SL95

SL95

Company type	Tram model
Industry	Public transport
Predecessor	SL79 (partially replaced)
Founded	1999
Headquarters	Oslo , Norway
Products	Low-floor articulated trams

SL95 Tram Overview

The SL95 represents a fleet of 32 low-floor, articulated trams operating within the Oslo Tramway network. Manufactured by the Italian companies Ansaldo and Firema—later known as AnsaldoBreda and currently Hitachi Rail Italy—these vehicles were delivered over a period spanning from 1999 to 2004. Each tram consists of three sections supported by eight axles and offers a total capacity of 212 passengers, including seating for 88 individuals. The designation "SL95" originates from the year the order was placed, 1995, although initial expectations aimed for deliveries between 1997 and 1998. Production and deployment faced significant delays due to numerous technical difficulties such as excessive noise, wintertime freezing issues, and corrosion problems.

Measuring approximately 33.12 meters in length, 2.6 meters in width, and standing 3.62 meters tall, these aluminum-bodied trams weigh close to 65 tonnes and deliver a power output of around 840 kilowatts. Their operation is confined to lines 13, 17, and 18 on the tramway. The SL95’s considerable weight and large turning radius limit their use on other routes; however, they are uniquely bi-directional within the fleet, making them essential for service on lines 17 and 18 along the Ullevål Hageby Line. Each unit was priced near 20 million Norwegian kroner, though financial concessions were granted due to delivery delays and technical shortcomings.

Plans are underway to phase out the SL95 trams alongside older SL79 models, with replacements by new SL18 vehicles scheduled between 2020 and 2024.

Background

During the early 1990s, Oslo Sporveier faced the necessity of acquiring new trams for their network. Apart from the 40 articulated SL79 trams delivered between 1982 and 1990, the fleet consisted mainly of several series of non-articulated trams with trailers dating back to before 1960. The most numerous among these were 13 SM53 units, 11 refurbished SM83 trams along with 28 trailers, and additionally, 34 SM91 vehicles purchased secondhand from the Gothenburg Tramway in 1991. Various options were explored for new rolling stock, including ordering more SL79s, procuring motorized trailers compatible with SL79 units, investing in new low-floor trams, purchasing vehicles from ČKD Tatra, acquiring the 11 used TT Class 8 trams from Trondheim, retrofitting SL79s with additional sections, or buying used articulated trams internationally. The choices to buy secondhand vehicles or to rebuild the SL79s were rapidly dismissed. In January 1991, Oslo Sporveier trialed a non-articulated Tatra tram on their lines.

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In 1995, Oslo Sporveier tested a Variotram manufactured by ABB, borrowed from Chemnitz, Germany (photo shown)

Historically, Oslo Sporveier had always commissioned custom-built trams. However, for the 1995 procurement, the preference shifted toward acquiring a pre-existing tram design. For an extended period, collaboration with Storstockholms Lokaltrafik was contemplated since they required new vehicles for two light rail lines in Stockholm, Sweden. In 1995, three different tram models underwent testing in Oslo, while additional trials took place in Stockholm.

The initial model tested was a six-axle articulated tram from Kassel, Germany, featuring an 80% low-floor design. However, Oslo Sporveier found its lack of air suspension and outward-opening door mechanism unsatisfactory. Another candidate was the ABB-built Variotram from the Chemnitz Stadtbahn, which offered a fully low-floor interior and measured 2.65 metres (8 ft 8 in) in width; it also had doors that opened outward. The tram’s width rendered it incompatible with some newly constructed stops. Despite its appealing characteristics, Oslo Sporveier considered it too experimental. The third tested vehicle was a six-axle Class T light rail vehicle from the Vienna tramway. This model was designed according to German light rail standards featuring high platforms and a minimum curve radius of 25 metres (82 ft 0 in). Consequently, it was unsuitable for operation on certain lines such as the Briskeby Line and could not navigate the loop at Jar on the Lilleaker Line.

