Administratively, Csepel was not part of Budapest until 1950. An electrified suburban railway line connected the island and the independent Erzsébetfalva (today Pestszenterzsébet) in 1912, but Csepel did not have a guided transport connection to Budapest.

There were plans for a suburban railway line to the city centre when it became part of the capital. Its implementation was decided in 1950, and the works were completed by 29 April 1951.

The suburban railway line to Csepel is the shortest. Construction began in 1950 and was completed in 1951, seventy years ago (Photo Fortepan/No.: 79899) 

It is the only suburban railway line that does not leave the territory of Budapest, and it is also the shortest. The 15 June 1951 issue of Autó-Motor reported on the development:

“The five-year plan enables several significant investments in transportation, one of which is the recently commissioned Csepel rapid transit system. For the workers of the industrial town of Csepel, rapid transit systems provide significant time savings and increased convenience while at the same time relieving traffic on some of the capital's heavily congested roads."

Presumably, many readers frowned (only in secret) at the reference to growing car traffic since, at the time, only the privileged could use a car, not an average person, so traffic was a fraction of what it is today.

The suburban railway's new cars in 1966. Seven of them still run today (Photo: Fortepan/No.: 178428) 

The trains of the new suburban railway line ran to Boráros Square, where it was possible to change not only to the tram on the Outer Ring Road but also to tram 2. Its line was extended, as its former southern terminus was originally on Fővám Square.

The new line was described in the 29 April 1951 issue of Kis Újság:

“Hundreds and thousands of workers on the battlefield, Boráros Square, won a battle for peace: the Csepel rapid transit line has been completed. Saturday at 8:30 a.m.: hard workers are on the job everywhere in the square, piles of stone and sand rise, tram rails are placed by large cranes, and paviours and asphalters work hard next to the bridge under construction. The final touches are being made at the Pest station of the Csepel rapid transit line, the traffic islands are being built. (…) The train starts: it is a wonderful experience to travel on this railway for the first time, which will fulfil its duty day after day. The test run starts: it runs along the Danube first, travels under the southern railway bridge, reaches the island of Csepel, it has already traversed the Danube Bridge, now running on the embankment. The first stop is Csepel Freeport. It keeps going, happy looks follow it everywhere, even the passengers on the bus admire it, here on Csepel Island, a multitude of workers feel: this railway was built for them."

The bridge under construction mentioned in the article was Petőfi Bridge. The suburban railway made the journey from Csepel or to Csepel much easier and faster because it was only 16 minutes long. So, the suburban railway became very popular. (The other line leading to Pesterzsébet was abolished in 1951, but only temporarily because it ran again between 1959 and 1978.)

There was an idea before the lines opening that the trains on it would be red, but the plans were discarded.

Old wagons and motor trains were used on the line in the 1950s. The new trains arrived in 1965. These were made in Hungary, but the traction engine came from the German Democratic Republic (GDR). Most of them were retired between 1994 and 1997, but seven of these old vehicles still operate on the Csepel line.

The other trains cannot be called young either. They were manufactured in the GDR in the 1970s.

The more modern trains of the suburban railway line in Csepel were also made in the 1970s (Photo: Balázs Both/pestbuda.hu) 

The suburban railway line to Csepel is the shortest, but Budapest's largest suburban railway accident happened on it. On 13 April 1978, a train from Csepel crashed into the Boráros Square station building. The accident claimed 18 lives.

There are few stops on the line. Their number increased in 2001 with the Müpa (Művészetek Palotája, 'Palace of Arts') – National Theater stop. The suburban railway line to Csepel has also become a “film star”, as it appears several times in the background of The Martian, which was shot in Hungary. The Bálna building was featured in the film as NASA, while Müpa appeared as the headquarters of the Chinese space agency.

The extension of the suburban railway line has been planned since its opening. According to the original plans, it would have been extended to Kálvin Square. The idea is to connect the suburban railway line to Csepel and Ráckeve underground with the northern line to Szentendre. The plans of the Budapest Development Centre also include the southern extension of the line to Erdősor Street in Csepel.

Cover photo: The suburban railway line in Csepel in 1951 in Tanácsház (now Szent Imre) Square (Source: Fortepan/No.: 16698)