Round Drogue Parachute
Drogue Chutes are used to provide tension on the towline after the pilot releases to keep the line from falling to the ground, and to allow tension to be applied to the towline to ensure a smoother rewind of the towline. Round drogues are the simplest drag producing device. Typical use involves attaching the drogue chute lines to the end of the towline, with a leader line attached to the apex of the drogue that connects to the pilot through a weaklink. In use, tension on the towline keeps the drogue deflated. Once the pilot releases, the drogue automatically inflates. Our round drogues are the finest available. In brand new yet military surplus condition, these drogues are vented and stabilized. They don't lock out and they allow favourably low line sink rates, and high tension to be applied (up to 200 pounds +) during rewind. Used to stabilize air dropped cargo loads during HALO operations these are now available to paraglider pilots at a fraction of their original cost.
NOTE - These drogues are designed to be a high drag device, as that's what allows us to build a decent tension during the rewind portion of the tow and helps to stack the line tightly on the winch drum. They work great on a scooter tow, or a hydraulic winch system with at least 5.5 HP available for rewind. THEY WILL NOT WORK on most electric systems that use starter motors, or their equivalent to rewind, simply because these systems can produce neither the line speed or the torque to function properly.
End of the Towline - How to Hook up your Drogue, Leader and Weak Links
Several people have asked us for a set of drawing or images on how we hook up a pilot to the end of the towline. There are lots of different ways this can be done, and a few of them are really bad ideas. If you look at the end of either of the towlines coming off our towboat, you will see the same setup used. The following text describes how we do it, why we do it, and perhaps, some things that don't work so well.
It all starts by attaching the drogue to the end of the towline. There are lots of drogues that can be used. For simplicities sake we really like the round vented drogue. It works perfectly with our winch. It provides the appropriate amount of drag to allow us to rewind our line with a tight stack on the spool, and it’s very reliable. We like to splice the line where it attaches through the parachute shroud line loops. Some people like to splice a quick link into the end of the line. You either have, or you will slam the drogue right through the tracking head on a rewind that comes in faster than planned. It’s much less damaging to smash a bunch of line into the tracking head, than a metal link. If it happens to nail you in the head during a rewind, you’ll appreciate NOT having a link there as well.
Here’s a picture of Victoria splicing a new drogue onto the end of the tow line. Thread the line into a fid (We’re using a #5 fid for our standard 1100# towline). Thread the fid and line through all 12 loops, and pull out 3 to 4 feet of line. Insert the fid back into the center of the line and feed it through until the loop is closed. Pull the fid back out of the line and smooth the line out. You should end up with a very neat installation with no knots. To remove the drogue if needed, you simply work the splice loose and you can pull it apart. In use, the harder you pull, the tighter the line grips. You can make a much shorter splice (around 12 inches or so) if you want to stitch the line so it can’t unthread accidentally.
If your drogue was supplied with a tie strap to keep the loops tidy and in order, you can cut it off now, since it’s no longer needed.
That takes care of attaching the drogue to the towline. Now you need to attach the pilot to the end of the drogue. Many pilots simply attach their weak links to the drogue. There’s nothing wrong with that system, except that if the line tension is reduced inadvertently during the tow, the drogue is going to inflate in the pilots face. To an experienced tow pilot it’s no big deal. To a novice tow pilot, it can be a traumatic experience and the potential for a pilot induced loss of control is pretty high.
We prefer to attach a short leader line to the end of the drogue for a couple reasons. First, is the simple fact that it gets the pilot away from the drogue, so an inadvertent opening is no big deal. Secondly, there are a few pilots who steadfastly refuse to use weak links for various reasons. We use a leader line that breaks at 865 pounds, so even if a weak link isn’t used, in the event of a serious over tow situation, the leader line will break, preventing a line break that might pose other, and significant issues.
To attach the leader to the drogue, we use a Stainless Steel 3/16” quick link. Loop the link through all the webbing straps at the apex of the drogue, and girth hitch the leader line through the other end.
If you unsure what weak links are for, please refer to our weak links page. You can also refer to that page to learn how to tie the double grapevine knot.
The best way to secure your weak links to the leader line is to girth hitch a small 1/8” Stainless steel quick link to the end of your towline. DO NOT use a plated steel one found in the typical hardware store. Stainless links have twice the tensile strength for the same size, and they don’t corrode or rust causing sharp edges that will damage your weak links. Some people like to skip the quick link altogether and simply girth hitch the weak links to the end of the line. THIS IS A MISTAKE for a couple reasons. When girth hitched, the link will never stretch evenly, so it will blow out with inconsistent results. Since the link isn’t free to rotate around anything, any pulses, or surges during the tow will actually occur at the interference point between the weak link and the closing loop of the tow bridle. In just a few tows, you will saw through the closure loops of your tow bridle, especially if you are using something like a friction style payout winch that isn’t know for the smooth tows you experience on a TowMeUp.com hydraulic system.
The quick link makes it simple to attach weak links to the leader line, and they are readily replaced. A keen observer will note that we almost always have a pair of solo links, and a tandem link attached to our quick link at all times and have asked why we do this. The reason is simple, and easily understood if you understand how weak links typically fail.
When you overload a weak link, the link will stretch. Initially it stretches elastically, so if it’s a light load, the link will stretch and then rebound back when the load is removed. Add a bit more load and the link will elongate, plastically. Once you remove the load the link will remain stretched. If you continue loading the link it will elongate around 60% in length and ultimately fail at the knot. The line can only stretch uni-directionally at the knot so it should ALWAYS fail at that point.
We keep 3 links on our line for comparative analysis purposes, as well as a time saver. If you only have a single link, you need to swap it out to change between solo and tandem pilots. With both solo and tandem links, you simply choose the most appropriate link. If you go to hook up solo and notice that one of the links is say an inch or 2 longer than the other one, what does it tell you?
You get bonus points if you realize that link has already stretched plastically and is likely to fail soon. A smart pilot would take their hook knife (you always tow with a hook knife… right?) and cut off this now defective link, and hook into the other link. No time is wasted, and the link should be replaced when the line is recovered by the towboat operator prior to the next tow. It’s always considerate to give the operator a heads up as well.