How to Build a 76 Foot Tilt Over Tower

(for antenna mast, light pole, or other light duty service)

This tilt over tower is designed to support up to 6 square feet of wind load at 76 feet above ground. Materials will cost approximately $1500.00 US and if you do all the labor manually you will invest about two man days in the basic construction and installation.

Materials:

3 ea. 6 inch x 4 foot auger earth anchors
1.6 cubic yards of concrete (48 ninety pound bags of ready mix)
30 feet heavy guage 60 inch tall mesh "hog wire" (commonly used to build hog fences and tomatoe cages).
2 ea. 20 foot x 4.5 inch schedule 40 aluminum pipe
1 ea. 20 foot x 4.0 inch schedule 40 aluminum pipe
1 ea. 20 foot x 3.5 inch schedule 40 aluminum pipe
1 ea. 20 foot x 3.0 inch schedule 40 aluminum pipe
1 ea. 20 foot x 2.5 inch schedule 40 aluminum pipe
2 ea. 16 inch x 1/2 inch galvanized bolts (with nuts and lock washers)
5 ea. 5 inch x 1/2 inch galvanized bolts (with nuts and lock washers)
2 ea. 4 inch x 1/2 inch galvanized bolts (with nuts and lock washers)
24 inchs of 2 inch x 2 inch galvanized steel angle iron
10 feet of #4 gauge solid copper ground wire

Tools:

Carpenter's Hammer
3/8 inch or 1/2 inch drill
1/2 inch spade bits for drill
2 adjustable wrenches
post hole digger or earth auger
two heavy duty pulleys (should be rated at 2,000 pounds
100 feet of 5/8 " rope
wheel barrow if you are mixing your own concrete
post hole digger
shovel
chipping bar

Construction:

Procure your tools and parts
Dig a 36 inch wide by 6 foot deep hole. If you have a problem with a shallow water table or sandy soil you can make the hole wider and shallower. Just remember you MUST use 1.6 or more cubic yards of concrete. An alternative size would be 48 inchs across and 40 inchs deep. If you are going to make the slab less than 40 inchs thick, I recommend you add ..25 cubic yards additional concrete for each 6 inchs you shave off. In no case should you reduce slab thickness below 24 inchs. A 24 inch slab would have to be very carefully reinforced and would have to be about ten feet in diameter to be safe.
Set one of your 6 inch earth anchors in the bottom center of the hole so that only a foot is left in the hole. This earth anchor is drilled into the ground in the bottom of the hole to act as your grounding point. Attach a heavy gauge (#4) solid copper wire to this earth anchor and extend it out of the hole well above ground.
Cut two 1 foot long pieces from each of your 20 foot sections of 4.5 inch aluminum. Use these to sleeve your 4.0 inch pipe at on one end and in the exact middle. This is done to reinforce the pipe where the long bolts will go through it. You have used two of four 1 foot long pieces.
Lay out the uprights and 4.0 inch riser on the ground so that the riser pole overlaps 14 feet of the uprights. The extra pieces from step four are used to keep the legs of the uprights properly separated. They are spacers which reinforce the upright poles and should be bolted between the legs of the uprights and set in the concrete.
Drill the holes and bolt the 4.5 inch uprights to the 4.0 inch riser pole. This will allow you to stand the uprights in the hole while you work on laying the concrete.
Set the uprights into the hole and level them
Cut your hog wire into managable sections and use your chipping bar to "wad" it up and push it into the hole around the uprights. When you are done you should have a hole full of wire in a pretty tight mesh. Alternatively you can play around with building a nice geometric patten with your pieces of wire and fill the hole that way.
Install the other two 6 inch earth anchors in the wire mesh so that they can be used as anchor points for your pulleys when you raise the tower. They should not be directly between the uprights, rather place one of them on the edge of the concrete on the side you intend to let the tower drop towards when taking the tower down. Place the other anchor 180 degrees across from the first. This will give you two tie downs which can be used later if you need them.
Level your uprights again.
Start mixing and pouring your concrete one or two bags at a time. After every eight bags you shold recheck the level on your uprights.
After the concrete is poured let it set for one week minimum before you stress it by raising your tower.
All that remains at this point is to sleeve the smaller aluminum sections together on the ground. They should be sleeved a minimum of 24". Place two bolts thru each sleeve section. The bolts should not be parallel. One should go front to back and the other should go side to side, thus forming an "X".
After your mast is assembled attach it to the first riser pole (the 4.0" pole) with a sleeve like the others.
Attach the stopping bar (2 inch by 2 inch galvanized steel angle iron) on the uprights. The purpose of this bar is to stop your mast from falling backwards when you get it fully raised. It should be located 4 feet from the ground. If you did not install a stopping bar, your mast could fall over backwards just as you get it fully raised.
Now attach your pulleys and rope to the mast and use your truck or a "come along" to raise your tilt over tower.