Škoda 15 T

Škoda 15 T ForCity uni-directional, bi-directional[1]
Manufacturer	Škoda Transportation
Designer	Miloš Zelingr, Patrik Kotas
Assembly	Plzeň, Czech Republic
Constructed	2009–present
Predecessor	Škoda 14 T Elektra
Capacity	43 (two body sections uni-directional) - 72 (five body sections bi-directional) (Seated)[1] 150 (two body sections uni-directional) - 539 (five body sections bi-directional) (Standing)[1]
Specifications
Train length	21.800 m (71 ft 6.3 in) (two body sections) 31.400 m (103 ft 0.2 in) (three body sections) 41.000 m (134 ft 6.2 in) (four body sections) 50.600 m (166 ft 0.1 in) (five body section)[1]
Width	2,300–2,650 mm (91–104 in)[1]
Height	3,600 mm (140 in)
Floor height	350 mm (13.78 in)/450 mm (17.72 in)[1]
Low-floor	100%[1]
Doors	4/6/8/10
Articulated sections	1 - 4[1]
Maximum speed	80 km/h (50 mph)[1]
Axle load	5.2 t (5.1 long tons; 5.7 short tons)
Steep gradient	85 ‰ (8.5%)
Power output	46.6 kW (62.5 hp)[2] x number of driven wheels[1]
Wheels driven	60% - 100%[1]
Bogies	pivoting and pivoting Jacobs (25°)
Minimum turning radius	18 m (59 ft)/15 m (49 ft)
Track gauge	950 mm (3 ft 1 3⁄8 in) - 1,524 mm (5 ft)[1]

Škoda 15 T ForCity ( Prague) uni-directional
Manufacturer	Škoda Transportation
Assembly	Plzeň, Czech Republic
Constructed	2009–present
Capacity	61 (Seated) 239 (Standing)
Specifications
Train length	31.400 m (103 ft 0.2 in)
Width	2,460 mm (97 in)
Height	3,600 mm (140 in)
Floor height	350 mm (13.78 in)/450 mm (17.72 in)
Low-floor	100%
Doors	6
Articulated sections	2 (3 body sections)
Maximum speed	limited to 60 km/h (37 mph)
Weight	42 t (41 long tons; 46 short tons)
Steep gradient	85 ‰ (8.5%)
Power output	745.6 kW (999.9 hp) (16 x 46.6 kW or 62.5 hp[2]
Wheels driven	100% (16/16)
Bogies	4 x pivoting and pivoting Jacobs (25°)
Minimum turning radius	18 m (59 ft)/15 m (49 ft)
Track gauge	1,435 mm (4 ft 8 1⁄2 in)

Škoda 15 T ForCity ( Riga) uni-directional
Manufacturer	Škoda Transportation
Assembly	Plzeň, Czech Republic
Constructed	2009–present
Capacity	60 (Seated) 260 (Standing)
Specifications
Train length	31.600 m (103 ft 8.1 in) 41.200 m (135 ft 2.0 in)
Width	2,500 mm (98 in)
Height	3,600 mm (140 in)
Floor height	350 mm (13.78 in)/450 mm (17.72 in)
Low-floor	100%
Doors	2 per body section
Articulated sections	2 (3 body sections) 3 (4 body sections)
Maximum speed	limited to 70 km/h (43 mph)
Weight	42 t (41 long tons; 46 short tons) ?
Steep gradient	(?)
Power output	559.2 kW (749.9 hp) (12 × 46.6 kW or 62.5 hp[2]
Wheels driven	75% (12/16) ?
Bogies	pivoting and pivoting Jacobs (25°)
Minimum turning radius	18 m (59 ft)/15 m (49 ft)
Track gauge	1,524 mm (5 ft)

Škoda 15T (also known as Škoda ForCity Alfa) is a 100% low-floor multiple-unit tram developed by VUKV a.s. and built by Škoda Transportation in Pilsen for the Prague tram network. It was a successor to the Škoda 14 T, featuring articulated bogies and more power to correct for problems found during the operation of the 14 T. The 15 T has articulated bogies at either end of the train, and Jacobs bogies between the segments. The tram has two double-doors in each segment (or four in bi-directional version) to allow fast boarding of passengers, and one extra side door leading to the driver's cabin.

