New York Consolidated Laws, Railroad Law - RRD § 79. Air-brakes

It shall be unlawful for any railroad or other company to haul or permit to be hauled or used on its line or lines within this state any freight train that has not a sufficient number of cars in it so equipped with continuous power or air-brakes that the engineer on the locomotive drawing such train can control its speed without requiring brakemen to use the common hand brake for that purpose.