The Kitakyu 8000 series, branded Polestar, is a Japanese city commuter electric multiple unit operated by the Kita-Osaka Kyūkō Railway since July 1986.
History[]
The 8000 series cars were designed to replace the 2000 series cars, which had no air-conditioning and were close to the end of their lifespan. The sets were manufactured by Alna Kōki.
The first set, 8001, began operation on 1 July 1986, initially an an 8-car set; the second set was also built as an 8-car set. Starting from April 1987, two additional cars were manufactured to be inserted into both sets, making them 9-cars long; all future sets to be built would be 9 cars in length. A further seven additional cars were manufactured from 1995 to 1996 to lengthen the sets to ten cars as the sets were intended for through-running to the Osaka Municipal Subway Midōsuji Line.
Starting from 2012, the sets were progressively refurbished, with improvements such as the replacement of traction motors and the changing of the headlights to full-LED fixtures; the sets have been further refurbished with further modernizations such as LCD destination indicators. With the introduction of the 9000 series sets however the sets have been progressively retired, with retirements beginning in 2014 with 8002. As of 2021 only three sets remain in service, all refurbished; these are 8003, 8006 and 8007.
Design[]
The 8000 series use a slanted design with dual low-mounted headlights. Originally shield beams, these were later converted to dual LED fixtures.
Specifications[]
Construction of the cars is of an aluminum alloy. Cars are 18.7 meters long. The sets used Toshiba INV002-A0 GTO variable frequency drives at first; these produced a wailing sound which steps up in pitch. These were later replaced by IGBT drives also manufactured by Toshiba due to the GTO drives's outdated technology and an unavailability of spare parts. These produce a hissing sound. The trains feature an electronic horn which produces a distinctive warbling noise; this horn is shared with the later 9000 series trains.
Preservation[]
The following 8000 series cars have been preserved:
| Number | Manufacturer | Date manufactured | Date retired | Previous sets | Location | Notes |
|---|---|---|---|---|---|---|
| 8005 | Alna Kōki | July 1989 | January 2018 | 8005 | Sasayama Santorium, Hyōgo, Japan | On company recreational facility, displayed alongside 2002 and various sections of 5652; repainted into original livery in 2022 |
| 8901 | February 1986 | March 2016 | 8001 | Momoyadai Depot, Osaka, Japan | Cab only; can be viewed from roadside |
The following 8000 series cars were preserved in the past but have since been scrapped:
| Number | Manufacturer | Date manufactured | Date retired | Previous sets | Last location | Notes |
|---|---|---|---|---|---|---|
| 8001 | Alna Kōki | February 1986 | March 2016 | 8001 | Momoyadai Depot, Osaka, Japan | Viewing possible on depot open days; removed and scrapped 2021 |
| Kitakyu rolling stock | ||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Active | 8000 "Polestar" • 9000 "Polestar II" | |||||||||||||||||||||||
| Withdrawn | 2000 • 7000 | |||||||||||||||||||||||