MF 88 explained

Background:
  1. 8FD5BB
MF 88
Interiorimage:Interieur MF88.jpg
Interiorcaption:Interior of MF 88 trainset
Service:1993–present
Manufacturer:GEC Alsthom, Faiveley, Renault, ANF
Replaced:Sprague-Thomson
Constructed:1990–1992
Yearscrapped:2013
Numberbuilt:27 cars (9 trainsets)
Numberscrapped:3 cars (1 trainset)
Successor:MF 19
Formation:3 cars per trainset
Capacity:425 people per trainset
Operator:RATP
Traction:GEC Alshtom GTO-VVVF
Traction Motors:3-phase AC induction motor type 4ELA 2552
Collectionmethod:Contact shoe
Uicclass:Bo'Bo'+2'2'+Bo'Bo'
Deceleration:0.9m/s2 (Service)
1.1m/s2 (Emergency)

The MF 88 (French: '''M'''étro '''F'''er appel d'offres de 19'''88'''; English: Steel-wheeled metro ordered in 1988) is a steel-wheel variant of electric multiple units used on Paris's Métro system. RATP contracted a consortium of manufacturers, with Ateliers du Nord de la France in charge of the project.

They were built following successful tests of a prototype train-set called the "BOA", derived from the MF 77, which tested new features such as open gangway connections between cars to improve passenger distribution and special bogies to reduce friction caused by the sharp curves found in the Métro network. The MF 88 introduced a number of innovations in its time, including AC induction motors and an on-board computer system using a new standard integrated computing architecture.[1] [2] It is planned for the MF 19 rolling stock to replace the MF 88 in 2025.[3]

Design

Carrying on the features of the BOA, a total of nine MF 88 train-sets were built, which have only ever operated on Line 7bis in a three-car formation. It was the first model with AC motors, supplied by GEC Alsthom,[4] as opposed to DC and with interconnecting gangways.[5] The MF 88 was also the first to adopt a new computing architecture, developed by TechnicAtome, over relay-based systems used in older Paris Metro rolling stock. It also introduced an independent-wheeled steering axle design,[4] but this turned out to cause several problems for RATP and was not adopted in subsequent Paris Metro rolling stock.

It was also the last model not newly built with automatic announcements and with user-activated doors (all subsequent models, as well as more recently the MF 77s on Line 13, have had all doors open at once). The high rate of wear-and-tear of the train-sets has made maintenance much more expensive than expected. The independent-wheeled steering axle design was found to be problematic and was causing excessive wear on the track.[6] This is because of the design flaw in the chassis, each intermediate bogie only has one axle, similar to a typical car, bus, some rubber-tyred trains (although the rubber-tyred lines of the Paris Métro use the typical 2-axle bogies), or certain railbuses, but unusual for a more “standard” railcar, especially one powered by electricity.[7]

Technical specifications

Formations

As of 1 September 2022, eight MF 88 trainsets were in service and were formed as shown below. One trainset was scrapped in 2013.[8]

As of 1 March 2022, eight trainsets are allocated to Pré Saint-Gervais depot for use on Line 7bis.

 /
 
 
Car No. 12 3
TypeM T M
Designation88M.xxx 88B. xxx 88M. xxx
EquipmentVVVF CP, SIV VVVF

Notes and References

  1. Book: Bancelin . J . Bordenave . H . Control, Computers, Communications in Transportation . Test and Development Bench for an In-Borne Computing Architecture . 10 July 1990 . 15-18. 10.1016/B978-0-08-037025-5.50008-6 . 978-0-08-037025-5 .
  2. Book: Boullie . JB . Brun . M . A new rolling stock architecture using safety computers and networks . Proceeding International Conference on Dependable Systems and Networks. DSN 2000 . 6 August 2002 . 157–162 . 10.1109/ICDSN.2000.857529. 0-7695-0707-7 .
  3. News: Philippe-Enrico . Attal . MF 19, le renouveau des rames fer du métro . 17 June 2024 . Rail Passion (Magazine) . 10 July 2018.
  4. Book: Allen . Geoffrey Freeman . Jane's World Railways 1991-92 . 1 November 1991 . Jane's Information Group . 9780710609557 . 74 . 33rd .
  5. Web site: Article MétroPole - « Le MF 88 » . French . 2006-01-05 . https://web.archive.org/web/20060716170337/http://www.metro-pole.net/expl/materiel/mf88/mf88.html . 2006-07-16 .
  6. Book: Gaston . Jacobs . Le métro de Paris : Un siècle de matériel roulant . 2001 . La Vie du Rail . 9782902808977 . 167-170.
  7. https://www.iledefrance-mobilites.fr/wp-content/uploads/2017/04/Deliberation_no2013-534_-_Schema_directeur_materiel_metro.pdf STIF - Schéma directeur du matériel métro
  8. Paris : le matériel RATP du métro à fin 2022. Réseaux urbains. 2023. Colin. Pierre. 169. 41–44.