Curtain tracks shall be of 14 gauge galvanized steel construction entirely enclosed except for slot in bottom, each half to be in one continuous piece except where splicing clamps are required. Each curtain carrier (Model 1701) shall be spaced on 12" centers and shall be of plated steel construction with two polyethylene wheels held to the steel block by a rust-proof nickel plated rivet, such wheels rolling on two separate parallel treads. Each curtain carrier shall consist of a free-moving plated swivel to accommodate curtain snap hook. Live-end (Model 1703) and Dead-end (Model 1704) pulley blocks shall be adjustable and shall be equipped with 1-13/16" diameter sleeve-bearing wheels adequately guarded. The manufacturer shall furnish two end stops (Model 1709) for placement at each track end and a tension floor pulley (Model 2865) for increasing cord tension. Stretch-resistant operating cord (Model 1728), for hand operated track systems, shall have synthetic center and shall be of 1/4" diameter, extra quality yarn. Machine operated tracks shall use 3/16" diameter wire center cable (Model 3529). Model 170 as manufactured by Automatic Devices Company of Allentown, PA
