Yet again I've been looking through the books and internet. I focused on 1 Peter 2:24 (KJV)
[SUP]24 [/SUP] Who his own self bare our sins in his own body on the tree, that we, being dead to sins, should live unto righteousness: by whose stripes ye were healed.
The English "tree" is from Greek [FONT="]ξύλον[/FONT][FONT="] (xylon[/FONT]) which more closely identifies a structure more likened to a natural tree trunk with suitable branches, assembled by wooden staves. Straight poles were favored for burning people "at the stake", there being no intent to prolong misery. The emperor Nero in Rome favored the pole, upon which were tied Christians soaked in pitch to provide torch light along the main street leading to his palace for special events there. Had the Roman army chosen a pole they would have hung him on it by the neck, or made to be a human torch.
There's a lot of variation attributed to whichever band of Roman guards were involved in anything, the Italian band being used to carry out Jesus' crucifixion. It has often been assumed to copy Nero's method by some, but Nero applied the pole method about 64 AD when those soldiers were retiring to civilian life. The Jewish priests appeared to desire the most dreaded instrument that afforded the most agony, which would be the Roman's half tau stave cross complete with half seat. Much effort was spent to keep the convicted criminals alive as long as possible to allow the largest audience, then end the spectacle by hastening death by sword or spear to vital parts, followed by breaking leg bones to detect signs of remaining life. In Jesus' case they didn't break bones per prophecy fulfillment, finding Him well dead from the spear wound to His side.