BVG Class F
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| BVG Class F | |
|---|---|
 An F79 train at Zoologischer Garten on the U9 | |
 Interior of an F87 train (before refurbishment) | |
| In service | 1973–present |
| Manufacturer | ABB Henschel, Adtranz, AEG, Orenstein & Koppel, Siemens, Waggon Union |
| Constructed | 1973–1994 |
| Entered service |
|
| Refurbished |
|
| Scrapped |
|
| Number built | 257 |
| Number in service | 208 |
| Number preserved | 3 |
| Number scrapped | 46 5 (F74) 1 (F76) 17 (F79.1) 19 (F79.2) 4 (F79.3) |
| Formation | Double units |
| Fleet numbers | 2500/01 - 2554/55 (F74) 2556/57 - 2636/37 (F76) 2638/39 - 2670/1 (F79.1) 2672/73 - 2710/11 (F79.2) 2712/13 - 2722/23 (F79.3) 2724/25 - 2800/01 (F84) 2802/03 - 2842/43 (F87) 2844/45 - 2902/03 (F90) 2904/05 - 3012/13 (F92) |
| Capacity | 235 (F74, F76) 250 (F79.1, F79.2) 246 (F79.3) 244 (F84 - F92) |
| Operator(s) | BVG (1973–present) |
| Specifications | |
| Car body construction | Aluminium |
| Car length | 32.1 metres (105 ft 3+3⁄4 in) (over anticlimbers) |
| Width | 2.65 metres (8 ft 8+5⁄16 in) |
| Height | 3.425 metres (11 ft 2+13⁄16 in) |
| Doors | 12 side doors per unit (6 per side) |
| Maximum speed | 72 kilometres per hour (45 mph) |
| Weight | F74: 38,100 kg (83,996 lb) F76: 37,800 kg (83,335 lb) |
| Prime mover(s) | electric motor |
| Electric system(s) | 750 V DC Third rail |
| Current collection method | Contact shoe |
| Safety system(s) | dead man's switch, |
| Coupling system | Scharfenberg |
The BVG class F is one of four train types designed for the large profile routes on the Berlin U-Bahn. 257 units (each consisting of two cars) were constructed between 1973 and 1994 in seven batches. These batches differ greatly in terms of design and technical equipment.
The prototype unit 2500/01 underwent testing from 1973 on. After successful experiments, regular production started the year after. 112 double units (batches F74 to F79) were delivered to West Berlin until the end of 1981, which was necessary to replace the remainder of the pre-war class C. 145 additional units, featuring various improvements, were built between 1984 and 1994 and partly replaced trains from the former East Berlin network after the German reunification.
Being built from 1995 to 2002 the BVG Class H became the successor of the class F.
Construction[]
The cars feature a simple design and are built using light metal. They are easily recognizable by their rectangular headlights and (excluding the F74) distinguishable from their predecessors (BVG Class D) by the modified front design with larger windshields and wipers. They are a constructive improvement of the class DL light metal trains. This allows for a high maximum acceleration of up to 1,5 m/s².
As mentioned before, there are differences between the nine batches in terms of technical components and design: Only the F74, being the first batch, basically uses the same front design as its class D predecessors, only using a different type of headlights, which also differs from the headlight type of all successing batches. While all F74 and F76 were equipped with rollsigns, the F79 was the first batch to make use of split-flap displays that featured different colours for the respective lines and also displayed their number. The F84 and F87 units were equipped with these displays as well. The F90 and F92 were the first batches to feature wider rollsigns that also display the route number; all F79, F84 and F87 were re-equipped with this type of rollsigns in the 1990s as well as all F76 units that underwent refurbishment between 2015 und 2018.
Differing from all previous batches and classes the F84 to F92, built between 1984 and 1994, were the first BVG trains to feature pivoting sliding doors instead of pocket sliding doors. This allows for a simpler car body construction and easier cleaning. Additionally the front was slightly altered by using a different type of front door with a black stripe connecting the front windows. The F84 unit 2770/71 was re-equipped with an open gangway in order to test this feature for the upcoming class H trains.[1]
The F trains are 20 centimeters longer than their predecessors, making room for wider doors and cabs. Moreover, they are the only Berlin U-Bahn class featuring transverse seating, with the exception of one class H unit (5018) where transverse seating was implemented as an experiment.
The maximum velocity of all class F units is 72 kph, however, the units equipped with three-phase propulsion (F79.3 to F92) were originally designed to reach 80 kph.
Types[]
Usually the units are summarized as F-Schaltwerker (standard direct current propulsion) F74 to F79 and F-Drehstromer (three-phase propulsion) F84 to F92. An exception to this is the F79.3 batch that also featured three-phase propulsion, mainly to test this new technology for upcoming orders. However, all F79.3 were retired between 1999 and 2003 as spare parts became harder to obtain and maintenance costs increased more and more. Two F79.3 units are preserved as training vehicles for the Berlin fire department and are stored in an unused tunnel near Jungfernheide station.
