A Low-Cost Life Saver

Q:
How do I make a closing loop? How do I know if mine needs replacing?

 

A:
It’s always fun to watch the blood drain from a rigger’s face when a jumper walks up with a broken main closing loop and asks for a replacement. A closing loop that breaks on a skydive can cause a number of dangerous situations including a horseshoe malfunction, in which the main bag trails out of the container but is still attached by the pilot chute pouch and risers, creating a whipping mess of suspension lines, bridle and bagged canopy above the jumper’s back. Using a closing loop until it breaks is the skydiving equivalent to flying an airplane until it runs out of gas.

Category C students in USPA’s Integrated Student Program learn to inspect the main closing loop before each jump to see that it’s “worn no more than 10 percent.” Nobody has ever formally disagreed with “10 percent” since USPA first published that advice in the 2001 Skydiver’s Information Manual, based on advice from Virginia rigger Harry Schoelpple. There’s no telling where he got it, but it seems sound.

Over the years, container manufacturers and jumpers have tried a number of materials for main closing loops, but the industry keeps coming back to what worked first—type-two or type-three nylon sheathing cord, so called because it is the material that forms the outside protective sleeve of the suspension lines used for round military troop parachutes.ASKARIGGER20101-0

Although both are used, type-two sheathing (top) is lighter and more popular for making closing loops than type-three sheathing (bottom).

Far and away, we skydivers see more closing loops made of type-two sheathing, the lighter of the two. Type-two sheathing has a dashed line tracing the length of it, where the type three sheathing has no tracer and is just one solid color. Both types can be natural (white) or dyed, and the tracer color varies. The slightly lighter-weight type two bends more sharply over the closing pin and provides a little more friction, which helps keep the rig closed until it’s time to open. Type two also wears slightly faster than the type-three sheathing, a reasonable tradeoff.

Para-Gear Equipment Co., a longtime supplier to the industry, sells the stuff as “type IIA sleeving” for 35 cents a yard. Most closing loops use between six inches to a foot of it, meaning a closing loop costs about a dime. Most of the labor to make one involves fishing a piece of thin wire from your gear bag.

1. Bend a piece of wire

ASKARIGGER20101-1

Anyone can make a closing loop. If you have a friend who plays guitar, especially electric guitar, see if you can get a discarded high-E string next time he or she changes the set. Otherwise, buy some thin picture wire from the local arts and crafts or hardware store. Cut a piece of wire about 18 inches long and bend it sharply in half.

2. Cut a piece of cordASKARIGGER20101-2

3. Mark your mid-pointASKARIGGER20101-3

Remove your old closing loop and save the washer to replace on your new one. Use a pair of scissors to cut a piece of sheathing about twice as long as the old closing loop from end to end, plus several inches. Too long is OK, but too short is not going to work. Remember—it’s only 35 cents a yard. Bend the cord in half and mark the mid-point.

4. Insert the bent wire in the endASKARIGGER20101-4

5. Exit a half inch from the mark

The sheathing is hollow like a tube. Thread the point of the bend in your wire up through from the end of the cord, making sure it doesn’t poke through the side on the way up. Stop about a half-inch before the mid-point of the cord. Then, work the point of the wire through the wall of the cord until it sticks out and you can see a small loop of wire.

6. Hook the loose endASKARIGGER20101-6

Take any twists out of the loose end of the cord, thread about one inch of it through the loop in the wire, and bend the cord back on itself.

7. Pull the loose end back through

 ASKARIGGER20101-7 

Work the wire loop with the loose end of the cord back through the hole you made in the side of the cord. You will have to massage it a bit to get it started. Extract the loop of wire out of the end of the cord where you started until the loose end comes with it. Be careful not to collapse the loop you made on the other end. Finally, slide the loop of wire off the loose end of the line and put it away where you can find it again next time.

8. Adjust loop length to about a half inchASKARIGGER20101-8

9. Tie a knot a half inch shorterASKARIGGER20101-9

Then adjust the loop diameter by pulling the loop and the loose end until it is about a half-inch long when folded flat. Use your thumb and forefinger to work out any internal twists and seat the loop, then loosely tie a simple overhand knot (like starting to tie your shoes). If the old loop was about the right length, adjust the knot so the distance from the knot to the loop is at least a half-inch shorter than the old loop. If your old loop was too loose or tight, adjust accordingly.

Slide the washer from the old closing loop onto the new one. Install the loop, stretch it with a pull-up cord, and then remove it and recheck the length. A little short is OK, because it will still stretch quite a lot during the first couple of pack jobs. Too long is not OK. To determine how tight your closing loop should be, check the owner’s manual for your container, consult with the manufacturer or ask your local rigger. A loose (too long) closing loop will not provide enough tension on the closing pin, creating an unnecessary risk of experiencing a horseshoe malfunction or a premature deployment.

10. Cut off the extra and burn the endASKARIGGER20101-10

Cut off some of the excess line below the knot, and carefully melt it with a cigarette lighter.

Voilà! New closing loop. Ten cents. Nobody has a premature container opening, nobody gets hurt. And you add weeks to your rigger’s life.

—Kevin Gibson | D-6943
Master Rigger
Nakorn Phanom, Thailand

Comments

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

William Butler
Thu, 07/28/2011 - 19:40

An excellent article. I will be sure to check my closing loop everytime I pack and replace it regularly. Thanks again!

William Butler

Post new comment

Please provide your full name. We will not post responses from anonymous sources.
The content of this field is kept private and will not be shown publicly.
Type the characters you see in this picture. (verify using audio)
Type the characters you see in the picture above; if you can't read them, submit the form and a new image will be generated. Not case sensitive.