12 in a row-competition

With many thanks to Kate Jones(USA) for this problem.
Start with a set of pentominoes :

Look for an arbitrary shape in the plane which contains a line of exactly 12 squares where each pentomino covers one of these squares.The shape must not contain holes.
Try to maximize the perimeter of the shape. In the example of Kate (see the red line), the perimeter is 54.
12 in a row

For solving the problem Exel can be used. We have a file containing the pentominoes.