| ATM Class 4900 | |
| Yearconstruction: | 1976–1978 |
| Yearservice: | 1976 |
| Numberbuilt: | 100 |
| Operator: | Azienda Trasporti Milanesi |
| Trainlength: | 29.21frac=4NaNfrac=4 |
| Width: | 2.38frac=4NaNfrac=4 |
| Height: | 3.75frac=4NaNfrac=4 |
| Lowfloor: | No |
| Floorheight: | 942frac=4NaNfrac=4 |
| Art-Sections: | Three |
| Wheeldiameter: | 690frac=8NaNfrac=8 |
| Wheelbase: | 1.8frac=4NaNfrac=4 |
| Maxspeed: | 600NaN0 |
| Electricsystem: | 600 V DC, overhead line |
| Collectionmethod: | Pantograph |
| Uicclass: | Bo′ 2′ 2′ Bo′ |
The ATM Class 4900, Nicknamed the "Jumbotram" is a series of articulated trams used by the ATM on the Milan urban tramway network.
They were built from 1976 to 1978 in two series, by Fiat Ferroviaria and Stanga, respectively, and were intended to be used on the future light rail lines, like the proposed circular line that should substitute the existing circular trolleybus line.
However such lines were never built, and the 4900 were used on the existing network.
Starting from 2008, some units were equipped with an air conditioning system, while in 2011 the 4950 car underwent both an aesthetic and functional revamping in order to gradually revamp the series. After a long phase of tests and checks conducted by the company operating the tram network, ATM, in 2014 this unit entered service and by mid-2015 another 19 revamped units were delivered by the AnsaldoBreda company. As of 2018, there were a total of 40 revamped trams in service out of a total of 51 envisioned by the contract; the last car was delivered by the end of 2019.[1]
In 2023, the cars which were not subject to the previous revamping still in service were repainted with Milan's yellow tram livery, which gradually replaced the original "arancio ministeriale" color scheme, so as to match the coloring of the other trams in service. The cars used a different scheme that the previous 4900 revamping.