 |
| This was the disaster of my "freestanding" tower |
 |
| The crank over base snapped in the 90 mile wind |
Back in the 1970s I acquired a Wilson tubular crank up crank over tower. It rested at 23 feet cranked down and cranked up to 45 feet "self supporting" . When I moved to the country I reconstructed it with a new cement slab and all was well until 2001 when a sheer wind hit the beam and tower at 90 mph and down it came bent and destroyed. So much for "free standing". Fortunately, I had a special insurance rider. I actually found a Wilson 55 for sale by the Arizona forestry service on eBay and there it was in me driveway on a flat bed truck $700 later. The crank over base was rebuilt and heavily welded (it actually had snapped at the base weld point)so let's try again but this time with guy wires!!
 |
| This is the tilt over which had to be supported by guy system |
Remember this tower cranks up and cranks over ,so how was I to engineer the guys? This is the purpose of this discussion for those of you faced with the similar engineering dilemma. No matter how high you have cranked up you want the guys to be attached. You want two guy levels, at all times. and when we crank over -- what happens to the guys?
The Wilson tubular tower series has gone the way of extinction but the similar design of the US TOWER MA series and this article may be relevant to those owners. Any crank up/ Crank over Rohn type tower with a winch crank over might benefit by these ideas. Do not risk the "free standing " tower coming down. It doesn't matter how much concrete you poured That puppy will flatten in a 90 mile wind for sure.
Here is what I did. I wanted winchable guy wires in 4 directions.. Two were on guy post out in the yard ,
Two were on the sides of the house.
The first guy wire is big 3/8 inch and it does not winch. It holds the tower at the top of the first section that does not crank up.It attaches with a turn buckle hook end hooked to an eye bolt. On my tower that is at the 23 foot level.( the level beyond which you cannot crank down.) The two house mounted guy points are ground mounted and house bracketed poles. One Guy point also serves as a 35 feet high mast for inverted vees but the lower guy comes down to just above the roof line on that 35 foot mast anchored by a house bracket and the lower guy line hooks on to and eye bolt.
On the southwest side of the house I use a telescoping mast held by a house bracket and in concrete at the base. Here again the lower and heavier guy wire hooks on to an eye bolt.
Still focused on the lower guy I had to concrete 2 properly positioned guy poles in my yard and the lower guy wire hooks to the eye bolt midway down the 5 foot guy post. .All our of the lower guys are removed by unhooking them when the tower is tilted for ground work.
Now for the top set of 4 guys. Here I used smaller diameter guy line. (1/4 inch) . Remember,If I crank the tower up or over you want the guy lines to follow. This was done using small winches that I got at Loews. The winch is affixed to the top of the guy posts and on the side of the house I put a pulley at the 12 foot mark on the side polls and the winch at shoulder level. I ran the top guy wire through the pulley and down to the winch and wound it onto the winch. In doing this I used enough guy wire on the winch spool so that when I cranked the tower over, I would pull out enough excess guy line on the winch that the tower would lean over and pull the loose line as it came down taking the excess line with it at no resistance as it goes but still attached to the winch .
The lower guys are unhooked from the eye bolts on a crank over but both sets of guys are attached permanently to the tower. I walk the lower guy lines over so they don't catch on anything when I crank the tower over and again the top guys have the excess pulled out of the winch so the loose excess just follow the tower over. Works perfect unless you forget something. Don't forget anything.!!
Ok work is done time for the crank up. At vertical, the first thing you do is secure the lower guys to the eye bolts on the guy poles. Then I want to crank up to about 40 feet(I only go 55 in combat) . So I crank up to 40 feet, The lower guys are in place. They don't move. Now I go to each guy post and winch in the top guy line until it is tight (not too tight -- you don't want to pull your tower down) . Then I go to the next winch and bring it tight -- and the next etc. THERE IT IS!! That baby is flying again with repairs done . 1 hour 45 minutes.all guys are reset and that baby ain't coming down. One word of advise. Do not set your top guy wire too low . I set it the first time 7 feet beneath the rotor. Big wind came and bent it over 7 feet from the top. Major error!! Set top guy wire two feet below beam the next time-- works perfect.
See other pictures below below.
I hope this helps some ham somewhere. Ask any question a tw5zo@arrl.net
I know . You need to see Crank over pictures. When I do that, I'm Pretty pumped and I don't think pictures. This system works great . It obviously is given to your particular real estate. but I have 2 acres and did not want guys running everywhere. This idea had great merit for your creativity. Crank over - Crank up -- never climb!!
