Bar Tack Question

[divekennene 0]

Just got my main back from having a reline done. About 25 % of the bar tacks where the lines attach to the canopy are like the ones noted with the blue arrow in the picture I attached...should I be concerned about this?

[sid 1]

they look okay to me, as long as they trap both sections of the line (the part inside and the outer sleeve) they should be fine........

Pete Draper,

Just because my life plan is written on the back of a Hooter's Napkin, it's still a life plan.... right?

[diablopilot 2]

What's making you think there is something wrong with them?

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You're not as good as you think you are. Seriously.

[PeteS 0]

Looks like a zigzag stitch to me. Should be ok, watch for any unraveling of the stitching. Check if the same stitch is at the stabilizer to b,c,or d line junction or the cascade points. learn how to inspect these and other parts of your gear and you will have confidence.

[divekennene 0]

Any other bar tack I have seen is the typical "obvious" zig zag pattern. These are real close to a straight stitch and my rigger suggested I ask about it.

[Colson 0]

Call, (or have your rigger call) whoever did it and ask them about it. They are the only ones who know for sure what they did, even if it is wrong. Go to the source.

[riggermick 7]

looks ok to me. Remember, it's the fingertrap not the stiching that holds the line in place. The stitching is there to stop joint slippage when the lines are not under tension, the larks head knot that loops around the line attach tape helps a little too with the whole tension/ no tension thing.

Mick.

[riggerpaul 1]

I know it will sound a bit strange, but I have carefully picked open the stitching on main canopy lines many times, and what I usually find is a zigzag, not a bartack.

Bartacks have a couple of rows of straight stitching underneath the zigzag. The zigzag is sewn over the straight stitching.

What I have been taught is that a true bartack should not be used in an area where stretching along the length of the bartack will be needed. The explanation was that the true bartack, having straight stitching under the zigzags, does not have the ability to stretch, and damage to the material or the stitching can occur when you load the line.

You can easily see true bartacks attaching the line attachment tabs to the bottom skin of the canopy. The photo supplied has a great example.

Now, I'm not trying to say that all canopies are this way, but I have seen lots that are. I have never picked open the lines on a reserve, so I don't presume to tell you which stitches are used there.

As far as why some lines look one way and others look different, that's because the factory lineset comes with about half of the stitching already done. Different manufacturers may choose differently what to sew and what to leave for the installer. For example, a typical PD main lineset has the A-B lines (and C-D lines too) already cascaded and sewn, as well as pre-sewn loops at the A (and C) canopy attachment ends and at the link end of the line. The installer needs to larkshead the B (and D) lines to the canopy and sew them. I have also seen linesets where the loops are all sewn, but the B and D lines need to be cascaded into the A and C lines. With this sort of design, the installer needs to stitch the cascades, not the attachment loops.

All this is because when you are using cascaded lines, something must be sewn after the line is installed on the canopy. Canopies that do not use cascaded lines do not have this problem. All the sewing on non-cascaded suspension lines can be done at the factory (except for where the stabilizers are attached to the outside lines, of course).

[RIGGER 0]

What do you mean by TRUE BARTACK ?

Cheers

[rushmc 23]

When the Dash M Ravens had an issue they specified a bar tack

See the linkhttp://www.precision.aero/sb/SB20011221-r1f.pdf

"America will never be destroyed from the outside,
if we falter and lose our freedoms,
it will be because we destroyed ourselves."
Abraham Lincoln

[riggerpaul 1]

I'll try to answer both Shlomo's and Marc's questions in a single post.

Quote

What do you mean by TRUE BARTACK ?

Cheers

Many people confuse simple zigzag stitches with bartacks. I find this to be especially true when it is a center start-stop oversewn zigzag like the one PD uses on the linesets I have taken apart.

But "true" bartacks have the straight stitching underneath the oversewn zigzag.

I mentioned this in the paragraph above where I said "true bartacks", so I though it was clear what I meant by "true bartack".

Quote

When the Dash M Ravens had an issue they specified a bar tack

See the linkhttp://www.precision.aero/sb/SB20011221-r1f.pdf

The OP was talking about the stitching securing the fingertraps on his new lineset.

In my post I especially pointed out that you could see a bartack on the line attachment tab in the picture.

The Dash-M fix was to add a second bartack to the line attachment tab. It didn't have anything to do with the line itself.

The bartack on the line attachment tab is not subject to longitudinal stretching the way the stitching on the fingertraps is.

[rushmc 23]

Quote

I'll try to answer both Shlomo's and Marc's questions in a single post.

Quote

What do you mean by TRUE BARTACK ?

Cheers

Many people confuse simple zigzag stitches with bartacks. I find this to be especially true when it is a center start-stop oversewn zigzag like the one PD uses on the linesets I have taken apart.

But "true" bartacks have the straight stitching underneath the oversewn zigzag.

I mentioned this in the paragraph above where I said "true bartacks", so I though it was clear what I meant by "true bartack".

Quote

When the Dash M Ravens had an issue they specified a bar tack

See the linkhttp://www.precision.aero/sb/SB20011221-r1f.pdf

The OP was talking about the stitching securing the fingertraps on his new lineset.

In my post I especially pointed out that you could see a bartack on the line attachment tab in the picture.

The Dash-M fix was to add a second bartack to the line attachment tab. It didn't have anything to do with the line itself.

The bartack on the line attachment tab is not subject to longitudinal stretching the way the stitching on the fingertraps is.

You are correct and my post was more to show what a "true bar tack" was as opposed to where it is being used.

It was also good to see a post that pointed out that the bar tack itself is not intended to hold tension but rather keep the finger trap in place when not under tension

marc

"America will never be destroyed from the outside,
if we falter and lose our freedoms,
it will be because we destroyed ourselves."
Abraham Lincoln