Editing Railway coupling (section)

{{Short description|Mechanism for connecting rolling stock in a train}}
{{Other uses|Coupling (disambiguation)}}
{{train topics}}
[[File:St Pancras railway station MMB G3 395009.jpg|thumb|250px|[[Scharfenberg coupler]] on a [[Southeastern (train operating company)|Southeastern]] [[British Rail Class 395|Class 395]]]]
[[File:Scharfenberg coupler in action ICE Leipzig-short.webm|thumb|Video of [[ICE T]] coupling at [[Leipzig Hauptbahnhof]]]]

A '''coupling''' or '''coupler''' is a mechanism, typically located at each end of a [[rolling stock|rail vehicle]], that connects them together to form a train. The equipment that connects the couplers to the vehicles is the '''draft gear''' or '''draw gear''', which must absorb the stresses of the coupling and the acceleration of the train.

Throughout the history of rail vehicles, a variety of coupler designs and types have been developed worldwide. Key design considerations include strength, reliability, easy and efficient handling, and operator safety. Automatic couplers engage automatically when the cars are pushed together. Modern versions not only provide a mechanical connection, but can also couple brake lines and data lines. 

Different countries use different types of couplers. While North American railroads and China use [[Janney coupler]]s,  railroads in the former [[Soviet Union]] use [[SA3 coupler]]s and the European countries use [[Scharfenberg coupler|Scharfenberg]] and [[Buffers and chain coupler|screw couplers]]. Challenges and complications arise when coupling vehicles with different couplers. [[Barrier vehicle|Barrier cars]], also called ''match cars'', cars with [[dual coupling|dual couplers]], or adapters are used to accomplish this task.