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I had this idea pop into my head this morning while getting ready for work. I’m not sure how my brain was even functioning at 5:15am but...

My idea addresses being able to clear a slider-up line over. I hope I can explain this properly.

Rather than having one lower brake line you would have two. One would be your SBS length with just a loop at the end (we’ll call this part 1). The loop at the end would be used as the finger trap. It would not be attached to the toggle in any way (other than through the loop at the end when stowed) so when you release the brake this line would come off and flap in the breeze. This line would go through the slider grommets and the keeper ring. This line is what would drive the slider down and is what would hold the appropriate opening SBS.

The second lower brake line (part 2) would be just like your standard slider down setup. You would stow the brakes the same way except you might not need to do the LRT method because there would be no force on this line during opening. This line would not run through the slider grommet or the keeper ring. The only difference is that you would need to add a finger trap to make the line looser (only a couple of inches) or you might be able to just use your SBS on this line instead. The reason for making this line looser is to prevent the two lines from trapping the slider in between them.

When the brakes are stowed you would have to put the toggle through two finger traps for slider up, one on each line (part 1 and part 2). For slider down you would put the toggle through the finger trap of line part 2 and the “L” part of the LRT for line part 1. If you had a line over (slider up) all you would have to do to clear it is just release the stowed brakes, just like you would slider down.

There are a few benefits to this setup. First and foremost is the easy ability to clear a slider up line over while using standard cloth toggles. Also I think it would be easier to grab “Big Grab” toggles and pull than it would be to use WLO toggles and have to find the little tab to release the line, especially if the canopy is spinning. I must admit I’ve never had to do it or try it so I don’t know. Second of all, you would never have to physically move your toggles on the brake lines up or down because they would be the same whether you where jumping slider up or down. Lastly, flying slider up or down would be the same in the aspect that the brake lines (part 2) would never go through the slider grommets.

There are downsides to this as well. A more complicated system, slack in the part 2 brake line may interfere or snag on something during deployment. Although I would only make it 2-3 inches longer, I’m not sure. Also if you were to blow a toggle on opening while jumping slider up there is a possibility that the toggle could get wrapped around the slider before it descends and could hold the slider up. But I’m thinking that a blown toggle would be a little less likely with this setup because you would have to put the toggle through 2 finger traps instead of just one, a little more friction. This in turn could also be a downside in the fact that because of the friction, releasing the toggle may be harder or it may be easier to have a hang-up.

I know a slider-up line over can be addressed by using WLO toggles so maybe I'm beating a dead horse with this but I thought I'd post this just to share and maybe start a bit of a technical discussion I suppose. Do you have any ideas, comments, suggestions, or anything else about this setup?

Edit to change DBS to SBS.

Russel,

It's a great idea but the free line (part 1) the one without the toggle that goes through the slider has to be your SBS not the DBS to work properly. If you use part 1 as your DBS then you end up using it on slider up deplyoment.

Am I reading this right?

PS:

The noromal slider down line will have the DBS and the Super SBS. When doing slider down you just need this one and use the DBS.

When doing slider up you add the extra line with the normal SBS at the very end, route it through the slider, ring, and stow it with the Super SBS of the toggle line.

Interesting idea. When the Multi first came out, I gather a lot of people were worried about a "triangle of death", which (such is my understanding) related to fabric (or someting else vital) getting trapped in the closed loops between the various multi attachments.

Now, closed loops in the lines aren't anthing new above the cascades. It might be worth considering whether closed loops below the cascades would be any more problematic.

I'll rig it up tonight (with the part 1 your SBS) and check it out on few skydives.

Yes you are right, my mistake. But I suppose when jumping slider down you could use either part 1 or part 2 for the DBS. It just depends how many finger traps you want on each line part. I will edit the first post appropriately.

Really? Cool!! I didn't expect anyone to actually do this. I'd be very interested to hear how it goes.

Edited for spelling

Here is a pic of the set up called the "Russel Line".

The back line is the part 1 (the slider up line) that is routed through the slider and ring.

Note the Super SBS on the toggle line, and also the slider tailgate, , recommended for this set up (just trap all the normal tailgate lines + the slider up line )

I will skydive the system and post the results.

What happens if you have a premature brake fire??? Could the free line wrap up in the slider??? Just food for thought ??

Yeah, I mentioned that as one of the bad points to the set up.

Excerpt from first post. "...I’m thinking that a blown toggle would be a little less likely with this setup because you would have to put the toggle through 2 finger traps instead of just one, a little more friction. This in turn could also be a downside in the fact that because of the friction, releasing the toggle may be harder or it may be easier to have a hang-up."

How confusing was it to set the brakes with all those lines? Did you add the slidergate specifically for this setup or do you always use one?

Thanks for the pic!

Edit to add: Good luck on the jump! Is your reserve in date!?!

There is a small problem in the set up: The normal toggle line has to go through the slider because the slack is not enough to travel all way up and then down again...that might be a problem and could defeat the whole purpose...unless a new set of cascade is made...more thinking and rigging are needed...stay tuned...

No Russel, I have been using the slider tailgate for quite sometime.