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The SL95 entered service initially on the Ullevål Hageby Line; pictured at John Colletts plass

After completing these trials in Oslo, representatives were dispatched to evaluate compatible systems beyond the city’s borders. Upon their return, negotiations commenced with three manufacturers: Duewag, Bautzen, and Ansaldo/Firema. Ultimately, Oslo Sporveier contracted Ansaldo/Firema to supply 17 units during 1997–98, with an option to purchase an additional 15 vehicles. The initial batch cost approximately Template:NOK, equating to around NOK 20 million per tram. Exercising the option increased the total order to 32 units. This acquisition enabled replacement of all non-articulated trams and ensured that no vehicle in the fleet would exceed an age of 18 years. While initially planned as a debt-financed purchase, by 1999 Oslo Sporveier opted to lease the trams through Skandinaviska Enskilda Banken. Due to labor disputes concerning privatization of tram and metro operations in Oslo, ownership of all trams and metro trains—including the SL95 fleet—was transferred in 2007 to Oslo Vognselskap, a municipally owned limited company.

Construction and delivery

In January 1997, two bogies were mounted and tested on an ST55-tram trailer. Subsequently, on 10 February 1997, a driver's cab mock-up was produced in Italy and shipped to Oslo to refine the interior design. On 8 April 1997, Oslo Sporveier approved an order for an additional 13 trams; however, the complete options could not be fulfilled due to budget constraints. Concurrently, a decision was made to retire all SM91 trams, while retaining some SM83 units after the full SL95 fleet had been delivered. By 1998, the delivery of the first unit, tram no. 141, was scheduled for 23 May, with plans to commence its regular service on 23 June. The mock-up was dismantled on 12 February. Nonetheless, completion of the tram was delayed until October, when representatives from the tram operator had their initial opportunity to drive it at Firema's facility. The postponement resulted from the factory roof being blown off during a storm. As compensation for this incident, a discount of NOK 1 million per tram was granted.

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A tram operating on the Kolsås Line in 2007 after Oslo Metro services along this route had ceased.

Tram no. 141 arrived in Oslo on 5 January 1999 in three segments. These sections were assembled and tested across the entire network by the end of that month before tram no. 142 was delivered. The planned delivery interval was set at two weeks. Between April and June, voltage upgrades were implemented on parts of the Lilleaker Line, increasing it from 600 to 750 V; this included compatibility tests with the SL95 trams to confirm their operation under the higher voltage.

The first scheduled deployment of tram no. 141 occurred on 30 May when it began service on the recently extended Ullevål Hageby Line. This extension added approximately 1.6 kilometres (0.99 mi) reaching Rikshospitalet, serving the new national hospital facility. Unlike other tram lines in Oslo, this terminal station lacks a turning loop, necessitating use of only bidirectional trams; SL95 was uniquely equipped for this within Oslo Sporveier's fleet. Due to delivery delays, service initially terminated at John Colletts plass, where a turning loop is available.

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Tram no. 171 at Bekkestua in 2007

Tram no. 142 entered scheduled operation on 1 June 1999, followed by tram no. 143 arriving on 3 June. To accommodate these new vehicles on targeted lines, Oslo Sporveier undertook infrastructure improvements at various locations. The SL95 requires a minimum vertical curve radius of 500 metres (1,600 ft), prompting upgrades at Wessels plass and Gamlebyen. Although curve adjustments were needed at Geita Bridge as well, these were not executed because the trams exceeded the bridge’s maximum load capacity. Additionally, the minimum horizontal curve radius allowed is 17 metres (55 ft 9 in), which prevents operation through the intersection of Riddervolds gate and Inkognitogata where the radius measures only 16.5 metres (54 ft 2 in). Consequently, SL95 trams cannot serve the Briskeby Line, so all services to Majorstuen utilize SL79 units instead. Temporary restrictions preventing two SL95 trams from passing each other were enforced on several tight sections such as the S-curve between Kirkeristen and Stortorvet, but these areas were swiftly reconstructed.

