S1/S2 (Amsterdam Metro)
| Industry | Rail vehicle manufacturing |
|---|---|
| Products | Electric multiple units, trams |
S1 and S2 train sets, collectively referred to as S1/S2, were electric multiple units deployed on the Amsterdam Metro network in the Netherlands. Built by the Belgian manufacturer La Brugeoise et Nivelles (BN), GVB placed an order for 13 S1 units in 1988, followed by a subsequent order of 12 S2 units in 1991, intended for the newly established Amstelveen Line (Line 51). Initially envisioned as a conventional metro line, it was ultimately developed as a hybrid tram-metro system known as sneltram (express tram) following opposition from local communities. Between Amsterdam Centraal and Amsterdam Zuid, trains operated on a 750 V DC third rail typical of metro systems; beyond Zuid, they transitioned to 600 V DC overhead electrification, functioning as faster trams sharing infrastructure with tram line 5 and public roadways.
The Amstelveen Line commenced service on 30 November 1990 utilizing the S1 fleet; however, technical difficulties restricted the number of operational vehicles and caused capacity constraints. With financial restitution and technical assistance from BN, combined with delivery of the S2 units starting in 1993, most operational challenges were addressed. This progress allowed for coupled train operations by 1994. Nevertheless, the vehicles’ high speeds and sharply contoured fronts resulted in fatal collisions at level crossings in Amstelveen, prompting public outcry and subsequent safety enhancements. Additionally, the complexity of switching between two different voltage and power supply systems at Amsterdam Zuid contributed to reliability issues.
Following the closure of the Amstelveen branch in 2019—replaced by a standard tram line—the S1/S2 trains continued service on the revised Line 51 and other metro routes. After over three decades of operation, the earliest units were withdrawn and dismantled in 2023. A commemorative event took place in 2024, during which one unit was preserved for historical purposes.
Background
In February 1985, the municipalities of Amsterdam and its suburb Amstelveen reached an agreement to construct a sneltram route extending from Amsterdam Centraal station to southern Amstelveen, later known as the Amstelveen Line. This express tram concept represented a compromise solution: while Amstelveen advocated for a full metro connection, political resistance within Amsterdam—stemming from previous protests—prevented such development. The express tram shared segments of track with an existing tram line within Amstelveen, featuring 15 level crossings—a rarity for typical metro operations. The line functioned as a metro service between Amsterdam Centraal and Amsterdam Zuid, then switched to tram mode for the remainder of the journey. This route was eventually designated as Line 51.
Since no current rolling stock could seamlessly transition between metro and tram modes during operation, GVB sought manufacturers capable of designing suitable vehicles based solely on technical schematics. They engaged several German companies alongside Belgian firm La Brugeoise et Nivelles (BN). BN was ultimately awarded the contract, resulting in an order for 13 trains in 1988 exclusively for Line 51. These units were delivered ahead of the line’s inauguration in 1990 from BN’s production facility in Bruges. BN was also responsible for manufacturing the 11G and 12G trams used on standard tram lines.
A fleet reassessment in 1989 identified a need to increase vehicle numbers by an additional 12 units; however, delays in funding approval postponed their procurement until early 1991. The first two of these arrived in 1993, with the remaining ten delivered by 1994. Operational capacity was enhanced when coupled train sets began running in March 1994. The original batch of thirteen trains (numbered 45–57) received the S1 classification, while the subsequent twelve units (58–69) were designated S2. Although GVB’s metro division managed operations, maintenance responsibilities for the Amstelveen section rested with its tram division.
