E501 series
A 10-car E501 series formation on a Jōban Line service, January 2020
In service	1995–Present
Manufacturer	Kawasaki Heavy Industries, Tokyu Car Corporation
Replaced	401 series
Constructed	1995–1997
Entered service	December 1995
Refurbished	2011–2012
Number built	60 vehicles
Number in service	60 vehicles (8 sets)
Formation	5/10 cars per trainset
Fleet numbers	K701–K704, K751–K754
Operators	JR East
Depots	Katsuta
Lines served	Jōban Line, Mito Line
Specifications
Car body construction	Stainless steel
Car length	20,420 mm (67 ft 0 in) (end cars) 20,000 mm (65 ft 7 in) (intermediate cars)
Width	2,890 mm (9 ft 6 in)
Doors	4 pairs per side
Maximum speed	120 km/h (75 mph)
Traction system	Original: GTO–VVVF (Siemens) Current: IGBT–VVVF (Toshiba)
Traction motors	MT70 3-phase AC induction motor
Power output	120 kW (161 hp) × 4 per motored car
Transmission	Gear Ratio: 16:97
Acceleration	2.0 km/(h⋅s) (1.2 mph/s)
Deceleration	4.2 km/(h⋅s) (2.6 mph/s)
Electric system(s)	1,500 V DC / 20 kV 50 Hz AC (overhead catenary)
Current collector(s)	Pantograph
Safety system(s)	ATS-PS
Track gauge	1,067 mm (3 ft 6 in)

The E501 series (E501系) is a dual-voltage AC/DC electric multiple unit (EMU) train type operated on local services by East Japan Railway Company (JR East) in Japan since December 1995.^[1]

Built jointly by Kawasaki Heavy Industries and Tokyu Car,^[2] the design is derived from the 209 series commuter EMU, and were initially operated as 10+5-car formations on Jōban Line services out of Ueno in Tokyo, but were modified with the addition of toilets and transferred to Jōban Line and Mito Line local services in the Mito area from March 2007.^[3]

As of 1 October 2018, four ten-car sets (K701–K704) are based at Katsuta Depot and formed with four motored ("M") cars and six non-powered trailer ("T") cars.^[4]

• Cars 3 and 8 each have one single-arm pantograph.^[4]
• Cars 1 and 10 have a wheelchair space.^[4]
• Cars 1 and 10 each have a universal design toilet.^[4]
• Car 8 is designated as a mildly air-conditioned car.^[4]

As of 1 October 2018, four five-car sets (K751–K754) are based at Katsuta Depot and formed with two motored ("M") cars and three non-powered trailer ("T") cars.^[4]

• Cars 3 has one single-arm pantograph.^[4]
• Cars 1 and 5 have a wheelchair space.^[4]
• Cars 1 has a universal design toilet.^[4]
• Car 4 is designated as a mildly air-conditioned car.^[4]

• 
  Interior view, January 2007

The first 10+5-car train was originally scheduled to be delivered in time for entry into service from the March 1995 timetable revision, but deliveries from Kawasaki Heavy Industries in Kobe were delayed until May due to the effects of the Great Hanshin earthquake in January of that year.^[3] The first trains ultimately entered revenue service from the start of the 1 December 1995 timetable revision.^[5][4]

Between September and October 2006, modifications were made to the side windows to allow some windows to be opened.^[5] From October 2006, the fleet underwent modifications to add toilets, and from the start of the 18 March 2007 timetable revision, the E501 series trains were displaced from Jōban Line services out of Ueno by E531 series sets, and were transferred to local services on the Jōban Line north of Tsuchiura and on the Mito Line.^[3] Between 2011 and 2012, the fleet underwent a life-extension refurbishment programme, which involved replacing electrical and brake equipment.^[5] These trains were originally equipped with Siemens GTO-VVVF propulsion systems, which were similar to the Keikyu 2100 series and also produced a "do-re-mi-fa-so-la-ti-do" scale when starting up. As part of the refurbishment, the propulsion system was changed to Toshiba IGBT-VVVF.

Between December 2014 and December 2015, all PS29 lozenge-type pantographs were replaced with single-arm pantographs.^[4]

• 
  Intermediate motor car MoHa E501-7 showing the modified opening side windows, February 2009
• 
  The blocked-off window next to the retro-fitted toilet, January 2007
• 
  5-car set K752 in December 2008

The build details for the fleet are as shown below.^[4]

On 25 October 2023, JR East announced that an E501 5-car train has been modified to become the special E501 SAKIGAKE train. This particular set received a new livery that inspires the image of red and white plum blossoms. The interior features tables for customers to eat and have drinks while onboard the train as well as a refrigerator that stores the cold drinks.^[6] The set is numbered K754 and it entered service from 23 November 2023 on a special trip on the Joban and Mito lines between Mito and Yuki stations.^[7]

• 首都圏新系列車両 Profile: 209/E231/E233系グループの全貌 首都圏新系列車両PROFILE [Tokyo Area New-generation Rolling Stock Profile] (in Japanese). Japan: Ikaros Publishing. 15 April 2011. ISBN 978-4-86320-436-2.

Wikimedia Commons has media related to E501 series.

• JR East E501 series (in Japanese)