E991 series

The E991 series, branded TRY-Z, was a tilting Japanese non-revenue dual-voltage electric multiple unit operated by the East Japan Railway Company from November 1994 to March 1999. It was designed as a test train to evaluate future technologies to be implemented in future rolling stock.
==History==
This three-car tilting set was introduced in 1994 to test and evaluate technologies and features to be used in future train designs. It was branded the TRY-Z, with the "TRY" part of the name signifying the E991 series set as a test train that "tries to challenge ultimate technology developments".
The set, numbered K90, was tested on various lines from 1994 to 1999. K90 was withdrawn on 27 March 1999 and was scrapped; no cars from the set have been preserved.
The E991 series's legacy lived on in the E351 series sets introduced on the Chūō Main Line in December 1994.
==Design==
This three-car set had two different cab ends, each looking distinctly different from the other. Two of the three cars were powered.
==Specifications==
Cars were constructed of an aluminum alloy, but the method of construction varied by car. End cars were 21 meters long and intermediate cars were 20 meters long. The set uses two types of traction systems; one car uses two-level gate turn-off thyristor variable frequency drives, while another uses three-level insulated gate bipolar transistor drives. The GTO drives make a distinctive shriek that steps up in pitch, while the IGBT drives appear to produce a loud, hissing noise. The train used an active tilting system that allowed it to maintain speeds around curves.
==Gallery==
E991 Matsumoto 1995.jpg|K90 in 1995; note the different cab end
==Trivia==
*Some time in 2000, a four-car training set based on the 209 series was built by Kawasaki Heavy Industries that carries the same designation; both sets are unrelated apart from their designations.
Category:Unique locomotives
Category:Electric trainsets
Category:JR Group trains
Category:Tilting trainsets
Category:Hitachi locomotives
Category:Nippon Sharyo locomotives
Category:Tokyu Car locomotives
Category:Scrapped locomotives