MF 77

MF 77 is the designation of a type of oar used on the underground railway network of Paris.

History

To replace Spragues

With the beginning of the year 1970, whereas the deliveries of MF 67 were completed, of many technological advancements in particular in the equipment of traction/braking pushed the RATP to consider the project of a new material iron (in opposition to the material on tire) intended to replace the last materials travelling Sprague on the network.

Thus the RATP placed order in July 1975 of new trains called MF 77 near a consortium including/understanding the following industrialists:

Alsthom and the Franco-Belgian : Supply of the cases and general assembly
CEM Oerlikon : Supply of the engines
Creusot-Loire and ANF : Supply of the bogies
Jeumont-Schneider : Supply of the equipment of traction

The order related to the delivery of 1.000 cars including 600 motor coaches intended for the realization of 200 trains of 5 cars. Later the order was brought back to 187 trains is 935 cars. The first trains were delivered to the summer 1978 and first train MF 77 entered in service traveller on December 11th, 1978 on the line 13, whereas the total equipment of this line was finished only in 1979. Old MF 67 E of line 13 were transferred on the line 8 and the last whole Sprague disappeared in June 1980.

After line 13, MF 77 which followed, started to circulate on September 12th 1979 on the line 7 then thereafter, in June 1980, on the line 8. The delivery of this first order was completed in December 1982.

One second order of 10 trains had placed by an additional clause to contract on February 4th, 1983. These 10 trains were delivered during the year 1985 and 1986.

A material iron of second generation

Trains MF 77, intended for the long lines with prolongations in suburbs including/understanding of the air sections, was designed to circulate with the maximum speed of 100km/h. It also offered many equipment making it possible to improve its performances and comfort of the passengers compared with the former generations of materials iron.

Thus, the cars assembled on bogies with pneumatic suspension offered a better comfort of bearing. The traveller does not have any more the feeling of the wheels, contrary to MF 67 which them have suspensions " métalliques". MF 67 F however were equipped right from the start with the bogies of MF 77, in made defined in the schedule of conditions of manufacture of this material, then taken again for the future bogies of MF 77. Very first the delivered external one of this material was a broken white which was worth with MF 77 the nickname of “white subway”.

Most of the characteristics of MF 77 is resulting from suggestions received from the travellers. That in particular led to the creation of the corner-living room in end of car, to the lighting particularly successful although of very low costs and to the presence of mini-plans of subway close to the doors. One will also note the particular comfort of the blue foam seats (those are however much less robust than seats with the rigid framework).

And for the first time in the Parisian subway, the cars have nothing any more but three large doors per face, instead of 4 smaller usual, this with an aim of fighting against the “funnel effect” of people in front of the doors on the quay. That also decreases the seating capacity, but allows a place much more important for the legs.

Characteristics

External characteristics

MF 77 were the first trains of the RATP had a bent aspect. This aspect allows in fact to gain a few centimetres out of sitted gauge with height of shoulders of the travellers and thus to offer an improved interior comfort.

The cases, equipped with 3 doors by vis-a-vis total obliteration, let appear of broad openings of 1,575 meters allowing the simultaneous passage of two people, thus facilitating the travellers exchanges.

Large picture windows of 1,97 meters and the walls glazed in end of train offer a good visual continuity between the cars and an increased feeling of space.

The motor coaches have a 15,47 meters length, the trailers have they a 15,50 meters length, which gives trains a length total of 77,40 meters. This with obliged, for the stations of which the length is of 75 meters, with the creation of niches or short bench in tunnel in order to fix at it the equipment intended for the control of the trains.

The trains lost delivered to them white of origin in the years 1992 to 1995, occulted by the stripping of the trains to the colors of the new graphic charter of the control.

Interior characteristics

The colors inside the trains (the blue ones of the seats and the walls and the broken white of the ceilings and grounds) were the subject of esthetic studies and an investigation near the travellers.

