        0,   0,   0,
          100,   0,   0,
          100,   0,  30,
            0,   0,   0,
          100,   0,  30,
            0,   0,  30,

          // top rung right
          100,   0,   0,
          100,  30,   0,
          100,  30,  30,
          100,   0,   0,
          100,  30,  30,
          100,   0,  30,

          // under top rung
          30,   30,   0,
          30,   30,  30,
          100,  30,  30,
          30,   30,   0,
          100,  30,  30,
          100,  30,   0,

       