modified tail pocket

[tommyh 0]

After reading the two threads about tension knots I remembered reading about people using modified tail pockets with extra flaps of fabric in them to help separate the figure-eighted loops of lines, in theory reducing the chances of a tension knot. I believe these tail pockets have been in use for several years now, and was wondering if anybody had an opinion on wether they were beneficial or not.

Has anyone ever had a tension knot while using one?
Any other problems associated with this innovation?

thanks

[d_goldsmith 1]

I've been wondering about this too. I've also considerred a strip of masking tape over each side of each figure eight, but a friend mentioned that the tape could stick to other tape and cause line dump.

[PeteS 0]

On my tail pocket that I made for myself I have rubber band stows for all the lines. Velcrow wears out, and I do not want to think about it. The rubber bands are large size skydiving ones' cut very carefully in half. I have used this sub-300' all the way to terminal with good results.

[dploi 0]

I believe it was Space that first put this together. Pretty cool idea, and I bet it makes a difference.

[TomAiello 26]

I've used a tailpocket with stows like that (after seeing yours). Watching the video, it looks to me like there is a significant amount of wiggle imparted to the tail pocket and the pack job as the stows pop. I was concerned that if a rubber band hung up, it could spin the whole thing, so I stopped using that setup.

-- Tom Aiello

Tom@SnakeRiverBASE.com
SnakeRiverBASE.com

[460 0]

If I was using that setup, I would prefer ponytail rubber bands far more.

But, the tailpocket with the internal flaps is by far the best tailpocket system I have seen.

Looks like a death sandwich without the bread - Steve Deadman Morrell, BASE 174

[NickDG 23]

Try this test:

Lay the canopy down and anchor the bridle attachment point. Flake and fold per normal. Place the lines in the tailpocket without using the rubber bands – just figure eight or lay the stows side by side and close the flap like most people do. Now grab the container and run away. Note how smoothly the lines deploy and the lack of movement of the tailpocket.

Now do it again – but this time use the stow bands.

Leave the tailpocket flap open this time so you can see what's going on. On each stow point the stow band comes in contact with only the lines on the outside of the line bundle. The lines in the center of the bundle will deploy first (this is called the race track effect) and this is just asking for tension knots, especially slider up. Also note how the tension of the stow bands releasing will rock the tailpocket (sometimes violently) from side to side. This is why we removed the stow bands in the first place in BASE jumping and the reason skydivers went to the free-stow reserve bag for the same reason. Jumpers rarely see this phenomenon, but riggers saw it all the time when un-packing reserves in the old days when stows were used.

We can also look at this latest tandem fatality as (maybe) an example. Tandem reserves are too heavy for free stow reserve bags. During a terminal deployment there it a high risk of bag strip so the more traditional stowed bag is used. Believe me if you could guarantee never to have a high speed tandem reserve deployment there would be no stows on tandem reserve bags either.

NickD BASE 194

[460 0]

Consider doing a test with freestow tailpocket. While figure eighting the lines, drop the bend of the lines into the loop(s) below it. See how big of a knot that can be made and how easy or difficult it is to clear itself.

Looks like a death sandwich without the bread - Steve Deadman Morrell, BASE 174

[base283 0]

It wasn't I. But it was one my students. Peter the Rocket man designed it. I will ask him to supply details and photos. I should see him soon.
Take care,
space

[crwper 7]

Although I believe there are benefits to free-stowing the lines, and use this technique myself, I am somewhat suspicious of your proposed test. The reason is that if you leave the tailpocket open for the second test, the lines will be free to apply force directly to the stow, which will exaggerate the motion of the tailpocket side-to-side. If I was doing the test, I would prefer to keep everything except the stows the same between tests. I suspect having the lines pass through the constricted opening of the tailpocket will reduce somewhat the motion due to the stows.

Reading this thread, one thing which comes to mind is the freebag on Aerodyne's Icon. This bag uses a strip of elastic material on each side, tacked at regular intervals, for line stows. The result is a more consistent pull force than would be achieved with rubber bands. Such a system would slow your pack job a bit, but would avoid some of the problems associated with rubber band stows.

Me, I'll keep free-stowing for now.

Michael

Edited for poor Engrish.

[Calvin19 0]

this was why i was asking about the thread used in the keelpocket. I think that this multiple flaps in a triangle form is the best way to stow lines. as for the 'velcro wears out' thing, doesnt the manufactururs specify we should replace the keelpocket every 100 jumps ish? The tailpocket i am making will have 20 different triangle flaps, eachwith their own velcro. I am also making new experimental lines for my old dagger. with spanwise cascading and 10 risers. i think the modified (not neccesarily new) keelpockets will become more popular. but probably will be a bit less complicated than mine.

[TomAiello 26]

Have you considered using multiple tailpockets, for different line groups?

