by Mike Rose
Course 117
Tethering a balloon can be fun, but it is a lot of work and it can be very dangerous if the conditions are not right. Tethering a balloon is not natural. Balloons are meant to fly free with the wind and when you hold one back on tether you are acting against nature. I believe the most important aspect of a successful tether is the communication between the pilot, the crew, the spectators and any potential riders. If everyone knows what is expected of them and the weather conditions are favorable then your chances of a good safe tether are quite good. I have crew people who prefer not to use gloves when crewing for a free flight. If they are experienced crew I do not require them to wear gloves unless they are handling lines or cables. On a tether, however, every crew person is required to have a good pair of leather gloves. On a tether virtually every crew member will have the opportunity to handle the tether lines and I feel gloves are required in this situation.
For the most part tethering is a commercial event with a sponsor and the sponsor always has certain expectations. The pilot and crew must know these expectations in advance when planning the event. When choosing a place to tether I look for a field large enough to contain three good solid tie-off points and allow enough room for the balloon to be deflated at the end of the tether ropes in any direction. Powerlines anywhere near the tether operation make me very nervous and I always try to pick a place with no powerlines in the vicinity. Sometimes that is not possible when trying to meet the expectations of a sponsor, however, I always check out the site before I commit to the tether in the first place. My rule of thumb is no powerlines near enough to touch any part of the balloon, even if one or two of the tether lines should fail.
The lines used to tether the balloon can vary widely. I have seen pilots use anything from five-eighths inch nylon rope to two inch nylon straps. I personally don't like the straps because I think they can cause more injury to people than ropes. The straps are thin and can easily slide in your hand causing burns and cuts. I use a one inch nylon braided rope. I chose this material because it is easily purchased at hardware or marine supply stores, it is strong enough to hold the balloon, it is easy to handle and I know how to weave the rope into loops. I learned rope weaving from old time balloonist Dave Medema and I thank him for the knowledge. He didn't stick around long enough to teach me whipping, so if there is anyone out there who would be willing to pass that knowledge along I'd appreciate the help. Each of my ropes is 150 feet long and has a loop woven into each end.
I prefer to tie off to large vehicles for several reasons. Vehicles because I know what I am dealing with as far as weight goes. Large vehicles because I once picked up a small Mazda at the end of a tether rope. I don't like trees because you never know how healthy the tree is and it could be weakened by disease or insects. Small trees are not a good idea because you could conceivably pull them out of the ground. Telephone or electric poles are out. I don't want to be that close to wires. Light standards are also out because I don't want to drape the envelope over the light. I once tethered at a little used county airport and used airplane tie-offs sunk in the concrete airplane parking lot. I was doing fine until one of the tie-offs pulled completely out of the concrete. I'm not sure if it was just weak or if it was not designed to handle the direct upward pressure of the balloon. When vehicles are chosen for tie-off points I also make certain that a crew member has the keys to the vehicle. I know it sounds funny, but I don't want someone driving off when I am tethered to their vehicle.
I won't get into specifics on how to attach the tether rope to the balloon because every manufacturer has a different method. Some manufacturers even have special tether blocks that attach to the basket for this purpose. The rigging of the tether ropes should be handled by the pilot or a very experienced crew person who has had training on how to rig for a tether. Less experienced crew should do only what is asked of them. If you are asked to do something you are not sure of, don't be afraid to speak up and explain that you need help or direction in handling the task assigned.
I begin by placing my vehicle tie-off points. I place two upwind and one downwind forming a large triangle. The tie-off points form a triangle and I prefer to keep spectators well outside a circle that encompasses the entire triangle. After off loading the balloon in the middle of the tether area I brief the crew and the potential riders. If possible I will also speak to the spectators. In the crew briefing I explain what position and rope I want them to handle during the inflation and tether. If we are doing tether rides I have at least 2 crew people assigned to handle the passengers. I brief the passengers on where to stand during the inflation, and where to move to when it is their turn to enter the basket. If I know in advance who is going to ride I will divide the passengers into groups of 2 or 3 depending on estimated weight and I try to keep the passenger loads close to the same total weight when possible. If it is not possible to brief the riders I brief the crew on what I want for passenger loads. It is much easier, more fuel efficient and safer to have your passenger loads nearly the same for each ascension.