Initial operations and start-up challenges
Trial runs for the new tram vehicles commenced in May 1990. Several weeks prior to the official launch, a collision occurred between two trains during testing, which led to a reduced service frequency at the start. The S1 trains were formally introduced into operation on 30 November 1990. Within just one week, technical malfunctions or maintenance needs sidelined 5 out of the 13 units. BN later rectified design defects related to retractable footboards at no cost. Passenger capacity proved inadequate, causing some riders to be left behind during peak travel times. In February 1991, Line 51 was shortened from Centraal to Zuid because 11 vehicles were out of commission due to winter-related technical difficulties; full operations resumed seven months later in September. The GVB held the manufacturer responsible for both capacity shortages and technical faults, considering legal action for damages, while BN attributed the issues to initial operational teething problems typical of complex systems.
In October 1995, residents of Buitenveldert advocated for enhanced safety measures at express tram level crossings after three fatal incidents and several severe accidents occurred within a single month. They criticized the limited safety provisions—only flashing lights—despite trams traveling at high speeds enabled by traffic signals that promptly switch to allow tram passage. The front design of the S1/S2 units—with sharp contours, exposed couplings, and uncovered wheels—was deemed particularly dangerous, increasing the likelihood of serious injuries. In response, GVB announced plans to install fencing and warning signage at selected crossings. Subsequent investigations resulted in speed restrictions being imposed on certain crossings.
On 12 July 1999, an express tram caught fire at Weesperplein metro station due to a seized disc brake. Although no passengers were on board, smoke prompted evacuation across all station levels; two individuals suffered minor smoke inhalation. Over time, reliability improved and incidents became less frequent. Throughout their operational lifespan, approximately ten fatalities were recorded in collisions involving the express tram.
Later years and decommissioning
A municipal report from 2007 highlighted reliability concerns on the Amstelveen Line, primarily caused by mid-route mode changes, numerous level crossings, and track sharing with conventional trams. The line ceased operation on 2 March 2019 and was transformed into a dedicated tram route. Metro 51 preserved its path from Amsterdam Centraal to Zuid but extended westward to Isolatorweg, discontinuing its Amstelveen branch. Following this conversion, the S1/S2 vehicles underwent a final technical overhaul and were deployed on metro lines M50, M51, M53, and M54.
Although engineered for an approximate service life of three decades, the express tram units experienced escalating technical difficulties by the 2010s and were slated for retirement with the arrival of newer M7 metro trains. In March 2022, GVB introduced training simulators for all metro models except for the sneltrams in anticipation of their phase-out. By 2023, with new metro units in operation, Amsterdam’s regional transport authority officially retired the S1/S2 fleet. A farewell ceremony was held on 13 April 2024 at Gaasperplas metro station. Most units were dismantled by DDM in De Meern, where rooftop equipment was removed to facilitate transport clearance and components were salvaged for recycling. One vehicle was preserved as a museum exhibit.
Design and specifications
The S1 and S2 trainsets were engineered and manufactured by BN, with the electrical components supplied by a Dutch firm, specifically customized for GVB's distinctive transit line. Each trainset is composed of two connected cars (designated A and B), measuring a combined length of , a width of , and a height of (excluding the pantograph). Each car is supported by a single bogie containing two axles, alongside a Jacobs bogie positioned between the two cars. The wheels have a diameter of , with a wheelbase spanning . Bicycle storage racks are installed in car A—on the left side in S1 models and on the right side in S2 models. The unladen weight of the trainset is . Standard deceleration occurs at , while emergency braking can reach up to , both regulated through foot pedal controls.
In Amstelveen, it is possible to couple two units together; elsewhere, up to four units may operate simultaneously. Platforms in Amstelveen are designed to align precisely with the train width, whereas stations on other parts of the network accommodate a broader profile; here, retractable footboards are deployed to bridge the gap between platform and train. Amstelveen stops feature dual platform heights: high-floor platforms for express trams and low-floor platforms for standard trams. The S1/S2 trains maintain a high-floor design, facilitating level boarding throughout the entire system.
The electrical setup allows seamless transition between 750 V DC third-rail power used on the metro network and 600 V DC overhead lines employed by Amstelveen trams. This system energizes six motors that drive the train to a top speed of .
Bibliography
- Commissioned by GVB.