| MI 84 (Class Z 8100) | |
|---|---|
.jpg) A renovated MI 84 | |
| In service | 1984–present |
| Manufacturer | Alsthom and ANF |
| Constructed | 1984–1989 |
| Refurbished | 2018–present |
| Number built | 73 trainsets (292 cars) |
| Number in service | 41 trainsets (164 cars) (as of Dec 2020) |
| Number scrapped | 32 trainsets (128 cars) |
| Formation | 4 cars per trainset |
| Fleet numbers | Z 8341– Z 8486 |
| Operators | RATP, SNCF |
| Depots | Massy |
| Lines served |   (1984–2017)  (1984–present) |
| Specifications | |
| Car body construction | Aluminium |
| Train length | 104.16 m (341 ft 9 in) |
| Car length | 26 m (85 ft 4 in) |
| Width | 2.8 m (9 ft 2 in) |
| Height | 4.18 m (13 ft 9 in) |
| Doors | 4 pairs per side, per car |
| Maximum speed | 120 km/h (75 mph) |
| Weight | 205,000 kg (452,000 lb) |
| Traction system | |
| Traction motors | EHO 3262 A (750 V DC self ventilated) |
| Power output | 2,824 kW (3,787 hp) |
| Transmission | hollow shaft and cardan shaft ratio :4.047 |
| Acceleration | 2.3 mph/s (1.0 m/s2) |
| Deceleration | 2.5 mph/s (1.10 m/s²) (full service) 2.8 mph/s (1.20 m/s²) (emergency brake) |
| Electric system(s) | |
| Current collector(s) | Pantograph (type AM 62 BU) |
| Bogies | H-shape frame by ANF |
| Braking system(s) | Disc and regenerative, eddy current |
| Safety system(s) | EAS, KCVP, KCVB, SACEM[1] |
| Coupling system | Scharfenberg type |
| Multiple working | MI 79 or MI 84, maximum 3 trainsets (2 in operations) |
| Track gauge | 1,435 mm (4 ft 8+1⁄2 in) standard gauge |
The MI 84 (French: Matériel d'Interconnexion de 1984, English: interconnection rolling stock of 1984), also known as the Class Z 8100 is a dual-voltage electric multiple unit trainset that is operated on line B of the Réseau Express Régional (RER), a hybrid suburban commuter and rapid transit system serving Paris and its Île-de-France suburbs.
The 73 four-car trains were built by a consortium of French manufacturers Alsthom and ANF Industrie (which would be purchased by Bombardier in 1989 before the end of the deliveries). The final assembly of the trains was performed at Alstom's Valenciennes factory and ANF's Crespin factory between 1985 and 1990.
The design of the MI 84 was derived from the earlier MI 79 built for the RER B, but with modifications to make it better suited for the RER A line. The introduction of double-decker trainsets on the RER A allowed the MI 84 trains to be shifted to the RER B by 24 February 2017.