As for the reserve...I'll pack it in my CRW rig that has a Swift reserve (5 cell) so a cutway is going to be interesting

My First reserve ride was on a swift. A borrowed rig I had to count the cells like 3 times after I looked at it with confusion. thinking "this is awfly square and what the...

Normal toggle line... Do you mean the red brake line in the picture? If so then why does that have to go through the slider and not the black one? And what line has to go up and down?

Russel,

The cascade of the brake line ends up below the slider when it's all the way up. So if you have the black line pluged into the end of the cascade and routed it through the slider and ring then the normal toggle line (the red one) either has to go through the slider like the black one or if you want it to be outside the slider once the canopy is open, it has to have enough slack to go up from the cascade to the slider, into the grommet (oppisite way), and back down to the riser. A bit wordy, isn't it?

The solution I thought thus far is to have two separate brake line sets...

Would you need the full brake line set just to drive the slider? I've got no idea which of those lines really put force on the slider. All of them? Just some? Obviously below the cascade it's only one, but for the angle to work out do you need that one to come to some intermediate point between the attachments?

Oh, I get it now. Hmm...hadn't thought of that.

I've seen all over people saying it's the brake lines that force the slider down. Why is that? I've seen slider up jumps with the brakes routed outside the slider and it came down. I would think it's all the lines that force the slider down. Why specifically the brake lines more than the others? With nose first inflation the front should start to be driven down before any other part right?

Because they are further outside?

Wouldn't they be further back and outside. the outside A, B, C and D are also pushing down the slider, right?

I'm not going to pretend to be an expert on this, but I've heard from a few knowledgeable people that your brakelines takes most of the stress of deployment.

This makes sense, as even in shallow brakes, you have pulled the tail down far enough to increase the tension on the brakelines significantly, and this increase in tension is balanced out by a decrease in tension in the nearer linesets (D and maybe C's too).

Couple this with the fact that the brakelines sit right at the back of your canopy and therefore enjoy the maximum 'leverage' advantage and it makes sense that they will be most effective at driving the slider down.

This means the slider should/might still come down even with the brakelines routed outside it, it just won't come down as effectively as when the brakelines are inside.

anyone please feel free to correct me if I have this wrong

cya
sam

Hey Nick

what are the things circled in blue in the attached pic?

at first I thought, slider tie-downs for slider down jumps, but aren't they supposed to be on the front risers?

just curious

thanks
sam

The slider is brought down mainly by all the outside lines (A, B, C and D the latter in case on non-elliptical canopies) plus the cascades of the brake lines hence the greatest wear on the outside lines.

I've seen people jumping slider up with the brakes routed slider down: the slider did come down. I would not do it myself but...

No, the center A lines take the most impact that's why on some reserves the center A and B lines are non-cascaded.


They are slider tie-downs. On the front risers I use the bumpers to trap the grommets but on the rears to avoid possible "entrapments" with the toggles I just set the grommets on top of the bumpers and use the tie downs...

I have done it from airplanes. I found the slider noticeably slowed.

Ok then...for jumps you would normally do with a fine mesh slider, why don't you do it with a large mesh slider with the brake lines routed outside the grommets and keeper rings. Used with those risers I had made (blow free risers? [pics]) this might give you the same opening speed with the easy ability to clear line overs. Or is there a huge difference between brake lines in and out the slider grommets, bigger than the difference between large mesh and small mesh? Anyone?

Lots of questions very little empirical data

As for fine vs. large mesh I like fine mesh better and I know few other people who don't use large mesh anymore. Apparently fine mesh gives more consistent openings but again data is limited. That's the big problem with BASE, not much data and too many confounding variables.

On the other hand, brake lines are usually made with a heavier-guage line. I expect Poynter has something to say about it (and that the truth of the matter sides with you, since I'm just making this stuff up). Anyway, with respect to bringing the slider down, I wouldn't expect the center A lines to be particularly relevant, since they're in the center.

Parachute Lab does some really cool simulations, including some on ram-air canopies. Here's the tension along the warp direction on the bottom skin, slider-reefed. It's might be hard to make out -- the nose is to the left, and we're looking at a cutaway view of the right side of the canopy. Note that the forces are generally strongest near the tail. The parent page is a lot of fun for those with any inclination toward simulations.

[Cue "think less, jump more" in 3... 2... 1...]

The initial load is taken most by the center A lines. Also the brake lines are usually thicker (not the case in skydivig canopies for the most part) not because they have to take more load but because of the additional wear from the grommets and rings in the case of slider up.

Who said anythign about A lines and slider descent?


Do you know the time of the inflation of the simulation pic?

I have this habit of assuming that a reply is in the context of the message it replies to. I'm wierd like that.




No idea. But it looks to me like it's either very late (in which case there'd be no point in mentioning that it's slider-reefed), or a static simulation with the slider fixed at some point on the lines...

Interesting...Do you know any details on the model?

Canopy opening (RAM air) is one of the toughest problems in fluid dynamics...

I thought Vertigo (Apex now I guess) invented the WLO toggle for slider up line overs. Restricting the tail with a tailgate slider up, so long as it doesn't hangup, should restrict the brake lines to the extent should very rarely result in a lineover.

Not certain. From the other pics, it's 7-cell. If I recall correctly, they make reference to "Parafoil" at one point a lot of people seem to use that as a generic term from ram-air canopies.