JNR Class DD42

JNR Class DD42
Kashima Railway DD901 (ex-DD42 1) in February 2007
Technical specifications
Manufacturer(s)	Nippon Sharyo
Type of locomotive	Diesel locomotive
Constructed	1955
Number built	1
Classification	B-B
Dimensions	14,050 mm × 2,724 mm × 4,022 mm
Gauge	3 ft 6 in (1,067 mm)
Prime mover	DML61S/Z prime mover
Service information
In service	3 June 1957 – 31 March 1958 (in JNR service) July 1958 – 13 March 1988 (on private railways)
Number in service	None
Fleet numbers	DD42 1
Scrapped	2007
Preservation information
Preserved	None
Number scrapped	1

The JNR Class DD42 was a diesel-hydraulic locomotive operated by the Japanese National Railways and later by various incarnations of what would become the Kashima Railway from June 1957 to March 1988.

History

The DD42 was a prototype diesel-hydraulic locomotive used by the JNR, with a single locomotive prototyped while the company developed its own locomotives for domestic sales as well as potentially for export. A total of ten locomotives were prototyped; these were Hitachi's DF90, DF91 and DF93, Kawasaki's DF40, Kisha Seizō's DF41, Nippon Sharyo's DD42 and DD93, Shin-Mitsubishi's DD40 and DD91 and Toshiba's DD41.

One locomotive was built in September 1955 by Nippon Sharyo, with the serial number of 1766. Test runs would be conducted on the Meitetsu Nagoya Main Line. The locomotive was purchased by the Japanese National Railways on 3 June 1957, numbered DD42 1 and deployed at Nagoya Rolling Stock Center where it was mostly used for switching duties at the now-abandoned Sasajima Station. Deemed unsuitable for switching due to the arrangement of the drivers's cabs, DD42 1 was taken out of JNR service on 31 March 1958 and returned to Nippon Sharyo.

In July 1958, DD42 1 was purchased by the Jōsõ Tsukuba Railway and put into service pulling freight trains, renumbered DD901 and assigned to the Mitsukaido Depot. DD901 came under ownership of the Kantō Railway on 1 June 1965 when the Jōsõ Tsukuba Railway merged into the Kantō Railway. DD901's engine and transmission were replaced in March 1972; DD901 was later relocated to Ishioka Depot on the Hokota Line on 26 November 1974. The Hokota Line was spun off to the Kashima Railway on 1 April 1979. DD901 operated its final revenue service on 13 March 1988 before being struck off Kashima Railway's roster on 31 March 1988. The locomotive would be preserved at Ishioka Depot and later next to Hitachi-Ogawa Station until February 2007 when it was scrapped; the locomotive had undergone a cosmetic restoration that month.

Design

The DD42 featured a steeplecab-like design, giving it an appearance similar to that of a switching locomotive.

DD42 1 was designed in such a way that it had two driver's cabs, with the driver facing forwards; this would be good for main line work requiring long hours of sitting forwards, but unsuitable for shunting as the driver had to turn around physically to the other driver's cab to operate the locomotive from there.

Specifications

The DD42 was fitted with a DMF36 prime mover and a DS1.2/1.35 hydraulic transmission, both manufactured by Shinko Engineering; this prime mover produced 450 PS (331 kW). These were later replaced with a DMF31SB prime mover and a Niigata Converter DB138 hydraulic transmission; this prime mover produced 500 PS (368 kW).

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