# Seibu 9000 series

The Seibu 9000 series (西武9000系) is an electric multiple unit (EMU) train type operated by the private railway operator Seibu Railway on commuter services in the Tokyo area of Japan since 1993.

## Design

The 9000 series trains were built between 1993 and 1999 at Seibu's own Tokorozawa Factory by combining electrical equipment from former 101 series EMUs with new steel bodies based on the New 2000 series design. These were the last trains to be built at the Tokorozawa Factory before it closed in 2000.

## Fleet

As of 1 April 2015, the fleet consists of eight 10-car sets, numbered 9101 to 9108, based at Musashigaoka depot for use on Seibu Ikebukuro Line workings.

## Formations

10-car sets are formed as shown below with six motored ("M") cars and four non-powered trailer ("T") cars.
| Car No. | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| Designation | Tc1 | M1 | M2 | T1 | M3 | M4 | T2 | M5 | M6 | Tc2 |
| Numbering | 9100 | 9200 | 9300 | 9400 | 9500 | 9600 | 9700 | 9800 | 9900 | 9000 |
* Cars 2, 5, and 8 are each equipped with one single-arm pantograph.

## Interior

Seating consists of longitudinal bench seating throughout. Wheelchair spaces are provided in cars 2 and 9. Priority seats are provided at the end of each car.
* The interior of a 9000 series train in May 2016

## History

The first train entered service in 1993, with eight 10-car sets built by 1999. The fleet was refurbished between 2004 and 2008, with new underframe equipment and VVVF inverter control. Refurbished sets are identified by stickers on the cab end doors.

### Tamako Line transfer

Beginning in 2020, the 9000 series fleet was shortened to four-car formations and modified to accommodate driver-only operation for use on the Tamako Line. The first of these sets was set 9108, which entered service on the Tamako Line on 1 October 2020. As of 15 June 2021, the entire fleet has been modified for Tamako Line operation, excluding sets 9101, 9106, and 9107, which were scrapped beforehand.

## Livery variations
### "Red Lucky Train"

From July 2014, set 9103 was repainted in a "Red Lucky Train" livery in collaboration with the private railway operator Keikyu. In return, Keikyu painted one of its own N1000 series sets into an all-over yellow livery similar to the Seibu livery in May 2014. Set 9103 was repainted in an all-over red livery after it was modified for Tamako Line operation.
* Set 9103 in plain red livery in July 2023

### "L-train"

From 17 January 2016, set 9108 operated in a special "L-train" livery consisting of the Saitama Seibu Lions baseball team colour of dark blue with Seibu Lions logos. The set's Seibu Lions logos were removed following its modification for use on the Tamako Line.
* Set 9108 in all-over blue livery in July 2023

### "Seibu KPP Train"

From 4 June 2016, set 9101 operated in a special "Seibu KPP Train" pink livery to mark the 100th anniversary of Seibu Railway in 2015 and the fifth anniversary of singer Kyary Pamyu Pamyu. The train operated in this livery until 29 September 2016, after which date the Kyary Pamyu Pamyu vinyls were removed, with the trainset operating in all-over pink livery.
* Set 9101 in plain pink livery in March 2017