During the second half of 1860 the progress of the construction of the Porrettana railway highlighted the need to order locomotives suitable for the demanding Apennine route, so a construction order was issued for a group of 10 units to the prestigious Koechlin locomotive factory in Mulhouse.

Owing to company changes, the early numbering is complex but, under the Società per le strade ferrate dell'Alta Italia (SFAI), they became 1281-1290.

To cope with an increase in traffic, the company ordered a further batch of 10 locomotives, very similar but more powerful, from the Koechlin factory in 1871.

Several locomotives were scrapped following accident damage but 14 units survived and passed to the Italian State Railways (FS) in 1905.

The boiler supplied saturated steam at a maximum pressure of 8 bar (0.80 MPa; 120 psi) and the engine had two outside cylinders.

The sandbox was placed adjacent to the steam dome and the supply pipe delivered sand ahead of the second axle.

The length of the firebox was increased to make it more capacious and the continuous power output rose to 610 hp (450 kW).