MA&C roadbed construction

This is my spline sub-roadbed. I rip the splines on my table saw to a width of 1/8th" with 3/4" spacer blocks. It is attached to the risers with 4d coated sinker nails and wood glue. I attach the middle spline first in sections up to 20' and then come back and complete the sides after I'm satisfied with the alignment.