Lionel started producing ZW 250’s & VW 150’s starting in 1948. The ZW was rated at 250 Watts (180 to track at 15 amps) and evolved through the final ZW type R in 1966. The ZW evolved continually with parts and pieces continuously updated. The VW was rated as rated at 150 Watts (110 to track 8 amps max) and was built in 1948 and 1949 only. This page will show how the ZW’s evolved through time. After working with these for so many years it quickly becomes apparent that all of these changes were to build these cheaper with less parts and labor which thankfully made them run more quietly and cooler.