The General Roca Railway (FCGR) (native name: Ferrocarril General Roca) is a 5 ft 6 in (1,676 mm) broad gauge railway in Argentina which runs from Constitución station in Buenos Aires to the south of the country through the provinces of Buenos Aires, La Pampa, Neuquén and Río Negro.

With the purpose of helping to populate Patagonia and to contribute to the commercial development of the Argentina's southern provinces, the ASR built lines there through its subsidiary Ferrocarriles Patagónicos.

The Argentine State opened other lines across Patagonia, most notably the Patagonian Express, familiarly known as La Trochita that made its inaugural trip in 1935.

The BAGSR also took over the section built and operated by the Bahía Blanca and North Western Railway that extended to Darragueira and Toay in La Pampa Province.

The following broad gauge railway companies were added to the Ferrocarril Roca network after its 1948 nationalisation: Notes: In General Madariaga Partido (which included cities of Villa Gesell and Pinamar by that point) the Roca Railway owned a freight line branch that carried firewood to the dunes zone at the entrance to Pinamar.

After nationalisation, the Roca Railway decided to extend the branch another 470 meters, crossing the dunes and reaching the city of Pinamar.

Unlike old wooden coaches used until then, the American wagons were made of steel and came with comforts such as air conditioning and double glazing to insulate the passengers from noise, arm chairs, bars and restaurant carriage.

A high-speed 6000 HP Baldwin locomotive had been also designed to tow that train, since the original project was to run as an express service between Washington and Cincinnati.

After a probationary period, trains began to run express services to Mar del Plata with a journey time of about 5 hours.

In 1952 diesel locomotives by local company Fábrica Argentina de Locomotoras (FADEL) named Justicialista made their debut on the line.

In 1952, the locomotives began to serve on the Constitución-Mar del Plata section to tow the Marplatense express with a journey time of 3 hours and 45 minutes.

Apart from Mar del Plata, the Roca Railway ran trains to other tourist centres on the Atlantic coast such as Necochea (10 services per day during the summer) via Chas or Tandil.

The lack of maintenance and investments and the rise and competition from road and air transport were some of the contributing factors in the decline of Roca Railway services after World War II.

Until 1959, the Argentine railway network totalled 44,000 km in length, although rail lines would be dismantled after then in order to reduce the budgetary deficit.

The decreasing industrial activity in several regions of Argentina caused some freight railway lines to also be closed, such as Pereyra-Punta Lara-Ensenada (in the port of La Plata zone) in 1978.

One year later, the La Plata-Magdalena-Atalaya and Rufino de Elizalde-Lezama-Las Pipinas (served by passenger and freight trains that contributed to the commercialization of milk and cattle in the region) were also closed.

It was expected that FA would acquire diesel locomotives and build a 5 ft 6 in (1,676 mm) line from Puerto Madryn to Sierra Grande to extend railway to San Antonio Oeste.

As part of the privatisation process, freight services were granted in concession to Ferrosur Roca and Ferroexpreso Pampeano, while commuter rail lines were given to Metropolitano.

[7] In 2014, trains manufactured by China CNR Corporation were acquired by the National Government to run luxury services to Mar del Plata.