closing loop material

[uberchris 0]

what is the material/cord that is used to make closing loops called, specifically. i would like to order some.........thanks

gravity brings me down.........

[labrys 0]

A lot of them are made out of the type IIA material here:

http://www.paragear.com/templates/base_template.asp?group=32#W9680

I'm pretty sure there are other options too.

Owned by Remi #?

[monkycndo 0]

No need to buy a full roll. Get some from your rigger. You can also use gutted 550 cord. I did buy a whole roll and give away free closing loops to whomever needs one.

50 donations so far. Give it a try.

You know you want to spank it
Jump an Infinity

[uberchris 0]

thanks alot, looks like ill buy a few yards.

gravity brings me down.........

[DeNReN 0]

Buy several yards...and some different colours

stuff goes fast once you start making loops and diff colour loops are always cool.....I've a mostly red container so I use red closing loops

[chuckakers 426]

  Quote

what is the material/cord that is used to make closing loops called, specifically. i would like to order some.........thanks

Gutted Dacron 550 worked just fine for mains in the day, but I'm sure there will be a dozen modern-day experts that will tell me how lucky I am that I didn't die using it.

Chuck Akers
D-10855
Houston, TX

[Beatnik 2]

I use Type V like Jump Shack uses on the Racer. They are thicker than Type IIa and don't require a washer plus they last a long time.

http://www.paragear.com/templates/base_template.asp?group=32#W9720

[GLIDEANGLE 1]

I presume that you are asking about MAIN closing loops. Most reserve closing loops are made of really thin (1.8mm) hollow braid with a breaking strength of ~450 lbs (Spectra?). It is commonly known as "Cypres loop material".

The choices we make have consequences, for us & for others!

[Halfpastniner 0]

Use 1000 pound spectra. It will last a lot longer than the average closing loop.

BASE 1384

[JohnRich 4]

Caution: Thicker cord may seem better for longevity.
But it's still got to slide through the grommets unimpeded...

And once again, if you use something like 550-cord, remove the 7 strands from the inside, otherwise they can bunch up and create a lump that may NOT slide through the grommets, creating a pack closure at pull time.

[Anvilbrother 0]

That's what my rig has on it, been that way for 50 jumps plus whatever was put on it before me. It's nice and flexible and has no problem going through the grommets.

Postes r made from an iPad or iPhone. Spelling and gramhair mistakes guaranteed move along,

[JohnRich 4]

  Quote

That's what my rig has on it, been that way for 50 jumps plus whatever was put on it before me. It's nice and flexible and has no problem going through the grommets.

Yes, 1000-lb spectra is still pretty slim and slippery. But 1000-lb dacron isn't. So my warning wasn't specifically directed at the spectra comment, but was kind of a general warning about not making closing loops too thick.

[riggerrob 643]

Strong recommends using 1500 pound Spectra to close their tandems. Strong arrived at that standard after a few tandems (e.g. Steve West) suffered pre-mature openings in the doorway. That 1500 pound Spectra slides "just fine" through the #0 grommets used on most main containers.

Coincidentaly, Strong's factory-issue closing loops just happen to be the correct size for Sidewinder student containers, and it saves me arguing - with part-time packers - about loop length .....

[Beatnik 2]

  Quote

Strong recommends using 1500 pound Spectra to close their tandems. Strong arrived at that standard after a few tandems (e.g. Steve West) suffered pre-mature openings in the doorway. That 1500 pound Spectra slides "just fine" through the #0 grommets used on most main containers.

Wasn't the closing loop wear contributed to the use of a cable instead of a metal pin? That flexible pin creates a lot more friction on the loop and pretty much saws through it.

[riggerrob 643]

Yes, frayed cables increase wear on closing loops, but that was not the original problem.
The original problem was that the closing loop becomes a harness component when you pick up the student in the doorway. When the load from the side straps is transferred to the main container, which increases the load on the main closing loop.
When you load the main closing loop, you risk breaking it and opening the main container out-of-sequence (e.g. before the drogue is deployed.)

Tandem manufacturers started making tandem closing loops out of the same "gutted 550 cord" (300 pound tensile strength the same as solo main closing loops), then experimented with a variety of materials before Strong settled on 1500 pound Spectra for tandem main closing loops.

Flex-pins were a response to curved pins getting knocked loose in the airplane. Smooth flex-pins only wear out main closing loops slightly faster than stainless steel curved pins. Damaged flex-pins saw through main closing loops quickly.

Double closing loops were a second response to the problem of out-of-sequence deployments.

Broken main closing loops are one of the reasons we quit doing poised exits - from Cessnas - a long time ago. Just look at the still photos form Steve West's last jump. You can also find a few photos of King Airs with bent left, horizontal tails to reinforce that point.

Rob Warner
Vector Tandem Instructor since 1986
Strong Tandem Examiner

[Beatnik 2]

I see how there are multiple factors affecting this. There probably are a few other things that contribute to this as well than what has been mentioned so far. I can see how the addition of loads from shifting large amounts of weight in the harness can transfer elsewhere. Because of the nature of a closing loop and being distorted in different directions, the static and dynamic forces can easily add up to great amounts.

I understand the reason flex-pins were created, especially in this application but don't you think that the requirement to have a cable, of whatever length, to be extracted from the closing loop is going to produce more wear than a 1" or so smooth metal pin? Even if the cable is in good condition, it should do more damage to the closing loop.

It is interesting how many more factors need to be accounted for when the overall concept doesn't seem that complicated. That is something everyone developing something encounters. I know I have had my share.