It is not the Watchtower that states that Jesus died on a stake. The Bible says that Jesus died upon a stake. The original Greek word used to signify the instrument used in Jesus’ execution was staurous. The original meaning of the word meant, simply, an upright stake or a pole. But over the centuries that simple truth was gradually twisted to mean a stake with a crossbeam. This was obviously done to legitimize the use of the cross as a symbol of worship in Catholicism. (Wikipedia on meaning of staurous)
Common sense ought to dictate though, that, the most efficient means of execution by the Romans was nailing the victim to an already standing tree or pole.
Unfortunately, common sense doesn’t seem to factor into dearly-held religious beliefs. But ask yourself: Why go to the trouble of making a crossbeam when a single pole will do the job? Keep in mind that power tools did not exist back then. It was a lot of work and very time consuming to cut a tree down with crude hatchets or hand saws. A crossbeam would necessitate twice the work – more than that really, as a notch would have to be painstakingly chiseled into both timbers in order to fasten them together. It seems very unlikely that the Romans would have gone to all that trouble. It seems the Catholics have gone to a lot of trouble to construct one of their many myths.
As regards the positioning of Jesus’ hands, no one can say with certainty how his hands were positioned. A Watchtower artist may illustrate Jesus’ hands with one nail through them both, but that may not be how it was in reality. It may well be that Jesus had a nail through each hand nailed to each side of the stake. That would certainly fit within Jesus’ use of the plural – as in “nails.”
What we do know for certain is that variations of the cross were pagan symbols of worship long before the advent of Christianity. And given the fact that Christendom has derived virtually all of its beliefs and practices from pagandom, we may say with a high degree of certitude that the same was done with the cross.
(Supplemental information on stauros in the New Testament.)
Watchtower asks: Did Jesus Really Die on a Cross?