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SAFE Winch Launching
On Jul 5, 7:50*am, "Alistair Wright" wrote:
In all this discussion of winches, and the building thereof, no one has mentioned auto towing. The 'reverse auto tow' is the most efficient launch method I have ever encountered. We used it at the Essex Club at North Weald while I instructed there. You need a nice long runway, about 6000ft is ideal but shorter will do. The ingredients a 1) Two large automatic cars of about 100BHP - we used retired V6 Ford Zephyrs - we will call them car1 and car2. A driver and observer (who watches the glider) are required. 2) A large grooved pulley about six feet in diameter on a rotatable gimbal and anchored firmly to the ground. The pulley is at the opposite end of the runway to the launch point. 3) A piece of single strand piano wire the length of the runway. 4) Gliders with pilots. The wire is passed over the pulley and attached to car 1 which is sitting at the pulley and the other end to the glider via the usual rope, parachute, and weak link. Car 2 is sitting at the launch point. Slack is taken up, and at the all out signal car 1 sets off down the runway towards the glider which most obligingly lifts off, and sets off up what is now effectively a winch launch. Meanwhile car 2 sets off following the glider towards the pulley avoiding car 1, of course, which is driving at about 35- 40 mph towards the launch point. Glider releases, (we often got nearly 2000ft on a good day), and car 1 carries on the launch point while car 2 arrives at the pulley. The cable has launching tackle on both ends, so the next glider is coupled on and car 2 is connected to the cable and does the next launch .... need I go on? *We used to get 20 launches an hour using this method. No time is wasted retrieving cables. No need to buy an expensive winch, and the cheap cable lasted a long time. Ford Zephyrs were also fairly cheap from the scrap yard, and we had people in the club adept at fixing them. *As quite of lot of American clubs seem to have access to runways I cannot see why they cannot try this method of launching. I recommend it. Alistair Wright Having launched with EGC at North Weald a couple of occasions many years ago, my experience was a bit different. We got maybe 800ft in the K13, but I think the normal launch cars were broken down and a manually shifted Vauxhall was in use. Each time it shifted, the drogue chute was over the nose of the glider. I got 1200ft in the SHK on the other day. IIRC, airspace was limited to 2200ft until about five miles north. (Have to dig out an old chart that's archived somewhere). On the days I was there, only one vehicle was in use and on the first day, there was a wire snarl up on the pulley system (two big wheels) that delayed things for well over an hour. However, I do agree that the system may be very efficient. To that end, the old Cotswold GC system was, IMVHO, more elegant and required less people to operate http://www.coloradosoaring.org/think...ey/default.htm In addition to the long runway, CGC insisted on a lateral 2000ft clear zone around the pulley. Piano wire is nasty stuff when it breaks under tension. They also used rather more substantial tow vehicles and you couldn't launch modern K-21's, DG-50X's and 1000's and single seaters with Zephyr's. You can't discount the cost of powerful tow vehicles. We did okay at Enstone GC with an XJ6 Jag on auto tow. After many years, Cotswold GC reverted to winching. http://www.cotswoldgliding.co.uk/ They formerly had a history page about the reverse pulley, but I don't find anything on their web site now. They do mention that learning to glide is cheaper than learning to drive though;^) We do have some long runways in the US, but few are lacking runway lights or other obstacles that are too close to entertain reverse pulley launching. On these same runways, it's quite feasible to winch using the UHMWPE ropes. Regards, Frank Whiteley |
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I never felt concerned with any of my winch launches... even my 50ft cable break. And learning to operate the winch after going solo was also an experience I wouldn't give anything for. I'm happy with my aerotows as they get me a bit higher than any of my winch launches... but from one who has done both, I'd say that I would be happy with either. Both are as safe as the pilot being launched and the launch operator, be it winch or tow plane. |
#3
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SAFE Winch Launching
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#4
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SAFE Winch Launching
China Shenzhen ZHAOWEI Machinery & Electronics Co. Ltd engages in designing, manufacturing and marketing all kinds of electric motors. They are mainly suitable for the following applications: smart home application used in smart kitchen and laundry, medical instrument for personal care, smart E-transmission applied in automobile, industry automation applied in telecommunication and a great variety of plastic/metal planetary gearbox in different sizes.
In order to develop the oversea market, we are current seeking new partners around the world to create a bright future together. ZhaoWei is a right choice and excellent partnership with sincere services. Company: Shenzhen ZHAOWEI Machinery & Electronics Co., Ltd URL: http://www.zwgearbox.com/ Contact: Annie Liu Tel:+86-755-27322652 Fax:+86-755-27323949 Add: Blk. 18, Longwangmiao Industry Park, Fuyong Tn., Bao’an Dist., Shenzhen 518103, Guangdong, China |
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