FS Class ALn 668
| Industry | Rail transport manufacturing |
|---|---|
Area served | Italy, international railways |
| Products | Diesel railcars (ALn 668 series) |
The ALn 668 (Automotrice Leggera a nafta, meaning Light Diesel motor car) series represents a collection of diesel railcars manufactured by Fiat Ferroviaria spanning from the 1950s through the 1980s. These vehicles were primarily constructed for Italy's national railway company, Ferrovie dello Stato (FS), now operating as Trenitalia, alongside several private Italian rail operators. Additionally, adaptations of this model have been supplied to various international railways. A significant number of these railcars continue to be operational today.
A total of forty units from the 2400 series were entirely assembled by Breda in Milan.
The ALn 668 is widely recognized as the standard railcar model for FS. Its close counterpart, the Class ALn 663, shares identical mechanical components but features a different interior layout, resulting in a reduced seating capacity—from sixty-eight down to sixty-three seats.
Background
In the aftermath of World War II, FS faced the challenge of replacing a large portion of its fleet that had been destroyed. The new diesel railcars were designed with underfloor engines to optimize passenger space.
Initial prototypes such as the RALn 60, developed for Sicily’s narrow gauge lines (950mm) and tested starting in 1950, set the stage for Fiat’s railcar production that extended into the early 1990s. Despite this, these early models did not meet FS’s Service Material and Traction division’s stringent goals regarding operational availability and maintenance expenses, which aimed at creating a unified standard railcar across Italy.
In 1954, FS initiated a project focused on developing a new standard diesel railcar with priorities including exceptional reliability, straightforward operation and upkeep, predictable repair intervals, and overall cost-effectiveness—especially important given the ongoing electrification plans for main routes.
The specifications required twin engines, an adhesive weight ratio of no less than 50%, underfloor engine installation, and compliance with UIC’s 100-hour endurance test standards.
At that time, only Breda, OM, and FIAT had the capability to fulfill these criteria. Breda concentrated on TEE railcars and responded to FS only in 1959; OM aimed to revive the ALn 772 model and later contributed components to Fiat trailers and foreign versions of the ALn 668; FIAT promptly engaged using its industrial strength and autonomy regarding licensing. A key advantage for FIAT was its use of diesel engines based on widely produced truck models, which allowed for significant cost reductions, improved dependability, simplified maintenance procedures, and extensive spare parts availability—factors that played a crucial role in the ALn 668’s commercial triumph.
Variants
- ALn 668.1400 (80 units produced between 1954 and 1963)
- ALn 668.2400 (40 units produced between 1959 and 1964)
- ALn 668.1500 (75 units produced between 1965 and 1967)
- ALn 668.1600 (33 units produced between 1970 and 1971)
- ALn 668.1700 (20 units produced between 1971 and 1972)
- ALn 668.1800 (85 units produced between 1971 and 1973)
- ALn 668.1900 (42 units produced between 1975 and 1976)
- ALn 668.1000 (120 units produced between 1976 and 1979)
- ALn 668.1200 (60 units produced between 1979 and 1980)
- ALn 668.3000 (40 units produced between 1980 and 1981)
- ALn 668.3100 (150 units produced between 1980 and 1983)
- ALn 668.3300 (40 units produced between 1982 and 1983)
Ferrovie Emilia-Romagna
FER manages a fleet of twenty-nine ALn 668 railcars spanning series such as the .1000, .1700, .1900, and .3000 variants built from 1959 through to 1983; some of these have since been retired.
Ferrovie del Sud Est
FSE operates a fleet of 15 ALn 668 units, including the .1000 and .1900 series, mainly serving areas within Apulia such as Martina Franca, Taranto, and Lecce; nonetheless, a significant number are currently not in active service.
Sistemi Territoriali
Sistemi Territoriali oversees four ALn 668.1000 railcars, which were introduced in 1980 to run on secondary routes throughout the Veneto region.