N.Y. Railroad Law § 51: Weight of rail

§ 51. Weight of rail. The rail used in the construction or the

relaying of the track of every railroad hereafter built or relaid in

whole or in part shall be of iron or steel, weighing not less than

twenty-five pounds to the lineal yard on narrow-gauge roads, and on all

other roads not less than fifty-six pounds to the lineal yard on grades

of one hundred and ten feet to the mile or under, and not less than

seventy pounds to the lineal yard on grades of over one hundred and ten

feet to the mile, except for turnouts, sidings and switches.