Design

The Škoda 15 T ForCity was developed as highly modular; it is offered with up to five car body sections and 50.6 meters (166 ft 0 in) in length. It may be used on gauges from 950 mm (3 ft 1 ³⁄₈ in) up to 1,524 mm (5 ft) and the body may be 2,300–2,650 mm (90.6–104.3 in) wide. The tram can be uni-directional or bi-directional. It can have from 60% of wheels driven up to all of the wheels driven for networks in hilly cities. As the bogies are under articulations and don't interfere with the inner space of the body sections, there is unlimited choice of interior lay-out and location of doors.^[1]

The basic vehicle length can be modified. It is also possible to couple two or more vehicles. The tram's appearance and front design are user-defined.^[1]

Bogies

The fixed bogies which are used by most 100% low floor trams^[3] increase track wear and decrease the speed at which a tram can drive through a curve (usually 4–15 km/h (2.5–9.3 mph) in 20 m (65.62 ft) radius curve).^[4] The 15 T is designed to cope with these issues through Jacobs bogies under the articulations and pivoting bogies at the tram's ends. For a time it was said to be the only true 100% low floor tram with pivoting bogies in production. However, the Alstom Citadis X04, an experimental 100% low floor tram currently being developed with pivoting bogies (but with sections of high floor seating over the bogies), has made an initial production appearance as a modified Citadis 301 (with a fixed centre bogie) in Istanbul, and for Helsinki, a tram with similar interior solution and all pivoting bogies is undergoing trials as of 2015.^[5] With the same length of tramcar, the Škoda 15 T has also four bogies compared to the predecessor Škoda 14 T's three (same on most other 100% low floor trams) (fixed) bogies, which decreases the load each wheel puts on the track. The most of the tram floor is at height of 350 mm (13.78 in) above rail; the height over the bogies is 450 mm (17.72 in) above rail; the transition is inclined, without interior steps. The corridor above the central bogies is 700 mm (27.56 in) wide.^[6] The bogies may be all driven, or some of them may be idle ones, depending on the customer's preferences. The bogies have two axles and two-level springing. The mounted wheels are made of rubber-sprung wheels with integrated brake-discs and axle bearing. On the axle bearings there is a combined, dynamically resistant, primary rubber-bonded-metal-sprung bogie framework. This bogie framework supports four traction motors and one (in outer bogies) or two (in inner bogies) sprung swing bolsters. The secondary springing of the swing bolsters is secured by steel coil springs with parallel hydraulic rotating dampers. On the swing bolsters there are pivot bearings, which facilitate full rotation of the bogie below the body without any limitations.^[1]

Detail of pivoting bogie

Detail of pivoting bogie

Wheels and motors

All bogies are equipped with identical wheels, which have tyres damping rubber pads to minimize noise. Selected bogies could be equipped with a sanding system.^[1]

The vehicle is driven by traction units. Each unit consists of traction container on the vehicle roof and of four traction motors, which drive wheels of one driving bogie. Individual wheel drive on respective bogies secures perfect use of adhesive conditions and ideal ride both in bends and on straight lines. There are three-phase synchronous motors with permanent magnet excitation on rotor. They are fixed to the bogie framework from the wheels outside. The traction motors don't use a gear box - they drive tram wheels directly through a mechanically disconnectable jaw clutch.^[1]

While the drive is controlled by two control units connected together by fast serial communication, the safety circuits and functions are hardware-resolved.^[1]

Brakes

Braking is mainly done by electrodynamic brake enabling recuperation of the braking energy back to the electrical grid. If there is no need of it, the braking energy is being used primarily for feeding the vehicle's auxiliary equipment with the rest depleted in the brake resistors. The electrodynamic brake is able to automatically run even during grid's voltage failure. In case of failure, braking is automatically done by the system of friction disc brake, which will work until the vehicle comes to a complete halt. The friction disc brake is hydraulically controlled with an electric compression unit. Each bogies is also equipped with a pair of electromagnetic rail brakes with voltage of 24 V DC. The friction disc brake also ensures the parking brake function.^[1]

Doors

The vehicle has two double doors on each body unit (or four of them on bi-directional version), or alternatively there can be one door each side on each body unit located in place of any of the side panels. The driver has a separate door leading to the driver's cabin. The doors slide outwards. Each door is equipped with an individual control unit, which operates it and communicates with the vehicle central control unit. In selected double-doors area there could be either ramp or lift enabling easy entry for passengers with restricted mobility. There could be also a room for bicycles and prams.^[1]

Production

Prague

Škoda ForCity won the bidding process of the Prague transport company for 250 new trams in 2005. The order is worth 17 billion CZK (about 68 million CZK per unit (2,3 million € per unit - 1€ 2005=29,6CZK)).

The trials of the first prototype started in 2009, the first rides with passengers started in October 2010 and the last tramcar will be delivered in 2017. The prototype had 3 types of seats - wooden, plastic and with fabric upholstery. Passengers have decided in an internet poll that the wooden seats will be used in the delivered version.

