Siemens-Schuckert Orenstein & Koppel

Siemens-Schuckert Orenstein & Koppel
Siemens O&K during its last day serving Line H, alongside its replacement 300 Series train.
Manufacturer	Siemens-Schuckert, Orenstein & Koppel
Constructed	1934-1944 (Germany) 1955-1960 (Argentina)
Entered service	1934
Refurbishment	2013
Scrapped	2016 (non-refurbished)
Number in service	50 cars (refurbished Emepa cars)
Capacity	162 seated per car
Operator(s)	Buenos Aires Underground
Line(s) served	(current) (former)
Specifications
Car length	17m
Width	2.6m
Height	2.34m
Doors	4 per side
Maximum speed	65 km/h
Weight	32 tonnes per car
Power output	115kw per motor
Power supply	Overhead line (1500v)
Braking system(s)	Pneumatic
Track gauge	1,435 mm (4 ft 8 1⁄2 in)

The Siemens-Schuckert Orenstein & Koppel (normally abbreviated to Siemens O&K) is an underground car formerly used on the Buenos Aires Underground first built by Siemens-Schuckert and Orenstein & Koppel in 1934, 1937 and 1944 with a smaller number of cars built in Argentina during the 1950s. The Siemens O&K rolling stock made up the entirety of the trains used on the three lines built by the Hispanic-Argentine Company for Public Works and Finances (CHADOPyF) and has since served on every line of the Underground (with the exception of Line B, which uses third rail electrification) from 1934 to 2016, with cars refurbished by the Emepa Group and Alstom continuing to function on the network today.

As such, it has been the most widely used rolling stock in the Underground's history, and second only to the Brugeoise cars in the amount of years served, being the oldest cars in circulation at the time of their retirement in 2016.

The first Siemens-Schuckert Orenstein & Koppel cars were purchased in 1933 by the Hispanic-Argentine Company for Public Works and Finances (CHADOPyF) for the first line constructed by the company in the city, Line C (then known as Line 1, though it was the third to be built in the city), which was opened in 1934. The Siemens O&K rolling stock made up the entirety of the line until 2007, when Japanese Nagoya trains were transferred from Line D and the Siemens cars were all sent to the newly inaugurated Line H, with newer Nagoya trains also arriving in the country for Line C in 2014.

When Line D was completed by CHADOPyF in 1937, the line was similarly served by Siemens O&K cars in its entirety, though these were replaced in 1999 by Nagoya trains and later by Alstom Metropolis trains in 2004. In 1944, Line E was the last of the CHADOPyF lines to be opened and was equally inaugurated with new Siemens O&K rolling stock ordered from Germany. With the three lines operating the same rolling stock during this time, it was the most standardised period in terms of rolling stock in the history of the Buenos Aires Underground. The three lines remained uniform until 1968, when CAF-GEE rolling stock was purchased to bolster numbers in Lines D and E, though these cars shared a similar design and technical specifications to the Siemens cars.