Slidergate

[mknutson]

Slidergate: Some people have sewn a regular rubber band to the trailing edge of their slider and refer to this as a slidergate. This is not a slidergate.

Vertigo and Consolidated Rigging introduced the slidergate as as little loop on the trailing edge of the slider. The idea is to lark head a rubber band through it and then take a bight out of the steering lines and wrap the rubber band around it. Note that it’s just the steering lines, excluding the center C- and D-lines that you would put in a tailgate.



The main purpose of the slidergate is to help avoid line-overs, just as a tailgatesdo. However, many jumpers agree that with proper packing, the Reefing alone is sufficient to avoid line-overs on slider up jumps.

As of 2005, Vertigo continues to recommend using the slidergate on slider up jumps, in both their packing videos and by putting this loop on the sliders they sell.


Consolidated Rigging on the other hand, has discontinued the slidergate and no longer recommends it. Their theory is that the slidergate distorts the trim of the canopy during the opening sequence by pulling down more than necessary on the steering lines.


The Slider Tailgate (STG) on the other hand does not distort the trim of the canopy. This set up has been working well for some jumpers. To install a STG just sew a normal tailgate in the center of the trailing edge of the slider; you can bartack it or use a super tack with a surgeon knot followed by an over-head knot. Then just trap the normal tailgate line using the “normal” tailgate rubber band.

Johnny Utah:

The first time I heard of the "slider-gate" idea of attaching a tailgate onto the trailing edge of a slider was from Mark Hewitt in 1999. Mark and I were hanging out at a dropzone campground in Illinois and we got to talking about the different advancements in BASE gear through the last decade. I mentioned the tailgate and how much I liked the functionality of it. Out of nowhere Mark said something like, "We should put a tailgate on the trailing edge of the slider for slider-up jumps". One thing about Hewitt, he was a rigging genius. Back in those days I did the same thing as everyone else and just used a slider with nothing else as my reefing device for slider-up jumps. These days I like to use the masking tape for slider-up jumps if I have it available.

That would be cool if someone using this "slider-gate" would post what they think and what lines they include when setting it.

Hookit:

A similar version was used on skydiving canopies for years. A rubber band on the trailing edge of the slider was used to capture a bight of brake lines. The Airtimes Jonathon (and probably the short lived Tomcat) used it, other people/manufacturers used them as well.

I see no real disadvantages to using one on the slider. Being that I use tape or a tailgate on slider up jumps anyway, having one on the slider wouldn't matter to me.

Perceived pros and cons will probably include "I've used one for 100 jumps so far with out issue" . That enough would convince users of its benefit. Since I pretty much always use a tailgate or tape on slider up jumps, there really isn't much for me to comment on that either. It keeps working so I'll continue since in theory, it's safer than not using it.

Johnny Utah:

The rubberband on the slider technique has been around for ages. I used it on my para-foil back in the 80s.

You're correct that it is a way of reefing the brake lines. It not only holds the lines in the center (for a moment in time), it also shortens the brake lines even more than just the brake settings do. That's a nice advantage to reduce the chance of a line-over. For some reason though, I've never felt comfortable using it on BASE jumps. Maybe I just don't like creating a bunch of brake lines at my slider that then restricts the slider until it releases. But at the same time I use the main stow on every BASE jump (except a d-bag); but in my mind the main stow is cleaner and more bulletproof against hang-up... more so than multiple s-folds of just the brake lines. Of course I know the forces involved during opening will release a slider rubberband for sure. I guess I've just seen enough weird stuff happen to be a little paranoid about rigging and packing method on such low altitude deployments.

That's probably why I've never tried the "slider-gate". By the way, regardless of what others have tried to call the rubberband on the slider technique... that's not a slider-gate. That's a technique taken from skydiving. The slider-gate is a tail-gate sewn on the trailing edge of the slider.

...

Line-overs occur in the earliest stages of deployment right around and just after line-stretch. Theoretically I think reefing the steering lines more into the center even just for that brief moment in time can reduce the chance of a line over. However I do think the slider itself does a pretty good job of reefing the the steering lines, especially if the main stow is being used as well. (On higher airspeed jumps direct slider control is important to help the slider do it's job)

-BUT-

You make an excellent point about the slider starting to come down (with the slider-gate on it) before the slider-gate releases. Perhaps the slider could get in a weird position whereby the front grommets have gone down and the rear grommets are still up because the slider-gate is not sliding down smoothly. I don't think it's likely that this will cause the parachute to malfunction, but like we've all seen, weird stuff happens in the sport of parachuting.

In practical reality, the forces on the tail would easily open the slider-gate, but suppose you find yourself deploying this set up in really low airspeed. Also sometimes your deploying canopy gets some funky burble action off your body.

Here's another issue to consider if the slider-gate fails to open before the slider starts coming down. If the rubber-band was on the slider-gate too tight or the friction of the lines in the slider-gate caused the slider-gate to remain up as the slider started coming down, I wonder if the downward force of the slider could put slack in the bake lines below that point. If so, that would increase the chance of a tension-knot. Chances are, if a tension-knot did occur it may also cause a slider hang-up. (If a tension knot happens within a single line group, the slider may still come down)

For that reason I guess if the slider-gate was being used, one would want to put the rubber band on the very ends of it so that there is more room for the brake lines to slide up and down in it when it's set. 2 wraps might make more sense than 3. Also it would make sense to always make sure that you capture the lines above the slider grommets and never below the grommets.

I guess if I was using a slider-gate, I would prefer for it to release before the slider started coming down, but if there was a delay in it releasing, I would prefer for it to slide down with the slider and then release rather than stay up as the slider is trying to come down until it released.


To me the slider-gate complicates the slider-up configuration by adding one more element to the equation. I feel comfortable doing a neat packjob with just a slider, and if I have masking tape handy, even better. For the same reason I'm not a fan of the multi, I like to keep my set up simple and clean.

Still, it was cool to see how Mark brainstormed the idea.

Todo, add pictures of the slidergate.


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