How subway trains are made
The first electric rapid transit railway, the City & South London, opened in 1890.
- stations
- 8
- things upstream
- 85
- raw sources
- 27
- steps from the ground
- 10
The short version
Steel or aluminum panels are laser cut, formed and welded into a car shell, often by robots, then painted. Bogies, the wheeled chassis under each car, come from a separate shop, where plate is cut, robot-welded and milled. Final assembly bays add seats, wiring and traction motors. Completed cars then face static and rolling tests before they ship.
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Cut and form panels
Lasers cut stainless steel or aluminum sheet, and forming machines bend the pieces to shape. One Indian plant gives this work its own hall, along with the welding.
Goes in -
Weld the shell
Robots weld the pieces into a shell held to tight dimensions. A Siemens passenger coach, a cousin of the subway car, took more than 50,000 spot welds across its 85-foot length.
50,000+ welds on one coach
Goes in -
Paint and finish
The bare shell moves to a paint and finishing area, where temperature and humidity are controlled, and is prepared for final assembly.
Goes in -
Weld bogie frames
A plate cutter slices steel into shapes and a robot welds them into a frame. At one Australian maker the finished chassis measures about 4m by 3m and half a meter tall.
Goes in -
Mill the frames
A five-axis gantry mill does the final machining and inspection. One shop needs about three months for a batch of 12, enough for one trainset.
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Add suspension and motors
Bogies get their primary and secondary suspension and running gear in an assembly area. Traction motors and converters join the train management system, and the software is tested with the customer's signaling.
Goes in -
Fit out the car
In final assembly bays, wiring looms, interior fittings and seats go in, and each car comes together with its running gear.
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Run static, rolling tests
Completed cars go through static and rolling checks on dedicated test equipment. A rail siding then carries them out of the plant.
Worth repeating
- London's partly underground Metropolitan Railway, opened in 1863 with steam locomotives, was the world's first rapid transit system.
- Across most of Britain, the word subway means a pedestrian underpass, not a train.
- A heavy metro train can run to between six and fourteen cars, with 100 to 150 passengers in each.
Back to the ground
Follow every input upstream and subway train starts as these 27 raw sources.
Everything it is made of See it on the map
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Sources
- Metro Rail and EMU Rolling Stock Manufacturing Facility
- Hofmann Engineering: Gearing up for bogie production
- Siemens completes first car shell for Florida's Brightline rail service
- Rapid transit
Cite this page: "How subway trains are made." Assembly Line, 2026-11-03. https://assemblyline.org/make/subway-train