Siemens SD-400 and SD-460
| Industry | Transportation manufacturing |
|---|---|
| Headquarters | Florin, California , United States |
| Products | Light rail vehicles (Siemens SD-400, SD-460, S700, S70, S200) |
Siemens SD-400 and SD-460
The Siemens SD-400 and SD-460 are light rail vehicles (LRVs) manufactured by Siemens Mobility between 1985 and 2005, primarily serving markets in North and South America. The SD-400 was created through a collaboration between Siemens and Duewag, with assembly taking place at Duewag’s facility in Düsseldorf as well as Siemens’ plant in Florin, California. Following Siemens' acquisition of Duewag in 1999, the SD-460 production was consolidated entirely at the California location.
A major difference between the two models lies in their propulsion systems: the SD-400 is equipped with direct current (DC) motors, whereas the SD-460 utilizes alternating current (AC) motors paired with sophisticated IGBT-VVVF traction control technology. Both versions incorporate a high-floor layout featuring multiple doors on each side to facilitate level boarding at elevated platforms, along with an additional door fitted with steps for boarding from street level.
These LRVs were offered alongside earlier Siemens–Duewag products such as the U2 model, as well as later designs like the SD-100 and SD-160, all engineered to accommodate either high-platform or street-level passenger access. The SD-400 and SD-460 have been eventually replaced by Siemens’ low-floor S700 and S70 models designed for street-level boarding, and the high-floor S200 model intended for use at raised platforms.
Technical details
Both vehicles share a similar structural design characterized by a B-2-B truck setup beneath a double-ended articulated body. Each car seats 72 passengers and can carry up to 106 standing riders. On each side, there are four inward-opening double bifold doors positioned at a high level to enable level boarding, complemented by an additional low-level single door with steps located on the right side at each end for access from lower platforms. This configuration is particularly suited to systems like the Pittsburgh Light Rail, which operates both high-platform stations and street-level stops. Notably, Pittsburgh’s SD-400 units feature three door sets per side and omit left-side doors ahead of the articulation joint; other operators of the SD-400/460 generally do not regularly utilize the street-level doors.
Propulsion comes from four Siemens electric traction motors generating 200 horsepower (149 kW) each, resulting in a combined output of 800 horsepower (597 kW). The SD-400 is powered by DC motors, while the SD-460 incorporates modern AC motors controlled via advanced electronics based on insulated-gate bipolar transistor (IGBT) technology. Both models draw 750 volts from an overhead catenary system.
Production of over 80 SD-400 cars occurred between 1985 and 1993 at Siemens’ main plant in Germany, whereas nearly 70 SD-460 units have been manufactured since 1999 at the Californian facility. The SD-400 fleet operates within Pittsburgh Regional Transit’s Pittsburgh Light Rail, while the SD-460 serves Venezuela’s Valencia Metro. Additionally, both models are active on St. Louis’ MetroLink, managed by Metro Transit. In 2023, Metro authorized a $390.4 million agreement with Siemens for up to 55 new battery-hybrid Siemens S200 LRVs intended to replace aging SD-400/460 vehicles.
Operators
| Service | SD-400 | SD-460 | ||||
|---|---|---|---|---|---|---|
| Image | Built | Qty | Image | Built | Qty | |
| Pittsburgh Regional Transit (Pittsburgh Light Rail) |
1985–87 | 55 | — | |||
| Metro Transit (St. Louis) (MetroLink) |
1991–93 | 31 | 1999–2005 | 56 | ||
| Valencia Metro | — | 1999 | 12 | |||
See also
Additional Siemens light rail models designed for the U.S. market include:
- Siemens–Duewag U2 – high-floor light rail vehicle suited for boarding at elevated platforms or via street-level steps
- SD-100 and SD-160 – high-floor LRVs capable of boarding at both street level and raised platforms
- SD660 – low-floor vehicle specifically tailored for Portland, Oregon
- P2000 – high-floor LRV custom manufactured for the Los Angeles area
- S700 and S70 – low-floor LRVs designed for boarding directly from street level
- S200 – high-floor LRV intended for use with elevated platform boarding