First, we started by forming the posts 9" X 9" square. Each has two pieces of 3/8" re bar running longitudinally in diagonal corners about 2" from the surface of the concrete. There is also a 3' piece of the same size re bar which is bent double to form a loop which sticks out the top of the post a couple of inches to form a lifting eye. Keep in mind, each of these posts will weigh about 400 pounds so, a lifting point is pretty important. One last internal detail is to provide for the gate hinges which are the through bolted type using a 3/4" bolt, about 10" long. We pre-made a couple of holes through the posts by positioning 9" long pieces of 1" square tubing laterally through the forms making very sure they were in the correct position for the gate hinges and that they would be in absolute vertical alignment when the post was set. They were poured right here on the floor of the shed where I park the Caterpillar so that I could work in the shade. Here they are after the forms are removed:
Living in the Texas Hill Country is great and it is very beautiful, however, there is one big draw back and that pops up any time you want to dig a hole. You don't use post hole diggers to dig a post hole around this part of the country. Those are only for cleaning out the debris which is, hopefully, loosened after you have pounded away with your rock bar. There are times you hit something you simply can not get through. I can recall a couple times using a skid loader mounted rock bit with carbide teeth and and turning for 20 minutes with the front wheels of the loader completely off the ground, without cutting one inch into the rock. Fortunately, stuff that hard is rare as it is mostly limestone.
Here is how you set a 400 pound post in the hole and a closeup of one the hinge holes:
Here is the way I like to permanently set a post. We dig this caliche right out the hillside with the loader and mix 5 shovel fulls with 1 shovel full of portland cement and dry tamp it very tightly in the hole. You just can't believe what a rigid post this makes! Here are the photos in order - caliche, portland cement, mixing it all together, tamping it in the hole:
This is closeup of one of the hinges in place:
And here is the finished gate:
This is a 14 foot, 2" tubing gate purchased from Tractor Supply and it comes pre-painted. I would have liked to have built the gate myself but, you simply can not justify building one when they only cost $155 at Tractor Supply. There is about 100 feet of 2" tubing which would have probably cost more than the completed gate. By the time you add in hardware, painting, welding rod, etc., it is a no brainer.