| E331 series | |
|---|---|
 E331 series set AK1 in service on the Keiyo Line in May 2010 | |
| In service | 2007–2011 |
| Manufacturer | Kawasaki Heavy Industries, Tokyu Car Corporation |
| Constructed | 2006 |
| Entered service | 18 March 2007 |
| Scrapped | 2014 |
| Number built | 14 vehicles (1 set) |
| Number scrapped | 14 vehicles |
| Successor | E233-5000 series |
| Formation | 14 cars per trainset |
| Fleet numbers | AK1 |
| Operators | JR East |
| Depots | Keiyo (Shin-Narashino) |
| Lines served | Keiyo Line |
| Specifications | |
| Car body construction | Stainless steel[1] |
| Car length | 13.4 m (44 ft 0 in) (cars 2-6, 9-13) 16.5 m (54 ft 2 in) (cars 1, 7, 8, 14)[2] |
| Width | 2,989 mm (9 ft 9.7 in) |
| Doors | 3 pairs per side |
| Maximum speed | 120 km/h (75 mph) |
| Traction system | Variable frequency (IGBT) |
| Electric system(s) | 1,500 V DC overhead catenary |
| Bogies | DT73/TR257/TR258 |
| Safety system(s) | ATS-P, ATS-SN |
| Track gauge | 1,067 mm (3 ft 6 in) |
The E331 series (E331系) was an electric multiple unit (EMU) train introduced experimentally from 2007 on commuter services on the Keiyo Line in Japan operated by East Japan Railway Company (JR East). Only one trainset was built, and it differed significantly from other JR commuter EMUs in having articulated cars with shared bogies and using direct-drive motors.[2]