Two Get Very High (Part 1)

Two get very high - Part one. So there we were, 30,000' upside down, nothing on the clock but the maker's name. All good flying stories should start with a line like that. For Lev David and I, it was sort of true. Topping out at 30,334', briefly we were the highest people stood outside anywhere. We shook hands and the feeling was humbling and then we had to return to a pressing need. Relighting the pilot lights, they had gone out 834 feet beforehand. I knew that the chances of getting them lit before we had dropped below 25,000' were slim - the balloon factory in England had told me so! The story began as so many do in a Beer tent. Splashy Fen 2004 Underberg Kwa Zulu Natal. I had met Lev David, producer and presenter of East Coast Radio's breakfast show a month or two earlier. He stood on top of one of my balloons at the ABSA Stadium Durban. I was very impressed with his fearless manner. Live on the show they had spoken via sat phone to a climber on top of Kilimanjaro, Lev asked if the balloon could get higher and I said of course. Reaching the height of Everest at 29,000' and a bit seemed the way forward. With my beer head on, I had said the balloon could do it without really thinking about it. What would it matter we both would have forgotten the conversation by the morning. The conversation was forgotten but only for a couple of weeks. When revisited in the cold light of day, the problem of getting the balloon to height did not seem insurmountable. A quick check of the manufacturers slide rule load calculator proved that two of us could easily get up to 15,000' with a couple of hundred spare kilos of lift in hand. Sitting down with the formulas would be required for an accurate idea of what we could lift higher. Time to ask grown ups for help. I have a friend in Australia, Steve Griffin who makes a habit of taking small balloons to great heights. He holds several world records for one-man balloons and has even gone to the Arctic in order to get into efficient low temperatures. An email to Steve provided an excel spreadsheet which I had to modify slightly as he can't get much above 18,000' in a hopper. It had the maths sorted though. I ran the numbers and worked out that we would have at least 40Kg of spare lift at 30k. Working the old saying, measure twice cut once, I checked with another grown up, Simon Forse, the technical guy at Lindstrand balloons in England. He sent this jaunty equation, based on a 180 at an internal temp of 100C L = p x V Therefore L = V x p0 Im = 3.28084ft Where for 30Kft = 9143m or 9500m P0 = 0.43890 kgIm3 T0 = 226.4 0K V = 5100m3 T1 = 100 0C or 373 0K 0.60697 L = 5100 x 0.43890 L = 5100 x 0.43890 x 0.39303 L max = 879kg Ok so we could certainly lift the two of us. Getting into the stride of things it was time to address the environment in which we would be operating. The Internet, modern source of answers to everything quickly painted a picture. We potentially faced temperatures of -60C in 110 knot winds generally from the North West. I knew it was going to be cold but -60! The wind speed mattered not, other than selection of launch site. As long as it was slow for the landing. Every 18,000' that you climb halves the properties of the atmosphere at sea level. We would be operating close to