4. Rolling stock design

4.1 General technical design

The evolution of electric streetcars can be summed up as follows:

• 1881: first two-axle railcars with a traction motor transmitting its force by means of a chain, wooden body with external sheet metal finish;

• 1891: First bogie locomotives;

• 1915: first "Peter Witt" streetcars with front entrance and middle exit in Cleveland U.S.A., payment to a ticket collector seated near the exit door;

• 1928: Massive construction of "Peter Witt" railcars with automatic start in Milan (502 railcars), Turin (216 railcars), Naples (106 railcars), Trieste (48 railcars);

• 1935: appearance in the USA...