JNR Class DD11

The JNR Class DD11 is a diesel-hydraulic locomotive operated by the Japanese National Railways from 1954 to 1978.
==History==
The DD11 was a small diesel-hydraulic locomotive used by the JNR designed for switching. Initially intended for use on the Hakuhō Line alongside the KiHa 10000 series railbuses, their use was changed mainly to switching due to the repurposing of the Hakuhō Line.
A total of nine locomotives were built, all by Kisha Seizō; an initial set of three locomotives was manufactured in 1954 and another six in 1957 with a slightly different design. Around the same time the DD11s were built, Ōita Kōtsū ordered a set of two Class D31 locomotives, which are essentially identical to the DD11s. Their use of a single DMH17B engine made them weak, and as a result many of them found use switching light loads in industrial settings such as military bases and factories. All locomotives were withdrawn by 1978, with a number sold to private railways.
DD11 2 is the only preserved DD11, located in Hanoi, Vietnam; it was donated to the Vietnam Railways through a labor union fundraising campaign. It was cosmetically restored by the Japan-Vietnam Friendship Association in February 2023 at the Gia Lâm Train Factory and is intended to be preserved statically. DD11 8 was also preserved in Kitakyushu, painted in an orange and blue paint scheme but was scrapped around 2008.
==Design==
The DD11 featured a steeplecab-like design. It was based on the various switcher locomotives that Kisha Seizō was manufacturing at the time.
==Specifications==
The DD11s were fitted with a DMH17B prime mover, the same type used on the KiHa 10 series diesel railcars. The prime mover produced 320 PS (236 kW). This is coupled to two types of hydraulic transmissions, the TC2 and DF115 transmissions. The locomotives featured part standardization to reduce maintenance costs.
==Preservation==
The following Class DD11 locomotives have been preserved:
Number	Manufacturer	Date manufactured	Date retired 	Location 	Notes
DD11 2	Kisha Seizō 	1954 	1977 (JNR)2002 (Vietnam)	Gia Lâm Train Factory, Hanoi, Vietnam	Gift from JNR; cosmetically restored by Japan-Vietnam Friendship Association in February 2023
The following Class DD11 locomotives were preserved in the past but have since been scrapped:
Number	Manufacturer	Date manufactured	Date retired	Location 	Notes
DD11 8	Kisha Seizō 	1957 	1978 	Kitakyushu, Kyushu, Japan	Stored on site of former sports club and transportation museum, painted in blue and orange paintscheme; scrapped February 2008
==Gallery==
DD11 2 1968.jpg|DD11 2 in January 1968
File:JNR DL DD118.jpg
Category:JR Group trains
Category:B-B locomotives
Category:Diesel locomotives
Category:Diesel-hydraulic locomotives
Category:Kisha Seizō locomotives
Category:Japanese locomotives
Category:Sole survivor