Stroll Down the Lane

From facing lines: The end on the left presses out to meet the other end, then they Recycle and Veer Left. The centers Hammerlane and step forward.

\syhlines{g3s,b3s,g2s,b2s} \sxhbigbone{b2s,...,g1n,...,b3s,g4s} \syhlines{b1n,g2n,g3s,b4s}
3 1 3 1 2 4 2 4 2 4 1 3 3 1 4 2 1 3 2 4 3 1 4 2
before Stroll Down the Lane Press Out Hammerlane after