731 series

The 731 series is a Japanese suburban electric multiple unit operated by the Hokkaido Railway Company since December 1996.
==History==
The 731 series sets were constructed from 1996 to 2006 as the first full-fledged commuter train type ordered by JR Hokkaido, with their main purpose being to replace the 711 series sets on these services which were considered to be reaching the end of their service lives.
Two sets were built in 1996, followed by nineteen more in 1999. Two sets were refurbished in 2006 with some software changes to their traction systems. All sets are currently in service and are based at Sapporo Depot. The sets can (and actually do) operate in multiples with KiHa 201 series sets, and are also capable of operating in multiple with 721, 733 and 735 series sets. 
The 731 series sets are notable for their ability to operate in multiple with the KiHa 201 series diesel multiple units, and do so fairly frequently. This remains the only example of electric multiple units and diesel multiple units currently in service operating in multiple with each other in Japan.
Due to its outstanding functional and design features, it is the recipient of the 1997 Laurel Prize.
==Design==
The 731 series sets adopted a new body style started by the 721 series sets that forms the basic design language for later suburban-style trains that were to be built for JR Hokkaido, although there are some very obvious modifications between both sets' body styles. The sets have two pairs of headlights; a pair of top-mounted headlights and a pair of body-mounted headlights. The sets' body-mounted headlights use a combination of high-intensity discharge and shield-beam headlights, while the top-mounted headlights are simply shield-beam headlights.
==Specifications==
Construction is of stainless steel. End cars are 20.8 meters long, 2.8 meters wide and 3.64 meters high. The 731 series sets use insulated gate bipolar transistor variable frequency drives produced by Hitachi; these drives produce a melodic wail when the trains accelerate from idle. The two upgraded sets sport Hitachi IGBT drives as well, but produce a louder, higher-pitched hissing sound. Some older sets had their IGBT drives upgraded to newer-spec Hitachi drives, which produce a low hissing sound.
The 731 series sets, as mentioned above, are the first full-fledged commuter trains operated by JR Hokkaido. As such, the 731 series sets include features not seen on previous trains owned by JR Hokkaido, such as bench seating throughout. The sets also have polycarbonate window covers. The cabs of the cars are situated somewhat unusually high up to help improve visibility, while the overall shape of the cabs is unique in that the actual cab portion of the set is contoured forward.
==References==
*Wikipedia.org
Category:JR Group trains
Category:Electric trainsets
Category:Hitachi locomotives
Category:Kawasaki locomotives