The project was put in the charge of the French engineer Jean Louis Protche who solved the problem by designing a spiral tunnel between Piteccio and Corbezzi.

The line proposed by Cini started from Pistoia, up the Ombrone at a gradient of up to 20 per thousand to the district of San Felice.

From there it would climb the foothills of the Apennines for 16 km with grades of 12 to 25 per thousand and a 2,700 metre long tunnel through the mountains to Pracchia.

Ciardi challenged Cini’s proposal and contended that a railway through the Apennines should be designed to be part of the Italian national rail network that was forming at the time and this meant making the carriage of freight cheaper and transport travelers heading north faster.

Ciardi, abandoned his first proposal for a route across the Apennines along the valleys of the Bisenzio, Setta and Reno rivers, in places with grades over 12 per thousand.

The new route would pass through the Apennines at Gravigno, near Cantagallo at 480 meters above mean sea level with a 4 km long tunnel and a maximum gradient of 12 per thousand.

Tilting the balance, however, was Austria’s military interest in a fast connection with the port of Livorno and its belief that Pistoia was a militarily strategic point.

Austria therefore preferred Porrettana and lobbied Leopold II, Grand Duke of Tuscany who was obliged to support the Austrian interests.

On 14 March 1856, an agreement was signed in Vienna between the Austrian Empire, the Duchy of Parma and Modena, The Grand Duchy of Tuscany and the Papal States for the construction of the Central Italian Railway (Italian: Strada Ferrata dell'Italia Centrale) from Piacenza to Pistoia, with a branch to Mantua and anticipating strategic links with the existing lines of Lombardy and Veneto and extensions to Rome.

In 1856 after a series of works had been carried out in a manner that was not consistent with the purpose of building the railway, the project was entrusted to a company with capital subscribed by French, English and Italian shareholders.

The promotion of tourism in the mountains that Pistoia sought from the Porrettana line could not be achieved because of the increasing use of transit traffic for goods heading north and south did not allow the development of local passenger services, except at the spa town of Porretta Terme.

During the retreat from the Gothic Line in World War II, the German army systematically destroyed structures, buildings and everything that could be useful to the enemy.