Sähköjunayksiköt

Sähköjunayksiköt, often referred to as EMUs (Electric Multiple Units), are electric trains where the carriages are self-propelled and are permanently coupled together to form a single train set. This design distinguishes them from locomotive-hauled trains, where a separate locomotive provides the power. Each carriage in an EMU typically contains its own electric motor, which draws power from an external source, usually overhead lines or a third rail. This distributed power system allows for efficient acceleration and deceleration, making EMUs ideal for frequent-stop operations like commuter and urban rail services.

The development of EMUs began in the early 20th century, driven by the need for cleaner, quieter, and more efficient urban transportation. Their ability to quickly load and unload passengers, coupled with rapid acceleration, significantly reduces journey times in congested areas. Modern EMUs incorporate advanced technologies for passenger comfort, safety, and energy efficiency, including regenerative braking systems that capture energy during deceleration and feed it back into the power supply or storage. Various designs exist worldwide, tailored to specific network requirements and passenger capacities. Their operational flexibility and environmental advantages have made them a cornerstone of sustainable public transport.