185 series

185 series
A 185 series train on a Shonan Liner rapid service, July 2007
In service	March 1981-Present
Refurbishment	1993–1998
Number built	227 cars
Number in service	227 cars (31 sets)
Formation	5/7/10 cars per trainset
Operator(s)	JNR (1981–1987) JR East (1987–present)
Depot(s)	Ōmiya
Specifications
Car body construction	Steel
Car length	20,280 mm (66 ft 6 in) (end cars) 20,000 mm (65 ft 7 in) (intermediate cars)
Width	2,946 mm (9 ft 8.0 in)
Height	4,066 mm (13 ft 4.1 in)
Doors	2 per side
Maximum speed	110 km/h (70 mph)
Traction system	Resistor control
Power output	120 kW per traction motor
Electric system(s)	1,500 V DC
Current collection method	Overhead wire
Safety system(s)	ATS-P, ATC, D-ATC
Track gauge	1,067 mm (3 ft 6 in)

The 185 series (185系^?) is an electric multiple unit (EMU) train type operated by East Japan Railway Company (JR East) primarily on middle-distance limited express services centering on Tokyo.

The class is broadly divided into two variants: 185-0 series for use south-west of Tokyo, and 185-200 series originally for use north of Tokyo.

The 185 series was primarily intended to replace ageing 153 series EMUs used on Izu express trains from Tokyo to the Izu Peninsula. The requirement was also for a "general-purpose" train that could also be used occasionally on local services. This resulted in a design featuring 1,000 mm wide doors at either end of each car, compared with the standard limited express (e.g. 183 series) layout with 700 mm wide doors at one end of each car.

A total of eight 10-car sets (sets A1 to A8, including two Green cars) and seven 5-car sets (sets C1 to C7) were built between 1979 and 1980 (115 vehicles in total), and delivered to Tamachi depot. Initially, they were phased in on Izu express trains from March 1981, working alongside (and sometimes coupled with) the older 153 series trains. In October 1981, the Izu express was upgraded to become the Odoriko limited express, with all trains formed of 185 series sets.

In addition to the Odoriko services, sets are used on morning and evening "Liner" commuter services, including the Shōnan Liner. Since the start of the October 1981 timetable, 185 series sets have also been used on the 521M local service from Tokyo (depart 07:24) to Izu (arrive 09:48).

The Tamachi Depot fleet was transferred to Ōmiya Depot from the start of the 16 March 2013 timetable revision.

The 10-car sets A1 to A8 are formed as follows, with car 1 at the Izu end.

Cars 3, 7, and 9 each have one lozenge-type pantograph.

The 5-car sets C1 to C7 are formed as follows, with car 11 at the Izu end.