1968

Towards the end of the 1960s, Fiat Divisione Materiale Ferroviario developed a prototype version of the ALn.668 series featuring a turbocharged 221H engine. Initially registered ALn.668.1999, it is characterized by enlarged windows and a fully ribbed roof design. Its front headlamps are recessed, enhancing its streamlined appearance. The vehicle’s body structure underwent a comprehensive redesign, replacing the floor with uninterrupted corrugated sheet metal, which improved the longitudinal strength of the vehicle and provided complete insulation from noise sources such as engines and ventilation systems located beneath. This redesign also enhanced the thermal and acoustic insulation of the floor through the use of higher density glass wool, compared to earlier models in the ALn.668 series.

Two vestibules are located at the ends of the car body, arranged such that a small luggage compartment is situated between the entrance and the driver's cabin, while the opposite vestibule is allocated for first-class passengers. The overall length of the unit’s body was increased from 22'110 mm to 23'250 mm, which also extended the passenger module lengths from 1,600 mm to 1,700 mm. The ALn.668.1999 features "crane neck" bogies similar to those on the 1800 series and is capable of operating at speeds up to 130 km/h .

Despite successful functional tests conducted from 1968 to 1969, the Ferrovie dello Stato (FS) decided against further orders, including a planned twin prototype, judging its features overly extravagant for a vehicle intended for secondary lines. Unit ALn.668.1999 is not registered with the Ferrovie dello Stato (FS); instead, it was transferred to the Ferrovia Suzzara-Ferrara (FSF), which required rolling stock for the "Freccia Orobica" express service connecting Bergamo, Brescia, Verona, Poggio Rusco, Ferrara, Rimini, and Pesaro. It will be designated ALn 668 11.

Before its sale to FSF, the ALn 668.1999 railcar was used for a series of experimental test runs on the Bra-Ceva railway line. These tests, conducted in 1969, were part of a research initiative by FIAT to explore ways to improve train stability and passenger comfort at higher speeds, particularly on curved tracks. The railcar was fitted with a special "hydraulic chair", designed to study how lateral acceleration affected passengers and to evaluate methods for counteracting discomfort.

During the tests, researchers gradually increased lateral acceleration and recorded its effects, looking for ways to maintain stability and improve ride quality. Initially, response delays in the tilt mechanism were observed, leading to discomfort. To solve this, the FIAT research team, under the leadership of Oreste Santanera, introduced a gyroscope-based system to more accurately detect track transitions and improve synchronization with train movement.

These experiments proved that higher speeds on curved tracks could be achieved without compromising safety. The findings were later applied to the FIAT Y 0160 prototype, a more advanced simulation platform that led to the development of ETR.401, the first train in the Pendolino family. This research marked a significant step forward in railway technology, laying the foundation for modern high-speed tilting trains.
 

Concerns registration number(s): 668 1999

Sources: https://www.marklinfan.com/f/post.asp?method=Reply&TOPIC_ID=1590&FORUM_ID=50, https://it.wikipedia.org/wiki/Automotrice_FIAT_ALn_668.1999

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Latest update on the 18th of January 2025 at 21:43

Contributor(s): Tudor C.

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