The position of the tower at our old house allowed the cement mixer to position its chute over the hole for the pour. This was not possible at the new house. In this picture you can see the cement being poured into a concrete pump. The concrete was pumped through a hose to the back yard location of the tower footing.
A word about concrete: The tower footing specifications called for a five-bag mix of concrete. That means five bags of Portland cement per cubic yard of concrete; the remainder of the cubic yard being sand and gravel. I like to overbuild, especially if the additional cost is low. By specifying a six-bag mix substantial strength is added for a small additional cost.
Because it is cheaper to buy ready mix by the truck load, you may want
to consider doing what I did. In addition to the tower footing, I
added an extension to our pool deck and replaced our disintegrating black top
driveway with a concrete driveway at the same time. This was all
accomplished with just the one truck load of concrete. We negotiated
a package deal with the contractor, so the driveway and pool deck added
only 20% to the total cost.