Three constraints applied at once. The covers are lifted daily, which set the maximum panel size by what one person can handle rather than by what covers the channel in fewest pieces. The floor is washed down, which ruled out anything that holds residue. And the slab depth was limited, which constrained the bearing bar depth available.

Press locked stainless answered the first two: no weld bead to hold residue, and the same material across the whole surface. Acid passivation after fabrication restored the passive layer that cutting and forming disturb, which is what prevents rust spotting on a new stainless panel.

The depth constraint was handled by closing the bar pitch rather than deepening the bars, trading some drainage area for the stiffness the shallow section could not provide on its own.