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Only thing i know is they promote nose first inflation, and reduce the incidence of line over malfunctions. (i only know that because i read it in an article)

I have never seen one, How exactly do they work? anybody has a picture of one? why should amateur BASE jumpers jump with one in their rig?

The tailgate is a small piece of stiffened line, created by fingertrapping a piece of suspension line back into itself. It's perhaps 3 or 4 inches long. It's attached to a center C line by a fingertrapped bit of line, and is used to constrain a set of lines (usually the two center C lines, the two center D lines, and all the control lines), which promotes nose first inflation by allowing the unconstrained nose (lines) to inflate before the tailgate blows open, which then allows the tail to inflate.


I'll try to take some pictures, unless someone else beats me to it. There used to be some good diagrams on the Basic Research web site, but I'm unable to find them on the new Apex site. Does anyone know where they went?



To improve heading performance, promote nose first inflation, and probably most importantly inhibit line over malfunctions.

I'm not aware of any distinctions drawn by physics between amateur and professional jumpers, so it's likely that all BASE jumpers would find the tailgate useful.

I'm an amateur BASE jumper - I fall faster because I lack the Neo-like ability to warp the matrix and increase my loft. I've seen 808 do it...it's kinda cool.

Someone once compared my chiseled, sleek lines to the aerodynamic artistry of a pair of vise grips wrapped in redi-whip.

Oh...but I do use 3 wraps of masking tape on the tailgate lines in lieu thereof.

Tailgate

Here is a shot of what it looks like right before the tailgate lets go..............

Perfect picture.

:-)

hey! that's me! you bastard, way to post without my permission.

Hey, both you bastards, do you always use a tailgate on every jump? I've not heard of this. And don't you increase the likelyhood of a mal if it doesn't open?

Yes, on all slider down jumps.



If the tailgate fails to open, you are experiencing a malfunction, so the likelihood is 100%.


If this happens, it is almost always a result of two things:

1) The wrong rubber band. All of the cases I am aware of where a tailgate has hung up have used the wrong rubber band. Most of those cases used the old (black) rubber bands, which used to be sold by Roger Ponce under the brand name "skybands." These rubber bands were once recommended by the manufacturer, but are not any more.

2) The rubber band being tied onto the tailgate cord. This is usually done with the girth hitch or larkshead (two names for the same thing) know. If you tie the rubber band to the tailgate, it is very important to push the loops of rubber band outboard of the knot, so that they "roll" clear of the tailgate without encountering the extra bump of the knot, on which they can hang up. I know of one case in which a tailgate hung up that the rubber band was not tied to the tailgate (and in that case a very unusual and inappropriate rubber band was used).

In virtually every case I know of that a tailgate has hung up (all but one), both of these things were done--in other words a black rubber band was used, and it was tied onto the tailgate.

I prefer to use the regular (tan) tailgate rubber bands (they are basically the small stow bands from skydiving cut in half lengthwise), and not to tie them to my tailgate (basically accepting that I'll lose on every jump--I buy them in 5 pound bags).


The tailgate is really one of the fundamental pieces of modern BASE equipment, and has virtually (nothing is 100%) eliminated the line over from slider down BASE jumps. Prior to the invention of the tailgate, when most jumpers had no such reefing system (even then some jumpers used masking tape, which is still a good method), the incidence of line overs on slider down BASE jumps was probably around 1%. The good folks at Basic Research (now Apex), especially Anne Helliwell, deserve much credit for creating (and making standard) the tailgate, [noting that at the time Martin Tilley (now the owner of Asylum) was one of those folks].

Is there any known case of the "Blue Painter's Tape" hangup (too much tape) or lineover (too little tape)?

I am unaware of any cases of tape hangup, although I think that someone mentioned somewhere earlier on this forum that they'd found the tape to become much stronger when wet (?).

The tape is also less likely to hang up because it can be perfectly positioned.

A tailgate ought to be placed as high as possible up the lines, such that it is just below the line attachment tabs. Obviously, when you switch brake settings around, this means you ought to move the tailgate as well (because the change in brake settings results in a change in relative location of the attachment points). Most people don't do that, though, and I've seen some ridiculously low tailgate placements (as much as 8 inches below the lowest line attachments). Obviously, with tape you get to choose the proper location for your placement each time you apply the tape, so even if you switch between varying "deep" settings for various conditions, you can still "perfectly" place your "tailgate."


