The client uses a wheelchair. The passage from her bedroom to the bathroom crosses the head of the stairs, and the top step is very close, such that a small error in turning the chair out of the bedroom risks a front wheel rolling over the step and the wheelchair tipping over.
There was no room for a conventional stair gate, so one was designed along the lines of a level crossing barrier. The main pivot was made from a tubular door stop and a coach bolt, and the remaining joints made from a brass butt hinge and two coach screws. Brass tubes and washers were used to protect the softwood members. The design was such that in the vertical (stowed) position, the three moving members folded in a stack onto the fixed vertical member, thus minimising the obstruction to the stairs. For maximum strength in the down position, the lower bar was braced against the side walls, while the upper bar was inset into the vertical member at the hinge end, and into a notched plate secured to the opposite wall at the other end. The client wanted the gate to match the pine doors and skirtings in the passage, so the gate was made from pine where available, and otherwise from suitably-stained spruce.
The client can now use her wheelchair upstairs without her previous fear of it tipping her down the stairs.