The T-bar trellis system consists of posts in rows with a cross arm at 6 feet high. T-bars are less expensive to construct, less labor intensive, better suited to bee pollination, and they reduce the risk of botrytis infection. However, pergola systems tend to produce more yield per acre and the fruit are less susceptible to wind damage. Also, once the full canopy is established in a pergola, the shade reduces weed growth. The kiwivine fruiting canes are tied to wires on top of the cross arm.
Square posts are easier to work with.
Drive posts 2 to 3 feet into the ground. Use end posts that are at least 6 inches in diameter, and drive them at an angle with the top of the post leaning 1foot from perpendicular away from the row. Anchor the end posts well. The top of the cross arm is 6 feet above the ground. Cross arms usually are a 2 x 6 inch board bolted into a cut notch on the post.