Problem #$2$ Vertical Curve$-$ Finding Curve length.

The approach tangent to an equal$-$tangent vertical curve has a slope of $+3\%.$ The slope of the departure tangent is $-2\%.$ These two tangents intersect at station $26+00$ and elev. $231\mathrm{.}0$ft$.$ A se of subway rails passes below and perpendicular to the curve at station $28+50$ on the departure side. The maximum elevation of the railbed at that point is $195\mathrm{.}0ft.$ Allowing for depth of the roadway and the overpass structure, the minimum clearance between the roadbed and the railway surface is $26\mathrm{.}0ft.$

Determine the length of the curve to meet these conditions.