In 1921 ALCO-GE built twelve electric locomotives for the Paulista of which eight were designed for freight traffic. The first line that had been electrified with 3 kV DC was the one between Jundiahy and Campinas that was 45 km long and had inclines of 1.8 percent. The main reason for electrification was that fire wood for steam locomotives had become scarce and good coal was difficult to obtain.

The freight locomotives had two two-axle bogies with a 420 hp traction motor on each axle and a boxcab body that led to the nickname “Quadradinha”. Haulage capacity on 1.8 percent inclines was 700 tonnes at speeds between 19 and 26 km/h. When running downhill, they could use their regenerative brake. Originally numbered 204 to 211, they were later renumbered to 401 to 408. When FEPASA was founded in 1971, they became class 6400. They were withdrawn between 1974 and 1978.