Nankai 21000 series electric multiple unit, Japan

The EMU, built for the Nankai Electric Railway, was nicknamed the "Zoom Car" (or Maru Zoom). Introduced in 1958, these units were specifically engineered for the challenging, steep mountainous terrain of the Nankai Kōya Line leading up to Mount Koya. 

After retirement from regular Nankai service in 1997, some units were transferred to other operators like the Ōigawa Railway, where they continue to run as heritage tourist trains. 

Maximum speed: 100 km/h on flat plains and 30 km/h on steep mountain sections.
Length: 17,725 mm per car.
Width: 2,720 mm
Height: 4,000 mm
Weight: 37.0 tonnes per car.
Track Gauge: 1,067 mm (3 ft 6 in) narrow gauge.
Electric System: 1,500 V DC overhead line.
Traction Motor Output: 70 kW per motor.
Total Train Power: 280 kW per car. A standard 4-car set generated 1,120 kW because every single car in the formation was an all-motor vehicle
Motor Model: Toyo Denki TDK-820-B.
Control Method: Resistor control via the Toyo Denki ACD-10 system.

Acceleration Rate: 3.1 km/h/s
Deceleration Rate: 4.0 km/h/s
Engineered to descend and climb extreme 5.0% gradients on the Mount Koya line.