This is something I've always wondered about. "The Last Temptation of Christ" has Jesus carry only the beam--the "stipes" is already at the site. But, they've taken it out of the hole, they attach the beam, then nail the body, and lift the whole thing. Andy01's story "An Execution in Arlete" has Livia carry only the beam, but it has a hole in the middle which is fitted to the upright through a peg at the top of the upright which fits in the hole.
I think the execution party was more interested in making the crucifixion easier for them. I also think a cross that would hold up under the strain of a crucifixion would be too heavy to carry. But there would then have to be a way to secure the "patibulum" to the stipes that would also hold up under the strain, and doing it with a writhing body attached is probably a little difficult. Since the stipes at least was reused, there also had to be a relatively easy way to remove the patibulum after the "festivities" were finished. So, I like Andy01's idea best from an engineering standpoint. It is unlikely they would fashion the whole cross for each prisoner and waste a lot of wood--the stipes could accommodate a lot of different heights and weights. The patibulum might have to be more customized for each individual. Josephus says that during the siege of Jerusalem they ran out of wood and just nailed people up on the walls. So it was probably mostly a practical matter in each instance, and varied somewhat with the circumstances.
I have also read (Hegel, I think) that most crosses were about 6 feet tall and were only taller for a prisoner the Romans wanted particularly to display (don't know how he determined that, since descriptions are fairly sparse in ancient literature). Also, an historian of the Spartacus revolt said (sensibly) that crucifying six thousand people was expensive. Again, what's practical?
Personally, I prefer things being done in a way that is realistic and maybe actually happened or at least could happen. That makes it more interesting--it might really happen.
Good aspects Frank.
Due to my interest in roman history, and the to me exciting punishment of crucifiction,
the scenario at the execution site has always left countless questions for me, too.
If there has been something like a code of practice for the roman crucifiction, what were the single stages?
Today we think that the victims have been flogged, had to carry the crossbeam and were attached to
their crosses at a specific place, prepared for these executions.
That makes sense, so far.
I came to the conclusion (but that is my point of view, everything could have been possible), that part of the entertainment factor was, "how" the victims got crucified.
The teams crucifying had to humiliate the victims, deter, entertain and animate the audience.
Had to make sure the spectators accepted the dying as scapegoats.
Were responsible, to turn the crucifiction into a really breathtaking event.
So to say, raising the cross complete, just attaching the victim with the patibulum, nailing, tying, stripping could have
been elements that were deployed by the executioners, to create different scenarios and emotions for the crucified and the audience.
Bad enough that there is not that much documentation left, what role the crucifiction had really been playing in the roman culture,
or about the ways how it was done.
The shape of the crosses and who was actually carrying out the executions (female/male executioners) should also be considered.
How did the executioners behave?
What did they wear?
Hard to tell, but I'm pretty sure it was an outstanding spectacle.