The whole of trains MF 77 has a forced ventilation and radiators with thermostatic order bringing an essential source of heat in winter on the air portions of the lines on which they circulate.

Data sheet

In Paris 3 lines are equipped with MF77: lines 7, 8 and 13.

Many delivered oars: 197

Configuration with 5 cars: M+B+NA+B+M

This material (conceived at the origin for export) is designed to circulate in formation 7 cars but the RATP never uses this configuration because of length of the stations.

The M indicate the motor coaches with cabin of control which weigh 29,5 tons. B indicate the trailers which weigh each one 21,4 tons. NA indicates a motor coach without cabin which weighs in neutral 29 tons.

Dimensions:

Length of the driving cars: 15,47m
Length of the intermediate cars: 15m
Overall length of an oar in formation 5 cars
Width of the vehicles: 2,46m
Height of a car to the top of the guide rail: 3,46m
Height of the floor to the top of the guide rail: 1,045m
Height of the ceiling to the top of the guide rail: 2,14m
Distance enters the axes of two bogies of the same car: 10m
Footing of the driving bogie: 2,2m
Diameter of the new/worn wheels: 860mm/790mm
Mass of a train with 5 cars: 130,8 tons
Mass in load with 5 pax/m ²: 181,34 tons
Many doors: 3 by face of the type wavering sliding
Width of the doors after opening: 1,575m

Characteristic of exploitation:

Number of place sitted/upright (5 pax/m ²):
Driving M: 45/117
Driving NA: 52/120
Trailer b: 52/120
Is a total of 722 places per oar.
theoretical maximum Speed: 100 km/h
Average acceleration up to 38 km/h: 0,81 m/s ²
average Deceleration: -1m/s²

Equipment traction Braking: Each motor coach takes on board two choppers of current with thyristors to control two engines with D.C. current.

Characteristics of the Chopper:

Maximum Power: 750KW
normal Frequency of piloting: 300Hz (Possibility of carrying out Tests at Power Reduced to 3Hz for the breakdown service)
Frequency cut-off of the filter of entry (Low Master key) of 37,2Hz
continuous Shunting by thyristors

electric Braking with recovery until a decreasing speed of 3,5 km/h
Starting of the generator in braking by car excitation
Regenerative braking combined with mechanical braking
Switch traction braking carried out using thyristors and of diodes
principal Thyristor: 1800V/800A/40 micro seconds
Transmission of instruction traction braking by two current loops to continuous order.
Regulation with operational amplifier into Proportional Integral independent on the two phases.

Definition of the standard engine of traction MF5:

continuous Mode full field
Power: P= 266 KW
Tension: U= 720 V
Running: I= 400A
Speed: n=3055 tr/min for a speed of the train of 100 km/h
Mass: 1,5 tons
Driving compensated and car ventilated with a rate of minimum of 5% and maximum shunting of 76%

Characteristic electric:

nominal Food: 750 V
acceptable Beach of food: 450V with 900 V
Group turning 20 kVA providing Medium Average of 250 volt/250 Hz
low tension of order: 79V

Characteristic mechanics: Each train embarks 2 compressors which deliver each one: 1200 liters/min with 7,5 bars. This air is dried in a system with dessicat.

The bogies are single-engined aircrafts with pneumatic secondary suspension controlled to the load. Braking with electropneumatic order is ensured by shoe and disc brakes.

Evolutions

MF 77 of the line 13 are in the course of restoration, in particular for the installation of the system Ouragan on this line. The restorations also make it possible to refresh the interior of the cars which is seen equipped with the last innovations:

New seats antilacérations
New lighting
System of visual and sound advertisements
New détriplés bars of maintenance

On this occasion the trains lose the lattices with the ceiling so characteristic of this material. To also note the installation of new bill-posters of direction on the faces of the trains.

The first renovated oar service entrance traveller on January 17th, 2007.

See too

Internal bonds

External bonds

Images of first MF 77 renovated on the site of the RATP

References

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