Class 911 Shinkansen

The Class 911 Shinkansen was a diesel locomotive operated by the Japanese National Railways and its successor the Central Japan Railway Company from 1964 to 1995.
==History==
The Class 911 was designed by the JNR as a maintenance-of-way locomotive for use on the Shinkansen network. Three locomotives, numbered 911 1 through 911 3, were manufactured by Nippon Sharyo in 1964.
The Class 911's intended use was to tow malfunctioning Shinkansen trains; due to the reliability of the Shinkansen network these were never used for their intended purpose and as such were used for other tasks. The Class 911s would instead mainly be used to pull the Class 921 inspection cars, which were unable to run on their own; with the introduction of the Class 922 Shinkansen the Class 921 cars were no longer needed and the Class 911s which pulled them were instead relegated to pulling construction trains or for inspection of the Class 922s. The Class 911 set a world speed record for diesel locomotives in 1972 on a run from Shin-Osaka to Okayama prior to the opening of the San'yō Shinkansen, recording an average speed of 165 km/h (103 mph).
When the JNR was privatized in April 1987 and split into seven different companies, 911 2 came under the jurisdiction of the Central Japan Railway Company; 911 1 and 911 3 had been retired and scrapped prior to the JNR's privatization. 911 2 was retired in 1995 and was stored at Hamamatsu Works. No Class 911 locomotives have been preserved.
==Design==
The Class 911 featured a double cab design with high roofs, with portions of the cab raked backwards. The locomotives's numbers were located on rectangular plates below the driver's door, a trait carried over to modern JR Freight locomotives.
==Specifications==
Based on the Class DD51 locomotives, the Class 911s were painted in "Bright Blue" with "Marigold Yellow" accents, similar to many of JNR's maintenance of way locomotives.
911 1 was fitted with a DML61S prime mover, while 911 2 and 3 were fitted with a more powerful DML61Z prime mover. They were fitted with a variant of the DW2 hydraulic transmission used on the DD51s known as the DW2B, which featured a dual low- and high-speed setting for different applications. Having been built with train rescue in mind, the Class 911 locomotives featured a double-headed coupler for coupling both to regular trains and Shinkansen consists. To reduce the impact of train delays caused by malfunctioning trains, the Class 911 locomotives were capable of a maximum speed of 160 km/h (99 mph) and were designed to be able to haul a full 16-car Shinkansen consist up a 20‰ gradient.
The Class 911 locomotives are fitted with a version of automatic train control, the first locomotives in the world to be so equipped. Using a similar technology to what is fitted on the 0 Series Shinkansen, the train's speed changes depending on the signals they receive; if a 70 km/h (44 mph) signal is received while the locomotive is at a high speed, the prime mover makes a loud roar and slows down.
==Preservation==
The following Class 911 locomotives were preserved in the past but have since been scrapped:
Number	Manufacturer 	Date manufactured	Date retired	Last location 	Notes
911 2 	Nippon Sharyo	1964 	1995 	JR Central Hamamatsu Works, Hamamatsu, Japan	Scrapped circa 2000s
Category:JR Group trains
Category:B-B-B locomotives
Category:Diesel locomotives
Category:Nippon Sharyo locomotives
Category:Japanese locomotives
Category:Scrapped locomotives
Category:Scrapped diesel locomotives
Category:Built in 1964