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 = 7.519+
Found by David Cantrell
in July 2002. 		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