By mid-2000, delivery setbacks persisted; in June all trams were withdrawn from service for three weeks to undergo gearbox modifications. In October, ten out of thirteen trams were sidelined due to issues with radial run-out. The severity led to some vehicles developing new radial run-out problems shortly after repairs. Starting from 6 January 2001, SL95 units began operating on the Grünerløkka–Torshov Line, followed by deployment on the Ekeberg Line from 6 February; however, platform lengths on the latter remained insufficient.

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Trams no. 141 and no. 151 preparing for departure at their respective lines at Rikshospitalet

Operational challenges emerged significantly by March 2001 when Oslo Sporveier threatened to cancel its purchase agreement unless AnsaldoBreda—formed through a merger involving the original manufacturer—rectified ongoing issues. Complaints included noise levels exceeding contractual limits by about 15 dB and frequent breakdowns during cold spells in January and February when battery and rectifier failures occurred. It was agreed that AnsaldoBreda would replace all 256 traction motors to meet contract specifications. By June 1st, one tram fully compliant with contract requirements had been delivered; tram no. 155 remained undelivered but was undergoing manufacturer testing while tram no. 149 was tested in Oslo simultaneously. The fleet was temporarily withdrawn from service and gradually reintroduced following upgrades. In February 2002, tram no. 155 received new motors under a revised agreement stipulating full motor replacement across all units by December 2003 contingent upon satisfactory six-month trial results with no.155.

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SL79 alongside an SL95 tram in Storgata

The final day for SM91 trams in operation was November 1st, 2002; by then Oslo Sporveier had received delivery of twenty-seven SL95 units and could operate its entire network exclusively with articulated trams. Until early 2003, trams nos.142 and 149 underwent extended repairs. On July 8th, 2004 a software malfunction caused tram no.161 to become immobilized with doors locked despite emergency overrides; this occurred because its computer erroneously registered a stationary speed of 12.5 kilometres per hour (7.8 mph). Subsequently all trams were modified allowing drivers to override similar faults manually. The last deliveries concluded in 2004 with tram no.142 entering service in January 2005; at that time corrosion was detected inside articulation joints of tram no.141. In response, Oslo Sporveier initiated a refurbishment program in 2006 aiming to eliminate corrosion both externally and internally within SL95 units and simplify joint lubrication procedures which previously required complete decoupling of each vehicle; these enhancements were targeted for completion by 2009. Additionally, cold weather caused issues with frozen air supply systems preventing side mirror retraction during direction changes and disabling secondary suspension; this forced operations at walking speed without passengersTemplate:Fix/category.

Specifications

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Interior view (1999–late 2017).

The SL95 is an eight-axle, articulated tram capable of bidirectional operation, constructed solely for the Oslo Tramway by the Italian manufacturer Ansaldo. It consists of three connected sections, with a single bogie located under both the front and rear sections, and two bogies supporting the central section. The tram’s body is crafted from aluminum, featuring welded joints along the floor and roof while side panels are bolted to facilitate easier replacement of damaged parts. Measuring 33.12 meters (108 ft 8 in) in length, 2.6 meters (8 ft 6 in) in width, and 3.62 meters (11 ft 11 in) in height, the tram’s bogies have an axle spacing of 1.80 meters (5 ft 11 in). The distance from the center bogie to each end bogie is 9.85 meters (32 ft 4 in), while the spacing between the two central bogies is 5.17 meters (17 ft 0 in). The vehicle’s empty weight is 64.2 tonnes (63.2 long tons; 70.8 short tons), increasing to 78.3 tonnes (77.1 long tons; 86.3 short tons) when fully loaded.

Each of the four bogies houses two asynchronous three-phase induction motors mounted on a steel frame with two axles per bogie. The wheels have a diameter of 680-millimeter (27 in) when new, reducing to 610-millimeter (24 in) at the end of their service life. The axles are supported by rubber suspension within the bogies, which themselves are mounted on air suspension systems connected to the chassis. Ansaldo manufactures the MTA-F6-105V motors powering each unit, with each motor delivering 105 kilowatts (141 hp) at an operating voltage of Template:750 V DC. This configuration enables a top speed of 80 kilometres per hour (50 mph) and acceleration up to 1.5 m/s/s (3.4 mph/s). While capable of reversing direction, the tram’s speed is automatically restricted to 15 kilometres per hour (9.3 mph) when moving backward. When operating at 600 V, the total power output reaches 672 kilowatts (901 hp).

