The young guys still have a healthy fear of the place." "There was one scene where Robert Shaw was to step on the third rail", Sargent recalled. "When we were rehearsing the scene, Shaw accidentally stubbed his toe and the sparks from his special-effects boot flew everywhere. He turned white as a sheet. We had eight weeks of that. I think we got out just in time. It was like coal mining." According to a notation on IMDb, the crew wore surgical masks during the tunnel scenes. Shaw's biographer, John French, reported: "There were rats everywhere and every time someone jumped from the train, or tripped over the lines, clouds of black dust rose into the air, making it impossible to shoot until it had settled." Matthau, who had one scene in the tunnel, said, "There are bacteria down there that haven't been discovered yet. And bugs. Big ugly bugs from the planet Uranus. They all settled in the New York subway tunnels. I saw one bug mug a guy. I wasn't down there a long time—but long enough to develop the strangest cold I ever had. It stayed in my nose for five days, then went to my throat. Finally I woke up one morning with no voice at all, and they had to shut down for the day." According to Backstage, the filmmakers were the first to utilize a "flash" process developed by Movielab to bring out detail when shooting with low light in the tunnel. The process reportedly increased film speed by two stops. It allowed the filmmakers to use fewer lights and generators and cut five days out of the schedule. At least two different R22 trains portrayed Pelham 1-2-3. As it enters 28th Street station, the head car is labeled 7339. However, in an early scene at Grand Central, 7339 is seen on the express track across the platform. Later, after being cut from the rest of the train, the head car is labeled 7434. R22 cars first went into service in April 1957, and the vast majority of the 450 cars were scrapped in 1987. After two months in the tunnel, production moved to Filmways Studios at 246 East 127th Street in East Harlem, where a replica of the Transit Authority's Brooklyn control center was constructed. Built around 1920 as Cosmopolitan Studios, the facility was leased in 1928 by MGM for sound production and