The F76 unit 2578/79 was the first underground train in Europe to feature three-phase propulsion. As this was never intended for long term service, the unit was re-equipped with a regular direct current propulsion in 1980.
All F74 and several F76 and F79 were equipped with LZB devices to allow semi-automatic operation that was in regular use on the U9 until 1993. After the final shutdown of LZB in 1998 the devices were removed from all cars.
From 2009 to 2017 refurbished F79 units were in service on the U55 line (which became part of the extended U5 in December 2020), as two-car units were deemed sufficient for the short U55 that only featured three stations.[2] These units were the first to receive extensive refurbishment and served as prototypes for a refurbishment program concerning all F74, F76 and F79. All F84 and F87 (with the exception of one unit) already underwent a small refurbishment in the early 2000s, however, only the brown interior color was changed to the light grey of the F90 and F92 then.
Refurbishment and modernization[]
All remaining F74 and F76 units underwent an extensive modernization and refurbishment program between 2011 and 2018. The interior is now colored white with yellow handrails, now offering space for strollers and wheelchairs. The seat pads were changed to the modern black BVG design. Additionally, all units that underwent the modernization after summer 2015 were re-equipped with a new seat type also used in the new class IK. The door handles were replaced by buttons.
The first modernized F74 entered service in June 2012. In the first months of service several technical issues were discovered, especially when operating only with other modernized units. After the issues were resolved, regular operation resumed in December 2012. All modernized units remain fully compatible to non-modernized F trains.
The modernized units are called F74E and F76E, but can be summarized as FE as the two batches are now nearly identical to each other, excluding the front design. The last F74E entered service in September 2018, the F76 modernization was finished by the beginning of 2018 already. 63 units were modernized in total.
Originally the F79 were to undergo this program as well. However, it was later decided to exclude them from the modernization as their general condition was deemed too bad. They were only equipped with new seats and the door mechanics were adapted to the new door mechanics used in the FE units (excluding the replacement of the handles).[3]
Starting in early 2020, all F76E are being re-equipped with LED tail lights. All other F units, excluding the remainder of the F79, are to follow.[4]
Service[]
The F74 to F79 mainly operate on the U9 since they entered service in 1974. Since the retirement of the BVG class D they are also to be found on the U5 und U8, however, the BVG class H operates the majority of all trains on these lines.The F84 to F92 operate almost exclusively on the U6 and U7, very rare services on the U8 and U9 happen just as F74 to F79 units operating on the U6 and U7 from time to time.
The class F cannot operate on the lines U1 to U4, as these are part of the Kleinprofil (small profile) network. However, the small profile classes A3L82 and A3L92 share similarities with the younger F batches.
Retirement[]
As mentioned above, the F79.3 were the first F units to be retired as a consequence of increasing maintenance cost and difficulty. Besides that, only a few F74 and one F76 were pulled from service and subsequently scrapped in the 2000s after derailments and/or severe defects.[5] The F prototype 2500/01 was dismantled in the 2006 to receive material samples on which the feasibility of a modernization would be judged.
In November 2017 it was found that the remaining F79 units were increasingly suffering from structural defects in the aluminium car bodies, in which cracks were forming at a level that could no more be repaired by welding. The originally planned modernization was to counteract this, however, the damage was bigger than originally estimated. As a consequence the technical supervisory authority of Berlin ordered to retire all F79 units from 2019 on, at which the oldest F79 cars would be 40 years old.[3] As a result of their excessive structural damage 22 of 35 units were already pulled from service by the end of 2018 and scrapped between 2019 and 2020. In October 2021 the last F79 unit (2710/11) was retired.
All F74E and F76E as well as F84 to F92 remain in service. They are expected to be gradually replaced by the new , which is expected to enter service in 2023. One F74E was permanently taken out of service in 2021 after hitting a buffer stop while shunting.
Unit 2700/01 (F79) is on display at the German Museum of Technology since 2021.
References[]
- ^ "Auf dem Weg zur Berliner U-Bahn 2000 [signalarchiv.de]". signalarchiv.de. Retrieved 2021-05-24.
- ^ Berlin, Berliner Morgenpost- (2009-07-23). "Am Berliner Hauptbahnhof schweben die U-Bahnen". www.morgenpost.de (in German). Retrieved 2021-05-24.
- ^ a b "Der BVG droht Ärger wegen 80 neuer U-Bahn-Wagen". Retrieved 2017-12-16.
- ^ "Kurzmeldungen – U-Bahn". Berliner Verkehrsblätter. 6: 122. 2020.
- ^ "Kurzmeldungen – U-Bahn". Berliner Verkehrsblätter. 4: 79. 2018.
External links[]
- Commons: BVG class F. – Collection of pictures, videos and audio files
- Berlin U-Bahn
- Electric multiple units of Germany