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Tram at Abbediengen station

The braking system incorporates three distinct mechanisms: a primary regenerative dynamic brake, a secondary disc brake, and an emergency rail brake. During regenerative braking, energy is returned to the overhead power lines. The trams are engineered to function throughout a full operational day even if one bogie’s dynamic brakes are disabled, and for up to one hour if two bogies lose dynamic braking capability, relying solely on disc brakes in such cases.

Designed for bidirectional use, each tram features driver’s cabs at both ends equipped for ticket sales by the motorman. These cabs include doors that isolate them from passenger areas to prevent access from riders to the rear cab. There are four doors on each side: a single front door and three double doors toward the rear; additionally, each section contains one door apart from the front section. Operating doors on the left side requires engaging a safety switch by the motorman, while individual doors on the right side can be opened directly from within the driver’s cab. Approximately half of the tram’s length offers low-floor access with entry heights at 350 millimetres (14 in), encompassing three out of four doors. Seating capacity totals 88 seats—64 located in the high-floor area—accommodating up to 212 passengers overall. In 2019, all rollsigns were upgraded to LED displays similar to those used on SL79 trams.

Operation

Out of the total 72 trams in the fleet, 32 are SL95 models, which serve as a complement to the older SL79 trams. The SL95 is unique in being the only bidirectional tram type, enabling it to operate on the Ullevål Hageby Line, which is covered by lines 17 and 18. Since line 13 extends from line 17 at Sinsen, SL95 trams also run on this route. The Briskeby Line’s tight curve radius limits SL95 access, so they seldom travel to Majorstuen; when they do, their service is confined to the Frogner Line and/or the Homansbyen Line. Near the turn by the Inkognitogata stop on the Briskeby Line, a caution sign warns about SL95 trams. These vehicles operate on multiple lines including Ullevål Hageby, Ekeberg, Sinsen, Grünerløkka–Torshov, Lilleaker-Skøyen, and occasionally on the Homansbyen–Frogner routes. Each of these lines maintains a ten-minute interval between trams, resulting in a five-minute frequency on sections served by two overlapping lines.

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SL95 tram at Kirkeristen, illustrating the extensive roof-mounted equipment

In 2007, two SL95 trams were involved in a collision and subsequently sent to Firema for repairs. Unfortunately, Firema declared bankruptcy before completing the work, and as of October 2010, these trams had neither been fixed nor returned to service in Oslo. By 2010, Jøran Kallmyr, Commissioner for Environmental Affairs and Transport representing the Progress Party, indicated that both SL95 and the older SL79 trams were under consideration for replacement. The SL95 units faced issues such as excessive noise levels, frequent breakdowns, corrosion problems, axle fractures, and caused accelerated track wear due to their heavy weight. On 29 April 2013, all but two SL95 trams were temporarily withdrawn from operation after rust was found damaging the joints connecting their articulated sections.

Starting in 2012, these trams were fitted with an automatic train protection system enabling them to share tracks with metro trains on the Kolsås Line. In September 2012, Oslo Vognselskap announced plans to issue a tender for new trams intended to replace all existing SL79 and SL95 vehicles. This procurement would involve approximately seventy new trams alongside an extensive NOK 4 billion upgrade of tram infrastructure initiated by Ruter. According to Oslo Vognselskap, the forthcoming replacements will be similar in size to the SL95 but will weigh only around 40 tonnes (39 long tons; 44 short tons), reducing track wear considerably. Additionally, these new vehicles will feature a floor height of 30 centimeters (12 in). The introduction of replacement units began in 2020 with deliveries of the new SL18 trams and is expected to conclude by 2024 when all 87 new vehicles are operational. This renewal will also phase out the older SL79 models.