KiHa 57 series

The KiHa 57 series was a low-capacity commuter diesel multiple unit operated initially by the Japanese National Railways and later by the Shikoku Railway Company from July 1961 to October 1991. In essence, these were a variant of the KiHa 58 series cars that were optimized for use on steep gradients, particularly the Usui Pass.
==History==
In the 1950s, new express trains were being introduced by JNR throughout Japan. The Nagano Prefecture also needed new railcars, particularly those with the capability to scale the Usui Pass.
The Usui Pass featured a 66.7‰ gradient, and as such most normal locomotives could not go over the pass; as such, an Abt rack and pinion system would be used. Tread brakes of older trains featured a lever which would contact these racks and could not move; most trains at the time featured these tread brakes. However, a train with disc brakes could go up the pass without issue. As such, a diesel railcar capable of scaling the Usui Pass had to be constructed.
Alongside the production of the KiHa 58 series cars were the KiHa 57 series cars, intended for use on areas with steep gradients. The cars began service in July 1961 on the Shiga (today the Asama Shinkansen service) and Maruike express services and were often used around Nagano. When in the Abt rack and pinion sections of a line, the cars did not operate on their own or performed cooperative driving; instead they were towed by a JNR Class ED42 electric locomotive up the pass.
Come 1963 however, the Abt rack and pinion system was replaced with an adhesion railway system and the KiHa 57 series were considered redundant, with new JNR Class EF63 cars being used to haul passengers and freight up the Usui Pass. Afterwhich, the KiHa 57 series cars were relegated to use on the Nozawa express service on the Iiyama Line, the Suwa and Nobeyama circular express services and the Kiso express on the Chūō Main Line. The cars were refurbished in the 1970s, with the cars being relegated to the Koumi Line and other JNR lines, with even some making it to Shikoku.
Due to their age by the 1980s and being surplus to requirements, most of the cars were scrapped starting 1984. By JNR's privatization in 1987, only two cars, KiHa 57 19 and 22, were still in operation; JR Shikoku assumed ownership of both cars. Both cars were assigned to Matsuyama Depot and painted in JR Shikoku's corporate livery and were retired on 9 October 1991. No KiHa 57 series cars have been preserved, although a mockup of KiHa 57 26 using the cab of KiHa 58 624 and a custom-fabricated passenger compartment was constructed and is located at the Yokogawa service area on the Jōshin-etsu Expressway in Gunma.
==Design==
The KiHa 57 series use a squared-off design similar to many other railcars of the time, featuring dual top-mounted sealed beam headlights. The cars were initially painted with a Cream No.4 "Wheat" base coat with Red No.4 "Scarlet" accents, the standard livery for JNR's diesel express cars; the two cars in JR Shikoku's ownership were painted with a white base coat with light blue graphics.
==Specifications==
Construction is of steel. Compared to the KiHa 58 series cars, the KiHa 57 series cars feature disc brakes as opposed to tread brakes; these were intended to allow them to scale the Usui Pass. The KiHa 56 series cars are equipped with a 178 HP (180 PS) DMH17H prime mover, with power transmitted through a Niigata Converter hydraulic transmission.
Category:JR Group trains
Category:Diesel trainsets
Category:Fuji Heavy Industries locomotives
Category:Nippon Sharyo locomotives
Category:Teikoku Sharyō locomotives