Confer with conductors and other workers via radio-telephones or computers to exchange switching information. Signal crew members for movement of engines or trains, using lanterns, hand signals, radios, or telephones. Observe and respond to wayside and cab signals, including color light signals, position signals, torpedoes, flags, and hot box detectors. Drive engines within railroad yards or other establishments to couple, uncouple, or switch railroad cars. Inspect engines before and after use to ensure proper operation. Apply and release hand brakes. Read switching instructions and daily car schedules to determine work to be performed, or receive orders from yard conductors. Inspect the condition of stationary trains, rolling stock, and equipment. Observe water levels and oil, air, and steam pressure gauges in order to ensure proper operation of equipment. Spot cars for loading and unloading at customer locations. Inspect track for defects such as broken rails and switch malfunctions. Ride on moving cars by holding onto grab irons and standing on ladder steps. Operate track switches, derails, automatic switches, and retarders to change routing of train or cars. Receive, relay, and act upon instructions and inquiries from train operations and customer service center personnel. Couple and uncouple air hoses and electrical connections between cars. Report arrival and departure times, train delays, work order completion, and time on duty. Pull knuckles to open them for coupling. Provide assistance in aligning drawbars, using available equipment to lift, pull, or push on the drawbars. Drive locomotives to and from various stations in roundhouses to have locomotives cleaned, serviced, repaired, or supplied.