KiHa 55 series

KiHa 55 series is an umbrella term for a number of similar diesel multiple units operated by the Japanese National Railways from October 1956 to March 1987, mainly on express services. The KiHa 55 series family consists of the KiHa 55 (formerly KiHa 44800 series), KiHa 26, KiRoHa 25, KiRo 25, KiUNi 26, KiNi 26 and KiNi 56 series cars.
==History==
The KiHa 55 series cars were developed to feature performance that would surpass that of the KiHa 10 series cars in service. These were the first semi-express diesel railcars manufactured for the JNR, and these were often used on honor trains on the JNR. A total of 486 cars were manufactured by Fuji Heavy Industries (now Subaru Corporation), Niigata Tekkō (now Niigata Transys), Nippon Sharyo, Teikoku Sharyō (now defunct) and Tokyu Sharyō (now J-TREC) from 1956 to 1960.
With power that far surpassed the capabilities of steam locomotives and equivalent amounts of comfort interior wise, the cars became the driving force for the JNR to establish semi-express trains throughout Japan, with the cars enabling high-speed operation even on graded lines. The cars entered service on the Nikkō express service (now a limited express service) on 10 October 1956; these were immediately nicknamed the Nikkō Diesel Train or the Nikkō Train by commuters who rode on them.
The KiHa 55 series cars were a success for their performance, and more cars began manufacture immediately. These would be used throughout all regions from Japan, from Kyushu to even Hokkaido, despite the fact that the cars were not engineered for use in cold weather situations. In 1961, the KiHa 58 series railcars began production; these were regarded as superior in comfort to the KiHa 55 series cars, and thus operations of the latter were gradually reduced, even on honor trains.
These were later operated in tandem with the KiHa 58 series cars on express services, but with the number of KiHa 58 series cars increasing, operations of the KiHa 55 series cars was reduced even further. The cars were then switched from express services to local services on rural lines in 1982, but due to the surplus of KiHa 58 series cars with air conditioning waiting to be used, the KiHa 55 series met their end. On 31 March 1987, one day before JNR was privatized and split into seven different companies, JNR retired the entire series of KiHa 55 series cars, and began scrapping them shortly after. No KiHa 55 series cars have been preserved.
Despite none being preserved, the cars have cemented their legacy in JR history. A number of originally semi-express and express trains originally operated by KiHa 55 series cars have since been upgraded to limited express services, and the KiHa 55 series cars are credited for expanding honor train services from rural lines to city lines.
==Design==
The KiHa 55 series use a squared-off design similar to many other railcars of the time. These cars feature a single large headlight casing with dual sealed beam headlights. The cars are painted with a Cream No.4 "Wheat" base coat with Red No.4 "Scarlet" accents, the standard livery for JNR's diesel express cars.
==Specifications==
Construction is of steel. The cars feature large two-abreast seating similar to passenger cars with vinyl headrests. The cars featured onboard cooling through the use of fans. Toilets were equipped on some of the cars. The KiHa 55 series cars are equipped with a 158 HP (160 PS) DMH17B prime mover, with power transmitted through a Niigata Converter hydraulic transmission. The cars use the same DT19 bogies as many other trains of the time; ride quality was noted to be poor for these bogies, but as there were no other mass-produced bogies that were compatible with the cars at the time, JNR could only use these bogies.
==See also==
*Nankai KiHa 5501 series, similar series of railcars produced for Nankai Electric Railway
*Shimabara KiHa 55 series, similar series of railcars produced for Shimabara Railway
*Kantō Railway KiHa 755 series, similar railcar produced for Kantō Railway
Category:JR Group trains
Category:Diesel trainsets
Category:Fuji Heavy Industries locomotives
Category:Niigata Tekkō locomotives
Category:Nippon Sharyo locomotives
Category:Teikoku Sharyō locomotives
Category:Tokyu Car locomotives