A word of warning for planks that can be removed from a channel as a stall wall. They need a stiffening center support which is bolted THROUGH the planks, so that they can not be shifted or bent. We had a race mare at a training track many years ago. The stalls were built with plank walls, and not secured. It was all very old wood, very dry, very hard. She got cast in the night, and when we arrived to feed in the morning, she had kicked hard enough while cast to spread the boards, and her hind leg had gone between two of them, and they (naturally) snapped back together, holding her leg in there. We were two grooms, I opened the stall next door, and saw the leg coming through the wall, The other groom was opening the stall the mare was in, saw her standing there with her leg caught through the wall (she had got up like this, no one knows how). She was just standing there. The other groom pulled on the board (wrecked her back) and I got the job of lifting the leg out of the wall. Surprisingly, it was not broken, but severely damaged. It took a year for her to recover, and was heavily scarred.
So, keep this in mind when building stall walls where the planks slide down in channels in the wall, and may be considered to be “removable”. Use the center supporting vertical plank or metal flatbar, nailed or bolted solid to hold the horizonal planks from moving or spreading apart, should a horse get cast, and kick hard. Even “tongue and groove” boards can separate if not held together, if a horse kicks hard enough. Avoid disaster n advance if you can.