Road Tech - just a bit of an update for you - solid state motor controllers were first introduced in electric in 1966 in the US. The first companies were Allis Chalmers w/PWM (AC designed transistor controller) & Eaton Yale & Towne (I believed they called it a Tec 5 - I stand to be corrected on that point). Both companies claimed to be the first to introduce solid state controls in lift trucks. Shortly. after 1967, the rest of the industry, Clark, Lewis Shepperd, etc equipped their elctrics with GE SCR controls. Hyster & Towmotor did not have elctrics at that time. Hyster got into elctric by buying Lewis Sheppered.
I joined Allis Chalmers in 1967 & worked on the service/parts manuals for the PWM controls in their 8000/10000 electrics with dual drive motors. In 1966 AC enjoyed 32% market share of the sit down elcectric market but by 1969 it dropped to ~10% when other introduced the GE controllers.