63 series

63 series
A Yamanote Line 63 series, circa 1947
In service	1944–1963
Manufacturer	Kawasaki Heavy Industries
Constructed	1944–1950
Number built	688 vehicles
Number preserved	1 vehicle (as of April 2011)
Operator(s)	JGR (1944-1949) JNR (1949-1963) Kinki Nippon Railway (20 vehicles) Nagoya Railroad (20 vehicles) Nankai Railway (20 vehicles) Odakyu Electric Railway (20 vehicles) Sagami Railway (10 vehicles) Sanyo Electric Railway (14 vehicles) Tobu Railway (40 vehicles)
Line(s) served	Various
Specifications
Car body construction	Steel aluminium alloy (MoHa 63900-63902, SaHa 78200-78202)
Transmission	Cam shaft
Electric system(s)	1,500 V
Bogies	DT12 (TR25), DT13, DT14, DT15
Track gauge	1,067 mm (3 ft 6 in)

The 63 series (63系^?) (and its generic offshoots) was a commuter electric multiple unit operated by Japanese Government Railways (JGR) and Japanese National Railways (JNR). The cars that made up the 63 series were numbered as MoHa 63, SaHa 78 and KuHa 79.

The 63 series was originally introduced in 1944 as a means of transporting increasing number of workers commuting to factories of arms and other industries. Between 1944 and 1945, very few of these trains were in production, therefore postwar construction of these trains increased dramatically. These trains had brown, steel bodies. The cars were designed under the overall goal of mass transportation amid the serious shortage of supply in the wartime. This resulted in long body (20 meters), many doors (four per side), less seating, lack of ceiling and new design of side windows (consisting of three frames: only upper and lower frames can be opened).

In 1946, Kawasaki Heavy Industries began further production of the 63 series trains. This version had an aluminium alloy body instead of the steel body in war-time 63 series trains. Interior flooring was wood, luggage racks were installed, and seats were upholstered. However, the aluminium alloy used in exterior construction was easily prone to corrosion and the electrical systems were also prone to short-circuiting.

As a result of the loss of railways and rolling stock during World War II to supply steel for the war effort, demand for railway transportation was so great that some 63 series trains (120 vehicles) had to be supplied to private railway operators in Japan. Examples were Tobu Railway (40 vehicles), Kinki Nippon Railway (20 vehicles, classified as MoHa 1501) and Nagoya Railroad (20 vehicles, classified as 3700 series).