flying longer and faster, than did past BASE jumpers.

The only real consideration we have made to the newest among us is the implementation of BASE first jump courses. I'm proud of the way we made it "stupid" to bypass this training with making it a "regulation." But, it's possible I'm in the last generation that feels an obligation to pass on what I learned because someone(s) did it for me. The double edge sword of "paid for" courses is the fellow that dropped a thousand dollars for his training may not feel the same obligation to freely pass it on.
The catch-22 we need to be careful of is needing to "be there" for this next generation without stifling what could be the "next" big improvement in BASE gear or technique.

The next twenty years in BASE jumping will define the next fifty. It's going to challenge us in ways we don’t even comprehend yet. I think the most interesting and thrilling days of BASE are still ahead of us. Our problems, our teething pains really, with things like education, training, wing suits, and access will solve themselves in time.

I hope I'm "lucky" enough to be around to see it . . .

NickD
BASE 194

<<If you're looking for less drag why not go with a standard reserve free bag set-up?<<

With the snatch force of BASE sized pilot chute "bag strip" is what would worry me . . .

NickD
BASE 194

I know at least two guys that give free courses and end up sending students into the world that realize they have a duty to try and give something back to the sport.

The wheel will keep on spinning...

i did not take a course.
hopefully someday i can give the new guy what was given to me.
or take from the new guy what was taken from me.
(sleepless nights crewing, sitting in the getaway car, etc...)

I dont think there is another way.
lets ride.

I think he was referring to the student, not the instructor.

I don't want to get into a huge paid vs non-paid instructor argument... we've been down that road before... but I think the vast majority of people who offer courses, paid and unpaid, offer them because they care very much for the sport and the people who participate in it. My only comment on FJCs would be the importance of referring students to their respective locals when they finish. I know Tom does. I'm not aware of any jumpers in my vicinity that have taken any of the other FJCs so I really can't speak for them.

What I've sort of noticed trend-wise is this... yes there are a lot of people who are now wanting to get into the sport. A lot of these folks are people who have no real interest in being students of the sport... no interest in history, gear, etc. They just want to be taught how to huck themselves off of something so they can, for whatever motivation, call themselves a BASE jumper.

In my own personal experience, these types don't last very long in the sport. The serious BASE jumpers don't take these folks seriously because they don't take the sport seriously. So they sort of drift out of the scene.

The ones that remain, and the ones that I've met at the various places I've visited, are serious, inquisitive and passionate about the sport. Of course there are degrees, but with only maybe a couple exceptions most of the jumpers I've met with 50+ jumps or so seem to have their head screwed on pretty straight.

One thing I really like to see is when I run into BASE jumpers who were taught by someone that I taught. And those who were taught by someone who was taught by someone who was taught by me, etc. It goes back ten years in some cases. Kind of like a family tree. Ive had students of my students call me grandfather and greatgrandfather as I guess they see it that way. Its neat to see how the tree grows.

That's what I meant as well: "and end up sending students into the world that realize they have a duty to try and give something back to the sport."

Most of their students that I have met feel the obligation they have to the sport. So I don't think Nick has to worry quite yet.

I mentioned the use of a sleeve in another thread. The bridle goes through a grommet in the sleeve and attaches to the canopy (like with a d-bag). It can be designed to fit the pack tray and the lines stow similar to a free-bag. I think the biggest benefit for using it is at terminal airspeeds as it preserves the pack job until full line-stretch, which is when the canopy is extracted from the sleeve. I can see how this may reduce the chance of a tension knot or maybe even a line-over. Then again, it is one more component to the system. The chance of a bag-lock would be similar to having a bag-lock with a skydiving reserve.

The other benefit is that the sleeve slides down the bridle to the PC and envelops the PC…..less drag.

I personally dont use a sleeve. Not because I dont like the concept, but because Ive been satisfied without one. I do appreciate simplicity in my BASE gear.

Ah gotcha, I read your comment wrong. My bad.

Why do you think (or do you think that) we need Retractable bridles?

to avoid it catching somthing? would you have enough time to retract it and avoid the object, make the landing area.

The very thing that you are suggesting might be the thing that kills "you." Then again, BASE can kill ya...

This reminds me of the trick of grabbing someone's retractable pilot chute and pulling it to collapse their canopy. If you had an object strike, and somehow the retractable got caught on the object, this might make a bad situation worse... It's unlikely, but I thought I'd put it out there anyway.

Michael

good point Michael!
however unlikely it is, its very possible.