I am unaware of any cases of lineover with the tape method, but that doesn't really prove anything, as even if the tape (or tailgate) fails, the odds of line over are still relatively small. Adding the chance of a failure with the (resulting) odds of a line over occuring, you have a fairly small chance of actually observing the combination.

Actually that shot is after the tailgate let go. If it constricted the parachute so much as to only allow front first expansion everytime, it would be frightening.

I've freeze framed several openings and even with a tailgate, tail first expansion sometimes occurs.

Can you share these framegrabs?

those are awesome shots

Much better. Thanks for the close up. You are definitely correct. It looked like the lines were free of the tailgate on monitor I was looking at earlier.

On freefall jumps, I've seen many side to side, nose or even tail first expansion even with a properly secured tailgate. Either way though, it will help keep the lines in place until linestretch.

I believe there's a nice shot of it happening on a jump from Welshmans in Moab on the Team Hold My Beer dvd. I don't have the tape it was shot on so I'll have to wait till I get a new copy.

I THINK Faber has another shot of it on a jump we did from a small bridge but I'm not certain.

 
Greetings all!

Definitive answer:

A tailgate is at the end of a pick-up bed.

You open it, put down a blanket, lay down, focus your camera,put on your head phones to Pink Floyd and wait for your cell phone to vibrate, then shoot.

Newer memories for sure!

Joy

PS. On vacation for a bit, back to the numbers in about 10 days.

Yea, this thread needed more pics!

like tom said, ALL slider down/off jumps. never on slider up.

...just confirming what I recall from my FJC.

Slider up jumps do not use a tailgate because
when we pack the slider up, a rubber band is
used to keep the slider up until the force of
inflation starts to push the slider --- this
helps to stage the deployment and reduce
the chance of a lineover.

Is this basic understanding of slider-up correct?
(I pussied out before doing a slider-up jump).

Oh, and both the tailgate and rubber banding
the slider up are both types of "reefing" right?

Joy, I thought it was the Doors...people are strange! LOL!

In general, yes. Some people are using the tailgate slider up, however, in an effort to decrease the likelihood of (already very rare) slider up line over. In my opinion, using the tailgate slider up marginally slows the inflation, with the effect being most noticeable at lower airspeeds, and virtually imperceptible at terminal. Perhaps it is for this reason that the slider up use of the tailgate appears to have much more acceptance in some places than others (because some places have more terminal jumping).



Sort of. The slider is the reefing mechanism that reduces the chance of a line over. It keeps the lines constrained inside the width of the canopy, and in relative order, so that they are quite unlikely to slip around the outside (and/or over the front) of the fabric.

The direct control stow is intended to keep the slider up in the canopy until it reaches line stretch (so is the indirect control, or primary stow). Keeping the slider up in the canopy prior to line stretch (staging the deployment) ought to reduce the chance of a tension knot (because the slider won't be partially deploying down slack lines).



I suppose so. I'm not sure that there is a precise technical definition for "reefing", but I'd agree that the tailgate "reefs" the canopy, and the rubber band "reefs" (perhaps "constrains" or "stages" is a better word) the slider.

Thanks Tom.

[reply ALL slider down/off jumps. never on slider up.
why not on slider up jumps? it seems to be that the tailgate is another tool to use to help avoid lineovers. having a slider reefs the entire line set to slow the opening.
so,
1. canopy extraction
2. line stretch
3. slider drops
4. tailgate reefs inner C, D, brake lines, thus encouraging nose first inflation
5. canopy fully opens

I know people who use a tailgate when slider up, and people who dont. What makes this a never in your jumping? I understand it does very little, but everylittle bit counts, right? I just dont see a negative that isnt resolved with a small mesh slider.

nic

From my experience, because on some slider up jumps the tailgate slows the opening to an undesirable degree. On slider up jumps from the bridge here, for example, I do not use a tailgate because I think that yields an unacceptably slow opening from a relatively low slider up altitude.



