Keep Calm & Double Stow
Lots of things are just better in twos: peas in the pod, tickets to paradise, birds in the hand…and stows. Double stows are the way to go, dear reader. And today, we’re going to explain why that’s the case.
The good ol’ double stow has been the subject of a great many debates and discussions around the sport. In fact, there’s a very good chance that you’ve been pinned down on the dropzone somewhere, unable to escape, and regaled mightily on the topic against your will. Please don’t worry: we’re going to keep it light and fun and–hopefully–we’ll all be cheerfully stowing double by the time we’re done here.
Why do we double stow?
What’s the point of the double-stowing exercise? Some may argue it’s just to look cool, but that’s not the case (although we can all agree that a well-executed double stow does look pretty awesome). The real purpose of the double stow is to prevent, as much as possible, an out-of-sequence deployment, which can lead to a whole bunch of unpleasant opening scenarios, such as a hard opening, an asymmetric opening, line twists and so on. None of us want that unnecessary ouch (or, y’know, repack).
Hollie-Blue Allum Double Stowing Photo by Felix Wetterberg
So what exactly is an out-of-sequence deployment?
To understand that, we need to know what a proper opening sequence looks like. Here’s a step-by-step breakdown:
- we deploy our pilot chute, it inflates, creating tension on the bridle.
- The bridle pulls the closing pin and opens the main container flaps.
- The deployment bag then leaves the main container, and the line stows should unstow in the correct order as the lines are tensioned, with the final piece of the sequence being the “locking” stows (which keep the bag closed until the lines are at line stretch).
- Once those final, locking stows are released, the canopy leaves the deployment bag and starts to snivel and inflate, aided by the slider staying at the top of the lines.
- Once enough air enters the parachute, causing it to inflate through the nose and crossports, the slider is pushed down the lines, and voila –
- You’re open! ✨
An out-of-sequence deployment, then, is when any of these steps occur out of that very proper little sequence.
So… how does double stowing help prevent out-of-sequence deployments, exactly?
Let’s say some of the lines in a sloppily executed single locking stow slip out early, leaving the deployment bag–well–unlocked. At this point, it’s just begging for a security breach, no?
Well, in this situation, the remaining lines in that stow will have less tension. They can more easily fall out, allowing the bag to open before the other stows have released–or before the bag is at line stretch. If the canopy starts to inflate before the bag is at line stretch, the inflating canopy might just ferociously rip the rest of the lines out of their stows.
And now: Waterskiing. (Go with it.)
You can picture the dynamics of the situation by imagining a water skier. Imagine, in your mind’s lake, a waterskier being towed behind a boat, happy as a…well, waterskier, because waterskiing is fun. Now imagine that the boat slows down and creates slack in the rope. With the introduction of slack between the boat and the waterskier, the hapless athlete is uncoupled from the speed of the boat and is no longer accelerating with it. When the boat picks up speed and the slack clears, boom–the skier is suddenly jerked forward, perhaps directly onto their surprised little face. Poor waterskier. Nasty boat driver.
A canopy opening is similar. Simply put: slack is bad. Proper tension–from the time the pilot chute is deployed right through the canopy opening–is essential for a controlled deceleration. Without properly stowed rubber band stows, you may not have a properly staged deceleration. That can lead to at least a hard opening, maybe worse.
We know what you’re thinking.
But some of you may be rolling your eyes. We get it: your rubber bands feel plenty tight enough. Witness your hangnails! You know what you’re talking about.
But do you?
The shape of a rubber band when it’s attached to your deployment bag is not circular. It’s more of a teardrop shape. Therefore, the tension of the rubber band itself is not uniform unless it’s double-stowed. With a single stow, the tension in the deployment system can stretch the rubber band, allowing space for certain lines to escape the stow more easily. When double-stowed, any pull between the bag and the rubber band will actually cinch the lines tighter.
Hans, the Double Stow master himself. Photo by Lienbacher
And what about the dreaded bag lock?
Dropzone lore has it that double-stowing causes bag lock. That, friends, is absolute balderdash hogwash claptrap. We have the data on many thousands of recorded test jumps, we’ve never had a bag lock as a result of double stowing. You should worry about double-stows causing bag lock approximately as much as you should worry about the Otter being hit by a meteorite. Sure, we suppose the risk is mathematically non-zero, but c’mon.
Ready to learn how to double stow properly?
Pop over to YouTube for this Tip Tuesday, where you’ll spend a delightful five minutes watching the inimitable Double-Stow Beau demonstrate this essential technique.
Performance Designs Inc. – Locking Stow Myth
Simple Vs double lovage