Rigid Circles in Squares

The following pictures show n unit circles packed inside the largest known square (of side length s) so that the circles are rigid.


1.            2.            3.
s = 2
Trivial.
s = 2 + √2 = 3.414+
Trivial.
s = 2 + 1/√2 + √6/2 = 3.931+
Trivial.


4.            5.            6.
s = 4
Trivial.
s = 2 + √2 + √6 = 5.863+
Found by Erich Friedman
in 1998.
s = 4 + √3 = 5.732+
Found by Erich Friedman
in 1998.


7.            8.            9.
s = 5.985+
Found by David Cantrell
in August 2006.
s = 6.946+
Found by Craig Clapp
in August 2006.
s = 7.022+
Found by Erich Friedman
in 1998.


10.            11.            12.
s = 4 + √3 + √2/2 + √6/2 = 7.663+
Found by Craig Clapp
in October 2006.
s = 4 + √2 + √6 = 7.863+
Found by David Cantrell
in July 2002.
s = 7.983+
Found by Craig Clapp
in August 2006.


13.            14.            15.
s = 8.992+
Found by Craig Clapp
in August 2006.
s = 9.055+
Found by Craig Clapp
in August 2006.
s = 9.032+
Found by Craig Clapp
in August 2006.


16.            17.            18.
s = 9.177+
Found by David Cantrell
in July 2002.
s = 2 + 2√6 + 2√2 = 9.727+
Found by Clint Weaver
in July 2002.
s = 10.276+
Found by Craig Clapp
in August 2006.


19.            20.            21.
s = 10.348+
Found by Craig Clapp
in August 2006.
s = 10.497+
Found by Craig Clapp
in August 2006.
s = 10.530+
Found by Craig Clapp
in September 2006.


22.            23.            24.
s = 10.764+
Found by Craig Clapp
in August 2006.
s = 10.982+
Found by Craig Clapp
in September 2006.
s = 8 + 2√3 = 11.464+
Found by David Cantrell
in July 2002.


Are these circle packings by Craig Clapp rigid? 15   16   16   16   19   20   21   22   22   22