The problem is that (3) slider drops, is dependent on the pressure from the control lines (because outward pressure from the control lines is one of the prime drivers of slider deployment). Since the control lines are still constrained until (4), the slider is likely to deploy slower, or, in the worst case scenario, require pumping of the toggles/risers to bring it down.


Another way to approach this question would be to turn it on it's head:

What do we gain from using the tailgate that the slider doesn't already get us?

The slider is probably the best staging and reefing mechanism ever created for a ram air parachute. It is extremely effective at staging the deployment and controlling the lateral spread of the lines (most importantly the control lines). Does adding the tailgate make this an even better managed and staged process? I'm not certain.

Also, recall that the tailgate was developed and tested for slider down use. The opening pressure on the tailgate is likely to be very different on slider down and slider up openings. Further, just as it varies from a PCA to a 4 second slider down delay, it will vary from a 4 second slider up delay to a terminal deployment. I believe the manufacturer determined that the tailgate ought to take 12-14 pounds of pressure to open. Are these numbers going to be the same at terminal? Or at 4 seconds slider up? I don't know, but I expect that there would be some variance, meaning that to make the tailgate truly effective in these situations might require a different closure method (and closure strength).


I'm not saying it's a bad idea to use a tailgate slider up (I use it on longer delays, personally). But I am saying that it won't necessarily work the same slider up and slider down, and that if you want to use it that way, you should think about all the variables that could come into play.

Dave, to this day, I maintain those are my favorite BASE pictures you've ever taken.

I am confused and ignorant.

I picked up a Cruiselite a couple of years ago for low money out of curiosity, that had been 'configured' for BASE. It's in a box.

It has a modification to the upper skin on the centre-tail area, which looks like it is configured for stowing lines. It's about (from memory) 30cm wide, and 15cm deep, and is a pocket with velcro. Never seen anthing like it before or since, but I don't get out much. I just assumed this must be for 'tailgates', and put it away in the History Box.

Does anybody know what it actually is?

80% chance I'm getting suckered by a troll here, but...

That's a tailpocket. It's for stowing lines, because BASE rigs don't use bags. Any CRW jumper at the DZ ought to be able to explain it to you.

If you want a more in depth discussion, you should start a separate thread.

thanks for clearing that up. i was thinking both were called tailgates. but didnt want to ask

Thanks man. I'm not a troll, just a bit ignorant

Regards,

Darren

great shots. I like how you can see the multi's shadow on the first pic.

Regarding the use of masking tape, in especially hot and humid environments (such as the Gulf coast), the tape can bleed glue all over the place within a few days.

Regarding wet masking tape - when combined with being scrunched-up and wet it becomes extremely strong - easily done by letting the tape get in touch with wet grass and having even the slightest scrunch or twist in the tape.

Try it - take a length of masking tape and put a couple of twists in it, then wet it - try to break it either shear across or along it's length.

g.

I had a lineover on Sunday. Three-second delay slider down. I used 3-4 wraps of one inch masking tape. Unfortunately I don't think anyone got video.

Well, when my buddy and I were BASEing and taking tandem vids, we used the long, VHS labels from the tandem videos. Since we were in a windy place with high humidity, and all of that irrelivant paranoid stuff, it worked well.

Didn't have a lineover there at least. Try it, you'll never, ever have a lineover again. Smirk.

Why do we trap the inside c & d lines?

It seems like if something was going to get around the nose it would be one of the outside lines.

It keeps the other (tail) lines centered relative to the pack job. If you didn't get the center D lines, the control line bundle might wander left or right.

You get the center C lines because they are the center D lines anyway (the two are cascaded together and are one line below the cascade).

Does the stiffening of the fingertrapping make a significant difference over using cut to length pieces of much larger diameter suspension line? I have some very large dacron suspension line that is very close to the diameter and stiffness of the CR tailgate I have.

The fingertrapping creates a "soft spot" at the center of the tailgate which the eye in the c-line holds quite nicely. I expect that if you used a single large-diameter piece of cord, you'd lose tailgates more often. It also gives cleaner ends than I'd expect from a cord cut to length, which may or may not be important -- certainly a snag on your tailgate can ruin your whole day.