During the delivery of the first batch in 2011, the Prague transport company started negotiations with Škoda regarding instalment of air conditioning for the passenger compartment. It also raised concern, that 1000 horse power streetcar may be unnecessarily powerful and proposed solution used at Riga version, which has only three out of four bogies driven. In view of the transport company the price of additional air conditioning should be covered by elimination of the first bogie's engines. As of May 2011, it was not yet decided, whether this solution will be applied. Firstly there is issue that participants of the original tender may contest the change and require a new competition for the delivery of Prague's trams, secondly it has to be tested, whether 15 T without full adhesion would be able to drive on Prague's hilly network.^[7]

In May 2014, due to financial problems for the City of Prague, the Prague transport company and Škoda Transportation renegotiated the contract to provide for four extra years for delivery of the order and for fitting of full air-conditioning and WiFi in the last 125 trams of the order. By June 2014 the first 100 trams of the order had been delivered and the first of the modified trams (from the second half of the order) will be delivered in 2015.^[8]

Riga

The version for Riga has white-blue livery and a different front face

In May 2008 Škoda made a contract with the Riga transport company (Latvia) for delivery of 20 trams (with option for another 32) worth 1,3 billion CZK (about 65 million CZK per unit (2,6 million € per unit - 1€ 2008 = 25CZK)). The bidding process started in 2007 and altogether 9 companies took part in it. The Riga variant is three-segmented, like the Prague version, with air-conditioning for whole tram (Prague only for driver's cabin) and it is in white-blue livery. Unlike Prague's version, which has all bogies driven due to difficult adhesive conditions (Prague has hilly terrain), the Riga tram has 3 bogies driven (the 1st bogie doesn't have motors). The tram has upholstered seats similar to those in Škoda trolleybuses used in Riga.

The first tram was delivered to Riga in March 2010, the second in August 2010 and the other 18 were delivered before the end of 2011. The first rides with passengers were in June 2010 after preceding test-drives.

There are also 6 four-segmented tramcars (41 meters long) made for Riga, Latvia, as the town decided to apply a part of the preagreed option of 32 (which was part of the previous order for 20).^[9] These were delivered between June and October 2012.

In April 2016 Riga Transport (RS) awarded Škoda Transportation a €62.6m contract to supply 20 more, 15 T ForCity low-floor trams. The order comprises 15 three-section vehicles and five four-section LRVs. All 20 vehicles are due to be delivered next year. The 1524mm-gauge 600V dc vehicles will be used on Line 4, which links Riga Central Market with Imanta.^[10]

Other tenders

At the end of September 2010 Škoda entered bidding process for 12 new trams of German city of Rostock with the ForCity tram. Škoda did not win this tender.^[11]

The 15T was also submitted in a proposal for Helsinki, Finland, but did not win the tender. Currently, Škoda has entered a tender for Zürich, Switzerland.^[12]

In April 2011 Škoda announced it will start a lawsuit against transport authority of Essen, Germany, which announced a selection procedure for delivery of 27 new trams. Škoda believes the procedure's technical requirements to be so specific that they effectively reduced competition (contrary to European law), leaving Škoda not able to offer its bid.^[13]

Škoda 15T underwent testing and certification in the German city Chemnitz (previously known also as Karl-Marx-Stadt) in April–May 2012.^[14]

China

27Ts in Qingdao

In 2013 Škoda has signed an agreement with Chinese CSR Sifang to produce Škoda 15Ts for the Chinese market under licence. The 10-year agreement could cover up to 400 trams.^[15] The first unidirectional prototype was produced in 2014.^[16]

In 2015 CSR Sifang unveiled new bi-directional tram based on 15T designated as 27T. This vehicle is 2,650 mm wide and is bidirectional. Apart from the traditional overhead line vehicle can be powered by battery, Supercapacitor or hydrogen-fuelled.^[17][18][19]

In March 2016 first line of Qingdao Tram was inaugurated, served by fleet of seven CSR Sifang produced 27T trams. The trams are 32.5 m long and using hydrogen fuel cells to allow service at the parts of the route without overhead electrification.^[20]

Gallery

15T in Prague	15T in Riga	Interior (Prague)
Interior	The corridor within the articulation. The wooden seats were chosen by passengers in an internet poll	The front end of the tram, note the separate door leading to the driver’s cabin

Open Doors Day in Střešovice tram depot and transport museum

References

External links

Wikimedia Commons has media related to Škoda 15T.

• Information brochure