Siemens SD-100 and SD-160

The SD-100 and SD-160 are light rail vehicles (LRV) that were manufactured by Siemens Mobility between 1992 and 2013 for the North American market. The vehicles were all constructed at the Siemens facility in Florin, California.

The primary difference between the models is that the older SD-100 uses direct current motors and has folding doors, while the newer SD-160 uses alternating current motors and plug doors. Both models were built with a "high-floor" design and could be equipped for level boarding at high-platform stations or with steps and wheelchair lifts for passenger loading at street level.

This model was manufactured and marketed alongside the Siemens SD-400 and SD-460 LRV, which offered both level boarding at high-platform stations and steps for passenger loading at street level.

This model has been replaced by the Siemens S700 and S70, a low-floor LRV for passenger loading at street level and the Siemens S200, a high-floor LRV for level boarding at high-platform stations.

Currently, the Metropolitan Transportation System (MTS) of San Diego, California is in the process of donating its Siemens SD100 pairs to the Mendoza Transportation Society, which has an urban metro-tram service that connects four departments (Las Heras, Ciudad, Godoy Cruz and Maipú) of the Province of Mendoza, Argentine Republic. The donation consists of 39 pairs of the mentioned model, until June 2023 9 of the total pairs that are operating and providing regular service in Mendoza, Argentina have arrived, while for the remaining 30 MTS is expected to withdraw them from their service between this year and the next in order to coordinate the shipping logistics of these pairs between the two cities.

The arrival of these formations is important for Mendoza since it is carrying out works to double the route of its metro-tram service (it is estimated that they will end in 2026 or 2027), the arrival at the Mendoza International Airport and the department of Luján de Cuyo stands out. In addition, due to its speed compared to other means of transport, it is increasingly chosen and presents a greater demand for people, which is why it is also planned to join two pairs to increase passenger capacity.

History
Production of the SD-100 was launched in 1992 when the Regional Transportation District, located in Denver, Colorado placed an order for 49 vehicles. The physical design was derived from the U2A car that was built between 1985 and 1991, but built with more modern mechanical equipment.

The first vehicles rolled off the production line at the Siemens facility in Florin, California in 1994, in time for the start of Light Rail service in Denver.

In 1993, the San Diego Metropolitan Transit System ordered 52 SD-100 cars as the San Diego Trolley system was expanded with a new line, these entered service in 1995. As of 2021, they are currently being phased out and replaced by Siemens S700 cars.

The final order for the SD-100 came in 1996, when the Utah Transit Authority, located in Salt Lake City placed an order for 23 vehicles that were delivered before the start of the TRAX light rail service in 1999.

In 2001, Siemens launched the SD-160 light rail vehicle, which used alternating current motors instead of direct current motors and outward sliding doors. Calgary Transit ordered 72 vehicles for its CTrain service, while the Utah Transit Authority ordered 17 vehicles as it expanded the TRAX light rail service. Deliveries to both agencies started in 2003.

The physical design of the SD-160 was updated in 2005 with a new end cap that changed the look of the front/rear of the train. The Edmonton Transit Service ordered 57 of the redesigned SD-160 vehicles and Calgary Transit ordered 38.

Starting in late 2017, Calgary has been sending SD-160s to Sacramento for mid-life refurbishment. The refurbished units contain several components and electronics already present on the S200, the successor to the SD-160. Along with some electronic improvements, they have been upgraded to be compatible with Calgary's newer SD-160s, which were previously incompatible due to software differences. The refurbished fleet will eventually start to run with the newer units once the software has been adjusted to allow seamless operation.

Since 2022, 39 retired San Diego SD-100s were transferred to Metrotranvía Mendoza to supplement its existing fleet of Siemens–Duewag U2 which had also been purchased from San Diego.

Technical details
The SD-160's dimensions are 24.802 m by 2.654 m by 3.811 m and can be joined together to form trains of up to six cars in length. It is powered by four AC motors which provide a maximum of 580 kW and in most applications has a maximum governed speed of 80 km/h; however, in some applications it can be configured to reach higher speeds such as 90 km/h on Denver's RTD Light Rail lines. It accelerates at 1.07 m/s2 and decelerates at 1.31 m/s2, with emergency braking deceleration of 2.63 m/s2. The brakes also serve as a generator, regenerating power back to a city's electrical lines. The SD-160 has a passenger capacity of 236 passengers (standing) with 64 seats.

Compared to its predecessor, the Siemens–Duewag U2, the SD-160's driver's cabin is significantly larger, but its total length is still less than 25 m, allowing three vehicles to be combined and still be under the 75 m maximum length of a German streetcar train assembly. Each vehicle also features an onboard closed-circuit TV security camera system for increased passenger safety. Unlike the Siemens SD-100, the Siemens SD-160 does not use the bi-folded doors, instead using sliding doors similar to designs featured on the Siemens S70. In addition, both can be used together in mixed trains consisting of SD-100s and SD-160s. The new, streetcar-length S70 cars ordered for San Diego are designed to be compatible with the SD-100, allowing the SD-100 to operate in a mixed consist, sandwiched between two S70 cars.

The SD-160NG for Calgary have been taking over some features from the SD-460 series including IGBT equipment.