-- Tom Aiello

Tom@SnakeRiverBASE.com
SnakeRiverBASE.com

[nicknitro71 0]

On one of mine tail pockets I have sewn "baffles" on the inside top flap. These dividers are spaced about 1" apart and as they move towards the closing side of the flap they get increasingly smaller.

They are made such that there is a 1" gap in the middle-front to allow the next stow to move up.

When the tail pocket is closed all the stows are neatly divided and they are not in contact with each other.

I built it with the idea of avoiding tension knots although I have never had one even with conventional pockets.

Memento Audere Semper

903

[Calvin19 0]

I have thought of useing multiple tailpockets, but there is a few problems i can think of.

problems-
packing it would be a bitch, trying to do 2 figure 8s at the same time or dragging one linegroup before the other.
I think that if there was to be a tension knot in one linegroup, it could cause something even worse.

what i have thought of is 2 tailpockets on top of one another, the A/Bs in the bottom, and the C/D/brakes in the top. but it wouls also have the same problems.

[Calvin19 0]

as for the rubber band thing, I think that rubber bands are bad in general for BASE gear.

I dont use a rubber band for the tailgate, i use masking tape.
I only use the first bite on the lines for a sliderup packjob, and even then only about 5cm and one rubberband loop. i might even try masking tape for that.

i think that rubber bands can cause a lot more porblems than they can save.

[NickDG 23]

Doing the test with the tailpocket closed produces the same result. Except now the tailpocket Velcro can get blown open or the lines tangle even worse trying to get through the hole.

"So my keelpocket locked up and my tarp failed me." Gee, in a few years I'm not going to be able to understand you guys . . .

You know, building on what's come before is fine and is the way of BASE, but re-inventing a problem is not.

NickD BAE 194

[Zoter 0]

Quote

I dont use a rubber band for the tailgate, i use masking tape.

Why ?

[Calvin19 0]

Why? well, where do i start.

Rubberbands are scarce, i can find tape anywhere. one loses tailgates, they are hard to find, and hard to makeshift. i suck at cutting rubberbands in half. the black ones hang up. they break. they take a while to set up on a tailgate. I dont have to remember to take my tailgate off for sliderup jumps. paper tape decomposes faster than a rubberband. there are a few different kinds of common tape that can be used. tape can be placed closer to the canopy on the lines making the tailgate more effective.

did i miss anything?
why do you use rubber bands?
were you taught to? because i was. i just found something better and changed. or is it because everyone else does?

im just being mean. no worries bro.

[d_goldsmith 1]

I've been considerring switching to tape because "tape can be placed closer to the canopy on the lines making the tailgate more effective." I like the other points you made also, especially "dont have to take my tailgate off for sliderup jumps"

I have no experience using tape yet though, and am kind of scared that it will cause hesitation. Maybe I should use a fish weight to test the breaking pressure of a single, double, triple rap, ect...

[d_goldsmith 1]

Do you use tape at the control lines and again at the top of the d lines? If so, if your deep break setting kept the control lines low of the center C's, would you use tape at the top of the control lines, top of the c's and top of d's?

[Calvin19 0]

i do not, i tape at the top of the control lines. i think that if all the control lines are controled with tape, then there is no way other lines can get around it. but i dont know that much about lineovers. i pack a weird way now, deadmanwalking taught me a new way to wrap the outside cells around the packjob, and he swears it works better than a tailgate.

[yuri_base 1]

Quote

i pack a weird way now, deadmanwalking taught me a new way to wrap the outside cells around the packjob, and he swears it works better than a tailgate.

Same here (learned it from Miles). Seems to improve heading performance, too.

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[JaapSuter 0]

Quote

I have no experience using tape yet though, and am kind of scared that it will cause hesitation. Maybe I should use a fish weight to test the breaking pressure of a single, double, triple rap, ect...

Do a skydive with a medium to large sized canopy and slap six or seven wraps on that thing. It'll break. Then use two to four on your BASE jumps. If you're concerned, you can always put a tiny millimeter sized tear in it as you pack it to prime it.

Do not use duct tape...

The main thing to watch out for with masking tape is how it performs when wet. Some brands get stronger when wet. Buy some, soak it in water, then try to tear it.

Not that a packed rig would get soaked that easily, but remember the story of that guy that had a block of ice come out of his tray...

[d_goldsmith 1]

Awesome. I hadn't heard of priming tape yet, and didn't know that it could get stronger when wet. Thanks.

[TomAiello 26]

That packjob has been discussed at length in other threads (search for the Hong Hookitt Faber pack). The majority of the people using it still use tailgates.

I do not believe it is an adequate substitute for a tailgate.

-- Tom Aiello

Tom@SnakeRiverBASE.com
SnakeRiverBASE.com