3 adjectives to describe upright

In the morning the arduous labors of the building began again, and though the prodigious appetite of Bull at the breakfast table made even old Bridewell look askance, Bull had not been at work an hour handling the ponderous uprights and joists before his employer was smiling to himself.

To the stout uprights are lashed transverse bars supporting three long parallel timbers running the whole length of the floor; on these seven or eight transverse poles are laid, crossed by about a dozen longitudinal and slighter ones, on which a flooring of long strips of the outer wood of the coconut-tree is laid across.

I looked for some traces of the wooden uprights, but although there is ample proof that they existed there down to our own time, my search was vain.

3 adjectives to describe  upright