Since the line was constructed after many other east to west lines had already been laid these were crossed by constructing a large number of bridges. The otherwise near level course of the line was broken, at intervals, by short sharp gradients and this had an effect on the type of locomotives that could be used. In spite of this a considerable volume of goods and livestock traffic was carried by the line.
The original concession for the construction of the railway was granted to Diego de Alvear with the promulgation of Law N° 4.279 of 1903. That concession was then transferred to French-owned company "Sociedad Anónima Compañía del Ferrocarril Rosario a Puerto Belgrano" in December 1906. The concessionary was committed to build a dock in Puerto Belgrano, terminus of the line.
The Indian gauge 800-km. length railway ran from north to south, joining the cities of Rosario, Santa Fe and Punta Alta, crossing most of the main British-owned railway tracks. The railway had also a particular path with no stops in Buenos Aires but other cities of the Province such as Coronel Pringles and Coronel Suárez. The costs of construction were high so the railway required several engineering, for example the seven iron bridges that cross the Sauce Grande River, near Bahía Blanca.
The north-south orientation of the railway path revealed the purpose of competing against British companies for the traffic of merchandises in Buenos Aires. Nevertheless, the railway did not earn the expected profits due to better prices established by British railways. Besides, the RPBR crossed low developed agricultural areas instead of more fertile areas covered by British companies. For those reasons, the RPBR suffered a chronic deficit.
The line was built between 1906 and 1910 quickly, being definitely inaugurated for passenger and freight services in 1912. The military port of Bahía Blanca received all the goods necessary for the construction of the railway, including rail tracks and even prefabricated home for employees, steam locomotives and coaches. The line started in Rosario, reaching Punta Alta station and then Puerto Belgrano dock that was being built by then. A branch from Punta Alta to Bahía Blanca was built later.