JNR Class EF62

Class EF62

EF62 46 on a farewell tour in 1997

Type and origin Power type Electric Builder Kawasaki, Tōshiba, Tōyō & Kisha Build date 1962–1969

Specifications Configuration: ​  • UIC Co-Co Gauge 1,067 mm (3 ft 6 in) Wheel diameter 1,120 mm (3 ft 8 in) Length 18,000 mm (59 ft 1 in) Width 2,800 mm (9 ft 2 in) Height 4,060 mm (13 ft 4 in) Loco weight 96 tonnes (94 long tons; 106 short tons) Electric system(s) 1,500 V DC Traction motors DC

Performance figures Maximum speed 100 km/h (60 mph) Power output 2.55 MW (3,420 hp)

Career Operators JNR, JR East Number in class 54 Preserved 4 Disposition All withdrawn

The Class EF62 (EF62形^?) is a Co-Co wheel arrangement DC electric locomotive type built between 1962 and 1969 for use hauling passenger and freight on the Shinetsu Main Line and particularly over the extreme 66.7‰ gradient of the Usui Pass between Yokokawa and Karuizawa. The prototype, EF62 1, was built by Kawasaki Sharyō in 1962, with the full-production locomotives built by Kawasaki, Tōshiba, and Tōyō & Kisha delivered from 1963 onward.

The EF62s were the first adhesion locomotives used on the Shinetsu Main Line following the abandonment of the under-powered ED42 rack-and-pinion locos dating from the 1930s. They were designed to work in multiple with pairs of the specially-designed JNR Class EF63 "Sherpa" locomotives between Yokokawa and Karuizawa.

While high adhesion was clearly an important requirement, the locos had to be designed with a low axle load (16 t, compared to 18 t for the EF63s) allowing them to be used on other sections of the Shinetsu Main Line with stricter axle-load restrictions. The need to reduce overall weight was one reason behind the decision to use the unique Co-Co wheel arrangement rather than the more commonly used Bo-Bo-Bo arrangement.

The need to reduce unnecessary weight led to the EF62s being the first DC electric locomotives in Japan to include an electric generator (320 kW) for train heating rather than using a steam generator. The locos also made extensive use of FRP (fibreglass-reinforced plastic) for roof panels, again to reduce weight.

Adhesion working started between Yokokawa and Karuizawa in 1963, and the journey time between these two stations was reduced from the 42 minutes taken on the old rack-and-pinion line to 17 minutes (ascending) and 24 minutes (descending). This enabled train frequency to be increased, and freight trains of up 400 tonnes could be handled by an EF62 assisted by two EF63s. The EF62s were able to operate over the entire route from Ueno to Nagano, and were thus seen on a wide range of duties from freight to express passenger workings. The 1970s however saw a switch from loco-hauled to EMU passenger trains during the daytime, and so the EF62s primarily became freight locomotives.