Since the awning will be suspended above the bells, well above the height at which the walls are vertical and measurements can be taken directly, it has taken some time and experiment to determine the shape and dimensions of the space it will occupy and the awning itself.
The ropes that will reinforce the edges and the long diagonal of the awning have been rigged into their planned dimensions and hoisted up to their eventual location, and this has helped determine the size of the space and the size of the awning to cover it.
It appears that the awning should occupy a space 122″ square. This should cover the area through which water is dripping. This square begins about 64″ above the ledge, or 144″ (12′) above the ringing chamber floor.
However the awning itself will not be square. To direct water down off the awning, it will be lofted with three corners 64″ above the ledge and the fourth, on the north-west, 16″ above the ledge, resulting in a shape with a diagonal crease from SE to NW. As a result, its two horizontal sides will be 122″ long and its slanting sides will be about 127½” long. None of its corners will be right angles.
The bottom diagram shows views of the awning from eight directions, at awning height (it would be very difficult to actually get to that viewpoint in the bell chamber). The top of the awning is shown light-colored, the bottom dark-colored.