Before laying out the balloon I will temporarily rig the ropes to the tie-off vehicles. When I say this I do not mean a temporary knot. Each knot is tied as though it was the final knot that is expected to remain until the end of the tether operation. I say temporary because after the balloon is inflated and allowed to rise on the ropes it is often necessary to adjust the ropes to get an even load on each rope. My chase vehicle has a heavy metal bar welded to the frame for the trailer hitch and I use this as a tie-off point. When using other vehicles I often tie off to the frame or axle underneath the vehicle. I have heavy duty chains which I use to go around the frame or axle and I connect the tether rope to the chain. This keeps the tether rope from rubbing or getting cut on a sharp bumper or body part on the vehicle. I have always used a bowline knot to tie off to a tether point. This is a standard knot that each balloonist should know. It will hold a full load without getting so tight that it becomes difficult to untie. A bowline knot is a little tricky at first but it is easily learned and is the best knot I have found for securing tether lines.
After positioning the tie-off vehicles and rigging the lines to the vehicles and basket we do a normal inflation. After hot inflating I let the balloon rise to the top of the ropes and direct the crew to make any adjustments to the ropes that are necessary. A crew person is assigned to each of the three tether lines. Their primary responsibility is to keep all spectators away from the tether ropes. I don't even want to think about someone straddling a tether rope that suddenly goes taut as the balloon rises. These crew people are instructed to do whatever is necessary to keep people away from the lines. Only after all adjustments are made do I call for passengers. Once each passenger load is in the basket I give a briefing to cover what happens when we come down after the tether ride. I instruct them to hold on with two hands, bend their knees and to stay in the basket until I tell them to get out. This briefing is repeated to each and every passenger load. I don't want someone jumping out just as we touch down causing the balloon to rise quickly due to reduced weight in the basket. As the balloon reaches the ground the crew adds weight to the basket and brings out the next set of passengers. I select the next passenger and have that person enter the basket before one of the previous passengers exits. One in - one out - in that order with additional crew people to assist anyone who needs help. This continues until all of the passengers have been accommodated.
I try to limit my tether operations to a maximum of 2 hours. Tethering is hard work on the crew and with any operation exceeding 2 hours serious crew fatigue can become a factor. In the early 80's I set up a tether in the middle of the crowd at the Dayton Air Show. The tether was a spur of the moment decision and not pre-planned or announced to the crowd. There were thousands of people attending the air show and when we started giving rides I looked out and saw several hundred people in line. I agreed to stay up as long as I could and the Balloonmeister arranged for additional propane and fresh crew every hour. I logged 5 solid hours of actual tether time. In.. Out.. Up.. Down.. No time at the top of the tether.. Get as many up and down as possible. No one kept a count of passengers, but when I finished the line was just as long as when I started.
The weather in Dayton that day was clear and sunny with dead calm winds. The flags and wind socks were hanging limply throughout the day. Perfect conditions for tether rides. I'll give tether rides in winds up to five to six miles per hour. Over that I think it is to dangerous to give rides. If the winds are higher than that it is still possible to tether and keep the balloon up, but if you let it cool to come down it will often get soft and begin to cave in from the wind. In a windy tether I am the only one in the basket as I do not want to risk anyone else's safety.
What is adequate crew for a balloon giving tether rides? Well, one person on each of the three tether lines, at least two adding weight at each touch-down and one or two organizing the passengers. That comes to six or seven people. Anything less than that will affect the safety of the operation.
Coming next month, Refueling. As always, please forward comments or suggestions for future topics to me at P. O. Box 1362, Allen, Texas 75013 or balloon@flash.net.
For a more detailed discussion of tether operations see the Balloon Life special report, Tethering, in the August 1996 issue.