R1/R2 Curved Turnouts. The R1/R2 curved turnout is specially adapted for the curved track in these two radii, i.e. the inner curve on the turnout is the same as Radius 1, the outer curve is the same as Radius 2. In both cases the curves on these turnouts have a special geometry to enable these turnouts to be used in a large variety of ways. Curved Turnouts for Radii 1 and 2. The turnout branch is 42?. Optional Stop Turnout function included. An electric mechanism can be installed on these turnouts.