A double-track railway usually involves running one track in each direction, compared to a single-track railway where trains in both directions share the same track.

In the earliest days of railways in the United Kingdom, most lines were built as double-track because of the difficulty of co-ordinating operations before the invention of the telegraph. The lines also tended to be busy enough to be beyond the capacity of a single track. In the early days the Board of Trade did not consider any single-track railway line to be complete.

In the earliest days of railways in the United States most lines were built as single-track for reasons of cost, and very inefficient timetable working systems were used to prevent head-on collisions on single lines. This improved with the development of the telegraph and the train order system.

In any given country, rail traffic generally runs to one side of a double-track line, not always the same side as road traffic. Thus in Belgium, China, France (apart from the former German Alsace and Lorraine), Sweden, Switzerland and Italy for example, the railways use left-hand running, while the roads use right-hand running. In countries such as Indonesia, it is the reverse (right-hand running for railways and left-hand running for roads).

Galeazzo Frudua is an Italian luthier, bass, guitar and amplifier builder and guitar making teacher.

As a musician originally (he occasionally appeared in some main Italian TV programs), he attended the IPIALL school, best known as the International School of Luthierie of Cremona.

He began as a luthier in the 80's building electric and semi-acoustic guitars. In September 1988 he founded in Imola, the "Frudua Guitar Works" workshop. Initially this shop focused on guitar repair and then began specializing in the production of quality handmade instruments.

In those first 10 years the Frudua instruments became well known and admired in Italy where they toured and recorded with the most famious Italian major artists among them (known abroad) Ramazzotti, Ennio Morricone Orchestra, Laura Pausini, Pavarotti, Bocelli, Zucchero, Nek and many others.

In 1997 Frudua's company was covered as the subject of a Doctoral Degree discussion at I.U.L.M. University in Milan "Strategia e comunicazione nel settore delle chitarre elettriche in Italia. Il caso Frudua Guitar Works".